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Sample records for acetylcholinesterase biosensor based

  1. Acetylcholinesterase biosensor for carbaryl detection based on interdigitated array microelectrodes.

    PubMed

    Gong, Zhili; Guo, Yemin; Sun, Xia; Cao, Yaoyao; Wang, Xiangyou

    2014-10-01

    In this study, an acetylcholinesterase (AChE) biosensor with superior accuracy and sensitivity was successfully developed based on interdigitated array microelectrodes (IAMs). IAMs have a series of parallel microband electrodes with alternating microbands connected together. Chitosan was used as the enzyme immobilization material, and AChE was used as the model enzyme for carbaryl detection to fabricate AChE biosensor. Electrochemical impedance spectroscopy was used in conjunction with the fabricated biosensor to detect pesticide residues. Based on the inhibition of pesticides on the AChE activity, using carbaryl as model compounds, the biosensor exhibited a wide range, low detection limit, and high stability. Moreover, the biosensor can also be used as a new promising tool for pesticide residue analysis.

  2. Fenugreek hydrogel-agarose composite entrapped gold nanoparticles for acetylcholinesterase based biosensor for carbamates detection.

    PubMed

    Kestwal, Rakesh Mohan; Bagal-Kestwal, Dipali; Chiang, Been-Huang

    2015-07-30

    A biosensor was fabricated to detect pesticides in food samples. Acetylcholinesterase was immobilized in a novel fenugreek hydrogel-agarose matrix with gold nanoparticles. Transparent thin films with superior mechanical strength and stability were obtained with 2% fenugreek hydrogel and 2% agarose. Immobilization of acetylcholinesterase on the membrane resulted in high enzyme retention efficiency (92%) and a significantly prolonged shelf life of the enzyme (half-life, 55 days). Transmission electron microscopy revealed that, gold nanoparticles (10-20 nm in diameter) were uniformly dispersed in the fenugreek hydrogel-agarose-acetylcholinesterase membrane. This immobilized enzyme-gold nanoparticle dip-strip system detected various carbamates, including carbofuran, oxamyl, methomyl, and carbaryl, with limits of detection of 2, 21, 113, and 236 nM (S/N = 3), respectively. Furthermore, the fabricated biosensor exhibited good testing capabilities when used to detect carbamates added to various fruit and vegetable samples.

  3. Acetylcholinesterase inhibition-based biosensor for aluminum(III) chronoamperometric determination in aqueous media.

    PubMed

    Barquero-Quirós, Miriam; Domínguez-Renedo, Olga; Alonso-Lomillo, Maria Asunción; Arcos-Martínez, María Julia

    2014-05-07

    A novel amperometric biosensor for the determination of Al(III) based on the inhibition of the enzyme acetylcholinesterase has been developed. The immobilization of the enzyme was performed on screen-printed carbon electrodes modified with gold nanoparticles. The oxidation signal of acetylthiocholine iodide enzyme substrate was affected by the presence of Al(III) ions leading to a decrease in the amperometric current. The developed system has a detection limit of 2.1 ± 0.1 μM for Al(III). The reproducibility of the method is 8.1% (n = 4). Main interferences include Mo(VI), W(VI) and Hg(II) ions. The developed method was successfully applied to the determination of Al(III) in spiked tap water . The analysis of a certified standard reference material was also carried out. Both results agree with the certified values considering the respective associated uncertainties.

  4. Acetylcholinesterase Inhibition-Based Biosensor for Aluminum(III) Chronoamperometric Determination in Aqueous Media

    PubMed Central

    Barquero-Quirós, Miriam; Domínguez-Renedo, Olga; Alonso-Lomillo, Maria Asunción; Arcos-Martínez, María Julia

    2014-01-01

    A novel amperometric biosensor for the determination of Al(III) based on the inhibition of the enzyme acetylcholinesterase has been developed. The immobilization of the enzyme was performed on screen-printed carbon electrodes modified with gold nanoparticles. The oxidation signal of acetylthiocholine iodide enzyme substrate was affected by the presence of Al(III) ions leading to a decrease in the amperometric current. The developed system has a detection limit of 2.1 ± 0.1 μM for Al(III). The reproducibility of the method is 8.1% (n = 4). Main interferences include Mo(VI), W(VI) and Hg(II) ions. The developed method was successfully applied to the determination of Al(III) in spiked tap water. The analysis of a certified standard reference material was also carried out. Both results agree with the certified values considering the respective associated uncertainties. PMID:24811076

  5. An Acetylcholinesterase-Based Chronoamperometric Biosensor for Fast and Reliable Assay of Nerve Agents

    PubMed Central

    Pohanka, Miroslav; Adam, Vojtech; Kizek, Rene

    2013-01-01

    The enzyme acetylcholinesterase (AChE) is an important part of cholinergic nervous system, where it stops neurotransmission by hydrolysis of the neurotransmitter acetylcholine. It is sensitive to inhibition by organophosphate and carbamate insecticides, some Alzheimer disease drugs, secondary metabolites such as aflatoxins and nerve agents used in chemical warfare. When immobilized on a sensor (physico-chemical transducer), it can be used for assay of these inhibitors. In the experiments described herein, an AChE- based electrochemical biosensor using screen printed electrode systems was prepared. The biosensor was used for assay of nerve agents such as sarin, soman, tabun and VX. The limits of detection achieved in a measuring protocol lasting ten minutes were 7.41 × 10−12 mol/L for sarin, 6.31 × 10−12 mol/L for soman, 6.17 × 10−11 mol/L for tabun, and 2.19 × 10−11 mol/L for VX, respectively. The assay was reliable, with minor interferences caused by the organic solvents ethanol, methanol, isopropanol and acetonitrile. Isopropanol was chosen as suitable medium for processing lipophilic samples. PMID:23999806

  6. Electrochemical detection of malathion pesticide using acetylcholinesterase biosensor based on glassy carbon electrode modified with conducting polymer film.

    PubMed

    Guler, Muhammet; Turkoglu, Vedat; Kivrak, Arif

    2016-06-01

    Acetylcholinesterase (AChE) biosensor based on conducting poly([2,2̍';5̍' 2″]-terthiophene-3̍-carbaldehyde) (PTT) modified glassy carbon electrode (GCE) was constructed. AChE was immobilized on PTT film surface through the covalent bond between aldehyde and amino groups. The properties of PTT modified GCE were studied using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). The biosensor showed an oxidation peak at +0.83 V related to the oxidation of thiocholine, hydrolysis product of acetylthiocholine iodide (ATCI), catalyzed by AChE. The optimum current response of the biosensor was observed at pH 7.5-8.0, 40 °C and 120 U/cm(2) of AChE concentration. The biosensor showed a high sensitivity (183.19 μA/mM), a linear range from 0.015 to 1.644 mM, and a good reproducibility with 1.7 % of relative standard deviation (RSD). The biosensor showed a good stability. The interference of glycin, ascorbic acid, histidine, uric acid, dopamine, and arginine on the biosensor response was studied. An important analytical response from these inteferents that overlaps the biosensor response was not observed. The inhibition rate of malathion as a model pesticide was proportional to its concentrations from 9.99 to 99.01 nM. The detection limit was 4.08 nM.

  7. Study of Inhibition, Reactivation and Aging Processes of Pesticides Using Graphene Nanosheets/Gold Nanoparticles-Based Acetylcholinesterase Biosensor

    SciTech Connect

    Zhang, Lin; Long, Linjuan; Zhang, Weiying; Du, Dan; Lin, Yuehe

    2012-09-10

    Organophosphate (OP) and carbamate pesticides exert their toxicity via attacking the hydroxyl moiety of serine in the 'active site' of acetylcholinesterase (AChE). In this paper we developed a stable AChE biosensor based on self-assembling AChE to graphene nanosheet (GN)-gold nanoparticles (AuNPs) nanocomposite electrode for investigation of inhibition, reactivation and aging processes of different pesticides. It is confirmed that pesticides can inhibit AChE in a short time. OPs poisoning is treatable with oximes while carbarmates exposure is insensitive to oximes. The proposed electrochemical approach thus provides a new simple tool for comparison of pesticide sensitivity and guide of therapeutic intervention.

  8. Acetylcholinesterase based biosensor for monitoring of Malathion and Acephate in food samples: a voltammetric study.

    PubMed

    Raghu, P; Madhusudana Reddy, T; Reddaiah, K; Kumara Swamy, B E; Sreedhar, M

    2014-01-01

    Acetylcholinesterase (AChE) biosensor was developed through silica sol-gel (SiSG) immobilisation of AChE on the carbon paste electrode (CPE) and used as working electrode. AChE catalyses the cleavage of acetylthiocholine chloride (ASChCl or substrate) to thiocholine, which was oxidised to give a disulphide compound by dimerisation at 0.60V versus saturated calomel electrode. All the experiments were carried out in 0.1M phosphate buffer solution (PBS) at pH 7.0 and 0.1M KCl solution at room temperature. The limit of detection and limit of quantification values were found to be 0.058ppm, 0.044ppm and 0.194ppm, 0.147ppm for Malathion and Acephate, respectively. The response of the biosensor showed a good linearity range with an incubation time of 4min for Malathion and Acephate, respectively. This biosensor was used for the direct determination of pesticides without any pretreatment and it requires less time for analysis.

  9. An acetylcholinesterase (AChE) biosensor with enhanced solvent resistance based on chitosan for the detection of pesticides.

    PubMed

    Warner, John; Andreescu, Silvana

    2016-01-01

    Solvent tolerance of immobilized enzymes is important for many biosensing and biotechnological applications. In this paper we report an acetylcholinesterase (AChE) biosensor based on chitosan that exhibits high solvent resistance and enables sensitive detection of pesticides in presence of a high content of organic solvents. The solvent effect was established comparatively for the enzyme immobilized in chitosan and covalently cross-linked with glutaraldehyde. The activity of the immobilized AChE was dependent on the immobilization method and solvent type. The enzyme entrapped in chitosan fully conserved its activity in up to 25% methanol, 15% acetonitrile and 100% cyclohexane while the enzyme cross-linked with glutaraldehyde gradually lost its activity starting at 5% acetonitrile and methanol, and showed variable levels in cyclohexane. The detection limits of the biosensor for paraoxon were: 7.5 nM in 25% methanol, 100 nM in 15% acetonitrile and 2.5 μM in 100% cyclohexane. This study demonstrates that chitosan provides an excellent immobilization environment for AChE biosensors designed to operate in environments containing high amounts of organic solvents. It also highlights the effect of the immobilization material and solvent type on enzyme stability. These findings can enable future selection of the immobilization matrix and solvent type for the development of organic phase enzyme based systems.

  10. Critical evaluation of acetylthiocholine iodide and acetylthiocholine chloride as substrates for amperometric biosensors based on acetylcholinesterase.

    PubMed

    Bucur, Madalina-Petruta; Bucur, Bogdan; Radu, Gabriel-Lucian

    2013-01-25

    Numerous amperometric biosensors have been developed for the fast analysis of neurotoxic insecticides based on inhibition of cholinesterase (AChE). The analytical signal is quantified by the oxidation of the thiocholine that is produced enzymatically by the hydrolysis of the acetylthiocholine pseudosubstrate. The pseudosubstrate is a cation and it is associated with chloride or iodide as corresponding anion to form a salt. The iodide salt is cheaper, but it is electrochemically active and consequently more difficult to use in electrochemical analytical devices. We investigate the possibility of using acetylthiocholine iodide as pseudosubstrate for amperometric detection. Our investigation demonstrates that operational conditions for any amperometric biosensor that use acetylthiocholine iodide must be thoroughly optimized to avoid false analytical signals or a reduced sensitivity. The working overpotential determined for different screen-printed electrodes was: carbon-nanotubes (360 mV), platinum (560 mV), gold (370 mV, based on a catalytic effect of iodide) or cobalt phthalocyanine (110 mV, but with a significant reduced sensitivity in the presence of iodide anions).

  11. Critical Evaluation of Acetylthiocholine Iodide and Acetylthiocholine Chloride as Substrates for Amperometric Biosensors Based on Acetylcholinesterase

    PubMed Central

    Bucur, Madalina-Petruta; Bucur, Bogdan; Radu, Gabriel-Lucian

    2013-01-01

    Numerous amperometric biosensors have been developed for the fast analysis of neurotoxic insecticides based on inhibition of cholinesterase (AChE). The analytical signal is quantified by the oxidation of the thiocholine that is produced enzymatically by the hydrolysis of the acetylthiocholine pseudosubstrate. The pseudosubstrate is a cation and it is associated with chloride or iodide as corresponding anion to form a salt. The iodide salt is cheaper, but it is electrochemically active and consequently more difficult to use in electrochemical analytical devices. We investigate the possibility of using acetylthiocholine iodide as pseudosubstrate for amperometric detection. Our investigation demonstrates that operational conditions for any amperometric biosensor that use acetylthiocholine iodide must be thoroughly optimized to avoid false analytical signals or a reduced sensitivity. The working overpotential determined for different screen-printed electrodes was: carbon-nanotubes (360 mV), platinum (560 mV), gold (370 mV, based on a catalytic effect of iodide) or cobalt phthalocyanine (110 mV, but with a significant reduced sensitivity in the presence of iodide anions). PMID:23353142

  12. Ultra-sensitive biosensor based on genetically engineered acetylcholinesterase immobilized in poly (vinyl alcohol)/Fe-Ni alloy nanocomposite for phosmet detection in olive oil.

    PubMed

    El-Moghazy, A Y; Soliman, E A; Ibrahim, H Z; Noguer, T; Marty, J-L; Istamboulie, G

    2016-07-15

    An ultra-sensitive screen-printed biosensor was successfully developed for phosmet detection in olive oil, based on a genetically-engineered acetylcholinesterase (AChE) immobilized in a azide-unit water-pendant polyvinyl alcohol (PVA-AWP)/Fe-Ni alloy nanocomposite. Fe-Ni not only allowed amplifying the response current but also lowering the applied potential from 80 mV to 30 mV vs Ag/AgCl. The biosensor showed a very good analytical performance for phosmet detection, with a detection limit of 0.1 nM. This detection limit is lower than the allowable concentrations set by international regulations. In addition to the good reproducibility, operational and storage stability, the developed biosensor was successfully used for the determination of phosmet in olive oil samples without any laborious pre-treatment. The phosmet recovery rate was about 96% after a simple liquid-liquid extraction.

  13. A novel, sensitive, reusable and low potential acetylcholinesterase biosensor for chlorpyrifos based on 1-butyl-3-methylimidazolium tetrafluoroborate/multiwalled carbon nanotubes gel.

    PubMed

    Zamfir, Lucian-Gabriel; Rotariu, Lucian; Bala, Camelia

    2011-04-15

    A novel, low potential and highly sensitive acetylcholinesterase (AChE) biosensor was developed based on 1-butyl-3-methylimidazolium tetrafluoroborate/multiwalled carbon nanotube composite gel thiocholine sensor. Composite gel promoted electron transfer reaction at a lower potential (+50 mV) and catalyzed electrochemical oxidation of thiocholine with high sensitivity. AChE was immobilized in sol-gel matrix that provides a good support for enzyme without any inhibition effect from the ionic liquid. The amount of immobilized enzyme and incubation time with chlorpyrifos were optimized. Chlorpyrifos could be determined in the range of 10(-8)-10(-6)M with a detection limit of 4 nM. Fast and efficient enzyme reactivation was obtained at low obidoxime concentration (0.1mM). Moreover, the biosensor exhibited a good stability and reproducibility and could be use for multiple determinations of pesticide with no loss of the enzyme activity.

  14. Biosensor based on acetylcholinesterase immobilized onto layered double hydroxides for flow injection/amperometric detection of organophosphate pesticides.

    PubMed

    Gong, Jingming; Guan, Zhangqiong; Song, Dandan

    2013-01-15

    We developed a highly sensitive flow injection/amperometric biosensor for the detection of organophosphate pesticides (OPs) using layered double hydroxides (LDHs) as the immobilization matrix of acetylcholinesterase (AChE). LDHs provided a biocompatible microenvironment to keep the bioactivity of AChE, due to the intrinsic properties of LDHs (such as a regular structure, good mechanical, chemical and thermal stabilities, and swelling properties). By integrating the flow injection analysis (FIA) with amperometric detection, the resulting AChE-LDHs modified electrode greatly catalyzed the oxidation of the enzymatically generated thiocholine product, and facilitated the detection automation, thus increasing the detection sensitivity. The analytical conditions for the FIA/amperometric detection of OPs were optimized by using methyl parathion (MP) as a model. The inhibition of MP was proportional to its concentration ranging from 0.005 to 0.3μg mL(-1) and 0.3 to 4.0μg mL(-1) with a detection limit 0.6ng mL(-1) (S/N=3). The developed biosensor exhibited good reproducibility and acceptable stability.

  15. Acetylcholinesterase Biosensors for Electrochemical Detection of Organophosphorus Compounds: A Review

    PubMed Central

    Dhull, Vikas; Gahlaut, Anjum; Dilbaghi, Neeraj

    2013-01-01

    The exponentially growing population, with limited resources, has exerted an intense pressure on the agriculture sector. In order to achieve high productivity the use of pesticide has increased up to many folds. These pesticides contain organophosphorus (OP) toxic compounds which interfere with the proper functioning of enzyme acetylcholinesterase (AChE) and finally affect the central nervous system (CNS). So, there is a need for routine, continuous, on spot detection of OP compounds which are the main limitations associated with conventional analytical methods. AChE based enzymatic biosensors have been reported by researchers as the most promising tool for analysis of pesticide level to control toxicity and for environment conservation. The present review summarises AChE based biosensors by discussing their characteristic features in terms of fabrication, detection limit, linearity range, time of incubation, and storage stability. Use of nanoparticles in recently reported fabrication strategies has improved the efficiency of biosensors to a great extent making them more reliable and robust. PMID:24383001

  16. Biosensor Based on Self-Assembling Acetylcholinesterase on Carbon Nanotubes for Flow injection/Amperometric Detection of Organophosphate Pesticides and Nerve Agents

    SciTech Connect

    Liu, Guodong; Lin, Yuehe

    2006-02-01

    A highly sensitive flow-injection amperometric biosensor for organophosphate pesticides and nerve agents based on self-assembly of acetylcholinesterase (AChE) on carbon nanotube (CNT)-modified glassy carbon (GC) electrode is described. AChE is immobilized on the negatively-charged CNT surface by alternatively assembling a cationic polydiallyldimethylammonium chloride (PDDA) layer and an AChE layer. Transmission electron microscopy images confirm the formation of layer-by-layer nanostructures on carboxyl functionalized CNTs. The unique sandwich-like structure (PDDA/AChE/PDDA) on the CNT surface formed by self-assembly provides a favorable microenvironment to keep the bioactivity of AChE and to prevent enzyme molecule leakage. The electrocatalytic activity of CNT leads to a greatly improved electrochemical detection of the enzymatically generated thiocholine product, including a low oxidation overvoltage (+150 mV), higher sensitivity, and stability. The developed PDDA/AChE/PDDA/CNT/GC biosensor integrated into a flow injection system was used to monitor organophosphate pesticides and nerve agents, such as paraoxon. The sensor performance, including inhibition time and regeneration conditions, was optimized with respect to operating conditions. Under the optimal conditions, the biosensor was used to measure as low as 0.4 pM paraoxon with a 6-min inhibition time. The biosensor had excellent operational lifetime stability with no decrease in the activity of enzymes for more than 20 repeated measurements over a 1-week period. The developed biosensor system is an ideal tool for online monitoring of organophosphate pesticides and nerve agents.

  17. An ultra-sensitive acetylcholinesterase biosensor based on reduced graphene oxide-Au nanoparticles-β-cyclodextrin/Prussian blue-chitosan nanocomposites for organophosphorus pesticides detection.

    PubMed

    Zhao, Haiyan; Ji, Xueping; Wang, Beibei; Wang, Na; Li, Xianrui; Ni, Ruixing; Ren, Jujie

    2015-03-15

    This work reports a novel, ultrasensitive, and selective sensing platform based on a direct electrodeposition of electrochemical reduced graphene oxide (ERGO)-Au nanoparticles (AuNPs)-β-cyclodextrin (β-CD) and Prussian blue-chitosan (PB-CS) on glass carbon electrode (GCE) for efficiently fixed acetylcholinesterase (AChE) to fabricate organophosphorus pesticides (OPs) biosensor. The PB-CS not only effectively catalyzed the oxidation of thiocholine (TCh), but also shifted its oxidation potential from 0.68 to 0.2V, and accordingly the sensitivity of the biosensor was obviously improved. The synergistic effect between ERGO and AuNPs significantly promoted the electron transfer between PB and GCE, and remarkably enhanced the electrochemical oxidation of TCh. Besides, β-CD could interact with substrate by reversible bonding, which is contribute to increase the enrichment of the substrate and improve the selectivity and sensitivity of the biosensor. The integration of ERGO-AuNPs-β-CD with PB-CS provided an advantageous and high-performance platform for sensing applications. Based on the inhibition of OPs on AChE activity, the sensor showed wide linear ranges of 7.98-2.00×10(3)pgmL(-1) and 4.3-1.00×10(3)pgmL(-1) with low detection limits of 4.14pgmL(-1) and 1.15pgmL(-1) for malathion and carbaryl, respectively. The proposed biosensor exhibited short response time, good stability and high sensitivity, which can be used for direct analysis of practical samples.

  18. Amperometric acetylcholine biosensor based on self-assembly of gold nanoparticles and acetylcholinesterase on the sol-gel/multi-walled carbon nanotubes/choline oxidase composite-modified platinum electrode.

    PubMed

    Hou, Shihua; Ou, Zhongmin; Chen, Qiang; Wu, Baoyan

    2012-03-15

    A novel acetylcholinesterase (AChE)/choline oxidase (ChOx) bienzyme amperometric acetylcholine biosensor based on gold nanoparticles (AuNPs) and multi-walled carbon nanotubes (MWCNTs) has been successfully developed by self-assembly process in combination of sol-gel technique. A thiolated aqueous silica sol containing MWCNTs and ChOx was first dropped on the surface of a cleaned Pt electrode, and then AuNPs were assembled with the thiolated sol-gel network. Finally, the alternate deposition of poly (diallyldimethylammonium chloride) (PDDA) and AChE was repeated to assemble different layers of PDDA-AChE on the electrode for optimizing AChE loading. Among the resulting biosensors, the biosensor based on two layers of PDDA-AChE multilayer films showed the best performance. It exhibited a wide linear range, high sensitivity and fast amperometric response, which were 0.005-0.4mM, 3.395 μA/mM, and within 15s, respectively. The biosensor showed long-term stability and acceptable reproducibility. More importantly, this study could provide a simple and effective multienzyme immobilization platform for meeting the demand of the effective immobilization enzyme on the electrode surface.

  19. Determination of Parathion and Carbaryl Pesticides in Water and Food Samples Using a Self Assembled Monolayer/Acetylcholinesterase Electrochemical Biosensor

    PubMed Central

    Pedrosa, Valber A.; Caetano, Josiane; Machado, Sergio A. S.; Bertotti, Mauro

    2008-01-01

    An acetylcholinesterase (AchE) based amperometric biosensor was developed by immobilisation of the enzyme onto a self assembled modified gold electrode. Cyclic voltammetric experiments performed with the SAM-AchE biosensor in phosphate buffer solutions (pH = 7.2) containing acetylthiocholine confirmed the formation of thiocholine and its electrochemical oxidation at Ep = 0.28 V vs Ag/AgCl. An indirect methodology involving the inhibition effect of parathion and carbaryl on the enzymatic reaction was developed and employed to measure both pesticides in spiked natural water and food samples without pre-treatment or pre-concentration steps. Values higher than 91-98.0% in recovery experiments indicated the feasibility of the proposed electroanalytical methodology to quantify both pesticides in water or food samples. HPLC measurements were also performed for comparison and confirmed the values measured amperometrically. PMID:27873775

  20. Acetylcholinesterase-polyaniline biosensor investigation of organophosphate pesticides in selected organic solvents.

    PubMed

    Somerset, Vernon S; Klink, Michael J; Baker, Priscilla G L; Iwuoha, Emmanuel I

    2007-01-01

    The behavior of an amperometric organic-phase biosensor consisting of a gold electrode modified first with a mercaptobenzothiazole self-assembled monolayer, followed by electropolymerization of polyaniline in which acetylcholinesterase as enzyme was immobilized, has been developed and evaluated for organophosphorous pesticide detection. The voltammetric results have shown that the formal potential shifts anodically as the Au/MBT/PANI/AChE/PVAc thick-film biosensor responded to acetylthiocholine substrate addition under anaerobic conditions in selected organic solvent media containing 2% v/v 0.05 M phosphate buffer, 0.1 M KCl (pH 7.2) solution. Detection limits in the order of 0.147 ppb for diazinon and 0.172 ppb for fenthion in acetone-saline phosphate buffer solution, and 0.180 ppb for diazinon and 0.194 ppb for fenthion in ethanol-saline phosphate buffer solution has been achieved.

  1. Visible-light-activated photoelectrochemical biosensor for the study of acetylcholinesterase inhibition induced by endogenous neurotoxins.

    PubMed

    Huang, Qilin; Chen, Hua; Xu, Lili; Lu, Danqin; Tang, Linlin; Jin, Litong; Xu, Zhiai; Zhang, Wen

    2013-07-15

    In this report, a novel visible-light-activated photoelectrochemical biosensor was fabricated to study the inhibition of acetylcholinesterase (AChE) activity induced by two endogenous neurotoxins, 1(R)-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline [(R)-Sal] and 1(R),2(N)-dimethyl-6,7-dihydroxy-1,2,3,4-tetra-hydroisoquinoline [(R)-NMSal], which have drawn much attention in the study of the pathogenesis of neurodegenerative diseases such as Parkinson's disease. The photoelectrode was prepared by three steps, as follows. At first, nitrogen and fluorine co-doped TiO2 nanotubes (TNs) were obtained by anodic oxidation of a Ti sheet. Secondly, silver nanoparticles (AgNPs) were deposited onto the TNs through a microwave-assisted heating polyol (MAHP) process. At last, AChE was immobilized on the obtained photoelectrode and the biosensor was marked as AChE/Ag/NFTNs. Due to the nitrogen and fluorine co-doping, the photoelectrochemical biosensors can produce high photocurrent under visible light irradiation. Moreover, the presence of AgNPs greatly increased the photocurrent response of the biosensor. AChE/Ag/NFTNs hybrid system was used to study AChE inhibition induced by (R)-Sal and (R)-NMSal. The result proved that both (R)-Sal and (R)-NMSal exhibited mixed and reversible inhibition against AChE. This strategy is of great significance for the development of novel photoelectrochemical biosensors in the future.

  2. Surface stress-based biosensors.

    PubMed

    Sang, Shengbo; Zhao, Yuan; Zhang, Wendong; Li, Pengwei; Hu, Jie; Li, Gang

    2014-01-15

    Surface stress-based biosensors, as one kind of label-free biosensors, have attracted lots of attention in the process of information gathering and measurement for the biological, chemical and medical application with the development of technology and society. This kind of biosensors offers many advantages such as short response time (less than milliseconds) and a typical sensitivity at nanogram, picoliter, femtojoule and attomolar level. Furthermore, it simplifies sample preparation and testing procedures. In this work, progress made towards the use of surface stress-based biosensors for achieving better performance is critically reviewed, including our recent achievement, the optimally circular membrane-based biosensors and biosensor array. The further scientific and technological challenges in this field are also summarized. Critical remark and future steps towards the ultimate surface stress-based biosensors are addressed.

  3. Graphene-based biosensors

    NASA Astrophysics Data System (ADS)

    Lebedev, A. A.; Davydov, V. Yu.; Novikov, S. N.; Litvin, D. P.; Makarov, Yu. N.; Klimovich, V. B.; Samoilovich, M. P.

    2016-07-01

    Results of developing and testing graphene-based sensors capable of detecting protein molecules are presented. The biosensor operation was checked using an immunochemical system comprising fluorescein dye and monoclonal antifluorescein antibodies. The sensor detects fluorescein concentration on a level of 1-10 ng/mL and bovine serum albumin-fluorescein conjugate on a level of 1-5 ng/mL. The proposed device has good prospects for use for early diagnostics of various diseases.

  4. Development of novel enzyme potentiometric biosensor based on pH-sensitive field-effect transistors for aflatoxin B1 analysis in real samples.

    PubMed

    Stepurska, K V; Soldatkin, O O; Arkhypova, V M; Soldatkin, A P; Lagarde, F; Jaffrezic-Renault, N; Dzyadevych, S V

    2015-11-01

    This study aimed at the development and optimization of a potentiometric biosensor based on pH-sensitive field-effect transistors and acetylcholinesterase for aflatoxin B1 determination in real samples. Optimal conditions for bioselective elements operation were defined and analytical characteristics of the proposed biosensor were studied. The proposed biosensor characterized high operational stability and reproducibility of signal. Selectivity of acetylcholinesterase-biosensor to aflatoxins in relation to other groups of toxic substances was analyzed. The developed biosensor was applied to the determination of aflatoxin B1 in real samples (sesame, walnut and pea).

  5. An optical fiber biosensor for chlorpyrifos using a single sol-gel film containing acetylcholinesterase and bromothymol blue.

    PubMed

    Kuswandi, Bambang; Fikriyah, Chulaifah Indah; Gani, Agus Abdul

    2008-01-15

    An optical fiber biosensor consisting of acetylcholinesterase (AChE) and bromothymol blue (BTB) doped sol-gel film was employed to detect organophosphate pesticide chlorpyrifos. The main advantage of this optical biosensor is the use of a single sol-gel film with immobilized AChE and BTB. The compatibility of this mixture (AChE and BTB) with the sol-gel matrix has prevented leaching of the film. The immobilization of the enzyme and indicator was simple without chemical modification. The biosensing element on single sol-gel film has been placed inside the flow-cell for flow system. In the presence of a constant AChE, a color change of the BTB and the measured reflected signal at wavelength 622nm could be related to the pesticide concentration in the sample solutions. The performance of optical biosensor in the flow system has been optimized, including chemical and physical parameters. The response time of the biosensor is 8min. A linear calibration curve of chlorpyrifos against the percentage inhibition of AChE was obtained from 0.05 to 2.0mg/L of chlorpyrifos (18-80% inhibition, R(2)=0.9869, n=6). The detection limit for chlorpyrifos was 0.04mg/L. The results of the analysis of 0.5-1.5mg/L of chlorpyrifos using this optical biosensor agreed well with chromatographic method.

  6. Efficient immobilization of acetylcholinesterase onto amino functionalized carbon nanotubes for the fabrication of high sensitive organophosphorus pesticides biosensors.

    PubMed

    Yu, Guangxia; Wu, Weixiang; Zhao, Qiang; Wei, Xiaoyun; Lu, Qing

    2015-06-15

    This work introduced an efficient immobilization of acetylcholinesterase (AChE) onto amino functionalized carbon nanotubes (CNT-NH2), in order to fabricate high sensitive and practical organophosphorus pesticide (OPs) biosensors. Compared with the pristine, -COOH and -OH decorated CNTs, there were larger amount of enzymes adsorbed on the surface of CNT-NH2 with a favorable orientation and the best amperometric response was obtained on the AChE/CNT-NH2/GC electrode. Furthermore, the biosensor modified with CNT-NH2 showed a high affinity to acetylthiocholine chloride (ATCh) and could catalyze the hydrolysis of ATCh with an apparent Michaelis-Menten constant (Km) value of 67.4 µM. Using paraoxon as a model compound, wide linear ranges from 0.2 nM to 1 nM and 1 nM to 30 nM, and a low detection limit of 0.08 nM were obtained with satisfactory reproducibility and stability. Moreover, the biosensor had also been successfully employed for the determination of low concentrations of pesticides in real vegetable samples. This method could be extended to other functionalized nano-materials for their application in constructing biosensors.

  7. Nanomaterials-Based Optical Techniques for the Detection of Acetylcholinesterase and Pesticides

    PubMed Central

    Xia, Ning; Wang, Qinglong; Liu, Lin

    2015-01-01

    The large amount of pesticide residues in the environment is a threat to global health by inhibition of acetylcholinesterase (AChE). Biosensors for inhibition of AChE have been thus developed for the detection of pesticides. In line with the rapid development of nanotechnology, nanomaterials have attracted great attention and have been intensively studied in biological analysis due to their unique chemical, physical and size properties. The aim of this review is to provide insight into nanomaterial-based optical techniques for the determination of AChE and pesticides, including colorimetric and fluorescent assays and surface plasmon resonance. PMID:25558991

  8. Electrical percolation based biosensors.

    PubMed

    Bruck, Hugh Alan; Yang, Minghui; Kostov, Yordan; Rasooly, Avraham

    2013-10-01

    A new approach to label free biosensing has been developed based on the principle of "electrical percolation". In electrical percolation, long-range electrical connectivity is formed in randomly oriented and distributed systems of discrete elements. By applying this principle to biological interactions, it is possible to measure biological components both directly and electronically. The main element for electrical percolation biosensor is the biological semiconductor (BSC) which is a multi-layer 3-D carbon nanotube-antibody network. In the BSC, molecular interactions, such as binding of antigens to the antibodies, disrupt the network continuity causing increased resistance of the network. BSCs can be fabricated by immobilizing conducting elements, such as pre-functionalized single-walled carbon nanotubes (SWNTs)-antibody complex, directly onto a substrate, such as a Poly(methyl methacrylate) (PMMA) surface (also known as plexi-glass or Acrylic). BSCs have been demonstrated for direct (label-free) electronic measurements of antibody-antigen binding using SWNTs. If the concentration of the SWNT network is slightly above the electrical percolation threshold, then binding of a specific antigen to the pre-functionalized SWNT dramatically increases the electrical resistance due to changes in the tunneling between the SWNTs. Using anti-staphylococcal enterotoxin B (SEB) IgG as a "gate" and SEB as an "actuator", it was demonstrated that the BSC was able to detect SEB at concentrations of 1 ng/ml. Based on this concept, an automated configuration for BSCs is described here that enables real time continuous detection. The new BSC configuration may permit assembly of multiple sensors on the same chip to create "biological central processing units (CPUs)" with multiple biological elements, capable of processing and sorting out information on multiple analytes simultaneously.

  9. Aptamer-Based Fluorescent Biosensors

    PubMed Central

    Wang, Rongsheng E.; Zhang, Yin; Cai, Jianfeng; Cai, Weibo; Gao, Ting

    2011-01-01

    Selected from random pools of DNA or RNA molecules through systematic evolution of ligands by exponential enrichment (SELEX), aptamers can bind to target molecules with high affinity and specificity, which makes them ideal recognition elements in the development of biosensors. To date, aptamer-based biosensors have used a wide variety of detection techniques, which are briefly summarized in this article. The focus of this review is on the development of aptamer-based fluorescent biosensors, with emphasis on their design as well as properties such as sensitivity and specificity. These biosensors can be broadly divided into two categories: those using fluorescently-labeled aptamers and others that employ label-free aptamers. Within each category, they can be further divided into “signal-on” and “signal-off” sensors. A number of these aptamer-based fluorescent biosensors have shown promising results in biological samples such as urine and serum, suggesting their potential applications in biomedical research and disease diagnostics. PMID:21838688

  10. Alginate cryogel based glucose biosensor

    NASA Astrophysics Data System (ADS)

    Fatoni, Amin; Windy Dwiasi, Dian; Hermawan, Dadan

    2016-02-01

    Cryogel is macroporous structure provides a large surface area for biomolecule immobilization. In this work, an alginate cryogel based biosensor was developed to detect glucose. The cryogel was prepared using alginate cross-linked by calcium chloride under sub-zero temperature. This porous structure was growth in a 100 μL micropipette tip with a glucose oxidase enzyme entrapped inside the cryogel. The glucose detection was based on the colour change of redox indicator, potassium permanganate, by the hydrogen peroxide resulted from the conversion of glucose. The result showed a porous structure of alginate cryogel with pores diameter of 20-50 μm. The developed glucose biosensor was showed a linear response in the glucose detection from 1.0 to 5.0 mM with a regression of y = 0.01x+0.02 and R2 of 0.994. Furthermore, the glucose biosensor was showed a high operational stability up to 10 times of uninterrupted glucose detections.

  11. A Novel Acetylcholinesterase Biosensor: Core-Shell Magnetic Nanoparticles Incorporating a Conjugated Polymer for the Detection of Organophosphorus Pesticides.

    PubMed

    Dzudzevic Cancar, Hurija; Soylemez, Saniye; Akpinar, Yeliz; Kesik, Melis; Göker, Seza; Gunbas, Gorkem; Volkan, Murvet; Toppare, Levent

    2016-03-01

    To construct a sensing interface, in the present work, a conjugated polymer and core-shell magnetic nanoparticle containing biosensor was constructed for the pesticide analysis. The monomer 4,7-di(furan-2-yl)benzo[c][1,2,5]thiadiazole (FBThF) and core-shell magnetic nanoparticles were designed and synthesized for fabrication of the biosensing device. The magnetic nanoparticles were first treated with silica and then modified using carboxyl groups, which enabled binding of the biomolecules covalently. For the construction of the proposed sensor a two-step procedure was performed. First, the poly(FBThF) was electrochemically generated on the electrode surface. Then, carboxyl group modified magnetic nanoparticles (f-MNPs) and acetylcholinesterase (AChE), the model enzyme, were co-immobilized on the polymer-coated surface. Thereby, a robust and novel surface, conjugated polymer bearing magnetic nanoparticles with pendant carboxyl groups, was constructed, which was characterized using Fourier transform infrared spectrometer, cyclic voltammetry, scanning electron microscopy, and contact angle measurements. This novel architecture was then applied as an immobilization platform to detect pesticides. To the best of our knowledge, a sensor design that combines both conjugated polymer and magnetic nanoparticles was attempted for the first time, and this approach resulted in improved biosensor characteristics. Hence, this approach opens a new perspective in the field of enzyme immobilization and sensing applications. Paraoxon and trichlorfon were selected as the model toxicants. To obtain best biosensor performance, optimization studies were performed. Under optimized conditions, the biosensor in concern revealed a rapid response (5 s), a low detection limit (6.66 × 10(-3) mM), and high sensitivity (45.01 μA mM(-1) cm(-2)). The KM(app) value of poly(FBThF)/f-MNPs/AChE were determined as 0.73 mM. Furthermore, there was no considerable activity loss for 10 d for poly

  12. Bioactive Paper Sensor Based on the Acetylcholinesterase for the Rapid Detection of Organophosphate and Carbamate Pesticides

    PubMed Central

    Badawy, Mohamed E. I.; El-Aswad, Ahmed F.

    2014-01-01

    In many countries, people are becoming more concerned about pesticide residues which are present in or on food and feed products. For this reason, several methods have been developed to monitor the pesticide residue levels in food samples. In this study, a bioactive paper-based sensor was developed for detection of acetylcholinesterase (AChE) inhibitors including organophosphate and carbamate pesticides. Based on the Ellman colorimetric assay, the assay strip is composed of a paper support (1 × 10 cm), onto which a biopolymer chitosan gel immobilized in crosslinking by glutaraldehyde with AChE and 5,5′-dithiobis(2-nitrobenzoic) acid (DTNB) and uses acetylthiocholine iodide (ATChI) as an outside reagent. The assay protocol involves introducing the sample to sensing zone via dipping of a pesticide-containing solution. Following an incubation period, the paper is placed into ATChI solution to initiate enzyme catalyzed hydrolysis of the substrate, causing a yellow color change. The absence or decrease of the yellow color indicates the levels of the AChE inhibitors. The biosensor is able to detect organophosphate and carbamate pesticides with good detection limits (methomyl = 6.16 × 10−4 mM and profenofos = 0.27 mM) and rapid response times (~5 min). The results show that the paper-based biosensor is rapid, sensitive, inexpensive, portable, disposable, and easy-to-use. PMID:25484901

  13. Nanomaterials based biosensors for cancer biomarker detection

    NASA Astrophysics Data System (ADS)

    Malhotra, Bansi D.; Kumar, Saurabh; Mouli Pandey, Chandra

    2016-04-01

    Biosensors have enormous potential to contribute to the evolution of new molecular diagnostic techniques for patients suffering with cancerous diseases. A major obstacle preventing faster development of biosensors pertains to the fact that cancer is a highly complex set of diseases. The oncologists currently rely on a few biomarkers and histological characterization of tumors. Some of the signatures include epigenetic and genetic markers, protein profiles, changes in gene expression, and post-translational modifications of proteins. These molecular signatures offer new opportunities for development of biosensors for cancer detection. In this context, conducting paper has recently been found to play an important role towards the fabrication of a biosensor for cancer biomarker detection. In this paper we will focus on results of some of the recent studies obtained in our laboratories relating to fabrication and application of nanomaterial modified paper based biosensors for cancer biomarker detection.

  14. PRINCIPLES OF AFFINITY-BASED BIOSENSORS

    EPA Science Inventory

    Despite the amount of resources that have been invested by national and international academic, government, and commercial sectors to develop affinity-based biosensor products, little obvious success has been realized through commercialization of these devices for specific applic...

  15. Graphene-Based Biosensors: Going Simple.

    PubMed

    Morales-Narváez, Eden; Baptista-Pires, Luis; Zamora-Gálvez, Alejandro; Merkoçi, Arben

    2017-02-01

    The main properties of graphene derivatives facilitating optical and electrical biosensing platforms are discussed, along with how the integration of graphene derivatives, plastic, and paper can lead to innovative devices in order to simplify biosensing technology and manufacture easy-to-use, yet powerful electrical or optical biosensors. Some crucial issues to be overcome in order to bring graphene-based biosensors to the market are also underscored.

  16. Enzyme Nanoparticles-Based Electronic Biosensor

    SciTech Connect

    Liu, Guodong; Lin, Yuehe; Ostatna, V.; Wang, Joseph

    2005-06-28

    A novel method for fabricating electronic biosensors based on coupling enzyme nanoparticles and self assembly technology is illustrated. Redox horseradish peroxidase nanoparticles were prepared by desolvation with ethanol and subsequent crosslinking with glutaraldehyde. The cross-linked enzyme nanoparticles were functionalized by cysteine to introduce thiol groups on the nanoparticle surface. Immobilized enzyme nanoparticle on the gold electrode by self-assembly kept redox and electrocatalytic activities, and was used to develop reagentless biosensors for H2O2 detection without promoters and mediators. The new approach is simple, low cost and circumvents complications associated with solution systems. It is a universal immobilization method for biosensor, biomedical devices, biofuel cells and enzymatic bioreactors fabrication and expected to open new opportunities for biosensor, clinical diagnostics, and for bioanalysis, in general.

  17. Comparative investigation between acetylcholinesterase obtained from commercial sources and genetically modified Drosophila melanogaster: application in amperometric biosensors for methamidophos pesticide detection.

    PubMed

    de Oliveira Marques, Paulo Roberto Brasil; Nunes, Gilvanda Silva; dos Santos, Teresa Cristina Rodrigues; Andreescu, Silvana; Marty, Jean-Louis

    2004-11-01

    Genetically modified acetylcholinesterase (AChE) from Drosophila melanogaster (dm) and from commercial sources, Electric eel (ee), Bovine erythrocites (be) and Human erythrocites (he), were investigated as biological receptors for the detection of methamidophos pesticide based on inhibition studies. Most engineered variant of AChE from dm showed enhanced sensitivity toward methamidophos pesticide. Among 24 dmAChE variants tested, 12 presented a sensitivity comparable to the commercially available eeAChE, but higher than AChEs from be and he. Four were found more sensitive and six others were insensitive to methamidophos insecticide. The D375G,Y370F,Y374A,F376L mutant was the most sensitive, with a ki value of 2.2 X 10(6) mol(-1) L min(-1), three orders of magnitude higher than eeAChE (1.1 X 10(3) mol(-1) L min(-1)). The sensor constructed with genetically modified enzyme showed better characteristics with respect to detection limit and sensitivity compared with those using commercial eeAChE. Differential pulse polarography and chronoamperometry were used as electrochemical techniques to characterize the AChE biosensors. The lower detection limit of 1 ppb was obtained with D375G,Y370F,Y374A,F376L mutant of dmAChE, compared to 90 ppb for the commercial eeAChE. This study may stimulate scientists to develop more sensitive and selective procedures for organophosphorus insecticides detection by using engineered variant of dmAChE.

  18. Fiber optic-based biosensor

    NASA Technical Reports Server (NTRS)

    Ligler, Frances S.

    1991-01-01

    The NRL fiber optic biosensor is a device which measures the formation of a fluorescent complex at the surface of an optical fiber. Antibodies and DNA binding proteins provide the mechanism for recognizing an analyze and immobilizing a fluorescent complex on the fiber surface. The fiber optic biosensor is fast, sensitive, and permits analysis of hazardous materials remote from the instrumentation. The fiber optic biosensor is described in terms of the device configuration, chemistry for protein immobilization, and assay development. A lab version is being used for assay development and performance characterization while a portable device is under development. Antibodies coated on the fiber are stable for up to two years of storage prior to use. The fiber optic biosensor was used to measure concentration of toxins in the parts per billion (ng/ml) range in under a minute. Immunoassays for small molecules and whole bacteria are under development. Assays using DNA probes as the detection element can also be used with the fiber optic sensor, which is currently being developed to detect biological warfare agents, explosives, pathogens, and toxic materials which pollute the environment.

  19. Graphene-Based Optical Biosensors and Imaging

    SciTech Connect

    Tang, Zhiwen; He, Shijiang; Pei, Hao; Du, Dan; Fan, Chunhai; Lin, Yuehe

    2014-01-13

    This chapter focuses on the design, fabrication and application of graphene based optical nanobiosensors. The emerging graphene based optical nanobiosensors demonstrated the promising bioassay and biomedical applications thanking to the unique optical features of graphene. According to the different applications, the graphene can be tailored to form either fluorescent emitter or efficient fluorescence quencher. The exceptional electronic feature of graphene makes it a powerful platform for fabricating the SPR and SERS biosensors. Today the graphene based optical biosensors have been constructed to detect various targets including ions, small biomolecules, DNA/RNA and proteins. This chapter reviews the recent progress in graphene-based optical biosensors and discusses the opportunities and challenges in this field.

  20. Detoxification of organophosphate residues using phosphotriesterase and their evaluation using flow based biosensor.

    PubMed

    Mishra, Rupesh K; Istamboulie, George; Bhand, Sunil; Marty, Jean-Louis

    2012-10-01

    Among known pesticide groups, organophosphates (OPs) have grasped attention due to their hazardous nature and their applications as pesticides and chemical weapons. This work presents the development of cost-effective column based biosensor for detoxification of OPs in water and milk. Enzyme phosphotriesterase (PTE) was immobilized on an activated Sepharose 4B via covalent coupling using an Omnifit glass column. Three different OPs, ethyl paraoxon (EPOx), malaoxon (MAO) and chlorpyriphos-oxon (CPO) were spiked in water and milk to test the detoxification of OPs. Mixtures of these pesticides were also tested to check the cumulative detoxification in the real samples. The efficiency of detoxification was evaluated using a highly sensitive acetylcholinesterase (AChE) B394 biosensor based flow system. The column conditions were optimized for the detoxification studied. The method was shown to be promising when we tested real milk samples spiked with OPs. Detoxification obtained in milk was up to 86% whereas in water, 100% detoxification was obtained.

  1. Biosensors.

    ERIC Educational Resources Information Center

    Rechnitz, Garry A.

    1988-01-01

    Describes theory and principles behind biosensors that incorporate biological components as part of a sensor or probe. Projects major applications in medicine and veterinary medicine, biotechnology, food and agriculture, environmental studies, and the military. Surveys current use of biosensors. (ML)

  2. Device considerations for development of conductance-based biosensors

    PubMed Central

    Lee, Kangho; Nair, Pradeep R.; Scott, Adina; Alam, Muhammad A.; Janes, David B.

    2009-01-01

    Design and fabrication of electronic biosensors based on field-effect-transistor (FET) devices require understanding of interactions between semiconductor surfaces and organic biomolecules. From this perspective, we review practical considerations for electronic biosensors with emphasis on molecular passivation effects on FET device characteristics upon immobilization of organic molecules and an electrostatic model for FET-based biosensors. PMID:24753627

  3. Single bead-based electrochemical biosensor

    PubMed Central

    Liu, Changchun; Schrlau, Michael G.; Bau, Haim H.

    2009-01-01

    A simple, robust, single bead-based electrochemical biosensor was fabricated and characterized. The sensor’s working electrode consists of an electrochemically-etched platinum wire, with a nominal diameter of 25 μm, hermetically heat-fusion sealed in a pulled glass capillary (micropipette). The sealing process does not require any epoxy or glue. A commercially available, densely functionalized agarose bead was mounted on the tip of the etched platinum wire. The use of a pre-functionalized bead eliminates the tedious and complicated surface functionalization process that is often the bottleneck in the development of electrochemical biosensors. We report on the use of a biotin agarose bead-based, micropipette, electrochemical (Bio-BMP) biosensor to monitor H2O2 concentration and the use of a streptavidin bead-based, micropipette, electrochemical (SA-BMP) biosensor to detect DNA amplicons. The Bio-BMP biosensor’s response increased linearly as the H2O2 concentration increased in the range from 1×10−6 to 1.2×10−4 M with a detection limit of 5×10−7 M. The SA-BMP was able to detect the amplicons of 1 pg DNA template of B. Cereus bacteria, thus providing better detection sensitivity than conventional gel-based electropherograms. PMID:19767195

  4. Enhanced efficiency of a capillary-based biosensor over an optical fiber biosensor for detecting calpastatin.

    PubMed

    Bratcher, C L; Grant, S A; Vassalli, J T; Lorenzen, C L

    2008-06-15

    A capillary-based optical biosensor has been developed to detect calpastatin, an indicator of meat tenderness. Longissimus muscle samples (n=11) were extracted from beef carcasses at 0 and 48h post-mortem. These samples were assayed for calpastatin by traditional laboratory methods and with a newly developed capillary tube biosensor as well as for Warner-Bratzler shear force (WBSF) and crude protein and the responses were compared. Additionally, the response from the capillary-based biosensor was compared to a previously developed optical fiber biosensor. When the 0 and 48h sampling periods were combined, the capillary tube biosensor was moderately accurate in predicting calpastatin activity (R(2)=0.6058). There was less variation in the 0h capillary tube biosensor compared to the 0h pre-column (P=0.006) and post-column optical fiber biosensors (P=0.047), therefore the capillary tube biosensor is a more precise system of measurement. This research further advances the development of a calpastatin biosensor and makes online assessment one step closer to reality.

  5. Nanoparticles Modified ITO Based Biosensor

    NASA Astrophysics Data System (ADS)

    Khan, M. Z. H.

    2016-12-01

    Incorporation of nanomaterials with controlled molecular architecture shows great promise in improving electronic communication between biomolecules and the electrode substrate. In electrochemical applications metal nanoparticles (NPs) modified electrodes have been widely used and are emerging as candidates to develop highly sensitive electrochemical sensors. There has been a growing technological interest in modified indium tin oxide (ITO) electrodes due to their prominent optoelectronic properties and their wide use as a transducing platform. The introduction of NPs into the transducing platform is commonly achieved by their adsorption onto conventional electrode surfaces in various forms, including that of a composite. The aim of this review is to discuss the role of metallic NPs for surface fabrication of ITO thin films leading to detection of specific biomolecules and applications as a biosensor platform.

  6. Nanoparticles Modified ITO Based Biosensor

    NASA Astrophysics Data System (ADS)

    Khan, M. Z. H.

    2017-04-01

    Incorporation of nanomaterials with controlled molecular architecture shows great promise in improving electronic communication between biomolecules and the electrode substrate. In electrochemical applications metal nanoparticles (NPs) modified electrodes have been widely used and are emerging as candidates to develop highly sensitive electrochemical sensors. There has been a growing technological interest in modified indium tin oxide (ITO) electrodes due to their prominent optoelectronic properties and their wide use as a transducing platform. The introduction of NPs into the transducing platform is commonly achieved by their adsorption onto conventional electrode surfaces in various forms, including that of a composite. The aim of this review is to discuss the role of metallic NPs for surface fabrication of ITO thin films leading to detection of specific biomolecules and applications as a biosensor platform.

  7. Fiber optic-based regenerable biosensor

    DOEpatents

    Sepaniak, Michael J.; Vo-Dinh, Tuan

    1993-01-01

    A fiber optic-based regenerable biosensor. The biosensor is particularly suitable for use in microscale work in situ. In one embodiment, the biosensor comprises a reaction chamber disposed adjacent the distal end of a waveguide and adapted to receive therein a quantity of a sample containing an analyte. Leading into the chamber is a plurality of capillary conduits suitable for introducing into the chamber antibodies or other reagents suitable for selective interaction with a predetermined analyte. Following such interaction, the contents of the chamber may be subjected to an incident energy signal for developing fluorescence within the chamber that is detectable via the optical fiber and which is representative of the presence, i.e. concentration, of the selected analyte. Regeneration of the biosensor is accomplished by replacement of the reagents and/or the analyte, or a combination of these, at least in part via one or more of the capillary conduits. The capillary conduits extend from their respective terminal ends that are in fluid communication with the chamber, away from the chamber to respective location(s) remote from the chamber thereby permitting in situ location of the chamber and remote manipulation and/or analysis of the activity with the chamber.

  8. Nanomaterial-Based Electrochemical Biosensors and Bioassays

    SciTech Connect

    Liu, Guodong; Mao, Xun; Gurung, Anant; Baloda, Meenu; Lin, Yuehe; He, Yuqing

    2010-08-31

    This book chapter summarizes the recent advance in nanomaterials for electrochemical biosensors and bioassays. Biofunctionalization of nanomaterials for biosensors fabrication and their biomedical applications are discussed.

  9. A microfluidic paper-based device to assess acetylcholinesterase activity.

    PubMed

    Liu, Chunye; Gomez, Frank A

    2017-04-01

    Neurotransmitters play key roles in cell-to-cell communication. These chemical messengers are involved in many functional processes, including growth, reproduction, memory, and behavior. In this communication, we describe a novel microfluidic paper-based analytical device (μPAD) to detect acetylcholinesterase (AChE) activity and inhibitor screening through a colorimetric analysis. The μPAD is easily fabricated via a wax printing process whereby wax is deposited onto the surface of chromatographic paper, and heated to create a hydrophobic barrier. Separate solutions of 5,5'-dithiobis-(2-nitrobenzoic acid) (DTNB) and samples containing AChE and acetylthiocholine iodide (ATC) (or cysteine, Cys), respectively, are directly spotted onto the μPAD. DTNB and AChE/ATC (or Cys) flow towards each other where a reaction occurs to form the yellow colored 2-nitro-5-thiobenzoic acid anion (TNB(2-) ). The device is dried, scanned, and analyzed yielding a linear range of average inverse yellow intensities versus substrate concentration. An IC50 value (0.045 nM) with a known inhibitor, neostigmine bromide (NB), is obtained on the device. μPADs are low cost and easy to fabricate and have great potential to quantify neurotransmitter activity.

  10. Perspectives for the structure-based design of acetylcholinesterase reactivators.

    PubMed

    Ochoa, Rodrigo; Rodriguez, Carlos A; Zuluaga, Andres F

    2016-07-01

    Rational design of active molecules through structure-based methods has been gaining adepts during the last decades due to the wider availability of protein structures, most of them conjugated with relevant ligands. Acetylcholinesterase (AChE) is a molecular target with a considerable amount of data related to its sequence and 3-dimensional structure. In addition, there are structural insights about the mechanism of action of the natural substrate and drugs used in Alzheimer's disease, organophosphorus compounds, among others. We looked for AChE structural data useful for in silico design of potential interacting molecules. In particular, we focused on information regarding the design of ligands aimed to reactivate AChE catalytic activity. The structures of 178 AChE were annotated and categorized on different subsets according to the nature of the ligand, source organisms and experimental details. We compared sequence homology among the active site from Torpedo californica, Mus musculus and Homo sapiens with the latter two species having the closest relationship (88.9% identity). In addition, the mechanism of organophosphorus binding and the design of effective reactivators are reviewed. A curated data collection obtained with information from several sources was included for researchers working on the field. Finally, a molecular dynamics simulation with human AChE indicated that the catalytic pocket volume stabilizes around 600 Å(3), providing additional clues for drug design.

  11. Sensitive-cell-based fish chromatophore biosensor

    NASA Astrophysics Data System (ADS)

    Plant, Thomas K.; Chaplen, Frank W.; Jovanovic, Goran; Kolodziej, Wojtek; Trempy, Janine E.; Willard, Corwin; Liburdy, James A.; Pence, Deborah V.; Paul, Brian K.

    2004-07-01

    A sensitive biosensor (cytosensor) has been developed based on color changes in the toxin-sensitive colored living cells of fish. These chromatophores are highly sensitive to the presence of many known and unknown toxins produced by microbial pathogens and undergo visible color changes in a dose-dependent manner. The chromatophores are immobilized and maintained in a viable state while potential pathogens multiply and fish cell-microbe interactions are monitored. Low power LED lighting is used to illuminate the chromatophores which are magnified using standard optical lenses and imaged onto a CCD array. Reaction to toxins is detected by observing changes is the total area of color in the cells. These fish chromatophores are quite sensitive to cholera toxin, Staphococcus alpha toxin, and Bordatella pertussis toxin. Numerous other toxic chemical and biological agents besides bacterial toxins also cause readily detectable color effects in chromatophores. The ability of the chromatophore cell-based biosensor to distinguish between different bacterial pathogens was examined. Toxin producing strains of Salmonella enteritis, Vibrio parahaemolyticus, and Bacillus cereus induced movement of pigmented organelles in the chromatophore cells and this movement was measured by changes in the optical density over time. Each bacterial pathogen elicited this measurable response in a distinctive and signature fashion. These results suggest a chromatophore cell-based biosensor assay may be applicable for the detection and identification of virulence activities associated with certain air-, food-, and water-borne bacterial pathogens.

  12. Recent advances in biosensor based endotoxin detection.

    PubMed

    Das, A P; Kumar, P S; Swain, S

    2014-01-15

    Endotoxins also referred to as pyrogens are chemically lipopolysaccharides habitually found in food, environment and clinical products of bacterial origin and are unavoidable ubiquitous microbiological contaminants. Pernicious issues of its contamination result in high mortality and severe morbidities. Standard traditional techniques are slow and cumbersome, highlighting the pressing need for evoking agile endotoxin detection system. The early and prompt detection of endotoxin assumes prime importance in health care, pharmacological and biomedical sectors. The unparalleled recognition abilities of LAL biosensors perched with remarkable sensitivity, high stability and reproducibility have bestowed it with persistent reliability and their possible fabrication for commercial applicability. This review paper entails an overview of various trends in current techniques available and other possible alternatives in biosensor based endotoxin detection together with its classification, epidemiological aspects, thrust areas demanding endotoxin control, commercially available detection sensors and a revolutionary unprecedented approach narrating the influence of omics for endotoxin detection.

  13. Design of nanostructured-based glucose biosensors

    NASA Astrophysics Data System (ADS)

    Komirisetty, Archana; Williams, Frances; Pradhan, Aswini; Konda, Rajini B.; Dondapati, Hareesh; Samantaray, Diptirani

    2012-04-01

    This paper presents the design of glucose sensors that will be integrated with advanced nano-materials, bio-coatings and electronics to create novel devices that are highly sensitive, inexpensive, accurate, and reliable. In the work presented, a glucose biosensor and its fabrication process flow have been designed. The device is based on electrochemical sensing using a working electrode with bio-functionalized zinc oxide (ZnO) nano-rods. Among all metal oxide nanostructures, ZnO nano-materials play a significant role as a sensing element in biosensors due to their properties such as high isoelectric point (IEP), fast electron transfer, non-toxicity, biocompatibility, and chemical stability which are very crucial parameters to achieve high sensitivity. Amperometric enzyme electrodes based on glucose oxidase (GOx) are used due to their stability and high selectivity to glucose. The device also consists of silicon dioxide and titanium layers as well as platinum working and counter electrodes and a silver/silver chloride reference electrode. Currently, the biosensors are being fabricated using the process flow developed. Once completed, the sensors will be bio-functionalized and tested to characterize their performance, including their sensitivity and stability.

  14. Raman Spectroscopy Cell-based Biosensors

    PubMed Central

    Notingher, Ioan

    2007-01-01

    One of the main challenges faced by biodetection systems is the ability to detect and identify a large range of toxins at low concentrations and in short times. Cell-based biosensors rely on detecting changes in cell behaviour, metabolism, or induction of cell death following exposure of live cells to toxic agents. Raman spectroscopy is a powerful technique for studying cellular biochemistry. Different toxic chemicals have different effects on living cells and induce different time-dependent biochemical changes related to cell death mechanisms. Cellular changes start with membrane receptor signalling leading to cytoplasmic shrinkage and nuclear fragmentation. The potential advantage of Raman spectroscopy cell-based systems is that they are not engineered to respond specifically to a single toxic agent but are free to react to many biologically active compounds. Raman spectroscopy biosensors can also provide additional information from the time-dependent changes of cellular biochemistry. Since no cell labelling or staining is required, the specific time dependent biochemical changes in the living cells can be used for the identification and quantification of the toxic agents. Thus, detection of biochemical changes of cells by Raman spectroscopy could overcome the limitations of other biosensor techniques, with respect to detection and discrimination of a large range of toxic agents. Further developments of this technique may also include integration of cellular microarrays for high throughput in vitro toxicological testing of pharmaceuticals and in situ monitoring of the growth of engineered tissues.

  15. Electronic Biosensors Based on III-Nitride Semiconductors.

    PubMed

    Kirste, Ronny; Rohrbaugh, Nathaniel; Bryan, Isaac; Bryan, Zachary; Collazo, Ramon; Ivanisevic, Albena

    2015-01-01

    We review recent advances of AlGaN/GaN high-electron-mobility transistor (HEMT)-based electronic biosensors. We discuss properties and fabrication of III-nitride-based biosensors. Because of their superior biocompatibility and aqueous stability, GaN-based devices are ready to be implemented as next-generation biosensors. We review surface properties, cleaning, and passivation as well as different pathways toward functionalization, and critically analyze III-nitride-based biosensors demonstrated in the literature, including those detecting DNA, bacteria, cancer antibodies, and toxins. We also discuss the high potential of these biosensors for monitoring living cardiac, fibroblast, and nerve cells. Finally, we report on current developments of covalent chemical functionalization of III-nitride devices. Our review concludes with a short outlook on future challenges and projected implementation directions of GaN-based HEMT biosensors.

  16. Electronic Biosensors Based on III-Nitride Semiconductors

    NASA Astrophysics Data System (ADS)

    Kirste, Ronny; Rohrbaugh, Nathaniel; Bryan, Isaac; Bryan, Zachary; Collazo, Ramon; Ivanisevic, Albena

    2015-07-01

    We review recent advances of AlGaN/GaN high-electron-mobility transistor (HEMT)-based electronic biosensors. We discuss properties and fabrication of III-nitride-based biosensors. Because of their superior biocompatibility and aqueous stability, GaN-based devices are ready to be implemented as next-generation biosensors. We review surface properties, cleaning, and passivation as well as different pathways toward functionalization, and critically analyze III-nitride-based biosensors demonstrated in the literature, including those detecting DNA, bacteria, cancer antibodies, and toxins. We also discuss the high potential of these biosensors for monitoring living cardiac, fibroblast, and nerve cells. Finally, we report on current developments of covalent chemical functionalization of III-nitride devices. Our review concludes with a short outlook on future challenges and projected implementation directions of GaN-based HEMT biosensors.

  17. Recent advances in biosensors based on enzyme inhibition.

    PubMed

    Amine, A; Arduini, F; Moscone, D; Palleschi, G

    2016-02-15

    Enzyme inhibitors like drugs and pollutants are closely correlated to human and environmental health, thus their monitoring is of paramount importance in analytical chemistry. Enzymatic biosensors represent cost-effective, miniaturized and easy to use devices; particularly biosensors based on enzyme inhibition are useful analytical tools for fast screening and monitoring of inhibitors. The present review will highlight the research carried out in the last 9 years (2006-2014) on biosensors based on enzyme inhibition. We underpin the recent advances focused on the investigation in new theoretical approachs and in the evaluation of biosensor performances for reversible and irreversible inhibitors. The use of nanomaterials and microfluidic systems as well as the applications of the various biosensors in real samples is critically reviewed, demonstrating that such biosensors allow the development of useful devices for a fast and reliable alarm system.

  18. Synthesis and in vitro acetylcholinesterase and butyrylcholinesterase inhibitory potential of hydrazide based Schiff bases.

    PubMed

    Rahim, Fazal; Ullah, Hayat; Taha, Muhammad; Wadood, Abdul; Javed, Muhammad Tariq; Rehman, Wajid; Nawaz, Mohsan; Ashraf, Muhammad; Ali, Muhammad; Sajid, Muhammad; Ali, Farman; Khan, Muhammad Naseem; Khan, Khalid Mohammed

    2016-10-01

    To discover multifunctional agents for the treatment of Alzheimer's disease, a series of hydrazide based Schiff bases were designed and synthesized based on multitarget-directed strategy. We have synthesized twenty-eight analogs of hydrazide based Schiff bases, characterized by various spectroscopic techniques and evaluated in vitro for acetylcholinesterase and butyrylcholinesterase inhibition. All compounds showed varied degree of acetylcholinesterase and butyrylcholinesterase inhibition when compared with standard Eserine. Among the series, compounds 10, 3 and 24 having IC50 values 4.12±0.01, 8.12±0.01 and 8.41±0.06μM respectively showed potent acetylcholinesterase inhibition when compared with Eserine (IC50=0.85±0.0001μM). Three compounds 13, 24 and 3 having IC50 values 6.51±0.01, 9.22±0.07 and 37.82±0.14μM respectively showed potent butyrylcholinesterase inhibition by comparing with eserine (IC50=0.04±0.0001μM). The remaining compounds also exhibited moderate to weak inhibitory potential. Structure activity relationship has been established. Through molecular docking studies the binding interaction was confirmed.

  19. A catechol biosensor based on electrospun carbon nanofibers

    PubMed Central

    Li, Dawei; Pang, Zengyuan; Chen, Xiaodong; Luo, Lei; Cai, Yibing

    2014-01-01

    Summary Carbon nanofibers (CNFs) were prepared by combining electrospinning with a high-temperature carbonization technique. And a polyphenol biosensor was fabricated by blending the obtained CNFs with laccase and Nafion. Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR) and field emission scanning electron microscope (FE-SEM) were, respectively, employed to investigate the structures and morphologies of the CNFs and of the mixtures. Cyclic voltammetry and chronoamperometry were employed to study the electrocatalysis of the catechol biosensor. The results indicated that the sensitivity of the biosensor was 41 µA·mM−1, the detection limit was 0.63 µM, the linear range was 1–1310 µM and the response time was within 2 seconds, which excelled most other laccase-based biosensor reported. Furthermore, the biosensor showed good repeatability, reproducibility, stability and tolerance to interferences. This novel biosensor also demonstrated its promising application in detecting catechol in real water samples. PMID:24778958

  20. Biosensor based on Prussian blue nanocubes/reduced graphene oxide nanocomposite for detection of organophosphorus pesticides

    SciTech Connect

    Zhang, Lin; Zhang, Aidong; Du, Dan; Lin, Yuehe

    2012-07-13

    We demonstrate a facile procedure to efficiently prepare Prussian blue nanocubes/reduced graphene oxide (PBNCs/rGO) nanocomposite by directly mixing Fe3+ and [Fe(CN)6]3 in the presence of GO in polyethyleneimine aqueous solution, resulting in a novel acetylcholinesterase (AChE) biosensor for detection of organophosphorus pesticides (OPs). The obtained nanocomposite was characterized by X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and energy dispersive X-ray (EDX) microanalysis. It was clearly observed that the nanosheet has been decorated with cubic PB nanoparticles and nearly all the nanoparticles are distributed uniformly only on the surface of the reduced GO. No isolated PB nanoparticles were observed, indicating the strong interaction between PB nanocubes and the reduced GO and the formation of PBNCs/rGO nanocomposite. The obtained PBNCs/rGO based AChE biosensor make the peak potential shift negatively to 220 mV. The AChE biosensor shows rapid response and high sensitivity for detection of monocrotophos. These results suggest that the PBNCs/rGO hybrids nanocomposite exhibited high electrocatalytic activity towards the oxidation of thiocholine, which lead to the sensitive detection of OP pesticides.

  1. Silicon-on-Insulator Nanowire Based Optical Waveguide Biosensors

    NASA Astrophysics Data System (ADS)

    Li, Mingyu; Liu, Yong; Chen, Yangqing; He, Jian-Jun

    2016-01-01

    Optical waveguide biosensors based on silicon-on-insulator (SOI) nanowire have been developed for label free molecular detection. This paper reviews our work on the design, fabrication and measurement of SOI nanowire based high-sensitivity biosensors employing Vernier effect. Biosensing experiments using cascaded double-ring sensor and Mach-Zehnder- ring sensor integrated with microfluidic channels are demonstrated

  2. Split luciferase-based biosensors for characterizing EED binders.

    PubMed

    Li, Ling; Feng, Lijian; Shi, Minlong; Zeng, Jue; Chen, Zijun; Zhong, Li; Huang, Li; Guo, Weihui; Huang, Ying; Qi, Wei; Lu, Chris; Li, En; Zhao, Kehao; Gu, Justin

    2017-04-01

    The EED (embryonic ectoderm development) subunit of the Polycomb repressive complex 2 (PRC2) plays an important role in the feed forward regulation of the PRC2 enzymatic activity. We recently identified a new class of allosteric PRC2 inhibitors that bind to the H3K27me3 pocket of EED. Multiple assays were developed and used to identify and characterize this type of PRC2 inhibitors. One of them is a genetically encoded EED biosensor based on the EED[G255D] mutant and the split firefly luciferase. This EED biosensor can detect the compound binding in the transfected cells and in the in vitro biochemical assays. Compared to other commonly used cellular assays, the EED biosensor assay has the advantage of shorter compound incubation with cells. The in vitro EED biosensor is much more sensitive than other label-free biophysical assays (e.g. DSF, ITC). Based on the crystal structure, the DSF data as well as the biosensor assay data, it's most likely that compound-induced increase in the luciferase activity of the EED[G255D] biosensor results from the decreased non-productive interactions between the EED subdomain and other subdomains within the biosensor construct. This new insight of the mechanism might help to broaden the use of the split luciferase based biosensors.

  3. Biosensor method and system based on feature vector extraction

    DOEpatents

    Greenbaum, Elias; Rodriguez, Jr., Miguel; Qi, Hairong; Wang, Xiaoling

    2013-07-02

    A system for biosensor-based detection of toxins includes providing at least one time-dependent control signal generated by a biosensor in a gas or liquid medium, and obtaining a time-dependent biosensor signal from the biosensor in the gas or liquid medium to be monitored or analyzed for the presence of one or more toxins selected from chemical, biological or radiological agents. The time-dependent biosensor signal is processed to obtain a plurality of feature vectors using at least one of amplitude statistics and a time-frequency analysis. At least one parameter relating to toxicity of the gas or liquid medium is then determined from the feature vectors based on reference to the control signal.

  4. Biosensor method and system based on feature vector extraction

    DOEpatents

    Greenbaum, Elias [Knoxville, TN; Rodriguez, Jr., Miguel; Qi, Hairong [Knoxville, TN; Wang, Xiaoling [San Jose, CA

    2012-04-17

    A method of biosensor-based detection of toxins comprises the steps of providing at least one time-dependent control signal generated by a biosensor in a gas or liquid medium, and obtaining a time-dependent biosensor signal from the biosensor in the gas or liquid medium to be monitored or analyzed for the presence of one or more toxins selected from chemical, biological or radiological agents. The time-dependent biosensor signal is processed to obtain a plurality of feature vectors using at least one of amplitude statistics and a time-frequency analysis. At least one parameter relating to toxicity of the gas or liquid medium is then determined from the feature vectors based on reference to the control signal.

  5. Acetylcholinesterase-based organophosphate nerve agent sensing photonic crystal.

    PubMed

    Walker, Jeremy P; Asher, Sanford A

    2005-03-15

    We developed a polymerized crystalline colloidal array (PCCA) photonic crystal sensing material that senses the organophosphorus compound parathion at ultratrace concentrations in aqueous solutions. A periodic array of colloidal particles is embedded in a hydrogel network with a lattice spacing such that it Bragg diffracts visible light. The molecular recognition agent for the sensor is the enzyme acetylcholinesterase (AChE), which binds organophosphorus compounds irreversibly, creating an anionic phosphonyl species. This charged species creates a Donnan potential, which swells the hydrogel network, which increases the embedded particle array lattice spacing and causes a red-shift in the wavelength of light diffracted. The magnitude of the diffraction red-shift is proportional to the amount of bound parathion. These AChE-PCCAs act as dosimeters for parathion since it irreversibly binds. Parathion concentrations as low as 4.26 fM are easily detected.

  6. Current Trends in Nanomaterial-Based Amperometric Biosensors

    PubMed Central

    Hayat, Akhtar; Catanante, Gaëlle; Marty, Jean Louis

    2014-01-01

    The last decade has witnessed an intensive research effort in the field of electrochemical sensors, with a particular focus on the design of amperometric biosensors for diverse analytical applications. In this context, nanomaterial integration in the construction of amperometric biosensors may constitute one of the most exciting approaches. The attractive properties of nanomaterials have paved the way for the design of a wide variety of biosensors based on various electrochemical detection methods to enhance the analytical characteristics. However, most of these nanostructured materials are not explored in the design of amperometric biosensors. This review aims to provide insight into the diverse properties of nanomaterials that can be possibly explored in the construction of amperometric biosensors. PMID:25494347

  7. Urea biosensors based on PVC membrane containing palmitic acid.

    PubMed

    Karakuş, Emine; Pekyardimci, Sule; Esma, Kiliç

    2005-01-01

    A new urea biosensor was prepared by immobilizing urease with four different procedures on poly(vinylchloride) (PVC) ammonium membrane electrode containing palmitic acid by using nonactine as an ammonium-ionophore. The analytical characteristics were investigated and were compared those of the biosensor prepared by using carboxylated PVC. The effect of pH, buffer concentration, temperature, urease concentration, stirring rate and enzyme immobilization procedures on the response to urea of the enzyme electrode were investigated. The linear working range and sensitivity of the biosensor were also determined. The urea biosensor prepared by using the PVC membranes containing palmitic acid showed more effective performance than those of the carboxylated PVC based biosensors. Additionally, urea assay in serum was successfully carried out by using the standard addition method.

  8. DNA biosensors based on self-assembled carbon nanotubes.

    PubMed

    Wang, S G; Wang, Ruili; Sellin, P J; Zhang, Qing

    2004-12-24

    DNA biosensors based on self-assembled multi-walled carbon nanotubes (MWNTs) were described in this paper, in which the probe DNA oligonucleotides were immobilized by forming covalent amide bonds between carboxyl groups at the nanotubes and amino groups at the ends of the DNA oligonucleotides. Hybridization between the probe and target DNA oligonucleotides was confirmed by the changes in the voltammetric peak of the indicator of methylene blue. Our results demonstrate that the DNA biosensors based on self-assembled MWNTs had a higher hybridization efficiency compared to those based on random MWNTs. In addition, the developed DNA biosensors also had a high selectivity of hybridization detection.

  9. Microfabrication of nanowires-based GMR biosensor

    NASA Astrophysics Data System (ADS)

    Bellamkonda, R.; John, T.; Mathew, B.; DeCoster, M.; Hegab, H.; Palmer, J.; Davis, D.

    2009-05-01

    This study focuses on the development of current-perpendicular-to plane (CPP) Giant Magnetoresistance (GMR) of CoNiCu/Cu multilayered nanowire based microfluidic sensors for the detection of magnetic nanoparticles and fluids. The visible measurable variations in electrical voltage due to changes in external magnetic field are later to be monitored in microfluidic biosensor for the detection of toxicants in cells. An early prototype device was fabricated and tested using both an aqueous nonmagnetic medium (water) and a commercially available ferrofluid solution. A magnetic field of 0.01T caused a resistance change of 1.37% for ferrofluid, while a 1.1% GMR was recorded for the water baseline.

  10. Biosensors based on DNA-Functionalized Graphene

    NASA Astrophysics Data System (ADS)

    Vishnubhotla, Ramya; Ping, Jinglei; Vrudhula, Amey; Johnson, A. T. Charlie

    Since its discovery, graphene has been used for sensing applications due to its outstanding electrical properties and biocompatibility. Here, we demonstrate the capabilities of field effect transistors (FETs) based on CVD-grown graphene functionalized with commercially obtained DNA oligomers and aptamers for detection of various biomolecular targets (e.g., complementary DNA and small molecule drug targets). Graphene FETs were created with a scalable photolithography process that produces arrays consisting of 50-100 FETs with a layout suitable for multiplexed detection of four molecular targets. FETs were characterized via AFM to confirm the presence of the aptamer. From the measured electrical characteristics, it was determined that binding of molecular targets by the DNA chemical recognition element led to a reproducible, concentration-dependent shift in the Dirac voltage. This biosensor class is potentially suitable for applications in drug detection. This work is funded by NIH through the Center for AIDS Research at the University of Pennsylvania.

  11. Biosensors based on surface plasmon-enhanced fluorescence spectroscopy.

    PubMed

    Dostálek, Jakub; Knoll, Wolfgang

    2008-09-01

    The implementation of surface plasmon-enhanced fluorescence spectroscopy (SPFS) to surface plasmon resonance (SPR) biosensors enables increasing their sensitivity by several orders of magnitude. In SPR-based biosensors, surface plasmons probe the binding of target molecules contained in a liquid sample by their affinity partners attached to a metallic sensor surface. SPR biosensors relying on the detection of refractive index changes allow for direct observation of the binding of large and medium size molecules that produces sufficiently large refractive index changes. In SPR biosensors exploiting SPFS, the capture of fluorophore-labeled molecules to the sensor surface is observed by the detection of fluorescence light emitted from the surface. This technique takes advantage of the enhanced intensity of electromagnetic field accompanied with the resonant excitation of surface plasmons. The interaction with surface plasmons can greatly increase the measured fluorescence signal through enhancing the excitation rate of fluorophores and by more efficient collecting of fluorescence light. SPFS-based biosensors were shown to enable the analysis of samples with extremely low analyte concentrations and the detection of small molecules. In this review, we describe the fundamental principles, implementations, and current state of the art applications of SPFS biosensors. This review focuses on SPFS-based biosensors employing the excitation of surface plasmons on continuous metal-dielectric interfaces.

  12. Synthesis and application of quantum dots-based biosensor

    NASA Astrophysics Data System (ADS)

    Hai Nguyen, Ngoc; Giang Duong, Thi; Hoang, Van Nong; Thang Pham, Nam; Cao Dao, Tran; Nga Pham, Thu

    2015-03-01

    Trichlorfon (TF) is one of the organophosphorus pesticides used widely in agriculture. The content of this paper includes the exploitation of dominant optical properties of the quantum dots consisting of a core and multilayer shell CdSe/ZnSe/ZnS (QD). A biosensor was fabricated on the basis of this QD for rapidly detecting the residues of trichlofon pesticide with concentrations of 0.01 ppm to 5 ppm. The measurements were carried out to examine the morphology of the QD structure and fluorescent properties such as transmission electron microscopy, x-ray diffraction, absorption spectroscopy and fluorescence spectroscopy. The linking mechanism among biological agents and the specificity of the acetylcholinesterase enzymes in hydrolysis reaction of acetylthiolcholine was applied to create the changes in surroundings, affecting the fluorescence of the QD. In particular, the mechanism of bioluminescence resonance energy transfer (BRET) is discussed to clearly explain the recombination of electrons and holes in the QD.

  13. Resistance-based biosensor of Multi-Walled Carbon Nanotubes.

    PubMed

    Kolosovas-Machuca, E S; Vera-Reveles, G; Rodríguez-Aranda, M C; Ortiz-Dosal, L C; Segura-Cardenas, Emmanuel; Gonzalez, Francisco J

    2015-01-01

    Multi-Walled Carbon Nanotubes (MWNTs) are a good choice for resistive biosensors due to their great resistance changes when immunoreactions take place, they are also low-cost, more biocompatible than single-walled carbon nanotubes, and resistive measurement equipment is usually not expensive and readily available. In this work a novel resistive biosensor based on the immobilization of an antigen through a silanization process over the surface of Multi-Walled Carbon Nanotubes (MWNTs) is reported. Results show that the biosensor increases its conductivity when adding the antigen and decreases when adding the antibody making them good candidates for disease diagnosis.

  14. Immobilization of Acetylcholinesterase on Screen-Printed Electrodes. Application to the Determination of Arsenic(III)

    PubMed Central

    Sanllorente-Méndez, Silvia; Domínguez-Renedo, Olga; Arcos-Martínez, M. Julia

    2010-01-01

    Enzymatic amperometric procedures for measuring arsenic, based on the inhibitive action of this metal on acetylcholinesterase enzyme activity, have been developed. Screen-printed carbon electrodes (SPCEs) were used with acetylcholinesterase covalently bonded directly to its surface. The amperometric response of acetylcholinesterase was affected by the presence of arsenic ions, which caused a decrease in the current intensity. The experimental optimum working conditions of pH, substrate concentration and potential applied, were established. Under these conditions, repeatability and reproducibility of biosensors were determined, reaching values below 4% in terms of relative standard deviation. The detection limit obtained for arsenic was 1.1 × 10−8 M for Ach/SPCE biosensor. Analysis of the possible effect of the presence of foreign ions in the solution was performed. The method was applied to determine levels of arsenic in spiked tap water samples. PMID:22294918

  15. Development of biosensor based on imaging ellipsometry and its applications

    NASA Astrophysics Data System (ADS)

    Jin, Gang

    2011-03-01

    We have reviewed the development of the biosensor based on imaging ellipsometry including its principle, methodology and general engineering model structure, mainly compared experimental setups between the previous one and the recently developed one. It's obvious that the sensitivity and the signal to noise ratio has been improved by a various spectroscopic light source, the optimization of polarized components setting and a cool CCD, especially the contribution of the CCD, which makes the biosensor available in more and more biomedical applications.

  16. Last Advances in Silicon-Based Optical Biosensors.

    PubMed

    Fernández Gavela, Adrián; Grajales García, Daniel; Ramirez, Jhonattan C; Lechuga, Laura M

    2016-02-24

    We review the most important achievements published in the last five years in the field of silicon-based optical biosensors. We focus specially on label-free optical biosensors and their implementation into lab-on-a-chip platforms, with an emphasis on developments demonstrating the capability of the devices for real bioanalytical applications. We report on novel transducers and materials, improvements of existing transducers, new and improved biofunctionalization procedures as well as the prospects for near future commercialization of these technologies.

  17. Porous silicon-based biosensor for pathogen detection.

    PubMed

    Mathew, Finny P; Alocilja, Evangelyn C

    2005-02-15

    A porous silicon-based biosensor for rapid detection of bacteria was fabricated. Silicon (0.01 ohmcm, p-type) was anodized electrochemically in an electrochemical Teflon cell containing ethanoic hydrofluoric acid solution to produce sponge-like porous layer of silicon. Anodizing conditions of 5 mA/cm2 for 85 min proved best for biosensor fabrication. A single-tube chemiluminescence-based assay, previously developed, was adapted to the biosensor for detection of Escherichia coli. Porous silicon chips were functionalized with a dioxetane-Polymyxin B (cell wall permeabilizer) mixture by diffusion and adsorption on to the porous surface. The reaction of beta-galactosidase enzyme from E. coli with the dioxetane substrate generated light at 530 nm. Light emission for the porous silicon biosensor chip with E. coli was significantly greater than that of the control and planar silicon chip with E. coli (P<0.01). Sensitivity of the porous silicon biosensor was determined to be 101-102 colony forming units (CFU) of E. coli. The porous silicon-based biosensor was fabricated and functionalized to successfully detect E. coli and has potential applications in food and environmental testing.

  18. Progress in chemical luminescence-based biosensors: A critical review.

    PubMed

    Roda, Aldo; Mirasoli, Mara; Michelini, Elisa; Di Fusco, Massimo; Zangheri, Martina; Cevenini, Luca; Roda, Barbara; Simoni, Patrizia

    2016-02-15

    Biosensors are a very active research field. They have the potential to lead to low-cost, rapid, sensitive, reproducible, and miniaturized bioanalytical devices, which exploit the high binding avidity and selectivity of biospecific binding molecules together with highly sensitive detection principles. Of the optical biosensors, those based on chemical luminescence detection (including chemiluminescence, bioluminescence, electrogenerated chemiluminescence, and thermochemiluminescence) are particularly attractive, due to their high-to-signal ratio and the simplicity of the required measurement equipment. Several biosensors based on chemical luminescence have been described for quantitative, and in some cases multiplex, analysis of organic molecules (such as hormones, drugs, pollutants), proteins, and nucleic acids. These exploit a variety of miniaturized analytical formats, such as microfluidics, microarrays, paper-based analytical devices, and whole-cell biosensors. Nevertheless, despite the high analytical performances described in the literature, the field of chemical luminescence biosensors has yet to demonstrate commercial success. This review presents the main recent advances in the field and discusses the approaches, challenges, and open issues, with the aim of stimulating a broader interest in developing chemical luminescence biosensors and improving their commercial exploitation.

  19. Amperometric catechol biosensor based on polyaniline-polyphenol oxidase.

    PubMed

    Tan, Yongyan; Guo, Xiaoxia; Zhang, Jinghui; Kan, Jinqing

    2010-03-15

    A novel catechol biosensor was described based on the immobilization of polyphenol oxidase (PPO) into polyaniline (PANI), which was easily constructed by direct electropolymerization of aniline in a solution containing ionic liquid, 1-ethyl-3-methylimidazolium ethyl sulfate (EMIES). The developed biosensor for the detection of catechol has a linear range of 1.25-150 micromol dm(-3). The maximum response current (I(max)) and the Michaelis-Menten constant (k'(m)) are 0.62 microA and 146 micromol dm(-3), respectively. The activation energy (E(a)) of the PPO catalytic reaction is 31.1 kJ mol(-1) in the B-R buffer. The biosensor shows good reproducibility (a relative standard deviation of 3.1% was obtained) and remarkable long-term stability (it retains 75% of the original activity after four months). The effects of potential and pH on the response current of the biosensor are also described.

  20. Novel Nanocomposite-based Potassium Ion Biosensor

    NASA Astrophysics Data System (ADS)

    Xue, R.; Gouma, P. I.

    2009-05-01

    Potassium ion (K+) is important in regulating normal cell function in the human body, specifically the heartbeat and the muscle function. Thus, it is important to be able to monitor potassium ion concentrations in human fluids. This paper describes a novel concept for a potassium ion biosensor that accurately, rapidly, and efficiently monitors the presence and records the concentration of potassium ions with high specificity, not only in serum and urine, but also in the sweat or even eye fluid. This specific biosensor design utilizes a nanomanufacturing technique, i.e. electrospinning, to produce advanced nano-bio-composites that specifically trace even minute quantities of potassium ions through the use of selective bio-receptors (ionophores) attached to high surface area nanofibers. Electroactive polymers are then employed as transducers to produce an electronic (rather than ionic) output that changes instantly with the change in K+ concentration. Such biosensors may be manufactured in a skin patch configuration.

  1. Novel amperometric glucose biosensor based on MXene nanocomposite

    PubMed Central

    Rakhi, R. B.; Nayuk, Pranati; Xia, Chuan; Alshareef, Husam N.

    2016-01-01

    A biosensor platform based on Au/MXene nanocomposite for sensitive enzymatic glucose detection is reported. The biosensor leverages the unique electrocatalytic properties and synergistic effects between Au nanoparticles and MXene sheets. An amperometric glucose biosensor is fabricated by the immobilization of glucose oxidase (GOx) enzyme on Nafion solubilized Au/ MXene nanocomposite over glassy carbon electrode (GCE). The biomediated Au nanoparticles play a significant role in facilitating the electron exchange between the electroactive center of GOx and the electrode. The GOx/Au/MXene/Nafion/GCE biosensor electrode displayed a linear amperometric response in the glucose concentration range from 0.1 to 18 mM with a relatively high sensitivity of 4.2 μAmM−1 cm−2 and a detection limit of 5.9 μM (S/N = 3). Furthermore, the biosensor exhibited excellent stability, reproducibility and repeatability. Therefore, the Au/MXene nanocomposite reported in this work is a potential candidate as an electrochemical transducer in electrochemical biosensors. PMID:27830757

  2. Aptamer-based sandwich-type biosensors.

    PubMed

    Seo, Ho Bin; Gu, Man Bock

    2017-01-01

    Sandwich-type biosensor platforms have drawn lots of attentions due to its superior features, compared to other platforms, in terms of its stable and reproducible responses and easy enhancement in the detection sensitivity. The sandwich-type assays can be developed by utilizing a pair of receptors, which bind to the different sites of the same target. In this mini-review paper, the sandwich-type biosensors using either pairs of aptamers or aptamer-antibody pairs are reviewed in terms of its targets and platforms, the schematic designs, and their analytical performance.

  3. A reduced graphene oxide based electrochemical biosensor for tyrosine detection.

    PubMed

    Wei, Junhua; Qiu, Jingjing; Li, Li; Ren, Liqiang; Zhang, Xianwen; Chaudhuri, Jharna; Wang, Shiren

    2012-08-24

    In this paper, a 'green' and safe hydrothermal method has been used to reduce graphene oxide and produce hemin modified graphene nanosheet (HGN) based electrochemical biosensors for the determination of l-tyrosine levels. The as-fabricated HGN biosensors were characterized by UV-visible absorption spectra, fluorescence spectra, Fourier transform infrared spectroscopy (FTIR) spectra and thermogravimetric analysis (TGA). The experimental results indicated that hemin was successfully immobilized on the reduced graphene oxide nanosheet (rGO) through π-π interaction. TEM images and EDX results further confirmed the attachment of hemin on the rGO nanosheet. Cyclic voltammetry tests were carried out for the bare glass carbon electrode (GCE), the rGO electrode (rGO/GCE), and the hemin-rGO electrode (HGN/GCE). The HGN/GCE based biosensor exhibits a tyrosine detection linear range from 5 × 10(-7) M to 2 × 10(-5) M with a detection limitation of 7.5 × 10(-8) M at a signal-to-noise ratio of 3. The sensitivity of this biosensor is 133 times higher than that of the bare GCE. In comparison with other works, electroactive biosensors are easily fabricated, easily controlled and cost-effective. Moreover, the hemin-rGO based biosensors demonstrate higher stability, a broader detection linear range and better detection sensitivity. Study of the oxidation scheme reveals that the rGO enhances the electron transfer between the electrode and the hemin, and the existence of hemin groups effectively electrocatalyzes the oxidation of tyrosine. This study contributes to a widespread clinical application of nanomaterial based biosensor devices with a broader detection linear range, improved stability, enhanced sensitivity and reduced costs.

  4. A reduced graphene oxide based electrochemical biosensor for tyrosine detection

    NASA Astrophysics Data System (ADS)

    Wei, Junhua; Qiu, Jingjing; Li, Li; Ren, Liqiang; Zhang, Xianwen; Chaudhuri, Jharna; Wang, Shiren

    2012-08-01

    In this paper, a ‘green’ and safe hydrothermal method has been used to reduce graphene oxide and produce hemin modified graphene nanosheet (HGN) based electrochemical biosensors for the determination of l-tyrosine levels. The as-fabricated HGN biosensors were characterized by UV-visible absorption spectra, fluorescence spectra, Fourier transform infrared spectroscopy (FTIR) spectra and thermogravimetric analysis (TGA). The experimental results indicated that hemin was successfully immobilized on the reduced graphene oxide nanosheet (rGO) through π-π interaction. TEM images and EDX results further confirmed the attachment of hemin on the rGO nanosheet. Cyclic voltammetry tests were carried out for the bare glass carbon electrode (GCE), the rGO electrode (rGO/GCE), and the hemin-rGO electrode (HGN/GCE). The HGN/GCE based biosensor exhibits a tyrosine detection linear range from 5 × 10-7 M to 2 × 10-5 M with a detection limitation of 7.5 × 10-8 M at a signal-to-noise ratio of 3. The sensitivity of this biosensor is 133 times higher than that of the bare GCE. In comparison with other works, electroactive biosensors are easily fabricated, easily controlled and cost-effective. Moreover, the hemin-rGO based biosensors demonstrate higher stability, a broader detection linear range and better detection sensitivity. Study of the oxidation scheme reveals that the rGO enhances the electron transfer between the electrode and the hemin, and the existence of hemin groups effectively electrocatalyzes the oxidation of tyrosine. This study contributes to a widespread clinical application of nanomaterial based biosensor devices with a broader detection linear range, improved stability, enhanced sensitivity and reduced costs.

  5. Printable Ultrathin Metal Oxide Semiconductor-Based Conformal Biosensors.

    PubMed

    Rim, You Seung; Bae, Sang-Hoon; Chen, Huajun; Yang, Jonathan L; Kim, Jaemyung; Andrews, Anne M; Weiss, Paul S; Yang, Yang; Tseng, Hsian-Rong

    2015-12-22

    Conformal bioelectronics enable wearable, noninvasive, and health-monitoring platforms. We demonstrate a simple and straightforward method for producing thin, sensitive In2O3-based conformal biosensors based on field-effect transistors using facile solution-based processing. One-step coating via aqueous In2O3 solution resulted in ultrathin (3.5 nm), high-density, uniform films over large areas. Conformal In2O3-based biosensors on ultrathin polyimide films displayed good device performance, low mechanical stress, and highly conformal contact determined using polydimethylsiloxane artificial skin having complex curvilinear surfaces or an artificial eye. Immobilized In2O3 field-effect transistors with self-assembled monolayers of NH2-terminated silanes functioned as pH sensors. Functionalization with glucose oxidase enabled d-glucose detection at physiologically relevant levels. The conformal ultrathin field-effect transistor biosensors developed here offer new opportunities for future wearable human technologies.

  6. Nanopillar based electrochemical biosensor for monitoring microfluidic based cell culture

    NASA Astrophysics Data System (ADS)

    Gangadharan, Rajan

    In-vitro assays using cultured cells have been widely performed for studying many aspects of cell biology and cell physiology. These assays also form the basis of cell based sensing. Presently, analysis procedures on cell cultures are done using techniques that are not integrated with the cell culture system. This approach makes continuous and real-time in-vitro measurements difficult. It is well known that the availability of continuous online measurements for extended periods of time will help provide a better understanding and will give better insight into cell physiological events. With this motivation we developed a highly sensitive, selective and stable microfluidic electrochemical glucose biosensor to make continuous glucose measurements in cell culture media. The performance of the microfluidic biosensor was enhanced by adding 3D nanopillars to the electrode surfaces. The microfluidic glucose biosensor consisted of three electrodes---Enzyme electrode, Working electrode, and Counter electrode. All these electrodes were enhanced with nanopillars and were optimized in their respective own ways to obtain an effective and stable biosensing device in cell culture media. For example, the 'Enzyme electrode' was optimized for enzyme immobilization via either a polypyrrole-based or a self-assembled-monolayer-based immobilization method, and the 'Working electrode' was modified with Prussian Blue or electropolymerized Neutral Red to reduce the working potential and also the interference from other interacting electro-active species. The complete microfluidic biosensor was tested for its ability to monitor glucose concentration changes in cell culture media. The significance of this work is multifold. First, the developed device may find applications in continuous and real-time measurements of glucose concentrations in in-vitro cell cultures. Second, the development of a microfluidic biosensor will bring technical know-how toward constructing continuous glucose

  7. Flexible Molybdenum Electrodes towards Designing Affinity Based Protein Biosensors

    PubMed Central

    Kamakoti, Vikramshankar; Panneer Selvam, Anjan; Radha Shanmugam, Nandhinee; Muthukumar, Sriram; Prasad, Shalini

    2016-01-01

    Molybdenum electrode based flexible biosensor on porous polyamide substrates has been fabricated and tested for its functionality as a protein affinity based biosensor. The biosensor performance was evaluated using a key cardiac biomarker; cardiac Troponin-I (cTnI). Molybdenum is a transition metal and demonstrates electrochemical behavior upon interaction with an electrolyte. We have leveraged this property of molybdenum for designing an affinity based biosensor using electrochemical impedance spectroscopy. We have evaluated the feasibility of detection of cTnI in phosphate-buffered saline (PBS) and human serum (HS) by measuring impedance changes over a frequency window from 100 mHz to 1 MHz. Increasing changes to the measured impedance was correlated to the increased dose of cTnI molecules binding to the cTnI antibody functionalized molybdenum surface. We achieved cTnI detection limit of 10 pg/mL in PBS and 1 ng/mL in HS medium. The use of flexible substrates for designing the biosensor demonstrates promise for integration with a large-scale batch manufacturing process. PMID:27438863

  8. Flexible Molybdenum Electrodes towards Designing Affinity Based Protein Biosensors.

    PubMed

    Kamakoti, Vikramshankar; Panneer Selvam, Anjan; Radha Shanmugam, Nandhinee; Muthukumar, Sriram; Prasad, Shalini

    2016-07-18

    Molybdenum electrode based flexible biosensor on porous polyamide substrates has been fabricated and tested for its functionality as a protein affinity based biosensor. The biosensor performance was evaluated using a key cardiac biomarker; cardiac Troponin-I (cTnI). Molybdenum is a transition metal and demonstrates electrochemical behavior upon interaction with an electrolyte. We have leveraged this property of molybdenum for designing an affinity based biosensor using electrochemical impedance spectroscopy. We have evaluated the feasibility of detection of cTnI in phosphate-buffered saline (PBS) and human serum (HS) by measuring impedance changes over a frequency window from 100 mHz to 1 MHz. Increasing changes to the measured impedance was correlated to the increased dose of cTnI molecules binding to the cTnI antibody functionalized molybdenum surface. We achieved cTnI detection limit of 10 pg/mL in PBS and 1 ng/mL in HS medium. The use of flexible substrates for designing the biosensor demonstrates promise for integration with a large-scale batch manufacturing process.

  9. Graphene Based Electrochemical Sensors and Biosensors: A Review

    SciTech Connect

    Shao, Yuyan; Wang, Jun; Wu, Hong; Liu, Jun; Aksay, Ilhan A.; Lin, Yuehe

    2010-05-01

    Graphene, emerging as a true 2-dimensional material, has received increasing attention due to its unique physicochemical properties (high surface area, excellent conductivity, high mechanical strength, and ease of functionalization and mass production). This article selectively reviews recent advances in graphene-based electrochemical sensors and biosensors. In particular, graphene for direct electrochemistry of enzyme, its electrocatalytic activity toward small biomolecules (hydrogen peroxide, NADH, dopamine, etc.), and graphene-based enzyme biosensors have been summarized in more detail; Graphene-based DNA sensing and environmental analysis have been discussed. Future perspectives in this rapidly developing field are also discussed.

  10. Electrochemical sensors and biosensors based on less aggregated graphene.

    PubMed

    Bo, Xiangjie; Zhou, Ming; Guo, Liping

    2017-03-15

    As a novel single-atom-thick sheet of sp(2) hybridized carbon atoms, graphene (GR) has attracted extensive attention in recent years because of its unique and remarkable properties, such as excellent electrical conductivity, large theoretical specific surface area, and strong mechanical strength. However, due to the π-π interaction, GR sheets are inclined to stack together, which may seriously degrade the performance of GR with the unique single-atom layer. In recent years, an increasing number of GR-based electrochemical sensors and biosensors are reported, which may reflect that GR has been considered as a kind of hot and promising electrode material for electrochemical sensor and biosensor construction. However, the active sites on GR surface induced by the irreversible GR aggregations would be deeply secluded inside the stacked GR sheets and therefore are not available for the electrocatalysis. So the alleviation or the minimization of the aggregation level for GR sheets would facilitate the exposure of active sites on GR and effectively upgrade the performance of GR-based electrochemical sensors and biosensors. Less aggregated GR with low aggregation and high dispersed structure can be used in improving the electrochemical activity of GR-based electrochemical sensors or biosensors. In this review, we summarize recent advances and new progress for the development of electrochemical sensors based on less aggregated GR. To achieve such goal, many strategies (such as the intercalation of carbon materials, surface modification, and structural engineering) have been applied to alleviate the aggregation level of GR in order to enhance the performance of GR-based electrochemical sensors and biosensors. Finally, the challenges associated with less aggregated GR-based electrochemical sensors and biosensors as well as related future research directions are discussed.

  11. Vertically Aligned Carbon Nanofiber based Biosensor Platform for Glucose Sensor

    SciTech Connect

    Al Mamun, Khandaker A.; Tulip, Fahmida S.; MacArthur, Kimberly; McFarlane, Nicole; Islam, Syed K.; Hensley, Dale

    2014-03-01

    Vertically aligned carbon nanofibers (VACNFs) have recently become an important tool for biosensor design. Carbon nanofibers (CNF) have excellent conductive and structural properties with many irregularities and defect sites in addition to exposed carboxyl groups throughout their surfaces. These properties allow a better immobilization matrix compared to carbon nanotubes and offer better resolution when compared with the FET-based biosensors. VACNFs can be deterministically grown on silicon substrates allowing optimization of the structures for various biosensor applications. Two VACNF electrode architectures have been employed in this study and a comparison of their performances has been made in terms of sensitivity, sensing limitations, dynamic range, and response time. The usage of VACNF platform as a glucose sensor has been verified in this study by selecting an optimum architecture based on the VACNF forest density. Read More: http://www.worldscientific.com/doi/abs/10.1142/S0129156414500062

  12. A glucose biosensor based on partially unzipped carbon nanotubes.

    PubMed

    Hu, Huifang; Feng, Miao; Zhan, Hongbing

    2015-08-15

    An amperometric glucose biosensor based on direct electron transfer of glucose oxidase (GOD) self-assembled on the surface of partially unzipped carbon nanotubes (PUCNTs) modified glassy carbon electrode (GCE) has been successfully fabricated. PUCNTs were synthesized via a facile chemical oxidative etching CNTs and used as a novel immobilization matrix for GOD. The cyclic voltammetric result of the PUCNT/GOD/GCE showed a pair of well-defined and quasi-reversible redox peaks with a formal potential of -0.470V and a peak to peak separation of 37mV, revealing that the fast direct electron transfer between GOD and the electrode has been achieved. It is notable that the glucose determination has been achieved in mediator-free condition. The developed biosensor displayed satisfactory analytical performance toward glucose including high sensitivity (19.50μA mM(-1)cm(-2)), low apparent Michaelis-Menten (5.09mM), a wide linear range of 0-17mM, and also preventing the interference from ascorbic acid, uric acid and dopamine usually coexisting with glucose in human blood. In addition, the biosensor acquired excellent storage stabilities. This facile, fast, environment-friendly and economical preparation strategy of PUCNT-GOD may provide a new platform for the fabrication of biocompatible glucose biosensors and other types of biosensors.

  13. Tin Oxide Nanorod Array-Based Electrochemical Hydrogen Peroxide Biosensor

    PubMed Central

    2010-01-01

    SnO2 nanorod array grown directly on alloy substrate has been employed as the working electrode of H2O2 biosensor. Single-crystalline SnO2 nanorods provide not only low isoelectric point and enough void spaces for facile horseradish peroxidase (HRP) immobilization but also numerous conductive channels for electron transport to and from current collector; thus, leading to direct electrochemistry of HRP. The nanorod array-based biosensor demonstrates high H2O2 sensing performance in terms of excellent sensitivity (379 μA mM−1 cm−2), low detection limit (0.2 μM) and high selectivity with the apparent Michaelis–Menten constant estimated to be as small as 33.9 μM. Our work further demonstrates the advantages of ordered array architecture in electrochemical device application and sheds light on the construction of other high-performance enzymatic biosensors. PMID:20596358

  14. Tin Oxide Nanorod Array-Based Electrochemical Hydrogen Peroxide Biosensor

    NASA Astrophysics Data System (ADS)

    Liu, Jinping; Li, Yuanyuan; Huang, Xintang; Zhu, Zhihong

    2010-07-01

    SnO2 nanorod array grown directly on alloy substrate has been employed as the working electrode of H2O2 biosensor. Single-crystalline SnO2 nanorods provide not only low isoelectric point and enough void spaces for facile horseradish peroxidase (HRP) immobilization but also numerous conductive channels for electron transport to and from current collector; thus, leading to direct electrochemistry of HRP. The nanorod array-based biosensor demonstrates high H2O2 sensing performance in terms of excellent sensitivity (379 μA mM-1 cm-2), low detection limit (0.2 μM) and high selectivity with the apparent Michaelis-Menten constant estimated to be as small as 33.9 μM. Our work further demonstrates the advantages of ordered array architecture in electrochemical device application and sheds light on the construction of other high-performance enzymatic biosensors.

  15. Recent advances in nanomaterial-based biosensors for antibiotics detection.

    PubMed

    Lan, Lingyi; Yao, Yao; Ping, Jianfeng; Ying, Yibin

    2017-05-15

    Antibiotics are able to be accumulated in human body by food chain and may induce severe influence to human health and safety. Hence, the development of sensitive and simple methods for rapid evaluation of antibiotic levels is highly desirable. Nanomaterials with excellent electronic, optical, mechanical, and thermal properties have been recognized as one of the most promising materials for opening new gates in the development of next-generation biosensors. This review highlights the current advances in the nanomaterial-based biosensors for antibiotics detection. Different kinds of nanomaterials including carbon nanomaterials, metal nanomaterials, magnetic nanoparticles, up-conversion nanoparticles, and quantum dots have been applied to the construction of biosensors with two main signal-transducing mechanisms, i.e. optical and electrochemical. Furthermore, the current challenges and future prospects in this field are also included to provide an overview for future research directions.

  16. Titanium dioxide-cellulose hybrid nanocomposite based conductometric glucose biosensor

    NASA Astrophysics Data System (ADS)

    Maniruzzaman, Mohammad; Mahadeva, Suresha K.; Khondoker, Abu Hasan; Kim, Jaehwan

    2012-04-01

    This paper investigates the feasibility of conductometric glucose biosensor based on glucose oxidase (GOx) immobilized TiO2-cellulose hybrid nanocomposite. TiO2 nanoparticles were blended with cellulose solution prepared by dissolving cotton pulp with lithium chloride/N, N-dimethylacetamide solvent to fabricate TiO2-cellulose hybrid nanocomposite. The enzyme (GOx) was immobilized into this hybrid material by physical adsorption method. The successful immobilization of GOx into TiO2-cellulose hybrid nanocomposite via covalent bonding between TiO2 and GOx was confirmed by X-ray photoelectron analysis. The linear response of our propose glucose biosensor is obtained in the range of 1-10mM with correlation coefficient of 0.93. Our study demonstrates TiO2-cellulose hybrid material as a potential candidate for an inexpensive, flexible and disposable glucose biosensor.

  17. Carbon nanomaterial-based electrochemical biosensors: an overview

    NASA Astrophysics Data System (ADS)

    Wang, Zhaoyin; Dai, Zhihui

    2015-04-01

    Carbon materials on the nanoscale exhibit diverse outstanding properties, rendering them extremely suitable for the fabrication of electrochemical biosensors. Over the past two decades, advances in this area have continuously emerged. In this review, we attempt to survey the recent developments of electrochemical biosensors based on six types of carbon nanomaterials (CNs), i.e., graphene, carbon nanotubes, carbon dots, carbon nanofibers, nanodiamonds and buckminsterfullerene. For each material, representative samples are introduced to expound the different roles of the CNs in electrochemical bioanalytical strategies. In addition, remaining challenges and perspectives for future developments are also briefly discussed.

  18. Genetically encoded biosensors based on engineered fluorescent proteins.

    PubMed

    Frommer, Wolf B; Davidson, Michael W; Campbell, Robert E

    2009-10-01

    Fluorescent proteins have revolutionized cell biology by allowing researchers to non-invasively peer into the inner workings of cells and organisms. While the most common applications of fluorescent proteins are to image expression, localization, and dynamics of protein chimeras, there is a growing interest in using fluorescent proteins to create biosensors for minimally invasive imaging of concentrations of ions and small molecules, the activity of enzymes, and changes in the conformation of proteins in living cells. This tutorial review provides an overview of the progress made in the development of fluorescent protein-based biosensors to date.

  19. Last Advances in Silicon-Based Optical Biosensors

    PubMed Central

    Fernández Gavela, Adrián; Grajales García, Daniel; Ramirez, Jhonattan C.; Lechuga, Laura M.

    2016-01-01

    We review the most important achievements published in the last five years in the field of silicon-based optical biosensors. We focus specially on label-free optical biosensors and their implementation into lab-on-a-chip platforms, with an emphasis on developments demonstrating the capability of the devices for real bioanalytical applications. We report on novel transducers and materials, improvements of existing transducers, new and improved biofunctionalization procedures as well as the prospects for near future commercialization of these technologies. PMID:26927105

  20. Indicator Based and Indicator - Free Electrochemical DNA Biosensors

    DTIC Science & Technology

    2007-11-02

    of genomic material from infectious organisms. Methylene blue (MB) is an aromatic heterocycle that binds strongly to DNA via intercalation. MB...detection of disease- related point mutation in the guanine bases of the cyanobacteria . The resulting biosensors offer great promise for mismatch

  1. An Evolution Based Biosensor Receptor DNA Sequence Generation Algorithm

    PubMed Central

    Kim, Eungyeong; Lee, Malrey; Gatton, Thomas M.; Lee, Jaewan; Zang, Yupeng

    2010-01-01

    A biosensor is composed of a bioreceptor, an associated recognition molecule, and a signal transducer that can selectively detect target substances for analysis. DNA based biosensors utilize receptor molecules that allow hybridization with the target analyte. However, most DNA biosensor research uses oligonucleotides as the target analytes and does not address the potential problems of real samples. The identification of recognition molecules suitable for real target analyte samples is an important step towards further development of DNA biosensors. This study examines the characteristics of DNA used as bioreceptors and proposes a hybrid evolution-based DNA sequence generating algorithm, based on DNA computing, to identify suitable DNA bioreceptor recognition molecules for stable hybridization with real target substances. The Traveling Salesman Problem (TSP) approach is applied in the proposed algorithm to evaluate the safety and fitness of the generated DNA sequences. This approach improves efficiency and stability for enhanced and variable-length DNA sequence generation and allows extension to generation of variable-length DNA sequences with diverse receptor recognition requirements. PMID:22315543

  2. Development of ESI-MS-based continuous enzymatic assay for real-time monitoring of enzymatic reactions of acetylcholinesterase.

    PubMed

    Fu, Qiang; Tang, Jun; Cui, Meng; Zheng, Zhong; Liu, Zhiqiang; Liu, Shuying

    2015-05-15

    The continuous enzymatic assay based on ESI-MS was developed to real-time monitoring of enzymatic reactions of acetylcholinesterase (AChE). The changes of product concentrations were continuously measured. Calibration curves were established for quantitative calculation. By this method, the Michaelis constant (Km) of acetylcholinesterase was determined to be 70.60±0.93μM and Huperzine A as an effective inhibitor of acetylcholinesterase displayed a mixed inhibition with competitive and noncompetitive inhibition behaviors. The half maximal inhibitory concentration (IC50) and inhibition constant (Ki) value of Huperzine A were also calculated as 48.51±1.16nM and 26.73±0.27nM, respectively. This method provides the rapid and accurate ways to monitor enzyme reactions.

  3. Amperometric urea biosensors based on sulfonated graphene/polyaniline nanocomposite

    PubMed Central

    Das, Gautam; Yoon, Hyon Hee

    2015-01-01

    An electrochemical biosensor based on sulfonated graphene/polyaniline nanocomposite was developed for urea analysis. Oxidative polymerization of aniline in the presence of sulfonated graphene oxide was carried out by electrochemical methods in an aqueous environment. The structural properties of the nanocomposite were characterized by Fourier-transform infrared, Raman spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy techniques. The urease enzyme-immobilized sulfonated graphene/polyaniline nanocomposite film showed impressive performance in the electroanalytical detection of urea with a detection limit of 0.050 mM and a sensitivity of 0.85 (μA · cm−2·mM−1. The biosensor achieved a broad linear range of detection (0.12–12.3 mM) with a notable response time of approximately 5 seconds. Moreover, the fabricated biosensor retained 81% of its initial activity (based on sensitivity) after 15 days of storage at 4°C. The ease of fabrication coupled with the low cost and good electrochemical performance of this system holds potential for the development of solid-state biosensors for urea detection. PMID:26346240

  4. Amperometric urea biosensors based on sulfonated graphene/polyaniline nanocomposite.

    PubMed

    Das, Gautam; Yoon, Hyon Hee

    2015-01-01

    An electrochemical biosensor based on sulfonated graphene/polyaniline nanocomposite was developed for urea analysis. Oxidative polymerization of aniline in the presence of sulfonated graphene oxide was carried out by electrochemical methods in an aqueous environment. The structural properties of the nanocomposite were characterized by Fourier-transform infrared, Raman spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy techniques. The urease enzyme-immobilized sulfonated graphene/polyaniline nanocomposite film showed impressive performance in the electroanalytical detection of urea with a detection limit of 0.050 mM and a sensitivity of 0.85 (μA · cm(-2)·mM(-1). The biosensor achieved a broad linear range of detection (0.12-12.3 mM) with a notable response time of approximately 5 seconds. Moreover, the fabricated biosensor retained 81% of its initial activity (based on sensitivity) after 15 days of storage at 4°C. The ease of fabrication coupled with the low cost and good electrochemical performance of this system holds potential for the development of solid-state biosensors for urea detection.

  5. Acetylcholinesterase-Based Electrochemical Multiphase Microreactor for Detection of Organophosphorous Compounds (Preprint)

    DTIC Science & Technology

    2007-04-01

    glutaraldehyde. The system was tested with malathion , an organophosphorus pesticide. The detection limit of the sensor in the parts-per-trillion range and...Electric eel acetylcholinesterase (EC 3.1.1.7) and the organophosphate, malathion , were purchased from Aldrich. Electric eel acetylcholinesterase is less...expensive than human acetylcholinesterase and allows us to use a non-toxic organophosphate. Malathion , commonly used as a pesticide, is not

  6. Detection of glycoalkaloids using disposable biosensors based on genetically modified enzymes.

    PubMed

    Espinoza, Michelle Arredondo; Istamboulie, Georges; Chira, Ana; Noguer, Thierry; Stoytcheva, Margarita; Marty, Jean-Louis

    2014-07-15

    In this work we present a rapid, selective, and highly sensitive detection of α-solanine and α-chaconine using cholinesterase-based sensors. The high sensitivity of the devices is brought by the use of a genetically modified acetylcholinesterase (AChE), combined with a one-step detection method based on the measurement of inhibition slope. The selectivity was obtained by using butyrylcholinesterase (BChE), an enzyme able to detect these two toxins with differential inhibition kinetics. The enzymes were immobilized via entrapment in PVA-AWP polymer directly on the working electrode surface. The analysis of the resulting inhibition slope was performed employing linear regression function included in Matlab. The high toxicity of α-chaconine compared to α-solanine due to a better affinity to the active site was proved. The inhibition of glycoalkaloids (GAs) mixture was performed over AChE enzyme wild-type AChE and BChE biosensors resulting in the detection of synergism effect. The developed method allows the detection of (GAs) at 50 ppb in potato matrix.

  7. Recent advances in electrochemical biosensors based on graphene two-dimensional nanomaterials.

    PubMed

    Song, Yang; Luo, Yanan; Zhu, Chengzhou; Li, He; Du, Dan; Lin, Yuehe

    2016-02-15

    Graphene as a star among two-dimensional nanomaterials has attracted tremendous research interest in the field of electrochemistry due to their intrinsic properties, including the electronic, optical, and mechanical properties associated with their planar structure. The marriage of graphene and electrochemical biosensors has created many ingenious biosensing strategies for applications in the areas of clinical diagnosis and food safety. This review provides a comprehensive overview of the recent advances in the development of graphene based electrochemical biosensors. Special attention is paid to graphene-based enzyme biosensors, immunosensors, and DNA biosensors. Future perspectives on high-performance graphene-based electrochemical biosensors are also discussed.

  8. Optical biosensors

    PubMed Central

    Damborský, Pavel; Švitel, Juraj

    2016-01-01

    Optical biosensors represent the most common type of biosensor. Here we provide a brief classification, a description of underlying principles of operation and their bioanalytical applications. The main focus is placed on the most widely used optical biosensors which are surface plasmon resonance (SPR)-based biosensors including SPR imaging and localized SPR. In addition, other optical biosensor systems are described, such as evanescent wave fluorescence and bioluminescent optical fibre biosensors, as well as interferometric, ellipsometric and reflectometric interference spectroscopy and surface-enhanced Raman scattering biosensors. The optical biosensors discussed here allow the sensitive and selective detection of a wide range of analytes including viruses, toxins, drugs, antibodies, tumour biomarkers and tumour cells. PMID:27365039

  9. Label-free biosensor based on long period grating

    NASA Astrophysics Data System (ADS)

    Baldini, Francesco; Chiavaioli, Francesco; Giannetti, Ambra; Brenci, Massimo; Trono, Cosimo

    2013-03-01

    Long period gratings have been recently proposed as label-free optical devices for biochemical sensing. A biochemical interaction along the grating region changes the biolayer refractive index and a change in the fiber transmission spectrum occurs. The fiber biofunctionalization was performed with a novel chemistry using Eudragit L100 copolymer as opposed to the commonly-used silanization procedure. An IgG/anti-IgG bioassay was carried out for studying the antigen/antibody interaction. The biosensor was fully characterized, monitoring the kinetics during the antibody immobilization and achieving the calibration curve of the assay. To compare the biosensor performance, two LPG-based biosensors with distinct grating periods were characterized following the same bioassay protocol. Experimental results demonstrated an enhancement of the biosensor performance when the fundamental core mode of a single-mode fiber couples with a higher order cladding mode. Considering an LPG manufactured on a bare optical fiber, in which the coupling occurs with the 7-th cladding mode, a dynamic signal range of 0.33 nm, a working range of 1.7 - 1450 mg L-1 and a LOD of 500 μg L-1 were achieved

  10. Analytical modeling of glucose biosensors based on carbon nanotubes

    PubMed Central

    2014-01-01

    In recent years, carbon nanotubes have received widespread attention as promising carbon-based nanoelectronic devices. Due to their exceptional physical, chemical, and electrical properties, namely a high surface-to-volume ratio, their enhanced electron transfer properties, and their high thermal conductivity, carbon nanotubes can be used effectively as electrochemical sensors. The integration of carbon nanotubes with a functional group provides a good and solid support for the immobilization of enzymes. The determination of glucose levels using biosensors, particularly in the medical diagnostics and food industries, is gaining mass appeal. Glucose biosensors detect the glucose molecule by catalyzing glucose to gluconic acid and hydrogen peroxide in the presence of oxygen. This action provides high accuracy and a quick detection rate. In this paper, a single-wall carbon nanotube field-effect transistor biosensor for glucose detection is analytically modeled. In the proposed model, the glucose concentration is presented as a function of gate voltage. Subsequently, the proposed model is compared with existing experimental data. A good consensus between the model and the experimental data is reported. The simulated data demonstrate that the analytical model can be employed with an electrochemical glucose sensor to predict the behavior of the sensing mechanism in biosensors. PMID:24428818

  11. Recent progress in design of protein-based fluorescent biosensors and their cellular applications.

    PubMed

    Tamura, Tomonori; Hamachi, Itaru

    2014-12-19

    Protein-based fluorescent biosensors have emerged as key bioanalytical tools to visualize and quantify a wide range of biological substances and events in vitro, in cells, and even in vivo. On the basis of the construction method, the protein-based fluorescent biosensors can be principally classified into two classes: (1) genetically encoded fluorescent biosensors harnessing fluorescent proteins (FPs) and (2) semisynthetic biosensors comprised of protein scaffolds and synthetic fluorophores. Recent advances in protein engineering and chemical biology not only allowed the further optimization of conventional biosensors but also facilitated the creation of novel biosensors based on unique strategies. In this review, we survey the recent studies in the development and improvement of protein-based fluorescent biosensors and highlight the successful applications to live cell and in vivo imaging. Furthermore, we provide perspectives on possible future directions of the technique.

  12. Fiber Optic Surface Plasmon Resonance-Based Biosensor Technique: Fabrication, Advancement, and Application.

    PubMed

    Liang, Gaoling; Luo, Zewei; Liu, Kunping; Wang, Yimin; Dai, Jianxiong; Duan, Yixiang

    2016-05-03

    Fiber optic-based biosensors with surface plasmon resonance (SPR) technology are advanced label-free optical biosensing methods. They have brought tremendous progress in the sensing of various chemical and biological species. This review summarizes four sensing configurations (prism, grating, waveguide, and fiber optic) with two ways, attenuated total reflection (ATR) and diffraction, to excite the surface plasmons. Meanwhile, the designs of different probes (U-bent, tapered, and other probes) are also described. Finally, four major types of biosensors, immunosensor, DNA biosensor, enzyme biosensor, and living cell biosensor, are discussed in detail for their sensing principles and applications. Future prospects of fiber optic-based SPR sensor technology are discussed.

  13. Cell-Based Biosensors: Electrical Sensing in Microfluidic Devices

    PubMed Central

    Kiilerich-Pedersen, Katrine; Rozlosnik, Noemi

    2012-01-01

    Cell-based biosensors provide new horizons for medical diagnostics by adopting complex recognition elements such as mammalian cells in microfluidic devices that are simple, cost efficient and disposable. This combination renders possible a new range of applications in the fields of diagnostics and personalized medicine. The review looks at the most recent developments in cell-based biosensing microfluidic systems with electrical and electrochemical transduction, and relevance to medical diagnostics. PMID:26859401

  14. Mechanism-Based Analysis of Acetylcholinesterase Inhibitory Potency of Organophosphates, Carbamates, and Their Analogs

    EPA Science Inventory

    Acetylcholinesterase (AChE) is a key enzyme in the nervous system of animals, terminating impulse transmission by rapid hydrolysis of the neurotransmitter acetylcholine. Organophosphate (OP) and carbamate esters can inhibit acetylcholinesterase (AChE) by binding covalently to a s...

  15. Development of a BLM-based intelligent biosensor

    NASA Astrophysics Data System (ADS)

    Liu, Sheng; Wei, Yunlong; Cai, Shaoxi; Tien, H. Ti; Ottova, Angelica L.

    2001-09-01

    Bilayer lipid membranes (BLMs) are promising 'smart' materials for biosensor and biomolecules. A novel pH-microbe of an acupuncture needle support with BLM modified by electron mediators was fabricated. An intelligent biosensor system BLM-based was developed. The intelligent system can automatically measure and analyze pH value of aqueous solution with probes BLMs-based and Si-chips thin-film as sensing elements. It can also give a warning message when the pH value of aqueous solution is over one threshold value. The intelligent system has communication interface of computer. A monitoring system based network can be constructed by connection the intelligence system with computers.

  16. Hydrazine detection using tyrosinase-based inhibition biosensor

    SciTech Connect

    Wang, J.; Chen, L.

    1995-10-15

    An amperometric biosensor for the determination of hydrazine compounds, based on their inhibitory effect on the activity of immobilized tyrosinase, has been developed. The hydrazine-tyrosinase interaction can be modeled as a reversible competitive inhibition. Kinetic parameters (K{sub i} and I{sub 0.5}) have been determined for various hydrazine compounds. The tyrosinase-based carbon paste electrode offers sensitive measurements to the low-micromolar level and good precision. The trend in sensitivity, methylhydrazine > hydrazine >dimethylhydrazine, reflects the degree of inhibition. The applicability to assays of unaltered river and drinking water samples is illustrated. Analogous measurements at disposable thick-film sensors are also reported. These inhibitor biosensors hold great promise for field-based monitoring of various hydrazines. 13 refs., 5 figs.

  17. Carbon nanotubes based functional materials for MSL and biosensor applications

    NASA Astrophysics Data System (ADS)

    Zhang, Nanyan

    In this thesis, several carbon nanotubes (CNTs) based functional materials have been successfully synthesized and systematically characterized. Their applications for MicroStereoLithography (MSL) and biosensor were further explored. A new mild oxidization method for oxidizing multi-walled CNTs was developed using potassium permanganate as the oxidant and assisted with phase transfer catalyst. The novel oxidization procedure gives significantly higher yield and high functional group density. Facilitated with the above functional groups, a variety of homogeneous polymer/CNTs nanocomposites were prepared through either chemical or physical interactions and they were systematically characterized. UV curable oligomers have been attached to the wall of the oxidized carbon nanotubes, and they were cured by MicroStereoLithography (MSL) UV light laser with both free radical and cationic polymerization mechanisms. Furthermore, graphite and several CNTs-based glucose thick film biosensors are fabricated and evaluated.

  18. A PKD Channel-based Biosensor for Taste Transduction

    NASA Astrophysics Data System (ADS)

    Wu, Chunsheng; Du, Liping; Hu, Liang; Zhang, Wei; Zhao, Luhang; Wang, Ping

    2011-09-01

    This study describes a micro electrode array (MEA)-based biosensor for taste transduction using heterologous expressed taste polycystic kidney disease-like (PKD) channels as molecular sensors. Taste PKD1L3/2L1 channels were expressed on the plasma membrane of human embryo kidney (HEK)-293 cells [1]. Then the cells were cultured on the surface of MEA chip [2] to record the responses of PKD channels to sour stimulations by monitoring membrane potential. The results indicate this MEA-based biosensor can record the special off-responses of PKD channels to sour stimulation in a non-invasive manner for a long term. It may provide an alternative tool for the research of taste transduction, especially for the characterization of taste ion channels.

  19. Photonic crystal biosensor based on angular spectrum analysis.

    PubMed

    Hallynck, Elewout; Bienstman, Peter

    2010-08-16

    The need for cost effective and reliable biosensors in e.g. medical applications is an ever growing and everlasting one. Not only do we strive to increase sensitivity and detection limit of such sensors; ease of fabrication or implementation are equally important. In this work, we propose a novel, photonic crystal based biosensor that is able to operate at a single frequency, contrary to resonance based sensors. In a certain frequency range, guided photonic crystal modes can couple to free space modes resulting in a Lorentzian shape in the angular spectrum. This Lorentzian can shift due to refractive index changes and simulations have shown sensitivities of 65 degrees per refractive index unit and more.

  20. Design and Development of Acetylthiocholine Electrochemical Biosensor Based on Zinc Oxide-Cerium Oxide Nanohybrid Modified Platinum Electrode.

    PubMed

    Gumpu, Manju Bhargavi; Nesakumar, Noel; Nagarajan, Srinidhi; Ramanujam, Sadhana; Krishnan, Uma Maheswari; Babu, K Jayanth; Rayappan, John Bosco Balaguru

    2017-03-16

    Acetylcholinesterase (AChE) enzyme has been predominantly used for the detection of pesticides and metal ions. But, these sensors respond to pesticides as well as metal ions at certain concentration, which results in poor selectivity. Hence in this work, the amount of thiocholine produced during AChE inhibition has been estimated to detect the residual activity of AChE enzyme in-turn to enhance the efficiency of the biosensor. In this context, Pt/ZnO-CeO2/AChE/Chitosan based biosensor has been developed for sensitive voltammetric quantification of thiocholine in AChE. The sensor exhibited enhanced electron transfer rate, good conductivity and biocompatibility. Both the intrinsic and extrinsic parameters were simultaneously optimized using second order polynomial regression to get the best conditions for ATCh determination. Under optimized experimental conditions, the redox peak current was linear over the concentration range of 0.1-1.5 mM with detection and quantification limit of 0.05 and 0.15 μM respectively and the sensitivity of 1.47 μA mM(-1).

  1. A Nanofluidic Biosensor Based on Nanoreplica Molding Photonic Crystal.

    PubMed

    Peng, Wang; Chen, Youping; Ai, Wu; Zhang, Dailin

    2016-12-01

    A nanofluidic biosensor based on nanoreplica molding photonic crystal (PC) was proposed. UV epoxy PC was fabricated by nanoreplica molding on a master PC wafer. The nanochannels were sealed between the gratings on the PC surface and a taped layer. The resonance wavelength of PC-based nanofluidic biosensor was used for testing the sealing effect. According to the peak wavelength value of the sensor, an initial label-free experiment was realized with R6g as the analyte. When the PC-based biosensor was illuminated by a monochromatic light source with a specific angle, the resonance wavelength of the sensor will match with the light source and amplified the electromagnetic field. The amplified electromagnetic field was used to enhance the fluorescence excitation result. The enhancement effect was used for enhancing fluorescence excitation and emission when matched with the resonance condition. Alexa Fluor 635 was used as the target dye excited by 637-nm laser source on a configured photonic crystal enhanced fluorescence (PCEF) setup, and an initial PCEF enhancement factor was obtained.

  2. A Nanofluidic Biosensor Based on Nanoreplica Molding Photonic Crystal

    NASA Astrophysics Data System (ADS)

    Peng, Wang; Chen, Youping; Ai, Wu; Zhang, Dailin

    2016-09-01

    A nanofluidic biosensor based on nanoreplica molding photonic crystal (PC) was proposed. UV epoxy PC was fabricated by nanoreplica molding on a master PC wafer. The nanochannels were sealed between the gratings on the PC surface and a taped layer. The resonance wavelength of PC-based nanofluidic biosensor was used for testing the sealing effect. According to the peak wavelength value of the sensor, an initial label-free experiment was realized with R6g as the analyte. When the PC-based biosensor was illuminated by a monochromatic light source with a specific angle, the resonance wavelength of the sensor will match with the light source and amplified the electromagnetic field. The amplified electromagnetic field was used to enhance the fluorescence excitation result. The enhancement effect was used for enhancing fluorescence excitation and emission when matched with the resonance condition. Alexa Fluor 635 was used as the target dye excited by 637-nm laser source on a configured photonic crystal enhanced fluorescence (PCEF) setup, and an initial PCEF enhancement factor was obtained.

  3. An immobilization free DNAzyme based electrochemical biosensor for lead determination.

    PubMed

    Tan, Yue; Qiu, Jiazhi; Cui, Meiying; Wei, Xiaofeng; Zhao, Mengmeng; Qiu, Bin; Chen, Guonan

    2016-02-07

    DNAzyme based electrochemical biosensors have the characteristics of high sensitivity and selectivity, but traditional DNAzyme based electrochemical biosensors need the immobilization of DNAzyme on the electrode surface first, and the procedures are time consuming and tedious, which limit their real application. In this study, a simple but sensitive immobilization free DNAzyme based electrochemical biosensor has been proposed and lead has been chosen as a model target because of the severe effects of lead toxicity. The different diffusivity and electrostatic repulsion between long and short DNA on the negatively charged ITO electrode can be used to discriminate the short and long DNA. Lead dependent DNAzyme was hybridized with its substrate (which was modified with methylene blue at the 3' terminal) beforehand. Since the DNAzyme/substrate complex contains a large negative charge, it cannot diffuse easily to the negatively charged ITO electrode surface and little electrochemical signal has been detected. The presence of lead would trigger the cleavage of the DNAzyme/substrate complex and cause the release of a methylene blue-labeled short-oligonucleotide into the solution. The methylene blue-labeled short-oligonucleotide can diffuse easily to the surface of the negatively charged ITO electrode and results in the enhanced electrochemical response being detected. Each lead can cleave a lot of DNAzyme/substrate complex to realize signal amplification. The enhanced electrochemical signal has a linear relationship with the Pb(2+) concentration in the range of 0.05-1 μM with a detection limit of 0.018 μM (S/N = 3). The proposed biosensor has been applied to detect Pb(2+) in water samples with satisfactory results.

  4. Effects of food surface topography on phage-based magnetoelastic biosensor detection

    NASA Astrophysics Data System (ADS)

    Horikawa, Shin; Chai, Yating; Zhao, Ruiting; Wikle, Howard C.; Chin, Bryan A.

    2014-05-01

    Phage-based magnetoelastic (ME) biosensors have proven useful in rapidly and inexpensively detecting food surface con- tamination. These biosensors are wireless, mass-sensitive biosensors and can be placed directly on food surfaces to detect the presence of target pathogens. Previously, millimeter-scale strip-shaped ME biosensors have been used to demonstrate direct detection of Salmonella Typhimurium on various fresh produce surfaces, including tomatoes, shell eggs, watermel- ons, and spinach leaves. Since the topography of these produce surfaces are different, and the biosensor must come into direct contact with Salmonella bacteria, food surfaces with large roughness and curvatures (e.g., spinach leaf surfaces) may allow the bacteria to avoid direct contact, thereby avoiding detection. The primary objective of this paper is, hence, to investigate the effects of food surface topography on the detection capabilities of the biosensors. Spinach leaf surfaces were selected as model surfaces, and detection experiments were conducted with differently sized biosensors (2 mm, 0.5 mm, and 150 μm in length). Spinach leaf roughness and curvatures of both adaxial (top) and abaxial (underside) surfaces were measured using a confocal laser scanning microscope. The experimental results showed that in spinach as the sen- sor was made smaller, the physical contact between the biosensors and bacteria were improved. Smaller sensors thereby enhance detection capabilities. When proper numbers of biosensors are used, micron-scale biosensors are anticipated to yield improved limits of detection over previously investigated millimeter-scale biosensors.

  5. Immunoaffinity-based biosensor for polycyclic aromatic hydrocarbons

    NASA Astrophysics Data System (ADS)

    Bargeron, C. Brent; Benson, Richard C.; Phillips, Terry E.; Scholl, Peter F.; Abubaker, Sala; Groopman, John D.; Strickland, Paul T.

    2001-05-01

    An automated biosensor for 1-hydroxypyrene-glucuronide (OHPG) has been developed using a sensor platform initially designed for aflatoxin. The platform is based on the properties of immunoaffinity for sample purification and concentration, and fluorescence for detection. Experiments have demonstrated capture, wash, elution, and quantitation with very good results. The device is handheld and battery- driven, and can be miniaturized further. The bed volume of the column was 0.1 ml with a capacity of about 400 ng of the OHPG. Analysis time was 10 - 11 minutes. The sensitivity was about 0.5 ppb. The antibodies for the system were developed previously and recognize OHPG. The biosensor relies upon microprocessor-controlled minifluidics and fluorometry.

  6. Nanomaterial-Based Biosensors for Detection of Pesticides and Explosives

    SciTech Connect

    Wang, Jun; Lin, Yuehe

    2009-01-01

    In this chapter, we describe nanomaterial-based biosensors for detecting OP pesticides and explosives. CNTs and functionalized silica nanoparticles have been chosen for this study. The biosensors were combined with the flow-injection system, providing great advantages for onsite, real-time, and continuous detection of environmental pollutants such as OPs and TNT. The sensors take advantage of the electrocatalytic properties of CNTs, which makes it feasible to achieve a sensitive electrochemical detection of the products from enzymatic reactions at low potential. This approach uses a large aspect ratio of silica nanoparticles, which can be used as a carrier for loading a large amount of electroactive species, such as poly(guanine), for amplified detection of explosives. These methods offer a new environmental monitoring tool for rapid, inexpensive, and highly sensitive detection of OPs or TNT compounds.

  7. Fluorescence based fiber optic and planar waveguide biosensors. A review.

    PubMed

    Benito-Peña, Elena; Valdés, Mayra Granda; Glahn-Martínez, Bettina; Moreno-Bondi, Maria C

    2016-11-02

    The application of optical biosensors, specifically those that use optical fibers and planar waveguides, has escalated throughout the years in many fields, including environmental analysis, food safety and clinical diagnosis. Fluorescence is, without doubt, the most popular transducer signal used in these devices because of its higher selectivity and sensitivity, but most of all due to its wide versatility. This paper focuses on the working principles and configurations of fluorescence-based fiber optic and planar waveguide biosensors and will review biological recognition elements, sensing schemes, as well as some major and recent applications, published in the last ten years. The main goal is to provide the reader a general overview of a field that requires the joint collaboration of researchers of many different areas, including chemistry, physics, biology, engineering, and material science.

  8. Biosensors based on GaN nanoring optical cavities

    NASA Astrophysics Data System (ADS)

    Kouno, Tetsuya; Takeshima, Hoshi; Kishino, Katsumi; Sakai, Masaru; Hara, Kazuhiko

    2016-05-01

    Biosensors based on GaN nanoring optical cavities were demonstrated using room-temperature photoluminescence measurements. The outer diameter, height, and thickness of the GaN nanorings were approximately 750-800, 900, and 130-180 nm, respectively. The nanorings functioned as whispering-gallery-mode (WGM)-type optical cavities and exhibited sharp resonant peaks like lasing actions. The evanescent component of the WGM was strongly affected by the refractive index of the ambient environment, the type of liquid, and the sucrose concentration of the analyzed solution, resulting in shifts of the resonant wavelengths. The results indicate that the GaN nanorings can potentially be used in sugar sensors of the biosensors.

  9. EQCM Immunoassay for Phosphorylated Acetylcholinesterase as a Biomarker for Organophosphate Exposures Based on Selective Zirconia Adsorption and Enzyme-Catalytic Precipitation

    SciTech Connect

    Wang, Hua; Wang, Jun; Choi, Daiwon; Tang, Zhiwen; Wu, Hong; Lin, Yuehe

    2009-03-01

    A zirconia (ZrO2) adsorption-based immunoassay by electrochemical quartz crystal microbalance (EQCM) has been initially developed, aiming at the detection of phosphorylated acetylcholinesterase (AChE) as a potential biomarker for bio-monitoring exposures to organophosphate (OP) pesticides and chemical warfare agents. Hydroxyl-derivatized monolayer was preferably chosen to modify the crystal serving as the template for directing the electro-deposition of ZrO2 film with uniform nanostructures. The resulting ZrO2 film was utilized to selectively capture phosphorylated AChE from the sample media. Horseradish peroxidase (HRP)-labeled anti-AChE antibodies were further employed to recognize the captured phosphorylated protein. Enzyme-catalytic oxidation of the benzidine substrate resulted in the accumulation of insoluble product on the functionalized crystal. Ultrasensitive EQCM quantification by mass-amplified frequency responses as well as rapid qualification by visual color changes of product could be thus achieved. Moreover, 4-chloro-1-naphthol (CN) was comparably studied as an ideal chromogenic substrate for the enzyme-catalytic precipitation. Experimental results show that the developed EQCM technique can allow for the detection of phosphorylated AChE in human plasma. Such an EQCM immunosensing format opens a new door towards the development of simple, sensitive, and field-applicable biosensor for biologically monitoring low-level OP exposures.

  10. Papers Based Electrochemical Biosensors: From Test Strips to Paper-Based Microfluidics

    SciTech Connect

    Liu, Bingwen; Du, Dan; Hua, Xin; Yu, Xiao-Ying; Lin, Yuehe

    2014-05-08

    Papers based biosensors such as lateral flow test strips and paper-based microfluidic devices (or paperfluidics) are inexpensive, rapid, flexible, and easy-to-use analytical tools. An apparent trend in their detection is to interpret sensing results from qualitative assessment to quantitative determination. Electrochemical detection plays an important role in quantification. This review focuses on electrochemical (EC) detection enabled biosensors. The first part provides detailed examples in paper test strips. The second part gives an overview of paperfluidics engaging EC detections. The outlook and recommendation of future directions of EC enabled biosensors are discussed in the end.

  11. Aptamer-based Field-Effect Biosensor for Tenofovir Detection.

    PubMed

    Aliakbarinodehi, N; Jolly, P; Bhalla, N; Miodek, A; De Micheli, G; Estrela, P; Carrara, S

    2017-03-15

    During medical treatment it is critical to maintain the circulatory concentration of drugs within their therapeutic range. A novel biosensor is presented in this work to address the lack of a reliable point-of-care drug monitoring system in the market. The biosensor incorporates high selectivity and sensitivity by integrating aptamers as the recognition element and field-effect transistors as the signal transducer. The drug tenofovir was used as a model small molecule. The biointerface of the sensor is a binary self-assembled monolayer of specific thiolated aptamer and 6-mercapto-1-hexanol (MCH), whose ratio was optimized by electrochemical impedance spectroscopy measurements to enhance the sensitivity towards the specific target. Surface plasmon resonance, performed under different buffer conditions, shows optimum specific and little non-specific binding in phosphate buffered saline. The dose-response behavior of the field-effect biosensor presents a linear range between 1 nM and 100 nM of tenofovir and a limit of detection of 1.2 nM. Two non-specific drugs and one non-specific aptamer, tested as stringent control candidates, caused negligible responses. The applications were successfully extended to the detection of the drug in human serum. As demonstrated by impedance measurements, the aptamer-based sensors can be used for real-time drug monitoring.

  12. Aptamer-based Field-Effect Biosensor for Tenofovir Detection

    PubMed Central

    Aliakbarinodehi, N.; Jolly, P.; Bhalla, N.; Miodek, A.; De Micheli, G.; Estrela, P.; Carrara, S.

    2017-01-01

    During medical treatment it is critical to maintain the circulatory concentration of drugs within their therapeutic range. A novel biosensor is presented in this work to address the lack of a reliable point-of-care drug monitoring system in the market. The biosensor incorporates high selectivity and sensitivity by integrating aptamers as the recognition element and field-effect transistors as the signal transducer. The drug tenofovir was used as a model small molecule. The biointerface of the sensor is a binary self-assembled monolayer of specific thiolated aptamer and 6-mercapto-1-hexanol (MCH), whose ratio was optimized by electrochemical impedance spectroscopy measurements to enhance the sensitivity towards the specific target. Surface plasmon resonance, performed under different buffer conditions, shows optimum specific and little non-specific binding in phosphate buffered saline. The dose-response behavior of the field-effect biosensor presents a linear range between 1 nM and 100 nM of tenofovir and a limit of detection of 1.2 nM. Two non-specific drugs and one non-specific aptamer, tested as stringent control candidates, caused negligible responses. The applications were successfully extended to the detection of the drug in human serum. As demonstrated by impedance measurements, the aptamer-based sensors can be used for real-time drug monitoring. PMID:28294122

  13. A liquid-crystal-based DNA biosensor for pathogen detection

    NASA Astrophysics Data System (ADS)

    Khan, Mashooq; Khan, Abdur Rahim; Shin, Jae-Ho; Park, Soo-Young

    2016-03-01

    A liquid-crystal (LC)-filled transmission electron microscopy (TEM) grid cell coated with the cationic surfactant dodecyltrimethylammonium bromide (DTAB), to which a single-stranded deoxyribonucleic acid probe (ssDNAprobe) was adsorbed at the LC/aqueous interface (TEMDTAB/DNA), was applied for the highly specific detection of target DNA molecules. The DTAB-coated E7 (used LC mixture) in the TEM grid (TEMDTAB) exhibited a homeotropic orientation, and changed to a planar orientation upon adsorption of the ssDNAprobe. The TEMDTAB/DNA was then exposed to complementary (target) ssDNA, which resulted in a planar-to-homeotropic configurational change of E7 that could be observed through a polarized optical microscope under crossed polarizers. The optimum adsorption density (2 μM) of ssDNAprobe enabled the detection of ≥0.05 nM complementary ssDNA. This TEMDTAB/DNA biosensor could differentiate complementary ssDNA from mismatched ssDNA as well as double-stranded DNA. It also successfully detected the genomic DNAs of the bacterium Erwinia carotovora and the fungi Rhazictonia solani. Owe to the high specificity, sensitivity, and label-free detection, this biosensor may broaden the applications of LC-based biosensors to pathogen detection.

  14. Resonant energy transfer based biosensor for detection of multivalent proteins.

    SciTech Connect

    Song, X.; Swanson, Basil I.

    2001-01-01

    We have developed a new fluorescence-based biosensor for sensitive detection of species involved in a multivslent interaction. The biosensor system utilizes specific interactions between proteins and cell surface receptors, which trigger a receptor aggregation process. Distance-dependent fluorescence self-quenching and resonant energy transfer mechanisms were coupled with a multivalent interaction to probe the receptor aggregation process, providing a sensitive and specific signal transduction method for such a binding event. The fluorescence change induced by the aggregation process can be monitored by different instrument platforms, e.g. fluorimetry and flow cytometry. In this article, a sensitive detection of pentavalent cholera toxin which recognizes ganglioside GM1 has been demonstrated through the resonant energy transfer scheme, which can achieve a double color change simultaneously. A detection sensitivity as high as 10 pM has been achieved within a few minutes (c.a. 5 minutes). The simultaneous double color change (an increase of acceptor fluorescence and a decrease of donor fluorescence intensity) of two similar fluorescent probes provides particularly high detection reliability owing to the fact that they act as each other's internal reference. Any external perturbation such as environmental temperature change causes no significant change in signal generation. Besides the application for biological sensing, the method also provides a useful tool for investigation of kinetics and thermodynamics of a multivalent interaction. Keywords: Biosensor, Fluorescence resonant energy transfer, Multivalent interaction, Cholera Toxin, Ganglioside GM1, Signal Transduction

  15. Aptamer-based Electrochemical Biosensor for Interferon Gamma Detection

    PubMed Central

    Liu, Ying; Tuleouva, Nazgul; Ramanculov, Erlan; Revzin, Alexander

    2010-01-01

    In this paper, we describe the development of an electrochemical DNA aptamer-based biosensor for detection of IFN-γ. A DNA hairpin containing IFN-γ-binding aptamer was thiolated, conjugated with Methylene Blue (MB) redox tag and immobilized on a gold electrode by self-assembly. Binding of IFN-γ caused the aptamer hairpin to unfold, pushing MB redox molecules away from the electrode and decreasing electron-transfer efficiency. The change in redox current was quantified using Square Wave Voltammetry (SWV) and was found to be highly sensitive to IFN-γ concentration. The limit of detection for optimized biosensor was 0.06 nM with linear response extending to 10 nM. This aptasensor was specific to IFN-γ in the presence of overabundant serum proteins. Importantly, the same aptasensor could be regenerated by disrupting aptamer-IFN-γ complex in urea buffer and re-used multiple times. Unlike standard sandwich immunoassays, the aptasensor described here allowed to detect IFN-γ binding directly without the need for multiple washing steps and reagents. An electrochemical biosensor for simple and sensitive detection of IFN-γ demonstrated in this paper will have future applications in immunology, cancer research and infectious disease monitoring. PMID:20815336

  16. A liquid-crystal-based DNA biosensor for pathogen detection

    PubMed Central

    Khan, Mashooq; Khan, Abdur Rahim; Shin, Jae-Ho; Park, Soo-Young

    2016-01-01

    A liquid-crystal (LC)-filled transmission electron microscopy (TEM) grid cell coated with the cationic surfactant dodecyltrimethylammonium bromide (DTAB), to which a single-stranded deoxyribonucleic acid probe (ssDNAprobe) was adsorbed at the LC/aqueous interface (TEMDTAB/DNA), was applied for the highly specific detection of target DNA molecules. The DTAB-coated E7 (used LC mixture) in the TEM grid (TEMDTAB) exhibited a homeotropic orientation, and changed to a planar orientation upon adsorption of the ssDNAprobe. The TEMDTAB/DNA was then exposed to complementary (target) ssDNA, which resulted in a planar-to-homeotropic configurational change of E7 that could be observed through a polarized optical microscope under crossed polarizers. The optimum adsorption density (2 μM) of ssDNAprobe enabled the detection of ≥0.05 nM complementary ssDNA. This TEMDTAB/DNA biosensor could differentiate complementary ssDNA from mismatched ssDNA as well as double-stranded DNA. It also successfully detected the genomic DNAs of the bacterium Erwinia carotovora and the fungi Rhazictonia solani. Owe to the high specificity, sensitivity, and label-free detection, this biosensor may broaden the applications of LC-based biosensors to pathogen detection. PMID:26940532

  17. Ultrasensitive detection of influenza viruses with a glycan-based impedimetric biosensor

    PubMed Central

    Hushegyi, András; Pihíková, Dominika; Bertók, Tomáš; Adam, Vojtech; Kizek, René; Tkac, Jan

    2016-01-01

    An ultrasensitive impedimetric glycan-based biosensor for reliable and selective detection of inactivated, but intact influenza viruses H3N2 was developed. Such glycan-based approach has a distinct advantage over antibody-based detection of influenza viruses since glycans are natural viral receptors with a possibility to selectively distinguish between potentially pathogenic influenza subtypes by the glycan-based biosensors. Build-up of the biosensor was carefully optimized with atomic force microscopy applied for visualization of the biosensor surface after binding of viruses with the topology of an individual viral particle H3N2 analyzed. The glycan biosensor could detect a glycan binding lectin with a limit of detection (LOD) of 5 aM. The biosensor was finally applied for analysis of influenza viruses H3N2 with LOD of 13 viral particles in 1 μl, what is the lowest LOD for analysis of influenza viral particles by the glycan-based device achieved so far. The biosensor could detect H3N2 viruses selectively with a sensitivity ratio of 30 over influenza viruses H7N7. The impedimetric biosensor presented here is the most sensitive glycan-based device for detection of influenza viruses and among the most sensitive antibody or aptamer based biosensor devices. PMID:26765527

  18. Digital biosensors with built-in logic for biomedical applications--biosensors based on a biocomputing concept.

    PubMed

    Wang, Joseph; Katz, Evgeny

    2010-10-01

    This article reviews biomolecular logic systems for bioanalytical applications, specifically concentrating on the prospects and fundamental and practical challenges of designing digitally operating biosensors logically processing multiple biochemical signals. Such digitally processed information produces a final output in the form of a yes/no response through Boolean logic networks composed of biomolecular systems, and hence leads to a high-fidelity biosensing compared with traditional single (or parallel) sensing devices. It also allows direct coupling of the signal processing with chemical actuators to produce integrated "smart" "sense/act" (biosensor-bioactuator) systems. Unlike common biosensing devices based on a single input (analyte), devices based on biochemical logic systems require a fundamentally new approach for the sensor design and operation and careful attention to the interface of biocomputing systems and electronic transducers. As common in conventional biosensors, the success of the enzyme logic biosensor would depend, in part, on the immobilization of the biocomputing reagent layer. Such surface confinement provides a contact between the biocomputing layer and the transducing surface and combines efficiently the individual logic-gate elements. Particular attention should thus be given to the composition, preparation, and immobilization of the biocomputing surface layer, to the role of the system scalability, and to the efficient transduction of the output signals. By processing complex patterns of multiple physiological markers, such multisignal digital biosensors should have a profound impact upon the rapid diagnosis and treatment of diseases, and particularly upon the timely detection and alert of medical emergencies (along with immediate therapeutic intervention). Other fields ranging from biotechnology to homeland security would benefit from these advances in new biocomputing biosensors and the corresponding closed-loop "add/act" operation.

  19. Development of mercury (II) ion biosensors based on mercury-specific oligonucleotide probes.

    PubMed

    Li, Lanying; Wen, Yanli; Xu, Li; Xu, Qin; Song, Shiping; Zuo, Xiaolei; Yan, Juan; Zhang, Weijia; Liu, Gang

    2016-01-15

    Mercury (II) ion (Hg(2+)) contamination can be accumulated along the food chain and cause serious threat to the public health. Plenty of research effort thus has been devoted to the development of fast, sensitive and selective biosensors for monitoring Hg(2+). Thymine was demonstrated to specifically combine with Hg(2+) and form a thymine-Hg(2+)-thymine (T-Hg(2+)-T) structure, with binding constant even higher than T-A Watson-Crick pair in DNA duplex. Recently, various novel Hg(2+) biosensors have been developed based on T-rich Mercury-Specific Oligonucleotide (MSO) probes, and exhibited advanced selectivity and excellent sensitivity for Hg(2+) detection. In this review, we explained recent development of MSO-based Hg(2+) biosensors mainly in 3 groups: fluorescent biosensors, colorimetric biosensors and electrochemical biosensors.

  20. Effect of glyphosate-based herbicide on acetylcholinesterase activity in tadpoles, Hoplobatrachus rugulosus.

    PubMed

    Ruamthum, W; Visetson, S; Milne, J R; Bullangpoti, V

    2011-01-01

    This study focused on the effects of a glyphosate-based herbicide on activity of the neuron enzyme, acetylcholinesterase (AchE), in the tadpole stage (stage 35-39) of the East Asian Bullfrog, Hoplobatrachus rugulosus. There were 4 herbicide concentration treatments consisting of glyphosate-based herbicide added at 21, 24, 27 and 30 microl to 1L de-chlorinated water in glass containers (10x15x20 cm). There were 4 replicates per treatment, each replicate using 20 tadpoles. The toxicity results were compared with tadpoles in distilled water as a control treatment. After 24, 48, 72 and 96 hours exposure to glyphosate-based herbicide concentrations, LC50 values of 25.21, 24.66, 24.16 and 23.63 microl/L, respectively, were recorded. AChE activities decreased significantly and markedly with herbicide concentration. Such inhibition of AChE activity by this glyphosate-based herbicide indicates the potential of such herbicides to disrupt ecological communities in water near where the herbicides are applied.

  1. Human Neural Cell-Based Biosensor

    DTIC Science & Technology

    2011-03-11

    neurons, motoneurons and astrocytes using defined medium conditions, (3) cell-based methods to detect botulinum toxin, and (4) fluorescence based assays...medium conditions, (3) cell-based methods to detect botulinum toxin, and (4) fluorescence based assays for proliferation, cell migration, mitochondrial...line will begin shortly. (3) Development of cell based methods to detect botulinum toxin There has been substantial progress in the development

  2. Human Neural Cell-Based Biosensor

    DTIC Science & Technology

    2011-06-11

    astrocytes using defined medium conditions, (3) cell-based methods to detect botulinum toxin, and (4) HTS amenable assays for proliferation...progenitors into dopaminergic neurons, motoneurons and astrocytes using defined medium conditions, (3) cell-based methods to detect botulinum toxin...cell line developed for potential commercial distribution. (3) Development of cell based methods to detect botulinum toxin There has been

  3. A capacitive biosensor based on an interdigitated electrode with nanoislands.

    PubMed

    Jung, Ha-Wook; Chang, Young Wook; Lee, Ga-yeon; Cho, Sungbo; Kang, Min-Jung; Pyun, Jae-Chul

    2014-09-24

    A capacitive biosensor based on an interdigitated electrode (IDE) with nanoislands was developed for label-free detection of antigen-antibody interactions. To enable sensitive capacitive detection of protein adsorption, the nanoislands were fabricated between finger electrodes of the IDE. The effect of the nanoislands on the sensitive capacitive measurement was estimated using horseradish peroxidase (HRP) as a model protein. Additionally, a parylene-A film was coated on the IDE with nanoislands to improve the efficiency of protein immobilization. By using HRP and hepatitis B virus surface antigen (HBsAg) as model analytes, the effect of the parylene-A film on the capacitive detection of protein adsorption was demonstrated.

  4. Gallium nitride electrodes for membrane-based electrochemical biosensors

    NASA Astrophysics Data System (ADS)

    Schubert, T.; Steinhoff, G.; von Ribbeck, H.-G.; Stutzmannn, M.; Eickhoff, M.; Tanaka, M.

    2009-10-01

    We report on the deposition of planar lipid bilayers (supported membranes) on gallium nitride (GaN) electrodes for potential applications as membrane-based biosensors. The kinetics of the lipid membrane formation upon vesicle fusion were monitored by simultaneous measurements of resistance and capacitance of the membrane using AC impedance spectroscopy in the frequency range between 50mHz and 50kHz. We could identify a two-step process of membrane spreading and self-healing. Despite its relatively low resistance, the membrane can be modeled by a parallel combination of an ideal resistor and capacitor, indicating that the membrane efficiently blocks the diffusion of ions.

  5. Photonic Crystal Biosensor Based on Optical Surface Waves

    PubMed Central

    Konopsky, Valery N.; Karakouz, Tanya; Alieva, Elena V.; Vicario, Chiara; Sekatskii, Sergey K.; Dietler, Giovanni

    2013-01-01

    A label-free biosensor device based on registration of photonic crystal surface waves is described. Angular interrogation of the optical surface wave resonance is used to detect changes in the thickness of an adsorbed layer, while an additional simultaneous detection of the critical angle of total internal reflection provides independent data of the liquid refractive index. The abilities of the device are demonstrated by measuring of biotin molecule binding to a streptavidin monolayer, and by measuring association and dissociation kinetics of immunoglobulin G proteins. Additionally, deposition of PSS/PAH polyelectrolytes is recorded in situ resulting calculation of PSS and PAH monolayer thicknesses separately. PMID:23429517

  6. Gallium nitride electrodes for membrane-based electrochemical biosensors.

    PubMed

    Schubert, T; Steinhoff, G; von Ribbeck, H-G; Stutzmannn, M; Eickhoff, M; Tanaka, M

    2009-10-01

    We report on the deposition of planar lipid bilayers (supported membranes) on gallium nitride (GaN) electrodes for potential applications as membrane-based biosensors. The kinetics of the lipid membrane formation upon vesicle fusion were monitored by simultaneous measurements of resistance and capacitance of the membrane using AC impedance spectroscopy in the frequency range between 50 mHz and 50 kHz. We could identify a two-step process of membrane spreading and self-healing. Despite its relatively low resistance, the membrane can be modeled by a parallel combination of an ideal resistor and capacitor, indicating that the membrane efficiently blocks the diffusion of ions.

  7. Nano-yarn carbon nanotube fiber based enzymatic glucose biosensor

    NASA Astrophysics Data System (ADS)

    Zhu, Zhigang; Song, Wenhui; Burugapalli, Krishna; Moussy, Francis; Li, Ya-Li; Zhong, Xiao-Hua

    2010-04-01

    A novel brush-like electrode based on carbon nanotube (CNT) nano-yarn fiber has been designed for electrochemical biosensor applications and its efficacy as an enzymatic glucose biosensor demonstrated. The CNT nano-yarn fiber was spun directly from a chemical-vapor-deposition (CVD) gas flow reaction using a mixture of ethanol and acetone as the carbon source and an iron nano-catalyst. The fiber, 28 µm in diameter, was made of bundles of double walled CNTs (DWNTs) concentrically compacted into multiple layers forming a nano-porous network structure. Cyclic voltammetry study revealed a superior electrocatalytic activity for CNT fiber compared to the traditional Pt-Ir coil electrode. The electrode end tip of the CNT fiber was freeze-fractured to obtain a unique brush-like nano-structure resembling a scale-down electrical 'flex', where glucose oxidase (GOx) enzyme was immobilized using glutaraldehyde crosslinking in the presence of bovine serum albumin (BSA). An outer epoxy-polyurethane (EPU) layer was used as semi-permeable membrane. The sensor function was tested against a standard reference electrode. The sensitivities, linear detection range and linearity for detecting glucose for the miniature CNT fiber electrode were better than that reported for a Pt-Ir coil electrode. Thermal annealing of the CNT fiber at 250 °C for 30 min prior to fabrication of the sensor resulted in a 7.5 fold increase in glucose sensitivity. The as-spun CNT fiber based glucose biosensor was shown to be stable for up to 70 days. In addition, gold coating of the electrode connecting end of the CNT fiber resulted in extending the glucose detection limit to 25 µM. To conclude, superior efficiency of CNT fiber for glucose biosensing was demonstrated compared to a traditional Pt-Ir sensor.

  8. Nano-yarn carbon nanotube fiber based enzymatic glucose biosensor.

    PubMed

    Zhu, Zhigang; Song, Wenhui; Burugapalli, Krishna; Moussy, Francis; Li, Ya-Li; Zhong, Xiao-Hua

    2010-04-23

    A novel brush-like electrode based on carbon nanotube (CNT) nano-yarn fiber has been designed for electrochemical biosensor applications and its efficacy as an enzymatic glucose biosensor demonstrated. The CNT nano-yarn fiber was spun directly from a chemical-vapor-deposition (CVD) gas flow reaction using a mixture of ethanol and acetone as the carbon source and an iron nano-catalyst. The fiber, 28 microm in diameter, was made of bundles of double walled CNTs (DWNTs) concentrically compacted into multiple layers forming a nano-porous network structure. Cyclic voltammetry study revealed a superior electrocatalytic activity for CNT fiber compared to the traditional Pt-Ir coil electrode. The electrode end tip of the CNT fiber was freeze-fractured to obtain a unique brush-like nano-structure resembling a scale-down electrical 'flex', where glucose oxidase (GOx) enzyme was immobilized using glutaraldehyde crosslinking in the presence of bovine serum albumin (BSA). An outer epoxy-polyurethane (EPU) layer was used as semi-permeable membrane. The sensor function was tested against a standard reference electrode. The sensitivities, linear detection range and linearity for detecting glucose for the miniature CNT fiber electrode were better than that reported for a Pt-Ir coil electrode. Thermal annealing of the CNT fiber at 250 degrees C for 30 min prior to fabrication of the sensor resulted in a 7.5 fold increase in glucose sensitivity. The as-spun CNT fiber based glucose biosensor was shown to be stable for up to 70 days. In addition, gold coating of the electrode connecting end of the CNT fiber resulted in extending the glucose detection limit to 25 microM. To conclude, superior efficiency of CNT fiber for glucose biosensing was demonstrated compared to a traditional Pt-Ir sensor.

  9. Electrochemical Sensors and Biosensors Based on Nanomaterials and Nanostructures

    SciTech Connect

    Zhu, Chengzhou; Yang, Guohai; Li, He; Du, Dan; Lin, Yuehe

    2014-10-29

    We report that considerable attention has been devoted to the integration of recognition elements with electronic elements to develop electrochemical sensors and biosensors.Various electrochemical devices, such as amperometric sensors, electrochemical impedance sensors, and electrochemical luminescence sensors as well as photoelectrochemical sensors, provide wide applications in the detection of chemical and biological targets in terms of electrochemical change of electrode interfaces. Here, this review focuses on recent advances in electrochemical sensors and biosensors based on nanomaterials and nanostructures during 2013 to 2014. The aim of this effort is to provide the reader with a clear and concise view of new advances in areas ranging from electrode engineering, strategies for electrochemical signal amplification, and novel electroanalytical techniques used in the miniaturization and integration of the sensors. Moreover, the authors have attempted to highlight areas of the latest and significant development of enhanced electrochemical nanosensors and nanobiosensors that inspire broader interests across various disciplines. Electrochemical sensors for small molecules, enzyme-based biosensors, genosensors, immunosensors, and cytosensors are reviewed herein (Figure 1). Such novel advances are important for the development of electrochemical sensors that open up new avenues and methods for future research. In conclusion, we recommend readers interested in the general principles of electrochemical sensors and electrochemical methods to refer to other excellent literature for a broad scope in this area.(3, 4) However, due to the explosion of publications in this active field, we do not claim that this Review includes all of the published works in the past two years and we apologize to the authors of excellent work, which is unintentionally left out.

  10. Electrochemical Sensors and Biosensors Based on Nanomaterials and Nanostructures

    DOE PAGES

    Zhu, Chengzhou; Yang, Guohai; Li, He; ...

    2014-10-29

    We report that considerable attention has been devoted to the integration of recognition elements with electronic elements to develop electrochemical sensors and biosensors.Various electrochemical devices, such as amperometric sensors, electrochemical impedance sensors, and electrochemical luminescence sensors as well as photoelectrochemical sensors, provide wide applications in the detection of chemical and biological targets in terms of electrochemical change of electrode interfaces. Here, this review focuses on recent advances in electrochemical sensors and biosensors based on nanomaterials and nanostructures during 2013 to 2014. The aim of this effort is to provide the reader with a clear and concise view of new advancesmore » in areas ranging from electrode engineering, strategies for electrochemical signal amplification, and novel electroanalytical techniques used in the miniaturization and integration of the sensors. Moreover, the authors have attempted to highlight areas of the latest and significant development of enhanced electrochemical nanosensors and nanobiosensors that inspire broader interests across various disciplines. Electrochemical sensors for small molecules, enzyme-based biosensors, genosensors, immunosensors, and cytosensors are reviewed herein (Figure 1). Such novel advances are important for the development of electrochemical sensors that open up new avenues and methods for future research. In conclusion, we recommend readers interested in the general principles of electrochemical sensors and electrochemical methods to refer to other excellent literature for a broad scope in this area.(3, 4) However, due to the explosion of publications in this active field, we do not claim that this Review includes all of the published works in the past two years and we apologize to the authors of excellent work, which is unintentionally left out.« less

  11. Human Neural Cell-Based Biosensor

    DTIC Science & Technology

    2010-12-10

    botulinum toxin, and (4) development of fluorescence based assays for proliferation, mitochondrial function and reactive oxygen species generation as sensor...dopaminergic neurons, motoneurons and astrocytes using defined medium conditions, (3) development of cell-based methods to detect botulinum toxin, and...neurons are the target cell type for botulinum toxin and would be a useful cell type for the detection of this potential bioterrorism agent. Astrocytes

  12. Cellular Silica Encapsulation for Development of Robust Cell Based Biosensors

    NASA Astrophysics Data System (ADS)

    Johnston, Robert; Rogelj, Snezna; Harper, Jason; Tartis, Michaelann

    2014-03-01

    In order to detect chemical and biological threats both on the battlefield and in civilian life, development of portable, robust detection systems capable of real-time identification of the chemical and biological agents are needed. Living cell-based sensors have proven effective as sensitive, specific, near real-time detectors; however, living cell-based sensors require frequent cell replenishment due to cell sensitivity to the ex-vivo environment, which limits sensor stability. Incorporation of living cells within a biocompatible matrix that provides mechanical protection and maintains access to the external environment may facilitate the development of long-term stable cell-based biosensors. We are exploring the use of a novel Chemical Vapor into Liquid (CViL) deposition process for whole cell encapsulation in silica. In CViL, the high vapor pressure of common silica alkoxides is utilized to deliver silica into an aqueous medium, creating a silica sol. Mixing of cells with the resulting silica sol facilitates encapsulation of cells in silica while minimizing cell contact with the cytotoxic products of silica generating reactions. Using fluorescence microscopy analysis with multiple silica specific markers, encapsulation of multiple eukaryotic cell types (Saccharomyces cerevisiae, Jurkat, HeLa, and U87 cells) with CViL generated silica is shown, providing a foundation for development of long -term stable cell-based biosensors with diverse sensing capabilities.

  13. Nanoparticle-based immunosensor with apoferritin templated metallic phosphate label for quantification of phosphorylated acetylcholinesterase

    SciTech Connect

    Du, Dan; Chen, Aiqiong; Xie, Yunying; Zhang, Aidong; Lin, Yuehe

    2011-05-15

    A new sandwich-like electrochemical immunosensor has been developed for quantification of organophosphorylated acetylcholinesterase (OP-AChE), an exposure biomarker of organophosphate pesticides and nerve agents. Zirconia nanoparticles (ZrO2 NPs) were anchored on a screen printed electrode (SPE) to preferably capture OP-AChE adducts by metal chelation with phospho-moieties, which was selectively recognized by lead phosphate-apoferritin labeled anti-AChE antibody (LPA-anti-AChE). The sandwich-like immunoreactions were performed among ZrO2 NPs, OP-AChE and LPA-anti-AChE to form ZrO2/OP-AChE/LPA-anti-AChE complex and the released lead ions were detected on a disposable SPE. The binding affinity was investigated by both square wave voltammetry (SWV) and quartz crystal microbalance (QCM) measurements. The proposed immunosensor yielded a linear response current over a broad OP-AChE concentrations range from 0.05 nM to 10 nM, with detection limit of 0.02 nM, which has enough sensitivity for monitoring of low-dose exposure to OPs. This method avoids the drawback of unavailability of commercial OP-specific antibody as well as amplifies detection signal by using apoferritin encoded metallic phosphate nanoparticle tags. This nanoparticle-based immunosensor offers a new method for rapid, sensitive, selective and inexpensive quantification of phosphorylated adducts for monitoring of OP pesticides and nerve agents exposures.

  14. Surface Plasmon Resonance Biosensor Based on Smart Phone Platforms.

    PubMed

    Liu, Yun; Liu, Qiang; Chen, Shimeng; Cheng, Fang; Wang, Hanqi; Peng, Wei

    2015-08-10

    We demonstrate a fiber optic surface plasmon resonance (SPR) biosensor based on smart phone platforms. The light-weight optical components and sensing element are connected by optical fibers on a phone case. This SPR adaptor can be conveniently installed or removed from smart phones. The measurement, control and reference channels are illuminated by the light entering the lead-in fibers from the phone's LED flash, while the light from the end faces of the lead-out fibers is detected by the phone's camera. The SPR-sensing element is fabricated by a light-guiding silica capillary that is stripped off its cladding and coated with 50-nm gold film. Utilizing a smart application to extract the light intensity information from the camera images, the light intensities of each channel are recorded every 0.5 s with refractive index (RI) changes. The performance of the smart phone-based SPR platform for accurate and repeatable measurements was evaluated by detecting different concentrations of antibody binding to a functionalized sensing element, and the experiment results were validated through contrast experiments with a commercial SPR instrument. This cost-effective and portable SPR biosensor based on smart phones has many applications, such as medicine, health and environmental monitoring.

  15. Surface Plasmon Resonance Biosensor Based on Smart Phone Platforms

    NASA Astrophysics Data System (ADS)

    Liu, Yun; Liu, Qiang; Chen, Shimeng; Cheng, Fang; Wang, Hanqi; Peng, Wei

    2015-08-01

    We demonstrate a fiber optic surface plasmon resonance (SPR) biosensor based on smart phone platforms. The light-weight optical components and sensing element are connected by optical fibers on a phone case. This SPR adaptor can be conveniently installed or removed from smart phones. The measurement, control and reference channels are illuminated by the light entering the lead-in fibers from the phone’s LED flash, while the light from the end faces of the lead-out fibers is detected by the phone’s camera. The SPR-sensing element is fabricated by a light-guiding silica capillary that is stripped off its cladding and coated with 50-nm gold film. Utilizing a smart application to extract the light intensity information from the camera images, the light intensities of each channel are recorded every 0.5 s with refractive index (RI) changes. The performance of the smart phone-based SPR platform for accurate and repeatable measurements was evaluated by detecting different concentrations of antibody binding to a functionalized sensing element, and the experiment results were validated through contrast experiments with a commercial SPR instrument. This cost-effective and portable SPR biosensor based on smart phones has many applications, such as medicine, health and environmental monitoring.

  16. Surface Plasmon Resonance Biosensor Based on Smart Phone Platforms

    PubMed Central

    Liu, Yun; Liu, Qiang; Chen, Shimeng; Cheng, Fang; Wang, Hanqi; Peng, Wei

    2015-01-01

    We demonstrate a fiber optic surface plasmon resonance (SPR) biosensor based on smart phone platforms. The light-weight optical components and sensing element are connected by optical fibers on a phone case. This SPR adaptor can be conveniently installed or removed from smart phones. The measurement, control and reference channels are illuminated by the light entering the lead-in fibers from the phone’s LED flash, while the light from the end faces of the lead-out fibers is detected by the phone’s camera. The SPR-sensing element is fabricated by a light-guiding silica capillary that is stripped off its cladding and coated with 50-nm gold film. Utilizing a smart application to extract the light intensity information from the camera images, the light intensities of each channel are recorded every 0.5 s with refractive index (RI) changes. The performance of the smart phone-based SPR platform for accurate and repeatable measurements was evaluated by detecting different concentrations of antibody binding to a functionalized sensing element, and the experiment results were validated through contrast experiments with a commercial SPR instrument. This cost-effective and portable SPR biosensor based on smart phones has many applications, such as medicine, health and environmental monitoring. PMID:26255778

  17. Numerical simulation on development of a SAW based biosensor

    NASA Astrophysics Data System (ADS)

    Ten, S. T.; Hashim, U.; Sudin, A.; Arshad, M. K. Md.; Liu, W. W.; Foo, K. L.; Voon, C. H.; Wee, F. H.; Lee, Y. S.; Salleh, N. H. M.; Nazwa, T.

    2016-07-01

    Surface acoustic waves can be generated at the free surface of an elastic solid. For this property, surface acoustic based devices were initially developed for the telecommunication purpose such as signal filters and resonators. The acoustic energy is strongly confined on the surface of the surface acoustic waves (SAW) based devices and consequent their ultra-sensitivity to the surface perturbation. This has made SAW permits the highly sensitive detection of utterly diminutive charges on the surface. Hence, SAW based devices have been modified to be sensors for the mass loading effect on its surface and this is perfectly for biosensor development. There have been a lot of complicated theoretical models for the SAW devices development since 1960 as signal filters and resonators such as from delta function model, equivalent circuit model, to the current SAW models such as coupling-of-modes (COM) model, P-matrix model and Computer Simulation Technology Studio Suite (CST). However, these models are more tailored for the telecommunication application purposes and very complex. Thus, this paper presents the finite element analysis (FEA) modeling, COMSOL Multiphysics which is used to study the mass loading effect on SAW which will be used as biosensor. This study managed to simulate the mass loading sensitivity of 8.71×107 kHz/g mm-2.

  18. Human Neural Cell-Based Biosensor

    DTIC Science & Technology

    2011-10-11

    types have potential for being physiologically relevant in vitro models for botulinum toxin detection and neuron-glia interactions, respectively...unknown neurotoxicants. (5) We developed an immunoblot based method for detecting botulinum toxin using the mixed neuronal hN2™ cell line, thus creating...a first generation human cellular model for botulinum toxin detection – standard of comparison for existing and future models.neurotoxicity

  19. Development of Biosensors Based on Carbon Nanotube Nanoelectrode Arrays

    SciTech Connect

    Lin, Yuehe; Tu, Yi; Lu, Fang; Ren, Zhifeng

    2004-12-28

    The fabrication, electrochemical characterization, and sensing applications of low-site density carbon nanotubes based nanoelectrode arrays (CNT-NEAs) are reported in this work. Spin-coating of an epoxy resin provides a new way to create the electrode passivation layer that effectively reduces the current leakage and eliminates the electrode capacitance by sealing the side-wall of CNTs. The CNT-NEAs fabricated in our work effectively use the open ends of CNTs for electrochemical sensing. The open ends of the CNTs have fast electron transfer rates similar to a graphite edge-plane electrode, while the side-walls present very slow electron transfer rates similar to the graphitic basal plane. Cyclic voltammetry showed the sigmoidal shape curves with low capacitive current and scan-rate-independent limiting current. The successful development of a glucose biosensor based on CNT-NEAs for the selective detection of glucose is also described. Glucose oxidase was covalently immobilized on the CNTs tips via carbodiimide chemistry by forming amide linkages between the amine residues and carboxylic acid groups on the open ends of CNTs. The biosensor effectively performs selective electrochemical detections of glucose in the presence of common interferences.

  20. Photonic crystal waveguide-based biosensor for detection of diseases

    NASA Astrophysics Data System (ADS)

    Chopra, Harshita; Kaler, Rajinder S.; Painam, Balveer

    2016-07-01

    A biosensor is a device that is used to detect the analytes or molecules of a sample by means of a binding mechanism. A two-dimensional photonic crystal waveguide-based biosensor is designed with a diamond-shaped ring resonator and two waveguides: a bus waveguide and a drop waveguide. The sensing mechanism is based on change in refractive index of the analytes, leading to a shift in the peak resonant wavelength. This mechanism can be used in the field of biomedical treatment where different body fluids such as blood, tears, saliva, or urine can be used as the analyte in which different components of the fluid can be detected. It can also be used to differentiate between the cell lines of a normal and an unhealthy human being. Average value of quality factor for this device comes out to be 1082.2063. For different analytes used, the device exhibits enhanced sensitivity and, hence, it is useful for the detection of diseases.

  1. Micro-photonic cylindrical waveguide based protein biosensor

    NASA Astrophysics Data System (ADS)

    Padigi, Sudhaprasanna Kumar; Asante, Kofi; Sekhar Reddy Kovvuri, Vijay; Kiran Kondama Reddy, Ravi; La Rosa, Andres; Prasad, Shalini

    2006-09-01

    In this paper we experimentally demonstrate the fabrication and operation of a rapidly prototyped optical cylindrical micro-waveguide based biosensor. This device works on the principle of variation to the light intensity and path of coupled input light due to the binding of protein bio-molecules onto the micro-waveguide surface as a method of physical transduction. The variation to the coupled light intensity and path is dependent on the nature of the bio-molecule and the density of the bio-molecules. This technique has been used to identify protein biomarkers for inflammation and thrombosis, namely myeloperoxidase (MPO) and C-reactive protein (CRP). The detection limit that has been demonstrated is pg ml-1. The detection speed is of the order of seconds from the time of injection of the bio-molecule. The optical signature that is obtained to identify a protein bio-molecule is entirely dependent on the nature of adsorption of the bio-molecule on to the cylindrical cavity surfaces. This in turn is dependent on the protein conformation and the surface charge of the bio-molecules. Hence a specific protein bio-molecule generates a unique optical identifier based on the nature of binding/adsorption to the cavity surface. This physical phenomenon is exploited to identify individual proteins. This technique is a demonstration of detection of nano-scale protein bio-molecules using the optical biosensor technique with unprecedented sensitivity.

  2. Angle-resolved diffraction grating biosensor based on porous silicon

    NASA Astrophysics Data System (ADS)

    Lv, Changwu; Jia, Zhenhong; Liu, Yajun; Mo, Jiaqing; Li, Peng; Lv, Xiaoyi

    2016-03-01

    In this study, an optical biosensor based on a porous silicon composite structure was fabricated using a simple method. This structure consists of a thin, porous silicon surface diffraction grating and a one-dimensional porous silicon photonic crystal. An angle-resolved diffraction efficiency spectrum was obtained by measuring the diffraction efficiency at a range of incident angles. The angle-resolved diffraction efficiency of the 2nd and 3rd orders was studied experimentally and theoretically. The device was sensitive to the change of refractive index in the presence of a biomolecule indicated by the shift of the diffraction efficiency spectrum. The sensitivity of this sensor was investigated through use of an 8 base pair antifreeze protein DNA hybridization. The shifts of the angle-resolved diffraction efficiency spectrum showed a relationship with the change of the refractive index, and the detection limit of the biosensor reached 41.7 nM. This optical device is highly sensitive, inexpensive, and simple to fabricate. Using shifts in diffraction efficiency spectrum to detect biological molecules has not yet been explored, so this study establishes a foundation for future work.

  3. Waveguide-Based Biosensors for Pathogen Detection

    PubMed Central

    Mukundan, Harshini; Anderson, Aaron S.; Grace, W. Kevin; Grace, Karen M.; Hartman, Nile; Martinez, Jennifer S.; Swanson, Basil I.

    2009-01-01

    Optical phenomena such as fluorescence, phosphorescence, polarization, interference and non-linearity have been extensively used for biosensing applications. Optical waveguides (both planar and fiber-optic) are comprised of a material with high permittivity/high refractive index surrounded on all sides by materials with lower refractive indices, such as a substrate and the media to be sensed. This arrangement allows coupled light to propagate through the high refractive index waveguide by total internal reflection and generates an electromagnetic wave—the evanescent field—whose amplitude decreases exponentially as the distance from the surface increases. Excitation of fluorophores within the evanescent wave allows for sensitive detection while minimizing background fluorescence from complex, “dirty” biological samples. In this review, we will describe the basic principles, advantages and disadvantages of planar optical waveguide-based biodetection technologies. This discussion will include already commercialized technologies (e.g., Corning’s EPIC® Ô, SRU Biosystems’ BIND™, Zeptosense®, etc.) and new technologies that are under research and development. We will also review differing assay approaches for the detection of various biomolecules, as well as the thin-film coatings that are often required for waveguide functionalization and effective detection. Finally, we will discuss reverse-symmetry waveguides, resonant waveguide grating sensors and metal-clad leaky waveguides as alternative signal transducers in optical biosensing. PMID:22346727

  4. Graphene- and aptamer-based electrochemical biosensor.

    PubMed

    Xu, Ke; Meshik, Xenia; Nichols, Barbara M; Zakar, Eugene; Dutta, Mitra; Stroscio, Michael A

    2014-05-23

    This study investigated the effectiveness of a graphene- and aptamer-based field-effect-transistor-like (FET-like) sensor in detecting lead and potassium ions. The sensor consists of a graphene-covered Si/SiO2 wafer with thrombin binding aptamer (TBA) attached to the graphene layer and terminated by a methylene blue (MB) molecule. K(+) and Pb(2+) both bind to TBA and cause a conformational change, which results in MB moving closer to the graphene surface and donating an electron. Thus, the abundance of K(+) and Pb(2+) can be determined by monitoring the current across the source and drain channel. Device transfer curves were obtained with ambipolar field effect observed. Current readings were taken for K(+) concentrations of 100 μM to 50 mM and Pb(2+) concentrations of 10 μM to 10 mM. As expected, I d decreased as ion concentration increased. In addition, there was a negative shift in V Dirac in response to increased ion concentration.

  5. Graphene- and aptamer-based electrochemical biosensor

    NASA Astrophysics Data System (ADS)

    Xu, Ke; Meshik, Xenia; Nichols, Barbara M.; Zakar, Eugene; Dutta, Mitra; Stroscio, Michael A.

    2014-05-01

    This study investigated the effectiveness of a graphene- and aptamer-based field-effect-transistor-like (FET-like) sensor in detecting lead and potassium ions. The sensor consists of a graphene-covered Si/SiO2 wafer with thrombin binding aptamer (TBA) attached to the graphene layer and terminated by a methylene blue (MB) molecule. K+ and Pb2+ both bind to TBA and cause a conformational change, which results in MB moving closer to the graphene surface and donating an electron. Thus, the abundance of K+ and Pb2+ can be determined by monitoring the current across the source and drain channel. Device transfer curves were obtained with ambipolar field effect observed. Current readings were taken for K+ concentrations of 100 μM to 50 mM and Pb2+ concentrations of 10 μM to 10 mM. As expected, I d decreased as ion concentration increased. In addition, there was a negative shift in V Dirac in response to increased ion concentration.

  6. GMR-based PhC biosensor: FOM analysis and experimental studies

    SciTech Connect

    Syamprasad, Jagadeesh; Narayanan, Roshni; Joseph, Joby; Takahashi, Hiroki; Sandhu, Adarsh; Jindal, Rajeev

    2014-02-20

    Guided Mode Resonance based Photonic crystal biosensor has a lot of potential applications. In our work, we are trying to improve their figure of merit values in order to achieve an optimum level through design and fabrication techniques. A robust and low-cost alternative for current biosensors is also explored through this research.

  7. Benzophenone-based derivatives: a novel series of potent and selective dual inhibitors of acetylcholinesterase and acetylcholinesterase-induced beta-amyloid aggregation.

    PubMed

    Belluti, Federica; Bartolini, Manuela; Bottegoni, Giovanni; Bisi, Alessandra; Cavalli, Andrea; Andrisano, Vincenza; Rampa, Angela

    2011-05-01

    The leading mechanistic theory of Alzheimer's disease (AD) is the "amyloid hypothesis" which states that the accumulation of the amyloid β protein (Aβ), and its subsequent aggregation into plaques, is responsible for the initiation of a cascade of events resulting in neurodegeneration and dementia. The anti-amyloid disease-modifying approach, based on the decrease in the production of Aβ, gained thus a paramount importance. The aim of this study was the design and synthesis of a new series of acetylcholinesterase inhibitors (AChEIs) endowed with anti-Aβ aggregating capability. These dual binding inhibitors, being able to interact both with the peripheral anionic site (PAS) of AChE and the catalytic subsite, proved to be able to inhibit the AChE-induced Aβ aggregation. Thus, starting from the lead compound 1, an AChEI composed by a benzophenone scaffold and a N,N'-methylbenzylamino group, a substantial modification aimed at targeting the PAS was performed. To this aim, different amino-terminal side chains were incorporated into this main framework, in order to mimic the diethylmethylammonium alkyl moiety of the pure PAS ligand propidium. The synthesized compounds proved to effectively and selectively inhibit AChE. Moreover, compounds 16a-c and 18a,b, with a propoxy and a hexyloxy tether respectively, showed a good activity against the AChE-induced Aβ aggregation. In particular, molecular modeling studies confirmed that compounds carrying the diethylaminopropoxy and the diethylaminohexyloxy side chains (compounds 16a and 19a, respectively) could suitably contact the PAS pocket of the enzyme.

  8. NiO nanoparticle-based urea biosensor.

    PubMed

    Tyagi, Manisha; Tomar, Monika; Gupta, Vinay

    2013-03-15

    NiO nanoparticles (NiO-NPs) have been exploited successfully for the fabrication of a urea biosensor. A thin film of NiO nanoparticles deposited on an indium tin oxide (ITO) coated glass substrate serves as an efficient matrix for the immobilisation of urease (Ur), the specific enzyme for urea detection. The prepared bioelectrode (Ur/NiO-NP/ITO/glass) is utilised for urea sensing using cyclic voltammetry and UV-visible spectroscopy. NiO nanoparticles act as electro-catalytic species that are based on the shuttling of electrons between Ni(2+) and Ni(3+) in the octahedral site and result in an enhanced electrochemical current response. The prepared bioelectrode (Ur/NiO-NPs/ITO/glass) exhibits a high sensitivity of 21.3 μA/(mM (*) cm(2)) and a good linearity in a wide range (0.83-16.65 Mm) of urea concentrations with fast response time of 5s. The low value of the Michaelis-Menten constant (K(m)=0.34 mM) indicates the high affinity of Ur towards the analyte (urea). The high catalytic activity, along with the redox behaviour of NiO-NPs, makes it an efficient matrix for the realisation of a urea biosensor.

  9. A simple enzyme based biosensor on flexible plastic substrate

    NASA Astrophysics Data System (ADS)

    Kanakamedala, Senaka K.; Alshakhouri, Haidar T.; Agarwal, Mangilal; Fang, Ji; DeCoster, Mark A.

    2010-08-01

    An enzyme based biosensor was fabricated by employing a simple, inexpensive and rapid xurography fabrication process. The electrodes and channel were made from the conducting polymer poly(3,4-ethyelenedioxythiphene) poly(styrene sulfonate) (PEDOT:PSS). PEDOT:PSS was selectively deposited using a polyimide tape mask. The tape mask was peeled off from the substrate after annealing the polymer in vacuum. Polymer wells of defined dimensions were made and were attached to the device to accommodate the solutions. This sensor utilizes the change in current as a parameter to measure different analyte concentrations. Initial experiments were done by using the sensor for glucose detection. The sensor is able to detect the glucose concentrations approximately from 1 μM to 10 mM range covering glucose in human saliva (8-210 μM). The glucose oxidase activity was independently measured using colorimetric method and the results indicate that the sensor retains the enzyme activity and can be used as a biosensor to detect various analytes. The analyte of interest can be measured by preloading the corresponding enzyme into the wells.

  10. Electrochemical DNA biosensor based on the BDD nanograss array electrode

    PubMed Central

    2013-01-01

    Background The development of DNA biosensor has attracted considerable attention due to their potential applications, including gene analysis, clinical diagnostics, forensic study and more medical applications. Using electroactive daunomycin as an indicator, the hybridization detection was measured by differential pulse voltammetry in this study. Results Electrochemical DNA biosensor was developed based on the BDD film electrode (fBDD) and BDD nanograss array electrode (nBDD). In comparison with fBDD and AuNPs/CA/fBDD electrode, the lower semicircle diameter of electrochemical impedance spectroscopy obtained on nBDD and AuNPs/CA/nBDD electrode indicated that the presence of nanograss array improved the reactive site, reduced the interfacial resistance, and made the electron transfer easier. Using electroactive daunomycin as an indicator, the hybridization detection was measured by differential pulse voltammetry. Conclusions The experimental results demonstrated that the prepared AuNPs/CA/nBDD electrode was suitable for DNA hybridization with favorable performance of faster response, higher sensitivity, lower detection limit and satisfactory selectivity, reproducibility and stability. PMID:23575250

  11. Escherichia coli bacteria detection by using graphene-based biosensor.

    PubMed

    Akbari, Elnaz; Buntat, Zolkafle; Afroozeh, Abdolkarim; Zeinalinezhad, Alireza; Nikoukar, Ali

    2015-10-01

    Graphene is an allotrope of carbon with two-dimensional (2D) monolayer honeycombs. A larger detection area and higher sensitivity can be provided by graphene-based nanosenor because of its 2D structure. In addition, owing to its special characteristics, including electrical, optical and physical properties, graphene is known as a more suitable candidate compared to other materials used in the sensor application. A novel model employing a field-effect transistor structure using graphene is proposed and the current-voltage (I-V) characteristics of graphene are employed to model the sensing mechanism. This biosensor can detect Escherichia coli (E. coli) bacteria, providing high levels of sensitivity. It is observed that the graphene device experiences a drastic increase in conductance when exposed to E. coli bacteria at 0-10(5) cfu/ml concentration. The simple, fast response and high sensitivity of this nanoelectronic biosensor make it a suitable device in screening and functional studies of antibacterial drugs and an ideal high-throughput platform which can detect any pathogenic bacteria. Artificial neural network and support vector regression algorithms have also been used to provide other models for the I-V characteristic. A satisfactory agreement has been presented by comparison between the proposed models with the experimental data.

  12. Magnetite nanoparticles for biosensor model based on bacteria fluorescence

    NASA Astrophysics Data System (ADS)

    Poita, A.; Creanga, D.-E.; Airinei, A.; Tupu, P.; Goiceanu, C.; Avadanei, O.

    2009-06-01

    Fluorescence emission of pyoverdine - the siderophore synthesized by iron scavenger bacteria - was studied using in vitro cultures of Pseudomonas aeruginosa with the aim to design a biosensor system for liquid sample iron loading. Diluted suspensions of colloidal magnetite nanoparticles were supplied in the culture medium (10 microl/l and 100 microl/l) to simulate magnetic loading with iron oxides of either environmental waters or human body fluids. The electromagnetic exposure to radiofrequency waves of bacterial samples grown in the presence of magnetic nanoparticles was also carried out. Cell density diminution but fluorescence stimulation following 10 microl/l ferrofluid addition and simultaneous exposure to radiofrequency waves was evidenced. The inhibitory influence of 100 microl/l ferrofluid combined with RF exposure was evidenced by fluorescence data. Mathematical model was proposed to approach quantitatively the dynamics of cell density and fluorescence emission in relation with the consumption of magnetite nanoparticle supplied medium. The biosensor scheme was shaped based on the response to iron loading of bacterial sample fluorescence.

  13. Disposable amperometric biosensor based on nanostructured bacteriophages for glucose detection

    NASA Astrophysics Data System (ADS)

    Kang, Yu Ri; Hwang, Kyung Hoon; Kim, Ju Hwan; Nam, Chang Hoon; Kim, Soo Won

    2010-10-01

    The selection of electrode material profoundly influences biosensor science and engineering, as it heavily influences biosensor sensitivity. Here we propose a novel electrochemical detection method using a working electrode consisting of bio-nanowires from genetically modified filamentous phages and nanoparticles. fd-tet p8MMM filamentous phages displaying a three-methionine (MMM) peptide on the major coat protein pVIII (designated p8MMM phages) were immobilized on the active area of an electrochemical sensor through physical adsorption and chemical bonding. Bio-nanowires composed of p8MMM phages and silver nanoparticles facilitated sensitive, rapid and selective detection of particular molecules. We explored whether the composite electrode with bio-nanowires was an effective platform to detect the glucose oxidase. The current response of the bio-nanowire sensor was high at various glucose concentrations (0.1 µm-0.1 mM). This method provides a considerable advantage to demonstrate analyte detection over low concentration ranges. Especially, phage-enabled bio-nanowires can serve as receptors with high affinity and specificity for the detection of particular biomolecules and provide a convenient platform for designing site-directed multifunctional scaffolds based on bacteriophages and may serve as a simple method for label-free detection.

  14. Surface plasmon resonance based biosensor technique: a review.

    PubMed

    Guo, Xiaowei

    2012-07-01

    Optical Surface plasmon resonance (SPR) biosensors represent the most advanced and developed optical label-free biosensor technology. Optical SPR biosensors are a powerful detection and analysis tool that has vast applications in environmental protection, biotechnology, medical diagnostics, drug screening, food safety and security. This article reviews the recent development of SPR biosensor techniques, including bulk SPR and localized SPR (LSPR) biosensors, for detecting interactions between an analyte of interest in solution and a biomolecular recognition. The concepts of bulk and localized SPs and the working principles of both sensing techniques are introduced. Major sensing advances on biorecognition elements, measurement formats, and sensing platforms are presented. Finally, the discussions on both biosensor techniques as well as comparison of both SPR sensing techniques are made.

  15. Recent approaches to improving selectivity and sensitivity of enzyme-based biosensors for organophosphorus pesticides: A review.

    PubMed

    Songa, Everlyne A; Okonkwo, Jonathan O

    2016-08-01

    Pesticide determination has attracted great attention due to the fact that they exhibit high acute toxicity and can cause long-term damage to the environment and human lives even at trace levels. Although classical analytical methods (including gas chromatography, high performance liquid chromatography, capillary electrophoresis and mass spectrometry) have been effectively used for analysis of pesticides in contaminated samples, they present certain limitations such as time-consuming sample preparation, complexity, and the requirement of expensive instrumentation and highly skilled personnel. For these reasons, there is an expanding need for analytical methods able to provide simple, rapid, sensitive, selective, low cost and reliable detection of pesticides at trace levels. Over the past decades, acetylcholinesterase (AChE) biosensors have emerged as simple, rapid and ultra-sensitive tools for toxicity detection of pesticides in the environment and food. These biosensors have the potential to complement or replace the classical analytical methods by simplifying or eliminating sample preparation and making field-testing easier and faster with significant decrease in cost per analysis. With the recent engineering of more sensitive AChE enzymes, the development of more reliable immobilization matrices and the progress in the area of microelectronics, AChE biosensors could become competitive for multi-analyte screening and soon be used for the development of portable instrumentation for rapid toxicity testing of samples. The enzymes organophosphorus hydrolase (OPH) and organophosphorus acid anhydrolase (OPAA) have also shown considerable potential in OP biosensor applications and they have been used for direct detection of OPs. This review presents the recent advances in the fabrication of enzyme biosensors for organophosphorus pesticides (OPs) and their possible applications for toxicity monitoring of organophosphorus pesticide residues in real samples. The focus will

  16. Possibility of Acetylcholinesterase Overexpression in Alzheimer Disease Patients after Therapy with Acetylcholinesterase Inhibitors.

    PubMed

    Kračmarová, Alžběta; Drtinová, Lucie; Pohanka, Miroslav

    2015-01-01

    Acetylcholinesterase is an enzyme responsible for termination of excitatory transmission at cholinergic synapses by the hydrolyzing of a neurotransmitter acetylcholine. Nowadays, other functions of acetylcholinesterase in the organism are considered, for example its role in regulation of apoptosis. Cholinergic nervous system as well as acetylcholinesterase activity is closely related to pathogenesis of Alzheimer disease. The mostly used therapy of Alzheimer disease is based on enhancing cholinergic function using inhibitors of acetylcholinesterase like rivastigmine, donepezil or galantamine. These drugs can influence not only the acetylcholinesterase activity but also other processes in treated organism. The paper is aimed mainly on possibility of increased expression and protein level of acetylcholinesterase caused by the therapy with acetylcholinesterase inhibitors.

  17. Structure-based 3D QSAR and design of novel acetylcholinesterase inhibitors

    NASA Astrophysics Data System (ADS)

    Sippl, Wolfgang; Contreras, Jean-Marie; Parrot, Isabelle; Rival, Yveline M.; Wermuth, Camille G.

    2001-05-01

    The paper describes the construction, validation and application of a structure-based 3D QSAR model of novel acetylcholinesterase (AChE) inhibitors. Initial use was made of four X-ray structures of AChE complexed with small, non-specific inhibitors to create a model of the binding of recently developed aminopyridazine derivatives. Combined automated and manual docking methods were applied to dock the co-crystallized inhibitors into the binding pocket. Validation of the modelling process was achieved by comparing the predicted enzyme-bound conformation with the known conformation in the X-ray structure. The successful prediction of the binding conformation of the known inhibitors gave confidence that we could use our model to evaluate the binding conformation of the aminopyridazine compounds. The alignment of 42 aminopyridazine compounds derived by the docking procedure was taken as the basis for a 3D QSAR analysis applying the GRID/GOLPE method. A model of high quality was obtained using the GRID water probe, as confirmed by the cross-validation method (q2 LOO=0.937, q2 L50% O=0.910). The validated model, together with the information obtained from the calculated AChE-inhibitor complexes, were considered for the design of novel compounds. Seven designed inhibitors which were synthesized and tested were shown to be highly active. After performing our modelling study the X-ray structure of AChE complexed with donepezil, an inhibitor structurally related to the developed aminopyirdazines, has been made available. The good agreement found between the predicted binding conformation of the aminopyridazines and the one observed for donepezil in the crystal structure further supports our developed model.

  18. Light-emission-based biosensor for detection of food pathogens: a review

    NASA Astrophysics Data System (ADS)

    Singh, Ashutosh; Singh, Rakesh K.; Bhunia, Arun K.

    2001-03-01

    Rapid detection, identification and enumeration of pathogenic microorganisms is highly important to the food industry to address the food safety concerns. Biosensors are devices that promise to achieve these objectives, these analytical devices can accurately and selectively estimate the levels of foodborne pathogens. The most widely applied biosensors are based on the optical properties like absorption, fluorescence, reflection, refraction, dispersion etc. This review is done to provide an overview of optic based biosensor and their application in the area of food safety. Working principles of Surface plasmon resonance , resonant mirror and fiber optic based biosensor are described in the article. Resonant mirror based biosensor has been used for the estimation of S. aureus, it was proven selective for the strain being tested (Cowan-1). The sensitivity of the assay was increased by using colloidal-gold conjugates in sandwich assay format. An integrated fiber optic based biosensor is used for detection of Salmonella typhimurium reducing the detection time to 30 min. Fiber optic based biosensors offer advantage of compactness, flexibility , resistance to electrical noise and small probe size.

  19. A novel conductometric biosensor based on hexokinase for determination of adenosine triphosphate.

    PubMed

    Kucherenko, I S; Kucherenko, D Yu; Soldatkin, O O; Lagarde, F; Dzyadevych, S V; Soldatkin, A P

    2016-04-01

    The paper presents a simple and inexpensive reusable biosensor for determination of the concentration of adenosine-5'-triphosphate (ATP) in aqueous samples. The biosensor is based on a conductometric transducer which contains two pairs of gold interdigitated electrodes. An enzyme hexokinase was immobilized onto one pair of electrodes, and bovine serum albumin-onto another pair (thus, a differential mode of measurement was used). Conditions of hexokinase immobilization on the transducer by cross-linking via glutaraldehyde were optimized. Influence of experimental conditions (concentration of magnesium ions, ionic strength and concentration of the working buffer) on the biosensor work was studied. The reproducibility of biosensor responses and operational stability of the biosensor were checked during one week. Dry storage at -18 °C was shown to be the best conditions to store the biosensor. The biosensor was successfully applied for measurements of ATP concentration in pharmaceutical samples. The proposed biosensor may be used in future for determination of ATP and/or glucose in water samples.

  20. Amperometric biosensor based on diamond paste for the enantioanalysis of L-lysine.

    PubMed

    Stefan-van Staden, Raluca-Ioana; Nejem, R'afat Mahmoud; van Staden, Jacobus Frederick; Aboul-Enein, Hassan Y

    2012-05-15

    An amperometric biosensor was proposed for the enantioanalysis of L-lysine. The biosensor is based on the impregnation of L-lysine oxidase in diamond paste. The potential used for the determination of l-lysine was 650 mV. The biosensor exhibited a linear concentration range between 1 and 100 nmol/L with a limit of detection of 4 pmol/L. The selectivity of the biosensor is high over other amino acids, such as L-serine, L-leucine, L-aspartic acid, L-glutamic acid, histamine, glycine. The proposed biosensor can be applied for the determination of L-lysine in serum samples and pharmaceutical compounds.

  1. Microbial fuel cell-based biosensors for environmental monitoring: a review.

    PubMed

    Sun, Jian-Zhong; Peter Kingori, Gakai; Si, Rong-Wei; Zhai, Dan-Dan; Liao, Zhi-Hong; Sun, De-Zhen; Zheng, Tao; Yong, Yang-Chun

    2015-01-01

    The microbial fuel cell (MFC) is an innovative technology that was initially designed to harness energy from organic waste using microorganisms. It is striking how many promising applications beyond energy production have been explored in recent decades. In particular, MFC-based biosensors are considered to be the next generation biosensing technology for environmental monitoring. This review describes recent advances in this emerging technology of MFC-based biosensors, with a special emphasis on monitoring of biochemical oxygen demand and toxicity in the environment. The progress confirms that MFC-based biosensors could be used as self-powered portable biosensing devices with great potential in long-term and remote environmental monitoring.

  2. Diagnosis of Dengue Infection Using Conventional and Biosensor Based Techniques

    PubMed Central

    Parkash, Om; Hanim Shueb, Rafidah

    2015-01-01

    Dengue is an arthropod-borne viral disease caused by four antigenically different serotypes of dengue virus. This disease is considered as a major public health concern around the world. Currently, there is no licensed vaccine or antiviral drug available for the prevention and treatment of dengue disease. Moreover, clinical features of dengue are indistinguishable from other infectious diseases such as malaria, chikungunya, rickettsia and leptospira. Therefore, prompt and accurate laboratory diagnostic test is urgently required for disease confirmation and patient triage. The traditional diagnostic techniques for the dengue virus are viral detection in cell culture, serological testing, and RNA amplification using reverse transcriptase PCR. This paper discusses the conventional laboratory methods used for the diagnosis of dengue during the acute and convalescent phase and highlights the advantages and limitations of these routine laboratory tests. Subsequently, the biosensor based assays developed using various transducers for the detection of dengue are also reviewed. PMID:26492265

  3. Mammalian cell-based biosensors for pathogens and toxins.

    PubMed

    Banerjee, Pratik; Bhunia, Arun K

    2009-03-01

    Cell-based biosensors (CBBs) have emerged as powerful functional tools for the rapid detection of hazards and threats associated with food, agriculture, environment and biosecurity. CBBs detect the functional aspects of a host-hazard interaction and render an accurate estimation of the risks. Assessing hazard-induced physiological responses, such as receptor-ligand interactions, signal transduction, gene expression, membrane damage, apoptosis and oncosis of living sensing organisms can provide insight into the basis of toxicity for a particular hazard. This review highlights the progress made in developing mammalian CBBs for pathogens and toxins, with special emphasis on multidisciplinary approaches that combine molecular biology and microbiology with methods used in physics and engineering, which led to the development of a three-dimensional cell-culture system and high-throughput screening employing optical and electrical systems.

  4. Ultrasensitive electrochemical cocaine biosensor based on reversible DNA nanostructure.

    PubMed

    Sheng, Qinglin; Liu, Ruixiao; Zhang, Sai; Zheng, Jianbin

    2014-01-15

    We proposed an ultrasensitive electrochemical cocaine biosensor based on the three-dimensional (3D) DNA structure conversion of nanostructure from Triangular Pyramid Frustum (TPFDNA) to Equilateral Triangle (ETDNA). The presence of cocaine triggered the aptamer-composed DNA nanostructure change from "Close" to "Open", leading to obvious faradaic impedance changes. The unique properties with excellent stability and specific rigid structure of the 3D DNA nanostructure made the biosensing functions stable, sensitive, and regenerable. The Faradaic impedance responses were linearly related to cocaine concentration between 1.0 nM and 2.0 μM with a correlation coefficient of 0.993. The limit of detection was calculated to be 0.21 nM following IUPAC recommendations (3Sb/b). It is expected that the distinctive features of DNA nanostructure would make it potentially advantageous for a broad range of biosensing, bionanoelectronics, and therapeutic applications.

  5. Nanocoax-based molecular imprint polymer for electrochemical biosensor

    NASA Astrophysics Data System (ADS)

    Rizal, Binod; Archibald, Michelle; Simko, Laura; Connolly, Timothy; Shepard, Stephen; Burns, Michael; Chiles, Thomas; Naughton, Michael

    2013-03-01

    We have used molecular imprint polymerization (MIP) on planar, nanopillar, and nanocoax structures to fabricate label-free, all-electronic electrochemical biosensors with high selectivity and sensitivity. MIP-based films of ~ 7 nm thickness are formed on gold-coated surfaces by electropolymerization of a solution containing phenol and a target protein (streptavidin, at 100 μg/ml, or 1 nanomole concentration) and subsequent removal of exposed target protein, leaving behind its molecular imprint. With its molecular memory, MIP subsequently specifically recognizes and binds target protein with attomolar sensitivity, detected via differential pulse voltammetry. We will discuss and compare the results of MIP for different proteins on planar, nanopillar, and nanocoax structures, along with their respective ultimate sensitivities. Supported by the NIH grants NCI CA137681 and NIAID AI100216.

  6. Hydrodynamic focusing of conducting fluids for conductivity-based biosensors.

    PubMed

    Nasir, Mansoor; Ateya, Daniel A; Burk, Diana; Golden, Joel P; Ligler, Frances S

    2010-02-15

    Hydrodynamic focusing of a conducting fluid by a non-conducting fluid to form a constricted current path between two sensing electrodes is implemented in order to enhance the sensitivity of a 4-electrode conductance-based biosensor. The sensor has a simple two-inlet T-junction design and performs four-point conductivity measurements to detect particles immobilized between the sensing electrode pair. Computational simulations conducted in conjunction with experimental flow studies using confocal microscopy show that a flat profile for the focused layer is dependent on the Reynolds number for the chosen flow parameters. The results also indicate that a flat focused layer is desirable for both increased sensitivity as well as surface-binding efficiency. Proof of concept for conductance measurements in a hydrodynamically focused conducting fluid was demonstrated with entrapped magnetic beads.

  7. Analysis of an integrated optic micro racetrack resonator based biosensor

    NASA Astrophysics Data System (ADS)

    Malathi, S.; Hegde, Gopalkrishna; Srinivas, T.; Roy, Ugra M.

    2014-06-01

    Silicon-On- Insulator (SOI) technology has huge potential in fabricating compact devices for various applications such as integrated optic waveguides, directional couplers, resonators etc. In this work, we present the analysis of a biosensor based on an integrated optic racetrack resonator, interrogated by a bus waveguide. The biomaterial is applied as a cladding layer. Here we analyze the coupling between the resonator and the bus waveguide, and its dependence on the bio layer. In traditional analysis, the effective refractive index and resonator total path length are the factors influencing the resonant wavelength. Our analysis shows that all parametric values decrease with increase in waveguide width and spacing. The inclusion of waveguide mode overlap and perturbation in coupled mode equation results in enhanced resonator sensitivity of an order of magnitude

  8. Diagnosis of Dengue Infection Using Conventional and Biosensor Based Techniques.

    PubMed

    Parkash, Om; Shueb, Rafidah Hanim

    2015-10-19

    Dengue is an arthropod-borne viral disease caused by four antigenically different serotypes of dengue virus. This disease is considered as a major public health concern around the world. Currently, there is no licensed vaccine or antiviral drug available for the prevention and treatment of dengue disease. Moreover, clinical features of dengue are indistinguishable from other infectious diseases such as malaria, chikungunya, rickettsia and leptospira. Therefore, prompt and accurate laboratory diagnostic test is urgently required for disease confirmation and patient triage. The traditional diagnostic techniques for the dengue virus are viral detection in cell culture, serological testing, and RNA amplification using reverse transcriptase PCR. This paper discusses the conventional laboratory methods used for the diagnosis of dengue during the acute and convalescent phase and highlights the advantages and limitations of these routine laboratory tests. Subsequently, the biosensor based assays developed using various transducers for the detection of dengue are also reviewed.

  9. Toxin detection using a fiber-optic-based biosensor

    NASA Astrophysics Data System (ADS)

    Ogert, Robert A.; Shriver-Lake, Lisa C.; Ligler, Frances S.

    1993-05-01

    Using an evanescent wave fiber optic-based biosensor developed at Naval Research Laboratory, ricin toxin can be detected in the low ng/ml range. Sensitivity was established at 1 - 5 ng/ml using a two-step assay. The two-step assay showed enhanced signal levels in comparison to a one-step assay. A two-step assay utilizes a 10 minute incubation of an immobilized affinity purified anti-ricin antibody fiber optic probe in the ricin sample before placement in a solution of fluorophore-labeled goat anti-ricin antibodies. The specific fluorescent signal is obtained by the binding of the fluorophore-labeled antibodies to ricin which is bound by the immobilized antibodies on the fiber optic probe. The toxin can be detected directly from urine and river water using this fiber optic assay.

  10. Occupational exposure limits for 30 organophosphate pesticides based on inhibition of red blood cell acetylcholinesterase.

    PubMed

    Storm, J E; Rozman, K K; Doull, J

    2000-09-07

    Toxicity and other relevant data for 30 organophosphate pesticides were evaluated to suggest inhalation occupational exposure limits (OELs), and to support development of a risk assessment strategy for organophosphates in general. Specifically, the value of relative potency analysis and the predictability of inhalation OELs by acute toxicity measures and by repeated oral exposure NOELs was assessed. Suggested OELs are based on the prevention of red blood cell (RBC) acetylcholinesterase (AChE) inhibition and are derived using a weight-of-evidence risk assessment approach. Suggested OEL values range from 0.002 to 2 mg/m(3), and in most cases, are less than current permissible exposure levels (PELs) or threshold limit values(R) (TLVs(R)). The available data indicate that experimental data for most organophosphates evaluated are limited; most organophosphates are equally potent RBC AChE inhibitors in different mammalian species; NOELs from repeated exposure studies of variable duration are usually equivalent; and, no particular grouping based on organophosphate structure is consistently more potent than another. Further, relative potency analyses have limited usefulness in the risk assessment of organophosphates. The data also indicated that equivalent relative potency relationships do not exist across either exposure duration (acute vs. repeated) or exposure route (oral vs. inhalation). Consideration of all variable duration and exposure route studies are therefore usually desirable in the development of an OEL, especially when data are limited. Also, neither acute measures of toxicity nor repeated oral exposure NOELs are predictive of weight-of-evidence based inhalation OELs. These deviations from what is expected based on the common mechanism of action for organophosphates across exposure duration and route - AChE inhibition - is likely due to the lack of synchrony between the timing of target tissue effective dose and the experimental observation of equivalent

  11. Putrescine biosensor based on putrescine oxidase from Kocuria rosea.

    PubMed

    Bóka, Beáta; Adányi, Nóra; Szamos, Jenő; Virág, Diána; Kiss, Attila

    2012-10-10

    The novel putrescine oxidase based amperometric biosensor selectively measures putrescine, which can be considered as an indicator of microbial spoilage. Putrescine oxidase (PUOX, EC 1.4.3.10) was isolated from Kocuria rosea (Micrococcus rubens) by an improved and simplified purification process. Cells were grown on brain heart infusion medium supplemented with putrescine. Cell-free extract was prepared in Tris buffer (pH 8.0) by Bead-beater. A newly elaborated step based on three-phase partitioning (TPP) was applied in the purification protocol of PUOX. The purified enzyme was immobilized on the surface of a spectroscopic graphite electrode in redox hydrogel with horseradish peroxidase, Os mediator and poly(ethylene glycol) (400) diglycidyl ether (PEGDGE) as crosslinking agent. This modified working electrode was used in wall-jet type amperometric cell together with the Ag/AgCl (0.1M KCl) reference electrode and a platinum wire as auxiliary electrode in flow injection analysis system (FIA). Hydrogel composition, pH and potential dependence were studied. Optimal working conditions were 0.45 mLmin(-1) flow rate of phosphate buffer (66 mM, pH 8.0) and +50 mV polarizing potential vs. Ag/AgCl. The linear measuring range of the method was 0.01-0.25 mM putrescine, while the detection limit was 5 μM. Beer samples were investigated by the putrescine biosensor and the results were compared by those of HPLC reference method.

  12. Function-based Biosensor for Hazardous Waste Toxin Detection

    SciTech Connect

    James J Hickman

    2008-07-09

    There is a need for new types of toxicity sensors in the DOE and other agencies that are based on biological function as the toxins encountered during decontamination or waste remediation may be previously unknown or their effects subtle. Many times the contents of the environmental waste, especially the minor components, have not been fully identified and characterized. New sensors of this type could target unknown toxins that cause death as well as intermediate levels of toxicity that impair function or cause long term impairment that may eventually lead to death. The primary question posed in this grant was to create an electronically coupled neuronal cellular circuit to be used as sensor elements for a hybrid non-biological/biological toxin sensor system. A sensor based on the electrical signals transmitted between two mammalian neurons would allow the marriage of advances in solid state electronics with a functioning biological system to develop a new type of biosensor. Sensors of this type would be a unique addition to the field of sensor technology but would also be complementary to existing sensor technology that depends on knowledge of what is to be detected beforehand. We integrated physics, electronics, surface chemistry, biotechnology, and fundamental neuroscience in the development of this biosensor. Methods were developed to create artificial surfaces that enabled the patterning of discrete cells, and networks of cells, in culture; the networks were then aligned with transducers. The transducers were designed to measure electromagnetic fields (EMF) at low field strength. We have achieved all of the primary goals of the project. We can now pattern neurons routinely in our labs as well as align them with transducers. We have also shown the signals between neurons can be modulated by different biochemicals. In addition, we have made another significant advance where we have repeated the patterning results with adult hippocampal cells. Finally, we

  13. Nanoelectrode and nanoparticle based biosensors for environmental and health monitoring

    NASA Astrophysics Data System (ADS)

    Syed, Lateef Uddin

    Reduction in electrode size down to nanometers dramatically enhances the detection sensitivity and temporal resolution. Here we explore nanoelectrode arrays (NEAs) and nanoparticles in building high performance biosensors. Vertically aligned carbon nanofibers (VACNFs) of diameter ˜100 nm were grown on a Si substrate using plasma enhanced chemical vapor deposition. SiO2 embedded CNF NEAs were then fabricated using techniques like chemical vapor deposition, mechanical polishing, and reactive ion etching, with CNF tips exposed at the final step. The effect of the interior structure of CNFs on electron transfer rate (ETR) was investigated by covalently attaching ferrocene molecules to the exposed end of CNFs. Anomalous differences in the ETR were observed between DC voltammetry (DCV) and AC voltammetry (ACV). The findings from this study are currently being extended to develop an electrochemical biosensor for the detection of cancerous protease (legumain). Preliminary results with standard macro glassy carbon electrodes show a significant decrease in ACV signal, which is encouraging. In another study, NEA was employed to capture and detect pathogenic bacteria using AC dielectrophoresis (DEP) and electrochemical impedance spectroscopy (EIS). A nano-DEP device was fabricated using photolithography processes to define a micro patterned exposed active region on NEA and a microfluidic channel on macro-indium tin oxide electrode. Enhanced electric field gradient at the exposed CNF tips was achieved due to the nanometer size of the electrodes, because of which each individual exposed tip can act as a potential DEP trap to capture the pathogen. Significant decrease in the absolute impedance at the NEA was also observed by EIS experiments. In a final study, we modified gold nanoparticles (GNPs) with luminol to develop chemiluminescence (CL) based blood biosensor. Modified GNPs were characterized by UV-Vis, IR spectroscopy and TEM. We have applied this CL method for the

  14. Biosensors based on enzyme field-effect transistors for determination of some substrates and inhibitors.

    PubMed

    Dzyadevych, Sergei V; Soldatkin, Alexey P; Korpan, Yaroslav I; Arkhypova, Valentyna N; El'skaya, Anna V; Chovelon, Jean-Marc; Martelet, Claude; Jaffrezic-Renault, Nicole

    2003-10-01

    This paper is a review of the authors' publications concerning the development of biosensors based on enzyme field-effect transistors (ENFETs) for direct substrates or inhibitors analysis. Such biosensors were designed by using immobilised enzymes and ion-selective field-effect transistors (ISFETs). Highly specific, sensitive, simple, fast and cheap determination of different substances renders them as promising tools in medicine, biotechnology, environmental control, agriculture and the food industry. The biosensors based on ENFETs and direct enzyme analysis for determination of concentrations of different substrates (glucose, urea, penicillin, formaldehyde, creatinine, etc.) have been developed and their laboratory prototypes were fabricated. Improvement of the analytical characteristics of such biosensors may be achieved by using a differential mode of measurement, working solutions with different buffer concentrations and specific agents, negatively or positively charged additional membranes, or genetically modified enzymes. These approaches allow one to decrease the effect of the buffer capacity influence on the sensor response in an aim to increase the sensitivity of the biosensors and to extend their dynamic ranges. Biosensors for the determination of concentrations of different toxic substances (organophosphorous pesticides, heavy metal ions, hypochlorite, glycoalkaloids, etc.) were designed on the basis of reversible and/or irreversible enzyme inhibition effect(s). The conception of an enzymatic multibiosensor for the determination of different toxic substances based on the enzyme inhibition effect is also described. We will discuss the respective advantages and disadvantages of biosensors based on the ENFETs developed and also demonstrate their practical application.

  15. Bi nanowire-based thermal biosensor for the detection of salivary cortisol using the Thomson effect

    NASA Astrophysics Data System (ADS)

    Lee, Seunghyun; Hyun Lee, Jung; Kim, MinGin; Kim, Jeongmin; Song, Min-Jung; Jung, Hyo-Il; Lee, Wooyoung

    2013-09-01

    We present a study of a thermal biosensor based on bismuth nanowire that is fabricated for the detection of the human stress hormone cortisol using the Thomson effect. The Bi nanowire was grown using the On-Film Formation of Nanowires (OFF-ON) method. The thermal device was fabricated using photolithography, and the sensing area was modified with immobilized anti-cortisol antibodies conjugated with protein G for the detection of cortisol. The voltages were measured with two probe tips during surface modification to investigate the biochemical reactions in the fabricated thermal biosensor. The Bi nanowire-based thermal biosensor exhibited low detection limit and good selectivity for the detection of cortisol.

  16. Optical detection of sepsis markers using liquid crystal based biosensors

    NASA Astrophysics Data System (ADS)

    McCamley, Maureen K.; Artenstein, Andrew W.; Opal, Steven M.; Crawford, Gregory P.

    2007-02-01

    A liquid crystal based biosensor for the detection and diagnosis of sepsis is currently in development. Sepsis, a major clinical syndrome with a significant public health burden in the US due to a large elderly population, is the systemic response of the body to a localized infection and is defined as the combination of pathologic infection and physiological changes. Bacterial infections are responsible for 90% of cases of sepsis in the US. Currently there is no bedside diagnostic available to positively identify sepsis. The basic detection scheme employed in a liquid crystal biosensor contains attributes that would find value in a clinical setting, especially for the early detection of sepsis. Utilizing the unique properties of liquid crystals, such as birefringence, a bedside diagnostic is in development which will optically report the presence of biomolecules. In a septic patient, an endotoxin known as lipopolysaccharide (LPS) is released from the outer membrane of Gram-negative bacteria and can be found in the blood stream. It is hypothesized that this long chained molecule will cause local disruptions to the open surface of a sensor containing aligned liquid crystal. The bulk liquid crystal ampli.es these local changes at the surface due to the presence of the sepsis marker, providing an optical readout through polarizing microscopy images. Liquid crystal sensors consisting of both square and circular grids, 100-200 μm in size, have been fabricated and filled with a common liquid crystal material, 5CB. Homeotropic alignment was confirmed using polarizing microscopy. The grids were then contacted with either saline only (control), or saline with varying concentrations of LPS. Changes in the con.guration of the nematic director of the liquid crystal were observed through the range of concentrations tested (5mg/mL - 1pg/mL) which have been confirmed by a consulting physician as clinically relevant levels.

  17. Fluorescent Biosensor for Phosphate Determination Based on Immobilized Polyfluorene-Liposomal Nanoparticles Coupled with Alkaline Phosphatase.

    PubMed

    Kahveci, Zehra; Martínez-Tomé, Maria José; Mallavia, Ricardo; Mateo, C Reyes

    2017-01-11

    This work describes the development of a novel fluorescent biosensor based on the inhibition of alkaline phosphatase (ALP). The biosensor is composed of the enzyme ALP and the conjugated cationic polyfluorene HTMA-PFP. The working principle of the biosensor is based on the fluorescence quenching of this polyelectrolyte by p-nitrophenol (PNP), a product of the hydrolysis reaction of p-nitrophenyl phosphate (PNPP) catalyzed by ALP. Because HTMA-PFP forms unstable aggregates in buffer, with low fluorescence efficiency, previous stabilization of the polyelectrolyte was required before the development of the biosensor. HTMA-PFP was stabilized through its interaction with lipid vesicles to obtain stable blue-emitting nanoparticles (NPs). Fluorescent NPs were characterized, and the ability to be quenched by PNP was evaluated. These nanoparticles were coupled to ALP and entrapped in a sol-gel matrix to produce a biosensor that can serve as a screening platform to identify ALP inhibitors. The components of the biosensor were examined before and after sol-gel entrapment, and the biosensor was optimized to allow the determination of phosphate ion in aqueous medium.

  18. Nanomaterials-based enzyme electrochemical biosensors operating through inhibition for biosensing applications.

    PubMed

    Kurbanoglu, Sevinc; Ozkan, Sibel A; Merkoçi, Arben

    2017-03-15

    In recent years great progress has been made in applying nanomaterials to design novel biosensors. Use of nanomaterials offers to biosensing platforms exceptional optical, electronic and magnetic properties. Nanomaterials can increase the surface of the transducing area of the sensors that in turn bring an increase in catalytic behaviors. They have large surface-to-volume ratio, controlled morphology and structure that also favor miniaturization, an interesting advantage when the sample volume is a critical issue. Biosensors have great potential for achieving detect-to-protect devices: devices that can be used in detections of pollutants and other treating compounds/analytes (drugs) protecting citizens' life. After a long term focused scientific and financial efforts/supports biosensors are expected now to fulfill their promise such as being able to perform sampling and analysis of complex samples with interest for clinical or environment fields. Among all types of biosensors, enzymatic biosensors, the most explored biosensing devices, have an interesting property, the inherent inhibition phenomena given the enzyme-substrate complex formation. The exploration of such phenomena is making remarkably important their application as research and applied tools in diagnostics. Different inhibition biosensor systems based on nanomaterials modification has been proposed and applied. The role of nanomaterials in inhibition-based biosensors for the analyses of different groups of drugs as well as contaminants such as pesticides, phenolic compounds and others, are discussed in this review. This deep analysis of inhibition-based biosensors that employ nanomaterials will serve researchers as a guideline for further improvements and approaching of these devices to real sample applications so as to reach society needs and such biosensor market demands.

  19. A Bioanalytical Chemistry Experiment for Undergraduate Students: Biosensors Based on Metal Nanoparticles

    ERIC Educational Resources Information Center

    Niagi, John; Warner, John; Andreesco, Silvana

    2007-01-01

    The study describes the development of new biosensors based on metal nanoparticles because of its high surface area and large binding ability. The adopted procedure is extremely simple and versatile and can be used in various applications of electrochemistry.

  20. Oligonucleotide-based biosensors for in vitro diagnostics and environmental hazard detection.

    PubMed

    Jung, Il Young; Lee, Eun Hee; Suh, Ah Young; Lee, Seung Jin; Lee, Hyukjin

    2016-04-01

    Oligonucleotide-based biosensors have drawn much attention because of their broad applications in in vitro diagnostics and environmental hazard detection. They are particularly of interest to many researchers because of their high specificity as well as excellent sensitivity. Recently, oligonucleotide-based biosensors have been used to achieve not only genetic detection of targets but also the detection of small molecules, peptides, and proteins. This has further broadened the applications of these sensors in the medical and health care industry. In this review, we highlight various examples of oligonucleotide-based biosensors for the detection of diseases, drugs, and environmentally hazardous chemicals. Each example is provided with detailed schematics of the detection mechanism in addition to the supporting experimental results. Furthermore, future perspectives and new challenges in oligonucleotide-based biosensors are discussed.

  1. Electrochemical and optical biosensors based on nanomaterials and nanostructures: a review.

    PubMed

    Li, Ming; Li, Rui; Li, Chang Ming; Wu, Nianqiang

    2011-06-01

    Nanomaterials and nanostructures exhibit unique size-tunable and shape-dependent physicochemical properties that are different from those of bulk materials. Advances of nanomaterials and nanostructures open a new door to develop various novel biosensors. The present work has reviewed the recent progress in electrochemical, surface plasmon resonance (SPR), surface-enhanced Raman scattering (SERS) and fluorescent biosensors based on nanomaterials and nanostructures. An emphasis is put on the research that demonstrates how the performance of biosensors such as the limit of detection, sensitivity and selectivity is improved by the use of nanomaterials and nanostructures.

  2. Immune biosensors based on the SPR and TIRE: efficiency of their application for bacteria determination

    NASA Astrophysics Data System (ADS)

    Starodub, N. F.; Ogorodniichuk, J.; Lebedeva, T.; Shpylovyy, P.

    2013-11-01

    In this work we have designed high-specific biosensors for Salmonella typhimurium detection based on the surface plasmon resonance (SPR) and total internal reflection ellipsometry (TIRE). It has been demonstrated high selectivity and sensitivity of analysis. As a registering part for our experiments the Spreeta (USA) and "Plasmonotest" (Ukraine) with flowing cell have been applied among of SPR device. Previous researches confirmed an efficiency of SPR biosensors using for detecting of specific antigen-antibody interactions therefore this type of reactions with some previous preparations of surface binding layer was used as reactive part. It has been defined that in case with Spreeta sensitivity was on the level 103 - 107 cells/ml. Another biosensor based on the SPR has shown the sensitivity within 101 - 106 cells/ml. Maximal sensitivity was on the level of several cells in 10 ml (up to the fact that less than 5 cells) which has been obtained using the biosensor based on TIRE.

  3. Surface plasmon resonance based biosensor: A new platform for rapid diagnosis of livestock diseases

    PubMed Central

    Sahoo, Pravas Ranjan; Swain, Parthasarathi; Nayak, Sudhanshu Mohan; Bag, Sudam; Mishra, Smruti Ranjan

    2016-01-01

    Surface plasmon resonance (SPR) based biosensors are the most advanced and developed optical label-free biosensor technique used for powerful detection with vast applications in environmental protection, biotechnology, medical diagnostics, drug screening, food safety, and security as well in livestock sector. The livestock sector which contributes the largest economy of India, harbors many bacterial, viral, and fungal diseases impacting a great loss to the production and productive potential which is a major concern in both small and large ruminants. Hence, an accurate, sensitive, and rapid diagnosis is required for prevention of these above-mentioned diseases. SPR based biosensor assay may fulfill the above characteristics which lead to a greater platform for rapid diagnosis of different livestock diseases. Hence, this review may give a detail idea about the principle, recent development of SPR based biosensor techniques and its application in livestock sector. PMID:28096602

  4. Enzyme-linked, aptamer-based, competitive biolayer interferometry biosensor for palytoxin.

    PubMed

    Gao, Shunxiang; Zheng, Xin; Hu, Bo; Sun, Mingjuan; Wu, Jihong; Jiao, Binghua; Wang, Lianghua

    2017-03-15

    In this study, we coupled biolayer interferometry (BLI) with competitive binding assay through an enzyme-linked aptamer and developed a real-time, ultra-sensitive, rapid quantitative method for detection of the marine biotoxin palytoxin. Horseradish peroxidase-labeled aptamers were used as biorecognition receptors to competitively bind with palytoxin, which was immobilized on the biosensor surface. The palytoxin: horseradish peroxidase-aptamer complex was then submerged in a 3,3'-diaminobenzidine solution, which resulted in formation of a precipitated polymeric product directly on the biosensor surface and a large change in the optical thickness of the biosensor layer. This change could obviously shift the interference pattern and generate a response profile on the BLI biosensor. The biosensor showed a broad linear range for palytoxin (200-700pg/mL) with a low detection limit (0.04pg/mL). Moreover, the biosensor was applied to the detection of palytoxin in spiked extracts and showed a high degree of selectivity for palytoxin, good reproducibility, and stability. This enzyme-linked, aptamer-based, competitive BLI biosensor offers a promising method for rapid and sensitive detection of palytoxin and other analytes.

  5. Developing a high performance superoxide dismutase based electrochemical biosensor for radiation dosimetry of thallium 201

    NASA Astrophysics Data System (ADS)

    Salem, Fatemeh; Tavakoli, Hassan; Sadeghi, Mahdi; Riazi, Abbas

    2014-09-01

    To develop a new biosensor for measurement of superoxide free radical generated in radiolysis reaction, three combinations of SOD-based biosensors including Au/Cys/SOD, Au/GNP/Cys/SOD and Au/GNP/Cys/SOD/Chit were fabricated. In these biosensors Au, GNP, Cys, SOD and Chit represent gold electrode, gold nano-particles, cysteine, superoxide dismutase and chitosan, respectively. For biosensors fabrication, SOD, GNP, Cys and Chit were immobilized at the surface of gold electrode. Cyclic voltametry and chronoamperometry were utilized for evaluation of biosensors performances. The results showed that Au/GNP/Cys/SOD/Chit has significantly better responses compared to Au/Cys/SOD and Au/GNP/Cys/SOD. As a result, this biosensor was selected for dosimetry of ionizing radiation. For this purpose, thallium 201 at different volumes was added to buffer phosphate solution in electrochemical cell. To obtain analytical parameters of Au/GNP/Cys/SOD/Chit, calibration curve was sketched. The results showed that this biosensor has a linear response in the range from 0.5 to 4 Gy, detection limit 0.03 μM. It also has a proper sensitivity (0.6038 nA/Gy), suitable long term stability and cost effective as well as high function for radiation dosimetry.

  6. Electrochemical biosensors based on nanofibres for cardiac biomarker detection: A comprehensive review.

    PubMed

    Rezaei, Babak; Ghani, Mozhdeh; Shoushtari, Ahmad Mousavi; Rabiee, Mohammad

    2016-04-15

    The vital importance of early and accurate diagnosis of cardiovascular diseases (CVDs) to prevent the irreversible damage or even death of patients has driven the development of biosensor devices for detection and quantification of cardiac biomarkers. Electrochemical biosensors offer rapid sensing, low cost, portability and ease of use. Over the past few years, nanotechnology has contributed to a tremendous improvement in the sensitivity of biosensors. In this review, the authors summarise the state-of-the-art of the application of one particular type of nanostructured material, i.e. nanofibres, for use in electrochemical biosensors for the ultrasensitive detection of cardiac biomarkers. A new way of classifying the nanofibre-based electrochemical biosensors according to the electrical conductance and the type of nanofibres is presented. Some key data from each article reviewed are highlighted, including the mechanism of detection, experimental conditions and the response range of the biosensor. The primary aim of this review is to emphasise the prospects for nanofibres for the future development of biosensors in diagnosis of CVDs as well as considering how to improve their characteristics for application in medicine.

  7. Direct laser patterning of graphene-based biosensors

    NASA Astrophysics Data System (ADS)

    Komarov, I. A.; Golovin, A. V.; Rubtsova, E. I.; Bobrinetskiy, I. I.

    2016-12-01

    In this work we developed methods of maskless laser patterning of graphene oxide surface. By varying of laser pulses and energies we find optimal energy to make GO reduction in patterned areas. By laser reduction of graphene oxide, we made patterns which could be used for biosensors. We put aptamers on sensing structures and measured spectral properties of such structures. We showed stability of biosensor structures electric characteristics.

  8. Optimization of transport processes in etched track-based biosensors

    NASA Astrophysics Data System (ADS)

    Fink, Dietmar; Vacik, Jiri; Alfonta, Lital; Kiv, Arik; Mandabi, Yohai; Muñoz H., G.

    2012-08-01

    A diffusion calculation was performed to simulate the migration kinetics of both analytes and enzymatic reaction products in enzyme-clad nanopores of different sizes and shapes, to estimate the limits of detection, response time and cleaning time of such biosensors, via the maximum possible reaction product enrichment in such pores and the time required for saturation of the corresponding concentration distributions. From this, conclusions concerning the optimum biosensor dimensions are derived.

  9. General purpose, field-portable cell-based biosensor platform.

    PubMed

    Gilchrist, K H; Barker, V N; Fletcher, L E; DeBusschere, B D; Ghanouni, P; Giovangrandi, L; Kovacs, G T

    2001-09-01

    There are several groups of researchers developing cell-based biosensors for chemical and biological warfare agents based on electrophysiologic monitoring of cells. In order to transition such sensors from the laboratory to the field, a general-purpose hardware and software platform is required. This paper describes the design, implementation, and field-testing of such a system, consisting of cell-transport and data acquisition instruments. The cell-transport module is a self-contained, battery-powered instrument that allows various types of cell-based modules to be maintained at a preset temperature and ambient CO(2) level while in transit or in the field. The data acquisition module provides 32 channels of action potential amplification, filtering, and real-time data streaming to a laptop computer. At present, detailed analysis of the data acquired is carried out off-line, but sufficient computing power is available in the data acquisition module to enable the most useful algorithms to eventually be run real-time in the field. Both modules have sufficient internal power to permit realistic field-testing, such as the example presented in this paper.

  10. A silicon nanowire-based electrochemical glucose biosensor with high electrocatalytic activity and sensitivity

    NASA Astrophysics Data System (ADS)

    Su, Shao; He, Yao; Song, Shiping; Li, Di; Wang, Lihua; Fan, Chunhai; Lee, Shuit-Tong

    2010-09-01

    An electrochemical glucose biosensor was developed by immobilizing glucose oxidase (GOx) on an electrode decorated with a novel nanostructure, silicon nanowires (SiNWs) with in situ grown gold nanoparticles (AuNPs). The immobilized GOx displayed a pair of well-defined and quasi-reversible redox peaks with a formal potential (E°') of -0.376 V in a phosphate buffer solution. The fabricated glucose biosensor has good electrocatalytic activity toward oxidation of glucose. In addition, such resultant SiNWs-based glucose biosensor possesses high biological affinity. Particularly, the apparent Michaelis-Mentan constant was estimated to be 0.902 mM, which is much smaller than the reported values for GOx at a range of nanomaterials-incorporated electrodes. Consequently, this novel SiNWs-based biosensor is expected to be a promising tool for biological assays (e.g., monitoring blood glucose).

  11. Analytical investigation of bilayer lipid biosensor based on graphene.

    PubMed

    Akbari, Elnaz; Buntat, Zolkafle; Shahraki, Elmira; Parvaz, Ramtin; Kiani, Mohammad Javad

    2016-01-01

    Graphene is another allotrope of carbon with two-dimensional monolayer honeycomb. Owing to its special characteristics including electrical, physical and optical properties, graphene is known as a more suitable candidate compared to other materials to be used in the sensor application. It is possible, moreover, to use biosensor by using electrolyte-gated field effect transistor based on graphene (GFET) to identify the alterations in charged lipid membrane properties. The current article aims to show how thickness and charges of a membrane electric can result in a monolayer graphene-based GFET while the emphasis is on the conductance variation. It is proposed that the thickness and electric charge of the lipid bilayer (LLP and QLP) are functions of carrier density, and to find the equation relating these suitable control parameters are introduced. Artificial neural network algorithm as well as support vector regression has also been incorporated to obtain other models for conductance characteristic. The results comparison between analytical models, artificial neural network and support vector regression with the experimental data extracted from previous work show an acceptable agreement.

  12. Biosensor-based small molecule fragment screening with biolayer interferometry

    NASA Astrophysics Data System (ADS)

    Wartchow, Charles A.; Podlaski, Frank; Li, Shirley; Rowan, Karen; Zhang, Xiaolei; Mark, David; Huang, Kuo-Sen

    2011-07-01

    Biosensor-based fragment screening is a valuable tool in the drug discovery process. This method is advantageous over many biochemical methods because primary hits can be distinguished from non-specific or non-ideal interactions by examining binding profiles and responses, resulting in reduced false-positive rates. Biolayer interferometry (BLI), a technique that measures changes in an interference pattern generated from visible light reflected from an optical layer and a biolayer containing proteins of interest, is a relatively new method for monitoring small molecule interactions. The BLI format is based on a disposable sensor that is immersed in 96-well or 384-well plates. BLI has been validated for small molecule detection and fragment screening with model systems and well-characterized targets where affinity constants and binding profiles are generally similar to those obtained with surface plasmon resonsance (SPR). Screens with challenging targets involved in protein-protein interactions including BCL-2, JNK1, and eIF4E were performed with a fragment library of 6,500 compounds, and hit rates were compared for these targets. For eIF4E, a protein containing a PPI site and a nucleotide binding site, results from a BLI fragment screen were compared to results obtained in biochemical HTS screens. Overlapping hits were observed for the PPI site, and hits unique to the BLI screen were identified. Hit assessments with SPR and BLI are described.

  13. Urea biosensor based on an extended-base bipolar junction transistor.

    PubMed

    Sun, Tai-Ping; Shieh, Hsiu-Li; Liu, Chun-Lin; Chen, Chung-Yuan

    2014-01-01

    In this study, a urea biosensor was prepared by the immobilization of urease onto the sensitive membrane of an extended-base bipolar junction transistor. The pH variation was used to detect the concentration of urea. The SnO2/ITO glass, fabricated by sputtering SnO2 on the conductive ITO glass, was used as a pH-sensitive membrane, which was connected with a commercial bipolar junction transistor device. The gels, fabricated by the poly vinyl alcohol with pendent styrylpyridinium groups, were used to immobilize the urease. This readout circuit, fabricated in a 0.35-um CMOS 2P4M process, operated at 3.3V supply voltage. This circuit occupied an area of 1.0 mm × 0.9 mm. The dynamic range of the urea biosensor was from 1.4 to 64 mg/dl at the 10 mM phosphate buffer solution and the sensitivity of this range was about 65.8 mV/pUrea. The effect of urea biosensors with different pH values was considered, and the characteristics of urea biosensors based on EBBJT were described.

  14. Sulfite determination by a biosensor based on bay leaf tissue homogenate: very simple and economical method.

    PubMed

    Teke, Mustafa; Sezgintürk, Mustafa Kemal; Dinçkaya, Erhan

    2009-01-01

    Of all the food additives for which the FDA has received adverse reaction reports, the ones that most closely resemble true allergens are sulfur-based preservatives. Sulfites are used primarily as antioxidants to prevent or reduce discoloration of light-colored fruits and vegetables, such as dried apples and potatoes, and to inhibit the growth of microorganisms in fermented foods such as wine. This work aims to prepare an electrochemical biosensor based on bay leaf tissue homogenate that contains polyphenol oxidase enzyme abundantly for sulfite detection in foods. The principle of the biosensor is based on the inhibition effect of sulfites on polyphenol oxidase in the bioactive layer. Optimum conditions for the biosensor, such as temperature and pH, were investigated. Some stability parameters of the biosensor were also identified. The biosensor showed a linear calibration graph in the range of 25-100 microM sulfite. The biosensor presents a very simple, economical, reliable, and feasible method for sulfite detection in foods.

  15. New biosensor for detection of copper ions in water based on immobilized genetically modified yeast cells.

    PubMed

    Vopálenská, Irena; Váchová, Libuše; Palková, Zdena

    2015-10-15

    Contamination of water by heavy metals represents a potential risk for both aquatic and terrestrial organisms, including humans. Heavy metals in water resources can come from various industrial activities, and drinking water can be ex-post contaminated by heavy metals such as Cu(2+) from house fittings (e.g., water reservoirs) and pipes. Here, we present a new copper biosensor capable of detecting copper ions at concentrations of 1-100 μM. This biosensor is based on cells of a specifically modified Saccharomyces cerevisiae strain immobilized in alginate beads. Depending on the concentration of copper, the biosensor beads change color from white, when copper is present in concentrations below the detection limit, to pink or red based on the increase in copper concentration. The biosensor was successfully tested in the determination of copper concentrations in real samples of water contaminated with copper ions. In contrast to analytical methods or other biosensors based on fluorescent proteins, the newly designed biosensor does not require specific equipment and allows the quick detection of copper in many parallel samples.

  16. Oxygen sensing glucose biosensors based on alginate nano-micro systems

    NASA Astrophysics Data System (ADS)

    Chaudhari, Rashmi; Joshi, Abhijeet; Srivastava, Rohit

    2014-04-01

    Clinically glucose monitoring in diabetes management is done by point-measurement. However, an accurate, continuous glucose monitoring, and minimally invasive method is desirable. The research aims at developing fluorescence-mediated glucose detecting biosensors based on near-infrared radiation (NIR) oxygen sensitive dyes. Biosensors based on Glucose oxidase (GOx)-Rudpp loaded alginate microspheres (GRAM) and GOx-Platinum-octaethylporphyrin (PtOEP)-PLAalginate microsphere system (GPAM) were developed using air-driven atomization and characterized using optical microscopy, CLSM, fluorescence spectro-photometry etc. Biosensing studies were performed by exposing standard solutions of glucose. Uniform sized GRAM and GPAM with size 50+/-10μm were formed using atomization. CLSM imaging of biosensors suggests that Rudpp and PtOEP nanoparticles are uniformly distributed in alginate microspheres. The GRAM and GPAM showed a good regression constant of 0.974 and of 0.9648 over a range of 0-10 mM of glucose with a high sensitivity of 3.349%/mM (625 nm) and 2.38%/mM (645 nm) at 10 mM of glucose for GRAM and GPAM biosensor. GRAM and GPAM biosensors show great potential in development of an accurate and minimally invasive glucose biosensor. NIR dye based assays can aid sensitive, minimally-invasive and interference-free detection of glucose in diabetic patients.

  17. Phenol determination by an amperométrico biosensor based on lyophilized mushroom (Agaricus bisporus) tissue.

    PubMed

    Silva, L M C; de Mello, A C C; Salgado, A M

    2014-01-01

    A simple and inexpensive biosensor based on lyophilized mushroom tissue (Agaricus bisporus) was developed for amperometric determination of phenol. This fungi tissue contains tyrosinase (EC 1.14.18.1) enzyme that catalysis two sequential oxidation reactions with phenolic substrates. Both reactions involve molecular oxygen; therefore, the commercial Clark-type oxygen electrode was selected as a transducer. The lyophilized biocomponent was tested in two different forms: cubes (at two positions in the biosensor system) or powder. In characterization studies of the biosensor, some parameters such as time reaction, linear range and repeatability were investigated. For the best biosensor configuration, a linear response was observed from 0.1 to 10.0mg L(-1) phenol; variation coefficient and standard deviation were calculated as 0.02% and +/- 0.11mg L(-1), respectively.

  18. New Trends in the Design of Enzyme-based Biosensors for Medical Applications.

    PubMed

    Palchetti, Ilaria

    2016-01-01

    A biosensor is a self-contained integrated device, which is capable of providing specific quantitative or semiquantitative analytical information using a biological (or biomimetic) recognition element, which is retained in direct spatial contact with an electrochemical transduction element. One of the main features of biosensors is the remarkable selectivity that their biological components confer on them. Enzymes are the most common and well-developed recognition system of the family known as catalytic biosensors. This mini-review is focused on enzyme-based biosensors for medical applications. In particular, the new trends for the technology are described. A special emphasis is devoted to the non-invasive and painless monitoring of body metabolites, such as glucose.

  19. A glucose biosensor based on Prussian blue/chitosan hybrid film.

    PubMed

    Wang, Xueying; Gu, Haifang; Yin, Fan; Tu, Yifeng

    2009-01-01

    Based on electrodeposition of Prussian blue (PB) and chitosan (CS) directly on gold electrode, a hybrid film of PB/CS has been prepared. PB in this film shows a good stability compared with pure PB film when it worked in neutral and weak alkalescent solution and can act as redox mediator. It provides the potential application of such film in biosensor fabrication. A glucose biosensor was fabricated by electrodepositing glucose oxidase (GOD)/CS film on this PB/CS modified electrode. The optimum experimental conditions of biosensor for the detection of glucose have been studied in detail. Under the optimal conditions, a linear dependence of the catalytic current upon glucose concentration was obtained in the range of 2x10(-6) to 4x10(-4)M with a detection limit of 3.97x10(-7)M. The resulting biosensor could be applied to detect the blood sugar in real samples without any pretreatment.

  20. Acetylcholinesterase immobilized on magnetic beads for pesticides detection: application to olive oil analysis.

    PubMed

    Ben Oujji, Najwa; Bakas, Idriss; Istamboulié, Georges; Ait-Ichou, Ihya; Ait-Addi, Elhabib; Rouillon, Régis; Noguer, Thierry

    2012-01-01

    This work presents the development of bioassays and biosensors for the detection of insecticides widely used in the treatment of olive trees. The systems are based on the covalent immobilisation of acetylcholinesterase on magnetic microbeads using either colorimetry or amperometry as detection technique. The magnetic beads were immobilised on screen-printed electrodes or microtitration plates and tested using standard solutions and real samples. The developed devices showed good analytical performances with limits of detection much lower than the maximum residue limit tolerated by international regulations, as well as a good reproducibility and stability.

  1. Quantum dot-based microfluidic biosensor for cancer detection

    SciTech Connect

    Ghrera, Aditya Sharma; Pandey, Chandra Mouli; Ali, Md. Azahar; Malhotra, Bansi Dhar

    2015-05-11

    We report results of the studies relating to fabrication of an impedimetric microfluidic–based nucleic acid sensor for quantification of DNA sequences specific to chronic myelogenous leukemia (CML). The sensor chip is prepared by patterning an indium–tin–oxide (ITO) coated glass substrate via wet chemical etching method followed by sealing with polydimethylsiloxane (PDMS) microchannel for fluid control. The fabricated microfluidic chip comprising of a patterned ITO substrate is modified by depositing cadmium selenide quantum dots (QCdSe) via Langmuir–Blodgett technique. Further, the QCdSe surface has been functionalized with specific DNA probe for CML detection. The probe DNA functionalized QCdSe integrated miniaturized system has been used to monitor target complementary DNA concentration by measuring the interfacial charge transfer resistance via hybridization. The presence of complementary DNA in buffer solution significantly results in decreased electro-conductivity of the interface due to presence of a charge barrier for transport of the redox probe ions. The microfluidic DNA biosensor exhibits improved linearity in the concentration range of 10{sup −15} M to 10{sup −11} M.

  2. Quantum dot-based microfluidic biosensor for cancer detection

    NASA Astrophysics Data System (ADS)

    Ghrera, Aditya Sharma; Pandey, Chandra Mouli; Ali, Md. Azahar; Malhotra, Bansi Dhar

    2015-05-01

    We report results of the studies relating to fabrication of an impedimetric microfluidic-based nucleic acid sensor for quantification of DNA sequences specific to chronic myelogenous leukemia (CML). The sensor chip is prepared by patterning an indium-tin-oxide (ITO) coated glass substrate via wet chemical etching method followed by sealing with polydimethylsiloxane (PDMS) microchannel for fluid control. The fabricated microfluidic chip comprising of a patterned ITO substrate is modified by depositing cadmium selenide quantum dots (QCdSe) via Langmuir-Blodgett technique. Further, the QCdSe surface has been functionalized with specific DNA probe for CML detection. The probe DNA functionalized QCdSe integrated miniaturized system has been used to monitor target complementary DNA concentration by measuring the interfacial charge transfer resistance via hybridization. The presence of complementary DNA in buffer solution significantly results in decreased electro-conductivity of the interface due to presence of a charge barrier for transport of the redox probe ions. The microfluidic DNA biosensor exhibits improved linearity in the concentration range of 10-15 M to 10-11 M.

  3. Liquid crystal based biosensors for bile acid detection

    NASA Astrophysics Data System (ADS)

    He, Sihui; Liang, Wenlang; Tanner, Colleen; Fang, Jiyu; Wu, Shin-Tson

    2013-03-01

    The concentration level of bile acids is a useful indicator for early diagnosis of liver diseases. The prevalent measurement method in detecting bile acids is the chromatography coupled with mass spectrometry, which is precise yet expensive. Here we present a biosensor platform based on liquid crystal (LC) films for the detection of cholic acid (CA). This platform has the advantage of low cost, label-free, solution phase detection and simple analysis. In this platform, LC film of 4-Cyano-4'-pentylbiphenyl (5CB) was hosted by a copper grid supported with a polyimide-coated glass substrate. By immersing into sodium dodecyl sulfate (SDS) solution, the LC film was coated with SDS which induced a homeotropic anchoring of 5CB. Addition of CA introduced competitive adsorption between CA and SDS at the interface, triggering a transition from homeotropic to homogeneous anchoring. The detection limit can be tuned by changing the pH value of the solution from 12uM to 170uM.

  4. Microfabricated, amperometric, enzyme-based biosensors for in vivo applications.

    PubMed

    Weltin, Andreas; Kieninger, Jochen; Urban, Gerald A

    2016-07-01

    Miniaturized electrochemical in vivo biosensors allow the measurement of fast extracellular dynamics of neurotransmitter and energy metabolism directly in the tissue. Enzyme-based amperometric biosensing is characterized by high specificity and precision as well as high spatial and temporal resolution. Aside from glucose monitoring, many systems have been introduced mainly for application in the central nervous system in animal models. We compare the microsensor principle with other methods applied in biomedical research to show advantages and drawbacks. Electrochemical sensor systems are easily miniaturized and fabricated by microtechnology processes. We review different microfabrication approaches for in vivo sensor platforms, ranging from simple modified wires and fibres to fully microfabricated systems on silicon, ceramic or polymer substrates. The various immobilization methods for the enzyme such as chemical cross-linking and entrapment in polymer membranes are discussed. The resulting sensor performance is compared in detail. We also examine different concepts to reject interfering substances by additional membranes, aspects of instrumentation and biocompatibility. Practical considerations are elaborated, and conclusions for future developments are presented. Graphical Abstract ᅟ.

  5. A Graphene-Based Biosensing Platform Based on Regulated Release of an Aptameric DNA Biosensor.

    PubMed

    Mao, Yu; Chen, Yongli; Li, Song; Lin, Shuo; Jiang, Yuyang

    2015-11-09

    A novel biosensing platform was developed by integrating an aptamer-based DNA biosensor with graphene oxide (GO) for rapid and facile detection of adenosine triphosphate (ATP, as a model target). The DNA biosensor, which is locked by GO, is designed to contain two sensing modules that include recognition site for ATP and self-replication track that yields the nicking domain for Nt.BbvCI. By taking advantage of the different binding affinity of single-stranded DNA, double-stranded DNA and aptamer-target complex toward GO, the DNA biosensor could be efficiently released from GO in the presence of target with the help of a complementary DNA strand (CPDNA) that partially hybridizes to the DNA biosensor. Then, the polymerization/nicking enzyme synergetic isothermal amplification could be triggered, leading to the synthesis of massive DNA amplicons, thus achieving an enhanced sensitivity with a wide linear dynamic response range of four orders of magnitude and good selectivity. This biosensing strategy expands the applications of GO-DNA nanobiointerfaces in biological sensing, showing great potential in fundamental research and biomedical diagnosis.

  6. A biosensor for cholesterol based on gold nanoparticles-catalyzed luminol electrogenerated chemiluminescence.

    PubMed

    Zhang, Meihe; Yuan, Ruo; Chai, Yaqin; Chen, Shihong; Zhong, Huaan; Wang, Cun; Cheng, Yinfeng

    2012-02-15

    A novel cholesterol biosensor was prepared based on gold nanoparticles-catalyzed luminol electrogenerated chemiluminescence (ECL). Firstly, l-cysteine-reduced graphene oxide composites were modified on the surface of a glassy carbon electrode. Then, gold nanoparticles (AuNPs) were self-assembled on it. Subsequently, cholesterol oxidase (ChOx) was adsorbed on the surface of AuNPs to construct a cholesterol biosensor. The stepwise fabrication processes were characterized with cyclic voltammetry and atomic force microscopy. The ECL behaviors of the biosensor were also investigated. It was found that AuNPs not only provided larger surface area for higher ChOx loading but also formed the nano-structured interface on the electrode surface to improve the analytical performance of the ECL biosensor for cholesterol. Besides, based on the efficient catalytic ability of AuNPs to luminol ECL, the response of the biosensor to cholesterol was linear range from 3.3 μM to 1.0 mM with a detection limit of 1.1 μM (S/N=3). In addition, the prepared ECL biosensor exhibited satisfying reproducibility, stability and selectivity. Taking into account the advantages of ECL, we confidently expect that ECL would have potential applications in biotechnology and clinical diagnosis.

  7. A low cost color-based bacterial biosensor for measuring arsenic in groundwater.

    PubMed

    Huang, Chi-Wei; Wei, Chia-Cheng; Liao, Vivian Hsiu-Chuan

    2015-12-01

    Using arsenic (As) contaminated groundwater for drinking or irrigation has caused major health problems for humans around the world, raising a need to monitor As level efficiently and economically. This study developed a color-based bacterial biosensor which is easy-to-use and inexpensive for measuring As and could be complementary to current As detecting techniques. The arsR-lacZ recombinant gene cassette in nonpathogenic strain Escherichia coli DH5α was used in the color-based biosensor which could be observed by eyes or measured by spectrometer. The developed bacterial biosensor demonstrates a quantitative range from 10 to 500μgL(-1) of As in 3-h reaction time. Furthermore, the biosensor was able to successfully detect and estimate As concentration in groundwater sample by measuring optical density at 595nm (OD595). Among different storage methods used in this study, biosensor in liquid at 4°C showed the longest shelf life about 9d, and liquid storage at RT and cell pellet could also be stored for about 3-5d. In conclusion, this study showed that the As biosensor with reliable color signal and economical preservation methods is useful for rapid screening of As pollutant, providing the potential for large scale screening and better management strategies for environmental quality control.

  8. Acetylcholinesterase-reduced graphene oxide hybrid films for organophosphorus neurotoxin sensing via quartz crystal microbalance

    NASA Astrophysics Data System (ADS)

    Tang, Shi; Ma, Wenying; Xie, Guangzhong; Su, Yuanjie; Jiang, Yadong

    2016-09-01

    An acetylcholinesterase (AChE)-reduced graphene oxide (RGO) hybrid films based biosensor enabled by quartz crystal microbalance (QCM) has been developed for the detection of organophosphorus neurotoxin in gas phase at room temperature. To improve the sensing performance, RGO was used to immobilize large quantities of enzyme and provide a favorable microenvironment to maintain the enzyme activity. The experimental results reveal that the response of AChE-RGO/glutaraldehyde based sensors is about 8 times larger than that of the AChE with the sensitivity of 1.583 Hz/mg/m3. 1.0 mg amount of RGO, 5% concentration of glutaraldehyde and pH 6.8 is the optimal condition of this biosensor.

  9. Development of a 3D-QSAR model for acetylcholinesterase inhibitors using a combination of fingerprint, docking, and structure-based pharmacophore approaches - Conference Abstract

    EPA Science Inventory

    Acetylcholinesterase (AChE), a serine hydrolase vital for regulating the neurotransmitter acetylcholine in animals, has been used as a target for drugs and pesticides. With the increasing availability of AChE crystal structures, with or without ligands bound, structure-based appr...

  10. Development of 3D-QSAR model for acetylcholinesterase inhibitors using a combination of fingerprint, molecular docking, and structure-based pharmacophore approaches

    EPA Science Inventory

    Acetylcholinesterase (AChE), a serine hydrolase vital for regulating the neurotransmitter acetylcholine in animals, has been used as a target for drugs and pesticides. With the increasing availability of AChE crystal structures, with or without ligands bound, structure-based appr...

  11. Biosensor based on Butyrylcholinesterase for Detection of Carbofuran

    NASA Astrophysics Data System (ADS)

    Dey, Mousumi; Bhuvanagayathri, R.; Daniel, David K.

    2015-04-01

    Esterase enzymes play an important role in biology because they are responsible for the hydrolysis of choline esters. In their absence, the original state of the post synaptic membranes cannot be reestablished. Therefore, the aim of the work is to study the inhibiting action exerted by the group of compounds on these enzymes. Among these class of inhibiting compounds, pesticides are important because of the potential danger as a result of their large scale use in agriculture. Pesticides are generally determined using liquid or gas chromatography methods with various detection techniques. These methods are very sensitive and discriminating, however they require sample pretreatment such as extraction, preconcentration and clean up, which are skilled techniques and high cost treatment and also time consuming. In this study, acetyl cholinesterase and butyrylcholinesterase based biosensors have emerged as a promising tool for the detection and characterization of pesticides which are inhibitors of these enzymes. Although the physiological function of butyrylcholinesterase in comparison with acetyl cholinesterase is ambiguous, it has larger substrate specificity towards choline esters. Therefore, the development of a more selective electrode against choline, can lead to more sensitive determination of the inhibitor being investigated. Hence in the present work, a method based on inhibition of butyrylcholinesterase was attempted for quantification of carbofuran on the basis of cholinesterase inhibition. Butyrylcholinesterase with an activity of 10.2 units/mg was immobilized on a solid surface by cross linking with glutaraldehyde. The immobilized system was calibrated by correlating the inhibition of the butyrylcholinesterase activity with varying concentrations of the butyryl choline chloride and carbofuran. The sensing mechanism was investigated for its response to carbofuran concentrations ranging from 125 to 1,000 ppm. The effects of butyryl choline chloride

  12. A Review of Membrane-Based Biosensors for Pathogen Detection

    PubMed Central

    van den Hurk, Remko; Evoy, Stephane

    2015-01-01

    Biosensors are of increasing interest for the detection of bacterial pathogens in many applications such as human, animal and plant health, as well as food and water safety. Membranes and membrane-like structures have been integral part of several pathogen detection platforms. Such structures may serve as simple mechanical support, function as a part of the transduction mechanism, may be used to filter out or concentrate pathogens, and may be engineered to specifically house active proteins. This review focuses on membrane materials, their associated biosensing applications, chemical linking procedures, and transduction mechanisms. The sensitivity of membrane biosensors is discussed, and the state of the field is evaluated and summarized. PMID:26083229

  13. Graphene Electronic Device Based Biosensors and Chemical Sensors

    NASA Astrophysics Data System (ADS)

    Jiang, Shan

    Two-dimensional layered materials, such as graphene and MoS2, are emerging as an exciting material system for a new generation of atomically thin electronic devices. With their ultrahigh surface to volume ratio and excellent electrical properties, 2D-layered materials hold the promise for the construction of a generation of chemical and biological sensors with unprecedented sensitivity. In my PhD thesis, I mainly focus on graphene based electronic biosensors and chemical sensors. In the first part of my thesis, I demonstrated the fabrication of graphene nanomesh (GNM), which is a graphene thin film with a periodic array of holes punctuated in it. The periodic holes introduce long periphery active edges that provide a high density of functional groups (e.g. carboxylic groups) to allow for covalent grafting of specific receptor molecules for chemical and biosensor applications. After covalently functionalizing the GNM with glucose oxidase, I managed to make a novel electronic sensor which can detect glucose as well as pH change. In the following part of my thesis I demonstrate the fabrication of graphene-hemin conjugate for nitric oxide detection. The non-covalent functionalization through pi-pi stacking interaction allows reliable immobilization of hemin molecules on graphene without damaging the graphene lattice to ensure the highly sensitive and specific detection of nitric oxide. The graphene-hemin nitric oxide sensor is capable of real-time monitoring of nitric oxide concentrations, which is of central importance for probing the diverse roles of nitric oxide in neurotransmission, cardiovascular systems, and immune responses. Our studies demonstrate that the graphene-hemin sensors can respond rapidly to nitric oxide in physiological environments with sub-nanomolar sensitivity. Furthermore, in vitro studies show that the graphene-hemin sensors can be used for the detection of nitric oxide released from macrophage cells and endothelial cells, demonstrating their

  14. Amperometric choline biosensor based on multiwalled carbon nanotubes/zirconium oxide nanoparticles electrodeposited on glassy carbon electrode.

    PubMed

    Pundir, S; Chauhan, N; Narang, J; Pundir, C S

    2012-08-01

    A bienzymatic choline biosensor was constructed by coimmobilizing acetylcholinesterase (AChE) and choline oxidase (ChO) onto nanocomposite of carboxylated multiwalled carbon nanotubes (c-MWCNTs) and zirconium oxide nanoparticles (ZrO(2)NPs) electrodeposited on the surface of a glassy carbon electrode (GCE) and using it (AChE-ChO/c-MWCNT/ZrO(2)NPs/GCE) as working electrode, Ag/AgCl as reference electrode, and Pt wire as auxiliary electrode connected through a potentiostat. The enzyme electrode was characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and cyclic voltammetry (CV) studies, optimized, and evaluated. The biosensor exhibited optimum response within 4 s at +0.2V, pH 7.4, and 25 °C. The detection limit and working range of the biosensor were 0.01 μM and 0.05 to 200 μM, respectively. The half-life of the enzyme electrode was 60 days at 4 °C. The serum choline level, as measured by the biosensor, was 9.0 to 12.8 μmol/L (with a mean of 10.81 μmol/L) in apparently healthy persons and 5.0 to 8.4 μmol/L (with a mean of 6.53 μmol/L) in persons suffering from Alzheimer's disease. The enzyme electrode was unaffected by a number of serum substances.

  15. Engineering Rugged Field Assays to Detect Hazardous Chemicals Using Spore-Based Bacterial Biosensors.

    PubMed

    Wynn, Daniel; Deo, Sapna; Daunert, Sylvia

    2017-01-01

    Bacterial whole cell-based biosensors have been genetically engineered to achieve selective and reliable detection of a wide range of hazardous chemicals. Although whole-cell biosensors demonstrate many advantages for field-based detection of target analytes, there are still some challenges that need to be addressed. Most notably, their often modest shelf life and need for special handling and storage make them challenging to use in situations where access to reagents, instrumentation, and expertise are limited. These problems can be circumvented by developing biosensors in Bacillus spores, which can be engineered to address all of these concerns. In its sporulated state, a whole cell-based biosensor has a remarkably long life span and is exceptionally resistant to environmental insult. When these spores are germinated for use in analytical techniques, they show no loss in performance, even after long periods of storage under harsh conditions. In this chapter, we will discuss the development and use of whole cell-based sensors, their adaptation to spore-based biosensors, their current applications, and future directions in the field.

  16. A novel sensitive cell-based Love Wave biosensor for marine toxin detection.

    PubMed

    Zhang, Xi; Fang, Jiaru; Zou, Ling; Zou, Yingchang; Lang, Lang; Gao, Fan; Hu, Ning; Wang, Ping

    2016-03-15

    A novel HepG2 cell-based biosensor using Love Wave sensor was developed to implement the real-time and sensitive detection of a diarrheic shellfish poisoning (DSP) toxin, Okadaic acid (OA). Detachable Love Wave sensor unit and miniaturized 8-channel recording instrument were designed for the convenient experimental preparation and sensor response signal measurement. The Love Wave sensor, whose synchronous frequency is around 160 MHz, was fabricated with ST-cut quartz substrate. To establish a cell-based biosensor, HepG2 cells as sensing elements were cultured onto the Love Wave sensor surface, and the cell attachment process was recorded by this biosensor. Results showed this sensor could monitor the cell attachment process in real time and response signals were related to the initial cell seeding densities. Furthermore, cell-based Love Wave sensor was treated with OA toxin. This biosensor presented a good performance to various OA concentrations, with a wide linear detection range (10-100 μg/L). Based on the ultrasensitive acoustic wave platform, this cell-based biosensor will be a promising tool for real-time and convenient OA screening.

  17. A microfluidic paper-based electrochemical biosensor array for multiplexed detection of metabolic biomarkers

    NASA Astrophysics Data System (ADS)

    Zhao, Chen; Thuo, Martin M.; Liu, Xinyu

    2013-10-01

    Paper-based microfluidic devices have emerged as simple yet powerful platforms for performing low-cost analytical tests. This paper reports a microfluidic paper-based electrochemical biosensor array for multiplexed detection of physiologically relevant metabolic biomarkers. Different from existing paper-based electrochemical devices, our device includes an array of eight electrochemical sensors and utilizes a handheld custom-made electrochemical reader (potentiostat) for signal readout. The biosensor array can detect several analytes in a sample solution and produce multiple measurements for each analyte from a single run. Using the device, we demonstrate simultaneous detection of glucose, lactate and uric acid in urine, with analytical performance comparable to that of the existing commercial and paper-based platforms. The paper-based biosensor array and its electrochemical reader will enable the acquisition of high-density, statistically meaningful diagnostic information at the point of care in a rapid and cost-efficient way.

  18. A microfluidic paper-based electrochemical biosensor array for multiplexed detection of metabolic biomarkers

    PubMed Central

    Zhao, Chen; Thuo, Martin M; Liu, Xinyu

    2013-01-01

    Paper-based microfluidic devices have emerged as simple yet powerful platforms for performing low-cost analytical tests. This paper reports a microfluidic paper-based electrochemical biosensor array for multiplexed detection of physiologically relevant metabolic biomarkers. Different from existing paper-based electrochemical devices, our device includes an array of eight electrochemical sensors and utilizes a handheld custom-made electrochemical reader (potentiostat) for signal readout. The biosensor array can detect several analytes in a sample solution and produce multiple measurements for each analyte from a single run. Using the device, we demonstrate simultaneous detection of glucose, lactate and uric acid in urine, with analytical performance comparable to that of the existing commercial and paper-based platforms. The paper-based biosensor array and its electrochemical reader will enable the acquisition of high-density, statistically meaningful diagnostic information at the point of care in a rapid and cost-efficient way. PMID:27877606

  19. Electrochemical biosensor based on immobilized enzymes and redox polymers

    DOEpatents

    Skotheim, Terje A.; Okamoto, Yoshiyuki; Hale, Paul D.

    1992-01-01

    The present invention relates to an electrochemical enzyme biosensor for use in liquid mixtures of components for detecting the presence of, or measuring the amount of, one or more select components. The enzyme electrode of the present invention is comprised of an enzyme, an artificial redox compound covalently bound to a flexible polymer backbone and an electron collector.

  20. Amperometric cytochrome c3-based biosensor for chromate determination.

    PubMed

    Michel, Caroline; Battaglia-Brunet, Fabienne; Minh, Canh Tran; Bruschi, Mireille; Ignatiadis, Ioannis

    2003-12-15

    The chromate reductase activity of cytochrome c(3) (Cyt c(3), M(r) 13000), isolated from the sulfate-reducing bacterium Desulfomicrobium norvegicum, was used to develop an amperometric biosensor to measure chromate (CrO(4)(2-)) bioavailability. The performance of various biosensor configurations for qualitative and quantitative determination of Cr(VI) was studied. Biosensor properties depend on the technique used to immobilize the enzyme on the electrode (glassy carbon electrode). Immobilization of Cyt c(3) by entrapment in poly 3,4-ethylenedioxythiophene films denatured the enzyme, while application of an adsorption technique did not affect enzyme activity but the detection range was limited. The best results were obtained with dialysis membranes, which allowed the determination of Cr(VI) from 0.20 to 6.84 mg l(-1) (3.85-132 microM) with a sensitivity of 35 nA mg(-1) l (1.82 nA microM(-1)). No interference was observed with As(V), As(III) and Fe(III). Only a small amount of Cyt c(3) (372 ng of protein) was needed for this biosensor.

  1. Au/Si Nanorod-Based Biosensor for Salmonella Detection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Among several potentials of nanotechnology applications for food industry, development of nanoscale sensors for food safety and quality measurement are emerging. A novel biosensor for Salmonella detection was developed using Au/Si/ nanorods. The Si nanorods were fabricated by glancing angle depositi...

  2. Lignin and silicate based hydrogels for biosensor applications

    NASA Astrophysics Data System (ADS)

    Burrs, S. L.; Jairam, S.; Vanegas, D. C.; Tong, Z.; McLamore, E. S.

    2013-05-01

    Advances in biocompatible materials and electrocatalytic nanomaterials have extended and enhanced the field of biosensors. Immobilization of biorecognition elements on nanomaterial platforms is an efficient technique for developing high fidelity biosensors. Single layer (i.e., Langmuir-Blodgett) protein films are efficient, but disadvantages of this approach include high cost, mass transfer limitations, and Vromer competition for surface binding sites. There is a need for simple, user friendly protein-nanomaterial sensing membranes that can be developed in laboratories or classrooms (i.e., outside of the clean room). In this research, we develop high fidelity nanomaterial platforms for developing electrochemical biosensors using sustainable biomaterials and user-friendly deposition techniques. Catalytic nanomaterial platforms are developed using a combination of self assembled monolayer chemistry and electrodeposition. High performance biomaterials (e.g., nanolignin) are recovered from paper pulp waste and combined with proteins and nanomaterials to form active sensor membranes. These methods are being used to develop electrochemical biosensors for studying physiological transport in biomedical, agricultural, and environmental applications.

  3. Enzymatic biosensors based on SWCNT-conducting polymer electrodes.

    PubMed

    Le Goff, Alan; Holzinger, Michael; Cosnier, Serge

    2011-04-07

    This short review is focused on recent advances in the combination of conducting polymers and SWCNTs for the fabrication of electrochemical biosensors. The different properties of conducting polymers and SWCNTs are discussed in respect of their use in immobilizing and wiring biomolecules on electrode surfaces. We further describe the functionalization techniques used in the fabrication of these devices and their associated biosensing performances.

  4. A global benchmark study using affinity-based biosensors

    PubMed Central

    Rich, Rebecca L.; Papalia, Giuseppe A.; Flynn, Peter J.; Furneisen, Jamie; Quinn, John; Klein, Joshua S.; Katsamba, Phini S.; Waddell, M. Brent; Scott, Michael; Thompson, Joshua; Berlier, Judie; Corry, Schuyler; Baltzinger, Mireille; Zeder-Lutz, Gabrielle; Schoenemann, Andreas; Clabbers, Anca; Wieckowski, Sebastien; Murphy, Mary M.; Page, Phillip; Ryan, Thomas E.; Duffner, Jay; Ganguly, Tanmoy; Corbin, John; Gautam, Satyen; Anderluh, Gregor; Bavdek, Andrej; Reichmann, Dana; Yadav, Satya P.; Hommema, Eric; Pol, Ewa; Drake, Andrew; Klakamp, Scott; Chapman, Trevor; Kernaghan, Dawn; Miller, Ken; Schuman, Jason; Lindquist, Kevin; Herlihy, Kara; Murphy, Michael B.; Bohnsack, Richard; Andrien, Bruce; Brandani, Pietro; Terwey, Danny; Millican, Rohn; Darling, Ryan J.; Wang, Liann; Carter, Quincy; Dotzlaf, Joe; Lopez-Sagaseta, Jacinto; Campbell, Islay; Torreri, Paola; Hoos, Sylviane; England, Patrick; Liu, Yang; Abdiche, Yasmina; Malashock, Daniel; Pinkerton, Alanna; Wong, Melanie; Lafer, Eileen; Hinck, Cynthia; Thompson, Kevin; Primo, Carmelo Di; Joyce, Alison; Brooks, Jonathan; Torta, Federico; Bagge Hagel, Anne Birgitte; Krarup, Janus; Pass, Jesper; Ferreira, Monica; Shikov, Sergei; Mikolajczyk, Malgorzata; Abe, Yuki; Barbato, Gaetano; Giannetti, Anthony M.; Krishnamoorthy, Ganeshram; Beusink, Bianca; Satpaev, Daulet; Tsang, Tiffany; Fang, Eric; Partridge, James; Brohawn, Stephen; Horn, James; Pritsch, Otto; Obal, Gonzalo; Nilapwar, Sanjay; Busby, Ben; Gutierrez-Sanchez, Gerardo; Gupta, Ruchira Das; Canepa, Sylvie; Witte, Krista; Nikolovska-Coleska, Zaneta; Cho, Yun Hee; D’Agata, Roberta; Schlick, Kristian; Calvert, Rosy; Munoz, Eva M.; Hernaiz, Maria Jose; Bravman, Tsafir; Dines, Monica; Yang, Min-Hsiang; Puskas, Agnes; Boni, Erica; Li, Jiejin; Wear, Martin; Grinberg, Asya; Baardsnes, Jason; Dolezal, Olan; Gainey, Melicia; Anderson, Henrik; Peng, Jinlin; Lewis, Mark; Spies, Peter; Trinh, Quyhn; Bibikov, Sergei; Raymond, Jill; Yousef, Mohammed; Chandrasekaran, Vidya; Feng, Yuguo; Emerick, Anne; Mundodo, Suparna; Guimaraes, Rejane; McGirr, Katy; Li, Yue-Ji; Hughes, Heather; Mantz, Hubert; Skrabana, Rostislav; Witmer, Mark; Ballard, Joshua; Martin, Loic; Skladal, Petr; Korza, George; Laird-Offringa, Ite; Lee, Charlene S.; Khadir, Abdelkrim; Podlaski, Frank; Neuner, Phillippe; Rothacker, Julie; Rafique, Ashique; Dankbar, Nico; Kainz, Peter; Gedig, Erk; Vuyisich, Momchilo; Boozer, Christina; Ly, Nguyen; Toews, Mark; Uren, Aykut; Kalyuzhniy, Oleksandr; Lewis, Kenneth; Chomey, Eugene; Pak, Brian J.; Myszka, David G.

    2013-01-01

    To explore the variability in biosensor studies, 150 participants from 20 countries were given the same protein samples and asked to determine kinetic rate constants for the interaction. We chose a protein system that was amenable to analysis using different biosensor platforms as well as by users of different expertise levels. The two proteins (a 50-kDa Fab and a 60-kDa glutathione S-transferase [GST] antigen) form a relatively high-affinity complex, so participants needed to optimize several experimental parameters, including ligand immobilization and regeneration conditions as well as analyte concentrations and injection/dissociation times. Although most participants collected binding responses that could be fit to yield kinetic parameters, the quality of a few data sets could have been improved by optimizing the assay design. Once these outliers were removed, the average reported affinity across the remaining panel of participants was 620 pM with a standard deviation of 980 pM. These results demonstrate that when this biosensor assay was designed and executed appropriately, the reported rate constants were consistent, and independent of which protein was immobilized and which biosensor was used. PMID:19133223

  5. Zeolitic imidazolate framework-based electrochemical biosensor for in vivo electrochemical measurements.

    PubMed

    Ma, Wenjie; Jiang, Qin; Yu, Ping; Yang, Lifen; Mao, Lanqun

    2013-08-06

    This study demonstrates the first exploitation of zeolitic imidazolate frameworks (ZIFs) as the matrix for constructing integrated dehydrogenase-based electrochemical biosensors for in vivo measurement of neurochemicals, such as glucose. In this study, we find that ZIFs are able to serve as a matrix for coimmobilizing electrocatalysts (i.e., methylene green, MG) and dehydrogenases (i.e., glucose dehydrogenase, GDH) onto the electrode surface and an integrated electrochemical biosensor is readily formed. We synthesize a series of ZIFs, including ZIF-7, ZIF-8, ZIF-67, ZIF-68, and ZIF-70 with different pore sizes, surface areas, and functional groups. The adsorption capabilities toward MG and GDH of these ZIFs are systematically studied with UV-vis spectroscopy, confocal laser scanning microscopy, and Fourier transfer-infrared spectroscopy. Among all the ZIFs demonstrated here, ZIF-70 shows excellent adsorption capacities toward both MG and GDH and is thus employed as the matrix for our glucose biosensor. To construct the biosensor, we first drop-coat a MG/ZIF-70 composite onto a glassy carbon electrode and then coat GDH onto the MG/ZIF-70 composite. In a continuous-flow system, the as-prepared ZIF-based biosensor is very sensitive to glucose with a linear range of 0.1-2 mM. Moreover, the ZIF-based biosensor is more highly selective on glucose than on other endogenous electroactive species in the cerebral system. In the end, we demonstrate that our biosensor is capable of monitoring dialysate glucose collected from the brain of guinea pigs selectively and in a near real-time pattern.

  6. Nanostructured enzymatic biosensor based on fullerene and gold nanoparticles: preparation, characterization and analytical applications.

    PubMed

    Lanzellotto, C; Favero, G; Antonelli, M L; Tortolini, C; Cannistraro, S; Coppari, E; Mazzei, F

    2014-05-15

    In this work a novel electrochemical biosensing platform based on the coupling of two different nanostructured materials (gold nanoparticles and fullerenols) displaying interesting electrochemical features, has been developed and characterized. Gold nanoparticles (AuNPs) exhibit attractive electrocatalytic behavior stimulating in the last years, several sensing applications; on the other hand, fullerene and its derivatives are a very promising family of electroactive compounds although they have not yet been fully employed in biosensing. The methodology proposed in this work was finalized to the setup of a laccase biosensor based on a multilayer material consisting in AuNPs, fullerenols and Trametes versicolor Laccase (TvL) assembled layer by layer onto a gold (Au) electrode surface. The influence of different modification step procedures on the electroanalytical performance of biosensors has been evaluated. Cyclic voltammetry, chronoamperometry, surface plasmon resonance (SPR) and scanning tunneling microscopy (STM) were used to characterize the modification of surface and to investigate the bioelectrocatalytic biosensor response. This biosensor showed fast amperometric response to gallic acid, which is usually considered a standard for polyphenols analysis of wines, with a linear range 0.03-0.30 mmol L(-1) (r(2)=0.9998), with a LOD of 0.006 mmol L(-1) or expressed as polyphenol index 5.0-50 mg L(-1) and LOD 1.1 mg L(-1). A tentative application of the developed nanostructured enzyme-based biosensor was performed evaluating the detection of polyphenols either in buffer solution or in real wine samples.

  7. Microfabricated Electrochemical Cell-Based Biosensors for Analysis of Living Cells In Vitro

    PubMed Central

    Wang, Jun; Wu, Chengxiong; Hu, Ning; Zhou, Jie; Du, Liping; Wang, Ping

    2012-01-01

    Cellular biochemical parameters can be used to reveal the physiological and functional information of various cells. Due to demonstrated high accuracy and non-invasiveness, electrochemical detection methods have been used for cell-based investigation. When combined with improved biosensor design and advanced measurement systems, the on-line biochemical analysis of living cells in vitro has been applied for biological mechanism study, drug screening and even environmental monitoring. In recent decades, new types of miniaturized electrochemical biosensor are emerging with the development of microfabrication technology. This review aims to give an overview of the microfabricated electrochemical cell-based biosensors, such as microelectrode arrays (MEA), the electric cell-substrate impedance sensing (ECIS) technique, and the light addressable potentiometric sensor (LAPS). The details in their working principles, measurement systems, and applications in cell monitoring are covered. Driven by the need for high throughput and multi-parameter detection proposed by biomedicine, the development trends of electrochemical cell-based biosensors are also introduced, including newly developed integrated biosensors, and the application of nanotechnology and microfluidic technology. PMID:25585708

  8. pH-based fiber optic biosensors for use in clinical and biotechnological applications

    NASA Astrophysics Data System (ADS)

    Mueller, Cord; Hitzmann, Bernd; Schubert, Florian; Scheper, Thomas

    1995-05-01

    The development of pH-based fiber optic biosensors and their uses in clinical and biotechnological applications are described. Based on a pH-sensitive optode, different biosensors for urea, penicillin, glucose and creatinine were developed. A multichannel modular fluorimeter was used to measure signals from up to three optodes simultaneously. The pH value and the buffer capacity are critical factors for biosensors based on pH probes and influence the biosensor signal. A flow injection analysis (FIA) system is used to eliminate the latter influences. With this integrated system, samples can be analyzed sequentially by the injection of a defined volume of each sample into a continuously flowing buffer stream that transports the samples to the sensors. The complex signal is transformed and analyzed by a computer system. Characteristic features of the FIA peak give information about the buffer capacity in the solution. With the help of intelligent computing (neural networks) it is possible to recognize these features and relate them to the respective buffer capacity to obtain more accurate values. Various applications of these biosensors are discussed. The pH optode is also used to monitor enzymatic reactions in non aqueous solvents. In this case the production of acetic acid can be detected on line.

  9. Recent advances in DNA-based electrochemical biosensors for heavy metal ion detection: A review.

    PubMed

    Saidur, M R; Aziz, A R Abdul; Basirun, W J

    2017-04-15

    The presence of heavy metal in food chains due to the rapid industrialization poses a serious threat on the environment. Therefore, detection and monitoring of heavy metals contamination are gaining more attention nowadays. However, the current analytical methods (based on spectroscopy) for the detection of heavy metal contamination are often very expensive, tedious and can only be handled by trained personnel. DNA biosensors, which are based on electrochemical transduction, is a sensitive but inexpensive method of detection. The principles, sensitivity, selectivity and challenges of electrochemical biosensors are discussed in this review. This review also highlights the major advances of DNA-based electrochemical biosensors for the detection of heavy metal ions such as Hg(2+), Ag(+), Cu(2+) and Pb(2+).

  10. Optical waveguide biosensor based on cascaded Mach-Zehnder interferometer and ring resonator with Vernier effect

    NASA Astrophysics Data System (ADS)

    Jiang, Xianxin; Tang, Longhua; Song, Jinyan; Li, Mingyu; He, Jian-Jun

    2014-03-01

    Optical waveguide biosensors based on silicon-on-insulator (SOI) have been extensively investigated owing to its various advantages and many potential applications. In this article, we demonstrate a novel highly sensitive biosensor based on cascaded Mach-Zehnder interferometer (MZI) and ring resonator with the Vernier effect using wavelength interrogation. The experimental results show that the sensitivity reached 1,960 nm/RIU and 19,100 nm/RIU for sensors based on MZI alone and cascaded MZI-ring with Vernier effect, respectively. A biosensing application was also demonstrated by monitoring the interaction between goat and antigoat immunoglobulin G (IgG) pairs. This integrated high sensitivity biosensor has great potential for medical diagnostic applications.

  11. Label-Free Electrical Detection Using Carbon Nanotube-Based Biosensors

    PubMed Central

    Maehashi, Kenzo; Matsumoto, Kazuhiko

    2009-01-01

    Label-free detections of biomolecules have attracted great attention in a lot of life science fields such as genomics, clinical diagnosis and practical pharmacy. In this article, we reviewed amperometric and potentiometric biosensors based on carbon nanotubes (CNTs). In amperometric detections, CNT-modified electrodes were used as working electrodes to significantly enhance electroactive surface area. In contrast, the potentiometric biosensors were based on aptamer-modified CNT field-effect transistors (CNTFETs). Since aptamers are artificial oligonucleotides and thus are smaller than the Debye length, proteins can be detected with high sensitivity. In this review, we discussed on the technology, characteristics and developments for commercialization in label-free CNT-based biosensors. PMID:22346703

  12. Alkaline phosphatase inhibition based conductometric biosensor for phosphate estimation in biological fluids.

    PubMed

    Upadhyay, Lata Sheo Bachan; Verma, Nishant

    2015-06-15

    Determination of phosphate ions concentration is very important from both, environmental and clinical point of view. In this study, a simple and novel conductometric biosensor for indirect determination of the phosphate ions in aqueous solution has been developed. The developed biosensor is based on the inhibition of immobilized alkaline phosphatase activity, in the presence of the phosphate ions. This is the first time we developed a mono-enzymatic biosensor for indirect estimation of phosphate ions. The developed biosensor showed a broad linear response (as compared to other reported biosensors) for phosphate ions in the range of 0.5-5.0 mM (correlation coefficient=0.995), with a detection limit of 50 µM. Different optimized parameters were obtained as the buffer concentration of 30 mM, substrate concentration of 1.0mM, and a pH of 9.0. All the optimized parameters were analyzed by analysis of variance, and were found to be statistically significant at a level of α=0.05. The developed biosensor is also suitable to determine the serum phosphate concentration, with a recovery of 86-104%, while a recovery of 102% was obtained from the water samples that were spiked with 500 µM phosphate. A relative standard deviation in the conductance response for five successive measurements (n=5) did not exceed 7%, with a shelf life of 30 days. With a lower detection limit and a higher recovery, the biosensor provides a facile approach for phosphate estimation in biological fluids.

  13. Design of a toxicity biosensor based on Aliivibrio fischeri entrapped in a disposable card.

    PubMed

    Jouanneau, Sulivan; Durand-Thouand, Marie-José; Thouand, Gérald

    2016-03-01

    The degradation of the marine environment is a subject of concern for the European authorities primarily because of its contamination by hydrocarbons. The traditional methods (ISO 11348 standard) of general toxicity assessment are unsuitable in a context of in situ monitoring, such as seaports or bathing zones. Consequently, to address this issue, bacterial biosensors appear to be pertinent tools. This article presents the design of an innovative bioluminescent biosensor dedicated to in situ toxicity monitoring. This biosensor is based on the entrapment of the wild marine bioluminescent bacterial strain Aliivibrio fischeri ATCC® 49387™ in an agarose matrix within a disposable card. A pre-study was needed to select the most biological parameters. In particular, the regenerating medium's composition and the hydrogel concentration needed for the bacterial entrapment (mechanical resistance) were optimized. Based on these data, the ability of the bacterial reporter to assess the sample toxicity was demonstrated using naphthalene as a chemical model. The biosensor's results show a lower sensitivity to naphthalene (EC50 = 95 mg/L) compared with the results obtained using the reference method (EC50 = 43 mg/L). With this architecture, the biosensor is an interesting compromise among low maintenance, ease of use, appropriate sensitivity, relatively low cost and the ability to control online toxicity.

  14. MWCNTs based high sensitive lateral flow strip biosensor for rapid determination of aqueous mercury ions.

    PubMed

    Yao, Li; Teng, Jun; Zhu, Mengya; Zheng, Lei; Zhong, Youhao; Liu, Guodong; Xue, Feng; Chen, Wei

    2016-11-15

    Here, we describe a disposable multi-walled carbon nanotubes (MWCNTs) labeled nucleic acid lateral flow strip biosensor for rapid and sensitive detection of aqueous mercury ions (Hg(2+)). Unlike the conventional colloidal gold nanoparticle based strip biosensors, the carboxylated MWCNTs were selected as the labeling substrate because of its high specific surface area for immobilization of recognition probes, improved stability and enhanced detection sensitivity of the strip biosensor. Combining the sandwich-type of T-Hg(2+)-T recognition mechanism with the optical properties of MWCNTs on lateral flow strip, optical black bands were observed on the lateral flow strips. Parameters (such as membrane category, the MWCNTs concentration, the amount of MWCNT-DNA probe, and the volume of the test probe) that govern the sensitivity and reproducibility of the sensor were optimized. The response of the optimized biosensor was highly linear over the range of 0.05-1ppb target Hg(2+), and the detection threshold was estimated at 0.05 ppb within a 15-min assay time. The sensitivity was 10-fold higher than the conventional colloidal gold based strip biosensor. More importantly, the stability of the sensor was also greatly improved with the usage of MWCNTs as the labeling.

  15. Biosensors Based on Carbon Nanotubes/Nickel Hexacyanoferrate/Glucose Oxidase Nanocomposites

    SciTech Connect

    Cui, Xiaoli; Liu, Guodong; Lin, Yuehe

    2005-09-01

    Novel hybrid films based on carbon nanotubes (CNTs)/nickel hexacyanoferrate (NiHCF) nanocomposites were synthesized, characterized, and evaluated for chemical and bio-sensing properties. Nickel hexacyanoferrate particles were electrodeposited on the porous CNT thin-film to fabricate electrochemical sensors with improved sensitivity toward hydrogen peroxide. Transmission electron microscopy illustrated the deposition of nickel hexacyanoferrate nanoparticles on the surface of carbon nanotubes. The experimental results show the electrode modified with the hybrid nanocomposite film has higher electrocatalytic activity and stability for detection of hydrogen peroxide than the electrodes modified with carbon nanotube or nickel hexacyanoferrate alone. With glucose oxidase (GOx) as an enzyme model, we constructed a biosensor based on the CNTs/NiHCF/GOx nanocomposite. Excellent linear relationship up to 1.2 mM has been attained with a slope of 5.3 μA/mM for the glucose biosensor. The response time and detection limit (S/N = 3) of the biosensor was determined to be 10 s and 1 μM, respectively. The high sensitivity to glucose of the biosensor resulted from the high surface area of carbon nanotubes and excellent electrocatalytic activity of the modifiers. The biosensor also performed with excellent reproducibility and good stability.

  16. Luminescent Iridium(III) Complex Labeled DNA for Graphene Oxide-Based Biosensors.

    PubMed

    Zhao, Qingcheng; Zhou, Yuyang; Li, Yingying; Gu, Wei; Zhang, Qi; Liu, Jian

    2016-02-02

    There has been growing interest in utilizing highly photostable iridium(III) complexes as new luminescent probes for biotechnology and life science. Herein, iridium(III) complex with carboxyl group was synthesized and activated with N-hydroxysuccinimide, followed by tagging to the amino terminate of single-stranded DNA (ssDNA). The Ir-ssDNA probe was further combined with graphene oxide (GO) nanosheets to develop a GO-based biosensor for target ssDNA detection. The quenching efficiency of GO, and the photostability of iridium(III) complex and GO-Ir-ssDNA biosensor, were also investigated. On the basis of the high luminescence quenching efficiency of GO toward iridium(III) complex, the GO-Ir-ssDNA biosensor exhibited minimal background signals, while strong emission was observed when Ir-ssDNA desorbed from GO nanosheets and formed a double helix with the specific target, leading to a high signal-to-background ratio. Moreover, it was found that luminescent intensities of iridium(III) complex and GO-Ir-ssDNA biosensor were around 15 and 3 times higher than those of the traditional carboxyl fluorescein (FAM) dye and the GO-FAM-ssDNA biosensor after UV irradiation, respectively. Our study suggested the sensitive and selective Ir-ssDNA probe was suitable for the development of highly photostable GO-based detection platforms, showing promise for application beyond the OLED (organic light emitting diode) area.

  17. Detection of parathyroid hormone using an electrochemical impedance biosensor based on PAMAM dendrimers.

    PubMed

    Özcan, Hakkı Mevlüt; Sezgintürk, Mustafa Kemal

    2015-01-01

    This paper presents a novel hormone-based impedimetric biosensor to determine parathyroid hormone (PTH) level in serum for diagnosis and monitoring treatment of hyperparathyroidism, hypoparathyroidism and thyroid cancer. The interaction between PTH and the biosensor was investigated by an electrochemical method. The biosensor was based on the gold electrode modified by 12-mercapto dodecanoic (12MDDA). Antiparathyroid hormone (anti-PTH) was covalently immobilized on to poly amidoamine dendrimer (PAMAM) which was bound to a 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide/N-hydroxysuccinimide (EDC/NHS) couple, self-assembled monolayer structure from one of the other NH2 sites. The immobilization of anti-PTH was monitored by electrochemical impedance spectroscopy, cyclic voltammetry and scanning electron microscope techniques. After the optimization studies of immobilization materials such as 12MDDA, EDC-NHS, PAMAM, and glutaraldehyde, the performance of the biosensor was investigated in terms of linearity, sensitivity, repeatability, and reproducibility. PTH was detected within a linear range of 10-60 fg/mL. Finally the described biosensor was used to monitor PTH levels in artificial serum samples.

  18. Novel impedimetric dopamine biosensor based on boronic acid functional polythiophene modified electrodes.

    PubMed

    Dervisevic, Muamer; Senel, Mehmet; Cevik, Emre

    2017-03-01

    In this study we report a new, simple and first impedimetric biosensor based on 3-Thienyl boronic acid for dopamine detection. Biosensor electrode preparation is 1min long by simple electro-polymerization of 3-Thienyl boronic acid and copolymer Thiophene P(TBA0.50Th0.50). Strong interaction between dopamine and thin layer of boronic acid has provided bio-sensing electrode high selectivity and stability, linear range of 7.8 to 125μM, and detection limit of 0.3μM. Characterization and optimization studies were conducted using electrochemical impedance spectroscopy (EIS) and cyclic voltammogram (CV). In order to test reliability of proposed biosensor real sample application study has been conducted using non-diluted human urine and it has been found that biosensor selectivity and recovery is excellent. As well P(TBA0.50Th0.50) based electrode and dopamine interaction has been proven by single frequency impedance measurements. Biosensors acquired good reproducibility, stability, selectivity and very low interference.

  19. A biosensor for urea from succinimide-modified acrylic microspheres based on reflectance transduction.

    PubMed

    Ulianas, Alizar; Heng, Lee Yook; Ahmad, Musa

    2011-01-01

    New acrylic microspheres were synthesised by photopolymerisation where the succinimide functional group was incorporated during the microsphere preparation. An optical biosensor for urea based on reflectance transduction with a large linear response range to urea was successfully developed using this material. The biosensor utilized succinimide-modified acrylic microspheres immobilized with a Nile blue chromoionophore (ETH 5294) for optical detection and urease enzyme was immobilized on the surface of the microspheres via the succinimide groups. No leaching of the enzyme or chromoionophore was observed. Hydrolysis of the urea by urease changes the pH and leads to a color change of the immobilized chromoionophore. When the color change was monitored by reflectance spectrophotometry, the linear response range of the biosensor to urea was from 0.01 to 1,000 mM (R2 = 0.97) with a limit of detection of 9.97 μM. The biosensor response showed good reproducibility (relative standard deviation = 1.43%, n = 5) with no interference by major cations such as Na+, K+, NH4+ and Mg2+. The use of reflectance as a transduction method led to a large linear response range that is better than that of many urea biosensors based on other optical transduction methods.

  20. Amperometric nitrate biosensor based on Carbon nanotube/Polypyrrole/Nitrate reductase biofilm electrode.

    PubMed

    Can, Faruk; Korkut Ozoner, Seyda; Ergenekon, Pinar; Erhan, Elif

    2012-01-01

    This study describes the construction and characterization of an amperometric nitrate biosensor based on the Polypyrrole (PPy)/Carbon nanotubes (CNTs) film. Nitrate reductase (NR) was both entrapped into the growing PPy film and chemically immobilized via the carboxyl groups of CNTs to the CNT/PPy film electrode. The optimum amperometric response for nitrate was obtained in 0.1 M phosphate buffer solution (PBS), pH 7.5 including 0.1 M lithium chloride and 7 mM potassium ferricyanide with an applied potential of 0.13 V (vs. Ag/AgCl, 3 M NaCl). Sensitivity was found to be 300 nA/mM in a linear range of 0.44-1.45 mM with a regression coefficient of 0.97. The biosensor response showed a higher linear range in comparison to standard nitrate analysis methods which were tested in this study and NADH based nitrate biosensors. A minimum detectable concentration of 0.17 mM (S/N=3) with a relative standard deviation (RSD) of 5.4% (n=7) was obtained for the biosensor. Phenol and glucose inhibit the electrochemical reaction strictly at a concentration of 1 μg/L and 20 mg/L, respectively. The biosensor response retained 70% of its initial response over 10 day usage period when used everyday.

  1. Plasmonic Biosensors

    PubMed Central

    Hill, Ryan T.

    2015-01-01

    The unique optical properties of plasmon resonant nanostructures enable exploration of nanoscale environments using relatively simple optical characterization techniques. For this reason, the field of plasmonics continues to garner the attention of the biosensing community. Biosensors based on propagating surface plasmon resonances (SPRs) in films are the most well-recognized plasmonic biosensors, but there is great potential for the new, developing technologies to surpass the robustness and popularity of film-based SPR sensing. This review surveys the current plasmonic biosensor landscape with emphasis on the basic operating principles of each plasmonic sensing technique and the practical considerations when developing a sensing platform with the various techniques. The “gold standard” film SPR technique is reviewed briefly, but special emphasis is devoted to the up-and-coming LSPR-based and plasmonically coupled sensor technology. PMID:25377594

  2. Fabrication of Electrochemical Model Influenza A Virus Biosensor Based on the Measurements of Neuroaminidase Enzyme Activity.

    PubMed

    Anik, Ülkü; Tepeli, Yudum; Diouani, Mohamed F

    2016-06-21

    Neuroaminidase (NA) enzyme is a kind of glycoprotein that is found on the influenza A virus. During infection, NA is important for the release of influenza virions from the host cell surface together with viral aggregates. It may also be involved in targeting the virus to respiratory epithelial cells. In this study, a model electrochemical influenza A viral biosensor in which receptor-binding properties have been based on NA was developed for the first time. The biosensor's working principle is based on monitoring the interactions between fetuin A and NA enzyme. The assay was monitored step by step by using electrochemical impedance spectroscopy.

  3. The Simulation of the Recharging Method Based on Solar Radiation for an Implantable Biosensor

    PubMed Central

    Li, Yun; Song, Yong; Kong, Xianyue; Li, Maoyuan; Zhao, Yufei; Hao, Qun; Gao, Tianxin

    2016-01-01

    A method of recharging implantable biosensors based on solar radiation is proposed. Firstly, the models of the proposed method are developed. Secondly, the recharging processes based on solar radiation are simulated using Monte Carlo (MC) method and the energy distributions of sunlight within the different layers of human skin have been achieved and discussed. Finally, the simulation results are verified experimentally, which indicates that the proposed method will contribute to achieve a low-cost, convenient and safe method for recharging implantable biosensors. PMID:27626422

  4. Enzyme-based electrochemical biosensors for determination of organophosphorus and carbamate pesticides

    SciTech Connect

    Everett, W.R.; Rechnitz, G.A.

    1999-01-01

    A mini review of enzyme-based electrochemical biosensors for inhibition analysis of organophosphorus and carbamate pesticides is presented. Discussion includes the most recent literature to present advances in detection limits, selectivity and real sample analysis. Recent reviews on the monitoring of pesticides and their residues suggest that the classical analytical techniques of gas and liquid chromatography are the most widely used methods of detection. These techniques, although very accurate in their determinations, can be quite time consuming and expensive and usually require extensive sample clean up and pro-concentration. For these and many other reasons, the classical techniques are very difficult to adapt for field use. Numerous researchers, in the past decade, have developed and made improvements on biosensors for use in pesticide analysis. This mini review will focus on recent advances made in enzyme-based electrochemical biosensors for the determinations of organophosphorus and carbamate pesticides.

  5. Tetrahedral DNA nanostructure-based microRNA biosensor coupled with catalytic recycling of the analyte.

    PubMed

    Miao, Peng; Wang, Bidou; Chen, Xifeng; Li, Xiaoxi; Tang, Yuguo

    2015-03-25

    MicroRNAs are not only important regulators of a wide range of cellular processes but are also identified as promising disease biomarkers. Due to the low contents in serum, microRNAs are always difficult to detect accurately . In this study, an electrochemical biosensor for ultrasensitive detection of microRNA based on tetrahedral DNA nanostructure is developed. Four DNA single strands are engineered to form a tetrahedral nanostructure with a pendant stem-loop and modified on a gold electrode surface, which largely enhances the molecular recognition efficiency. Moreover, taking advantage of strand displacement polymerization, catalytic recycling of microRNA, and silver nanoparticle-based solid-state Ag/AgCl reaction, the proposed biosensor exhibits high sensitivity with the limit of detection down to 0.4 fM. This biosensor shows great clinical value and may have practical utility in early diagnosis and prognosis of certain diseases.

  6. Label-free DNA biosensor based on resistance change of platinum nanoparticles assemblies.

    PubMed

    Skotadis, Evangelos; Voutyras, Konstantinos; Chatzipetrou, Marianneza; Tsekenis, Georgios; Patsiouras, Lampros; Madianos, Leonidas; Chatzandroulis, Stavros; Zergioti, Ioanna; Tsoukalas, Dimitris

    2016-07-15

    A novel nanoparticle based biosensor for the fast and simple detection of DNA hybridization events is presented. The sensor utilizes hybridized DNA's charge transport properties, combining them with metallic nanoparticle networks that act as nano-gapped electrodes. The DNA hybridization events can be detected by a significant reduction in the sensor's resistance due to the conductive bridging offered by hybridized DNA. By modifying the nanoparticle surface coverage, which can be controlled experimentally being a function of deposition time, and the structural properties of the electrodes, an optimized biosensor for the in situ detection of DNA hybridization events is ultimately fabricated. The fabricated biosensor exhibits a wide response range, covering four orders of magnitude, a limit of detection of 1nM and can detect a single base pair mismatch between probe and complementary DNA.

  7. Construction of Protein-Based Biosensors Using Ligand-Directed Chemistry for Detecting Analyte Binding.

    PubMed

    Yamaura, Kei; Kiyonaka, Shigeki; Hamachi, Itaru

    2017-01-01

    Protein-based fluorescent biosensors are powerful tools for quantitative detection of biomolecules or drugs with high sensitivity under physiological conditions. However, conventional methods for construction of biosensors require structural data with high resolution or amino acid sequence information in most cases, which hampers applicability of this method to structurally complicated receptor proteins. To sidestep such limitations, we recently developed a new method that employs ligand-directed chemistry coupled with a bimolecular fluorescence quenching and recovery system, which enabled the conversion of various kinds of membrane-bound receptors to "turn-on" type fluorescent sensors. Here, we describe a protocol for construction of "turn-on" type fluorescent biosensors based on the GABAA receptor which permits quantitative analysis of the ligand affinity.

  8. Development of conductometric biosensors based on alkaline phosphatases for the water quality control

    NASA Astrophysics Data System (ADS)

    Berezhetskyy, A.

    2008-09-01

    Researches are focused on the elaboration of enzymatic microconductometric device for heavy metal ions detection in water solutions. The manuscript includes a general introduction, the first chapter contains bibliographic review, the second chapter described the fundamentals of conductometric transducers, the third chapter examining the possibility to create and to optimize conductometric biosensor based on bovine alkaline phosphatase for heavy metals ions detection, the fourth chapter devoted to creation and optimization of conductometric biosensor based on alkaline phosphatase active microalgae and sol gel technology, the last chapter described application of the proposed algal biosensor for measurements of heavy metal ions toxicity of waste water, general conclusions stating the progresses achieved in the field of environmental monitoring

  9. Diamond-based protective layer for optical biosensors

    NASA Astrophysics Data System (ADS)

    Majchrowicz, D.; Ficek, M.; Baran, T.; WÄ sowicz, M.; Struk, P.; Jedrzejewska-Szczerska, M.

    2016-09-01

    Optical biosensors have become a powerful alternative to the conventional ways of measurement owing to their great properties, such as high sensitivity, high dynamic range, cost effectiveness and small size. Choice of an optical biosensor's materials is an important factor and impacts the quality of the obtained spectra. Examined biological objects are placed on a cover layer which may react with samples in a chemical, biological and mechanical way, therefore having a negative impact on the measurement reliability. Diamond, a metastable allotrope of carbon with sp3 hybridization, shows outstanding properties such as: great chemical stability, bio-compatibility, high thermal conductivity, wide bandgap and optical transparency. Additionally it possesses great mechanical durability, which makes it a long-lasting material. The protective diamond thin films were deposited on the substrate using Microwave Plasma Assisted Chemical Vapor Deposition (MW PA CVD) system. The surface morphology and roughness was assessed with atomic force microscopy and profilometry. We have performed a series of measurements to assess the biocompatibility of diamond thin films with whole blood. The results show that thin diamond protective layer does not affect the red blood cells, while retaining the sensors high resolution and dynamic range of measurement. Therefore, we conclude that diamond thin films are a viable protective coating for optical biosensors, which allows to examine many biological elements. We project that it can be particularly useful not only for biological objects but also under extreme conditions like radioactive or chemically aggressive environments and high temperatures.

  10. Creatinine and urea biosensors based on a novel ammonium ion-selective copper-polyaniline nano-composite.

    PubMed

    Zhybak, M; Beni, V; Vagin, M Y; Dempsey, E; Turner, A P F; Korpan, Y

    2016-03-15

    The use of a novel ammonium ion-specific copper-polyaniline nano-composite as transducer for hydrolase-based biosensors is proposed. In this work, a combination of creatinine deaminase and urease has been chosen as a model system to demonstrate the construction of urea and creatinine biosensors to illustrate the principle. Immobilisation of enzymes was shown to be a crucial step in the development of the biosensors; the use of glycerol and lactitol as stabilisers resulted in a significant improvement, especially in the case of the creatinine, of the operational stability of the biosensors (from few hours to at least 3 days). The developed biosensors exhibited high selectivity towards creatinine and urea. The sensitivity was found to be 85 ± 3.4 mAM(-1)cm(-2) for the creatinine biosensor and 112 ± 3.36 mAM(-1)cm(-2) for the urea biosensor, with apparent Michaelis-Menten constants (KM,app), obtained from the creatinine and urea calibration curves, of 0.163 mM for creatinine deaminase and 0.139 mM for urease, respectively. The biosensors responded linearly over the concentration range 1-125 µM, with a limit of detection of 0.5 µM and a response time of 15s. The performance of the biosensors in a real sample matrix, serum, was evaluated and a good correlation with standard spectrophotometric clinical laboratory techniques was found.

  11. A Simple Visual Ethanol Biosensor Based on Alcohol Oxidase Immobilized onto Polyaniline Film for Halal Verification of Fermented Beverage Samples

    PubMed Central

    Kuswandi, Bambang; Irmawati, Titi; Hidayat, Moch Amrun; Jayus; Ahmad, Musa

    2014-01-01

    A simple visual ethanol biosensor based on alcohol oxidase (AOX) immobilised onto polyaniline (PANI) film for halal verification of fermented beverage samples is described. This biosensor responds to ethanol via a colour change from green to blue, due to the enzymatic reaction of ethanol that produces acetaldehyde and hydrogen peroxide, when the latter oxidizes the PANI film. The procedure to obtain this biosensor consists of the immobilization of AOX onto PANI film by adsorption. For the immobilisation, an AOX solution is deposited on the PANI film and left at room temperature until dried (30 min). The biosensor was constructed as a dip stick for visual and simple use. The colour changes of the films have been scanned and analysed using image analysis software (i.e., ImageJ) to study the characteristics of the biosensor's response toward ethanol. The biosensor has a linear response in an ethanol concentration range of 0.01%–0.8%, with a correlation coefficient (r) of 0.996. The limit detection of the biosensor was 0.001%, with reproducibility (RSD) of 1.6% and a life time up to seven weeks when stored at 4 °C. The biosensor provides accurate results for ethanol determination in fermented drinks and was in good agreement with the standard method (gas chromatography) results. Thus, the biosensor could be used as a simple visual method for ethanol determination in fermented beverage samples that can be useful for Muslim community for halal verification. PMID:24473284

  12. A simple visual ethanol biosensor based on alcohol oxidase immobilized onto polyaniline film for halal verification of fermented beverage samples.

    PubMed

    Kuswandi, Bambang; Irmawati, Titi; Hidayat, Moch Amrun; Jayus; Ahmad, Musa

    2014-01-27

    A simple visual ethanol biosensor based on alcohol oxidase (AOX) immobilised onto polyaniline (PANI) film for halal verification of fermented beverage samples is described. This biosensor responds to ethanol via a colour change from green to blue, due to the enzymatic reaction of ethanol that produces acetaldehyde and hydrogen peroxide, when the latter oxidizes the PANI film. The procedure to obtain this biosensor consists of the immobilization of AOX onto PANI film by adsorption. For the immobilisation, an AOX solution is deposited on the PANI film and left at room temperature until dried (30 min). The biosensor was constructed as a dip stick for visual and simple use. The colour changes of the films have been scanned and analysed using image analysis software (i.e., ImageJ) to study the characteristics of the biosensor's response toward ethanol. The biosensor has a linear response in an ethanol concentration range of 0.01%-0.8%, with a correlation coefficient (r) of 0.996. The limit detection of the biosensor was 0.001%, with reproducibility (RSD) of 1.6% and a life time up to seven weeks when stored at 4 °C. The biosensor provides accurate results for ethanol determination in fermented drinks and was in good agreement with the standard method (gas chromatography) results. Thus, the biosensor could be used as a simple visual method for ethanol determination in fermented beverage samples that can be useful for Muslim community for halal verification.

  13. A commercial MOSFET-based biosensor with a gold extended gate electrode

    NASA Astrophysics Data System (ADS)

    Lyu, Hong-Kun; Choi, Young-Sam; Shin, Jang-Kyoo; Kim, Jae-Hyun

    2009-05-01

    This paper presents a commercial metal-oxide-semiconductor field-effect transistor (MOSFET)-based biosensor with a gold extended-gate electrode for the electronic detection of C-reactive protein (CRP). From a component point of view, the commercial MOSFET-based biosensor consists of a commercial MOSFET with a socket for connecting the gold electrode which was fixed on a printed circuit board (PCB) and a reaction-vessel module which was assembled with the gold electrode and the Ag/AgCl reference electrode. The gold electrode with only one gold layer was fabricated on a glass substrate simply and it was used as the extended-gate metal to form a self-assembled monolayer (SAM). The binding of the CRP to anti-CRP was detected by measuring the electrical characteristics of the biosensor. Variation of the drain current before and after the interaction of CRP and anti-CRP was about 1.2mA on the measured IDS-VDS and real-time characteristics. The concentration of the CRP solution was adjusted to 10μg/ml by dissolving in PBS. The change of surface voltage of the gold extended-gate electrode was about 30mV by IDS-VGS characteristic curve of the commercial MOSFET. Therefore, it is confirmed that the detection of CRP is possible by measuring the drain current of the commercial MOSFET. The proposed biosensor might open up a new possibility for FET-based biosensors with lowcost and simple construction. It is expected that the commercial MOSFET-based biosensor with the gold extended-gate electrode could also be used for detecting various biomarkers by modifying the surface of the gold extended-gate electrode.

  14. Selective patterning of Si-based biosensor surfaces using isotropic silicon etchants.

    PubMed

    Biggs, Bradley W; Hunt, Heather K; Armani, Andrea M

    2012-03-01

    Ultra-sensitive, label-free biosensors have the potential to have a tremendous impact on fields like medical diagnostics. For the majority of these Si-based integrated devices, it is necessary to functionalize the surface with a targeting ligand in order to perform specific biodetection. To do this, silane coupling agents are commonly used to immobilize the targeting ligand. However, this method typically results in the bioconjugation of the entire device surface, which is undesirable. To compensate for this effect, researchers have developed complex blocking strategies that result in selective patterning of the sensor surface. Recently, silane coupling agents were used to attach biomolecules to the surface of silica toroidal biosensors integrated on a silicon wafer. Interestingly, only the silica biosensor surface was conjugated. Here, we hypothesize why this selective patterning occurred. Specifically, the silicon etchant (xenon difluoride), which is used in the fabrication of the biosensor, appears to reduce the efficiency of the silane coupling attachment to the underlying silicon wafer. These results will enable future researchers to more easily control the bioconjugation of their sensor surfaces, thus improving biosensor device performance.

  15. Nanomaterial-based biosensors using dual transducing elements for solution phase detection.

    PubMed

    Li, Ning; Su, Xiaodi; Lu, Yi

    2015-05-07

    Biosensors incorporating nanomaterials have demonstrated superior performance compared to their conventional counterparts. Most reported sensors use nanomaterials as a single transducer of signals, while biosensor designs using dual transducing elements have emerged as new approaches to further improve overall sensing performance. This review focuses on recent developments in nanomaterial-based biosensors using dual transducing elements for solution phase detection. The review begins with a brief introduction of the commonly used nanomaterial transducers suitable for designing dual element sensors, including quantum dots, metal nanoparticles, upconversion nanoparticles, graphene, graphene oxide, carbon nanotubes, and carbon nanodots. This is followed by the presentation of the four basic design principles, namely Förster Resonance Energy Transfer (FRET), Amplified Fluorescence Polarization (AFP), Bio-barcode Assay (BCA) and Chemiluminescence (CL), involving either two kinds of nanomaterials, or one nanomaterial and an organic luminescent agent (e.g. organic dyes, luminescent polymers) as dual transducers. Biomolecular and chemical analytes or biological interactions are detected by their control of the assembly and disassembly of the two transducing elements that change the distance between them, the size of the fluorophore-containing composite, or the catalytic properties of the nanomaterial transducers, among other property changes. Comparative discussions on their respective design rules and overall performances are presented afterwards. Compared with the single transducer biosensor design, such a dual-transducer configuration exhibits much enhanced flexibility and design versatility, allowing biosensors to be more specifically devised for various purposes. The review ends by highlighting some of the further development opportunities in this field.

  16. Disposable bioluminescence-based biosensor for detection of bacterial count in food.

    PubMed

    Luo, Jinping; Liu, Xiaohong; Tian, Qing; Yue, Weiwei; Zeng, Jing; Chen, Guangquan; Cai, Xinxia

    2009-11-01

    A biosensor for rapid detection of bacterial count based on adenosine 5'-triphosphate (ATP) bioluminescence has been developed. The biosensor is composed of a key sensitive element and a photomultiplier tube used as a detector element. The disposable sensitive element consists of a sampler, a cartridge where intracellular ATP is chemically extracted from bacteria, and a microtube where the extracted ATP reacts with the luciferin-luciferase reagent to produce bioluminescence. The bioluminescence signal is transformed into relevant electrical signal by the detector and further measured with a homemade luminometer. Parameters affecting the amount of the extracted ATP, including the types of ATP extractants, the concentrations of ATP extractant, and the relevant neutralizing reagent, were optimized. Under the optimal experimental conditions, the biosensor showed a linear response to standard bacteria in a concentration range from 10(3) to 10(8) colony-forming units (CFU) per milliliter with a correlation coefficient of 0.925 (n=22) within 5min. Moreover, the bacterial count of real food samples obtained by the biosensor correlated well with those by the conventional plate count method. The proposed biosensor, with characteristics of low cost, easy operation, and fast response, provides potential application to rapid evaluation of bacterial contamination in the food industry, environment monitoring, and other fields.

  17. An immuno-biosensor system based on quartz crystal microbalance for avian influenza virus detection

    NASA Astrophysics Data System (ADS)

    Liu, Shengping; Chen, Guoming; Zhou, Qi; Wei, Yunlong

    2007-12-01

    For the quick detection of Avian Influenza Virus (AIV), a biosensor based on Quartz Crystal Microbalance (QCM) was fabricated according to the specific bonding principle between antibody and antigen. Staphylococcal Protein A (SPA) was extracted from Staphylococcus and purified. Then SPA was coated on the surface of QCM for immobilizing AIV monoclonal antibodies. The use of AIV monoclonal antibody could enhance the specificity of the immuno-biosensor. A multi-channel piezoelectricity detection system for the immuno-biosensor was developed. The system can work for the quick detection of AIV antigen in the case of the entirely aqueous status owe to one special oscillating circuit designed in this work. The optimum conditions of SPA coating and AIV monoclonal antibody immobilization were investigated utilizing the multi-channel detection system. The preliminary application of the immuno-biosensor system for detection of AIV was evaluated. Results indicate that the immuno-biosensor system can detect the AIV antigens with a linear range of 3-200ng/ml. The system can accomplish the detection of AIV antigens around 40 minutes.

  18. New urea biosensor based on urease enzyme obtained from Helycobacter pylori.

    PubMed

    Dindar, Bahar; Karakuş, Emine; Abasıyanık, Fatih

    2011-11-01

    The urease enzyme of Helicobacter pylori was isolated from biopsy sample obtained from antrum big curvature cell extracts. A new urea biosensor was prepared by immobilizing urease enzyme isolated from Helicobacter pylori on poly(vinylchloride) (PVC) ammonium membrane electrode by using nonactine as an ammonium ionophore. The effect of pH, buffer concentration, and temperature for the biosensor prepared with urease from H. pylori were obtained as 6.0, 5 mM, and 25 °C, respectively. We also investigated urease concentration, stirring rate, and enzyme immobilization procedures in response to urea of the enzyme electrode. The linear working range of the biosensor extends from 1 × 10(-5) to 1 × 10(-2) M and they showed an apparent Nernstian response within this range. Urea enzyme electrodes prepared with urease enzymes obtained from H. pylori and Jack bean based on PVC membrane ammonium-selective electrode showed very good analytical parameters: high sensitivity, dynamic stability over 2 months with less decrease of sensitivity, response time 1-2 min. The analytical characteristics were investigated and were compared those of the urea biosensor prepared with urease enzyme isolated from Jack bean prepared at the same conditions. It was observed that rapid determinations of human serum urea amounts were also made possible with both biosensors.

  19. Nanometal-decorated exfoliated graphite nanoplatelet based glucose biosensors with high sensitivity and fast response.

    PubMed

    Lu, Jue; Do, Inhwan; Drzal, Lawrence T; Worden, Robert M; Lee, Ilsoon

    2008-09-23

    We report the novel fabrication of a highly sensitive, selective, fast responding, and affordable amperometric glucose biosensor using exfoliated graphite nanoplatelets (xGnPs) decorated with Pt and Pd nanoparticles. Nafion was used to solubilize metal-decorated graphite nanoplatelets, and a simple cast method with high content organic solvent (85 wt %) was used to prepare the biosensors. The addition of precious metal nanoparticles such as platinum (Pt) and palladium (Pd) to xGnP increased the electroactive area of the electrode and substantially decreased the overpotential in the detection of hydrogen peroxide. The Pt-xGnP glucose biosensor had a sensitivity of 61.5+/-0.6 microA/(mM x cm(2)) and gave a linear response up to 20 mM. The response time and detection limit (S/N=3) were determined to be 2 s and 1 microM, respectively. Therefore, this novel glucose biosensor based on the Pt nanoparticle coated xGnP is among the best reported to date in both sensing performance and production cost. In addition, the effects of metal nanoparticle loading and the particle size on the biosensor performance were systematically investigated.

  20. A novel biosensor based on Lactobacillus acidophilus for determination of phenolic compounds in milk products and wastewater.

    PubMed

    Sagiroglu, Ayten; Paluzar, Hatice; Ozcan, Hakki Mevlut; Okten, Suzan; Sen, Burhan

    2011-01-01

    Different branches of industry need to use phenolic compounds (PCs) in their production, so determination of PCs sensitively, accurately, rapidly, and economically is very important. For the sensitive determination of PCs, some biosensors based on pure polyphenol oxidase, plant tissue and microorganisms were developed before. But there has been no study to develop a microbial phenolic compounds biosensor based on Lactobacillus species, which contain polyphenol oxidase enzyme. In this study, we used different forms of Lactobacillus species as enzyme sources of biosensor and compared biosensor performances of these forms for determination of PCs. For this purpose, we used lyophilized Lactobacillus cells (containing L. bulgaricus, L. acidophilus, Streptococcus thermophilus), pure L. acidophilus, pure L. bulgaricus, and L. acidophilus- and L. bulgaricus adapted to catechol in Lactobacilli MRS Broth. The most suitable form was determined and optimization studies of the biosensor were carried out by using this form. For preparing the bioactive layer of the biosensor, the Lactobacillus cells were immobilized in gelatin by using glutaraldehyde. In the study, we used catechol as a substrate. Phenolic compound determination is based on the assay of the differences on the respiration activity of the cells on the oxygen meter in the absence and the presence of catechol. The microbial biosensor response depends directly on catechol concentration between 0.5 and 5.0 mM with 18 min response time. In the optimization studies of the microbial biosensor the most suitable microorganism amount was found to be 10 mg, and also phosphate buffer (pH 8.0; 50 mM) and 37.5 °C were obtained as the optimum working conditions. In the characterization studies of the microbial biosensor some parameters such as substrate specificity on the biosensor response and operational and storage stability were examine. Furthermore, the determination of PC levels in synthetic wastewater, industrial

  1. A disposable biosensor based on immobilization of laccase with silica spheres on the MWCNTs-doped screen-printed electrode

    PubMed Central

    2012-01-01

    Background Biosensors have attracted increasing attention as reliable analytical instruments in in situ monitoring of public health and environmental pollution. For enzyme-based biosensors, the stabilization of enzymatic activity on the biological recognition element is of great importance. It is generally acknowledged that an effective immobilization technique is a key step to achieve the construction quality of biosensors. Results A novel disposable biosensor was constructed by immobilizing laccase (Lac) with silica spheres on the surface of multi-walled carbon nanotubes (MWCNTs)-doped screen-printed electrode (SPE). Then, it was characterized in morphology and electrochemical properties by scanning electron microscopy (SEM) and cyclic voltammetry (CV). The characterization results indicated that a high loading of Lac and a good electrocatalytic activity could be obtained, attributing to the porous structure, large specific area and good biocompatibility of silica spheres and MWCNTs. Furthermore, the electrochemical sensing properties of the constructed biosensor were investigated by choosing dopamine (DA) as the typical model of phenolic compounds. It was shown that the biosensor displays a good linearity in the range from 1.3 to 85.5 μM with a detection limit of 0.42 μM (S/N = 3), and the Michaelis-Menten constant (Kmapp) was calculated to be 3.78 μM. Conclusion The immobilization of Lac was successfully achieved with silica spheres to construct a disposable biosensor on the MWCNTs-doped SPE (MWCNTs/SPE). This biosensor could determine DA based on a non-oxidative mechanism in a rapid, selective and sensitive way. Besides, the developed biosensor could retain high enzymatic activity and possess good stability without cross-linking reagents. The proposed immobilization approach and the constructed biosensor offer a great potential for the fabrication of the enzyme-based biosensors and the analysis of phenolic compounds. PMID:22986118

  2. A Multi-Walled Carbon Nanotube-based Biosensor for Monitoring Microcystin-LR in Sources of Drinking Water Supplies

    EPA Science Inventory

    A multi-walled carbon nanotube-based electrochemical biosensor is developed for monitoring microcystin-LR (MC-LR), a toxic cyanobacterial toxin, in sources of drinking water supplies. The biosensor electrodes are fabricated using dense, mm-long multi-walled CNT (MWCNT) arrays gro...

  3. Biosensor-based real-time monitoring of paracetamol photocatalytic degradation.

    PubMed

    Calas-Blanchard, Carole; Istamboulié, Georges; Bontoux, Margot; Plantard, Gaël; Goetz, Vincent; Noguer, Thierry

    2015-07-01

    This paper presents for the first time the integration of a biosensor for the on-line, real-time monitoring of a photocatalytic degradation process. Paracetamol was used as a model molecule due to its wide use and occurrence in environmental waters. The biosensor was developed based on tyrosinase immobilization in a polyvinylalcohol photocrosslinkable polymer. It was inserted in a computer-controlled flow system installed besides a photocatalytic reactor including titanium dioxide (TiO2) as photocatalyst. It was shown that the biosensor was able to accurately monitor the paracetamol degradation with time. Compared with conventional HPLC analysis, the described device provides a real-time information on the reaction advancement, allowing a better control of the photodegradation process.

  4. Development and Electrochemical Investigations of an EIS- (Electrolyte-Insulator-Semiconductor) based Biosensor for Cyanide Detection

    PubMed Central

    Turek, Monika; Ketterer, Lothar; Claβen, Melanie; Berndt, Heinz K.; Elbers, Gereon; Krüger, Peter; Keusgen, Michael; Schöning, Michael J.

    2007-01-01

    A cyanide biosensor based on a pH-sensitive p-doped electrolyte-insulator-semiconductor (EIS) structure with an immobilised enzyme (cyanidase) is realised at the laboratory scale. The immobilisation of the cyanidase is performed in two distinct steps: first, the covalent coupling of cyanidase to an N-hydroxysuccinimide- (NHS) activated Sepharose™ gel and then, the physical entrapment of NHS-activated Sepharose™ with the immobilised cyanidase in a dialysis membrane onto the EIS structure. The immobilisation of the cyanidase to the NHS-activated Sepharose™ is studied by means of gel electrophoresis measurements and investigations using an ammonia- (NH3) selective electrode. For the electrochemical characterisation of the cyanide biosensor, capacitance/voltage and constant capacitance measurements, respectively, have been carried out. A differential measurement procedure is presented to evaluate the cyanide concentration-dependent biosensor signals.

  5. Electrochemical DNA biosensor based on avidin-biotin conjugation for influenza virus (type A) detection

    NASA Astrophysics Data System (ADS)

    Chung, Da-Jung; Kim, Ki-Chul; Choi, Seong-Ho

    2011-09-01

    An electrochemical DNA biosensor (E-DNA biosensor) was fabricated by avidin-biotin conjugation of a biotinylated probe DNA, 5'-biotin-ATG AGT CTT CTA ACC GAG GTC GAA-3', and an avidin-modified glassy carbon electrode (GCE) to detect the influenza virus (type A). An avidin-modified GCE was prepared by the reaction of avidin and a carboxylic acid-modified GCE, which was synthesized by the electrochemical reduction of 4-carboxyphenyl diazonium salt. The current value of the E-DNA biosensor was evaluated after hybridization of the probe DNA and target DNA using cyclic voltammetry (CV). The current value decreased after the hybridization of the probe DNA and target DNA. The DNA that was used follows: complementary target DNA, 5'-TTC GAC CTC GGT TAG AAG ACT CAT-3' and two-base mismatched DNA, 5'-TTC GAC AGC GGT TAT AAG ACT CAT-3'.

  6. Biomolecule immobilization in biosensor development: tailored strategies based on affinity interactions.

    PubMed

    Prieto-Simín, B; Campàs, M; Marty, J-L

    2008-01-01

    The exponential development of biosensors as powerful analytical tools in the last four decades mainly relies on the high sensitivity and selectivity offered when detecting the target analyte. The transducer and the biological receptor are the bases of the biosensor development. Nevertheless, the bioreceptor immobilisation is also important, playing a key role in the retention of the biological activity, and thus affecting the sensitivity. Parameters such as shelf-life and surface regeneration also depend on the biomolecule immobilisation. Researchers are focusing their efforts towards random and oriented immobilisation procedures. Adsorption, entrapment, cross-linking and electrostatic interactions provide randomly immobilised biomolecules, sometimes partially hindering their biological activity. Covalent binding and affinity interactions may enable oriented biomolecule immobilisations, providing controlled, reproducible and highly active modified surfaces. This paper reviews the main immobilisation strategies used in the biosensors development, putting special emphasis on our contribution to mild and oriented immobilisation techniques.

  7. Simulation of the Recharging Method of Implantable Biosensors Based on a Wearable Incoherent Light Source

    PubMed Central

    Song, Yong; Hao, Qun; Kong, Xianyue; Hu, Lanxin; Cao, Jie; Gao, Tianxin

    2014-01-01

    Recharging implantable electronics from the outside of the human body is very important for applications such as implantable biosensors and other implantable electronics. In this paper, a recharging method for implantable biosensors based on a wearable incoherent light source has been proposed and simulated. Firstly, we develop a model of the incoherent light source and a multi-layer model of skin tissue. Secondly, the recharging processes of the proposed method have been simulated and tested experimentally, whereby some important conclusions have been reached. Our results indicate that the proposed method will offer a convenient, safe and low-cost recharging method for implantable biosensors, which should promote the application of implantable electronics. PMID:25372616

  8. AuNPs modified, disposable, ITO based biosensor: Early diagnosis of heat shock protein 70.

    PubMed

    Sonuç Karaboğa, Münteha Nur; Şimşek, Çiğdem Sayıklı; Sezgintürk, Mustafa Kemal

    2016-10-15

    This paper describes a novel, simple, and disposable immunosensor based on indium-tin oxide (ITO) sheets modified with gold nanoparticles to sensitively analyze heat shock protein 70 (HSP70), a potential biomarker that could be evaluated in diagnosis of some carcinomas. Disposable ITO coated Polyethylene terephthalate (PET) electrodes were used and modified with gold nanoparticles in order to construct the biosensors. Optimization and characterization steps were analyzed by electrochemical techniques such as electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). Surface morphology of the biosensor was also identified by electrochemical methods, scanning electron microscopy (SEM), and atomic force microscopy (AFM). To interpret binding characterization of HSP70 to anti-HSP70 single frequency impedance method was successfully operated. Moreover, the proposed HSP70 immunosensor acquired good stability, repeatability, and reproducibility. Ultimately, proposed biosensor was introduced to real human serum samples to determine HSP70 sensitively and accurately.

  9. The detection of Salmonella typhimurium on shell eggs using a phage-based biosensor

    NASA Astrophysics Data System (ADS)

    Chai, Yating; Li, Suiqiong; Horikawa, Shin; Shen, Wen; Park, Mi-Kyung; Vodyanoy, Vitaly J.; Chin, Bryan A.

    2011-06-01

    This paper presents the direct detection of Salmonella typhimurium on shell eggs using a phage-based magnetoelastic (ME) biosensor. The ME biosensor consists of a ME resonator as the sensor platform and E2 phage as the biorecognition element that is genetically engineered to specifically bind with Salmonella typhimurium. The ME biosensor, which is a wireless sensor, vibrates with a characteristic resonant frequency under an externally applied magnetic field. Multiple sensors can easily be remotely monitored. Multiple measurement and control sensors were placed on the shell eggs contaminated by Salmonella typhimurium solutions with different known concentrations. The resonant frequency of sensors before and after the exposure to the spiked shell eggs was measured. The frequency shift of the measurement sensors was significantly different than the control sensors indicating Salmonella contamination. Scanning electron microscopy was used to confirm binding of Salmonella to the sensor surface and the resulting frequency shift results.

  10. A yeast co-culture-based biosensor for determination of waste water contamination levels.

    PubMed

    Yudina, N Yu; Arlyapov, V A; Chepurnova, M A; Alferov, S V; Reshetilov, A N

    2015-10-01

    Artificial microbial co-cultures were formed to develop the receptor element of a biosensor for assessment of biological oxygen demand (BOD). The co-cultures possessed broad substrate specificities and enabled assays of water and fermentation products within a broad BOD range (2.4-80 mg/dm(3)) with a high correlation to the standard method (R = 0.9988). The use of the co-cultures of the yeasts Pichia angusta, Arxula adeninivorans and Debaryomyces hansenii immobilized in N-vinylpyrrolidone-modified poly(vinyl alcohol) enabled developing a BOD biosensor possessing the characteristics not inferior to those in the known biosensors. The results are indicative of a potential of using these co-cultures as the receptor element base in prototype models of instruments for broad application.

  11. A novel fiber optic biosensor for nitric oxide determination based on vicinal diaminobenzozcridine fluorescent probe

    NASA Astrophysics Data System (ADS)

    Ding, Liyun; Huang, Lanfen; Huang, Jun; Zhong, Yunming; Fan, Dian

    2010-04-01

    A novel fiber optic biosensor for the determination of nitric oxide based on vicinal diaminobenzozcridine (VDABA) fluorescent probe was designed and fabricated. The reaction conditions between VDABA and NO, which include concentration of VDABA, temperature and pH, were studied in-depth. The sensitivity of VDABA for NO detection under the optimum conditions and its optical properties were also investigated. The fluorescence responses were concentration-dependent and a good linear relationship (R2=0.9863) was observed over the range 1.8×10-6 to 9×10-6 mol/L NO, the regression equation was F = 3.8889[NO] (mol/L)+217.2. Besides, a complex sensitive film embedding VDABA in cellulose acetate (CA) was prepared, and a fiber optic NO biosensor was fabricated using this film. Then the change of fluorescence phase shift of this biosensor was studied preliminarily by means of the lock-in technology.

  12. A protease-based biosensor for the detection of schistosome cercariae

    PubMed Central

    Webb, A. J.; Kelwick, R.; Doenhoff, M. J.; Kylilis, N.; MacDonald, J. T.; Wen, K. Y.; McKeown, C.; Baldwin, G.; Ellis, T.; Jensen, K.; Freemont, P. S.

    2016-01-01

    Parasitic diseases affect millions of people worldwide, causing debilitating illnesses and death. Rapid and cost-effective approaches to detect parasites are needed, especially in resource-limited settings. A common signature of parasitic diseases is the release of specific proteases by the parasites at multiple stages during their life cycles. To this end, we engineered several modular Escherichia coli and Bacillus subtilis whole-cell-based biosensors which incorporate an interchangeable protease recognition motif into their designs. Herein, we describe how several of our engineered biosensors have been applied to detect the presence and activity of elastase, an enzyme released by the cercarial larvae stage of Schistosoma mansoni. Collectively, S. mansoni and several other schistosomes are responsible for the infection of an estimated 200 million people worldwide. Since our biosensors are maintained in lyophilised cells, they could be applied for the detection of S. mansoni and other parasites in settings without reliable cold chain access. PMID:27090566

  13. Nanotechnology and biosensors.

    PubMed

    Jianrong, Chen; Yuqing, Miao; Nongyue, He; Xiaohua, Wu; Sijiao, Li

    2004-09-01

    Nanotechnology is playing an increasingly important role in the development of biosensors. The sensitivity and performance of biosensors is being improved by using nanomaterials for their construction. The use of these nanomaterials has allowed the introduction of many new signal transduction technologies in biosensors. Because of their submicron dimensions, nanosensors, nanoprobes and other nanosystems have allowed simple and rapid analyses in vivo. Portable instruments capable of analyzing multiple components are becoming available. This work reviews the status of the various nanostructure-based biosensors. Use of the self-assembly techniques and nano-electromechanical systems (NEMS) in biosensors is discussed.

  14. Polymer slab waveguides for the optical detection of nanoparticles in evanescent field based biosensors

    NASA Astrophysics Data System (ADS)

    Teigell Beneitez, Nuria; Missinne, Jeroen; Schleipen, Jean; Orsel, Joke; Prins, Menno W. J.; Van Steenberge, Geert

    2014-02-01

    We present a polymer optical waveguide integration technology for the detection of nanoparticles in an evanescent field based biosensor. In the proposed biosensor concept, super-paramagnetic nanoparticles are used as optical contrast labels. The nanoparticles capture target molecules from a sample fluid and bind to the sensor surface with biological specificity. The surface-bound nanoparticles are then detected using frustration of an evanescent field. In the current paper we elaborate on the polymer waveguides which are used to generate a well-defined optical field for nanoparticle detection.

  15. Alcohol biosensor based on alcohol dehydrogenase and Meldola Blue immobilized into a carbon paste electrode.

    PubMed

    García Mullor, S; Sánchez-Cabezudo, M; Miranda Ordieres, A J; López Ruiz, B

    1996-05-01

    A yeast alcohol dehydrogenase amperometric carbon paste-based biosensor, with Meldola Blue as a mediator and a dialysis membrane with a very small molecular weight cut-off for protection, is described. The influence of membrane pore size on the stability and overall kinetics of the biosensor is shown using cyclic voltammetry and stationary potential measurements. The operating potential is + 50 mV vs. Ag/AgCl, KCl sat. reference electrode. Application of this device to the determination of ethanol in alcoholic beverages was achieved successfully. In these kinds of samples and at this working potential no interferences were found.

  16. Francisella tularensis detection using magnetic labels and a magnetic biosensor based on frequency mixing

    NASA Astrophysics Data System (ADS)

    Meyer, Martin H. F.; Krause, Hans-Joachim; Hartmann, Markus; Miethe, Peter; Oster, Jürgen; Keusgen, Michael

    2007-04-01

    A biosensor that uses resonant coils with a special frequency-mixing technique and magnetic beads as detectable labels has been established for the detection of Francisella tularensis, the causative agent for tularemia. The detection principle is based on a sandwich immunoassay using an anti-Ft antibody for immunofiltration immobilized to ABICAP ® polyethylene filters, and biotinylated with streptavidin-coated magnetic beads as labels. The linear detection range of this biosensor was found to be 10 4-10 6 cfu F. tularensis lipopolysaccharide (LPS) per ml. Tested sample matrices were physiological PBS buffer and rabbit serum.

  17. Nanostructured silicon-based biosensors for the selective identification of analytes of social interest

    NASA Astrophysics Data System (ADS)

    D'Auria, Sabato; de Champdoré, Marcella; Aurilia, Vincenzo; Parracino, Antonietta; Staiano, Maria; Vitale, Annalisa; Rossi, Mosè; Rea, Ilaria; Rotiroti, Lucia; Rossi, Andrea M.; Borini, Stefano; Rendina, Ivo; DeStefano, Luca

    2006-08-01

    Small analytes such as glucose, L-glutamine (Gln), and ammonium nitrate are detected by means of optical biosensors based on a very common nanostructured material, porous silicon (PSi). Specific recognition elements, such as protein receptors and enzymes, were immobilized on hydrogenated PSi wafers and used as probes in optical sensing systems. The binding events were optically transduced as wavelength shifts of the porous silicon reflectivity spectrum or were monitored via changes of the fluorescence emission. The biosensors described in this article suggest a general approach for the development of new sensing systems for a wide range of analytes of high social interest.

  18. Voltammetric detection of As(III) with Porphyridium cruentum based modified carbon paste electrode biosensor.

    PubMed

    Zaib, M; Saeed, A; Hussain, I; Athar, M M; Iqbal, M

    2014-12-15

    A novel biosensor based on carbon paste electrode modified with Porphyridium cruentum biomass was developed for the determination of As(III) in contaminated water. As(III) was first biosorbed-accumulated on the electrode surface at open circuit potential and then stripped off by applying anodic scan range of -0.8 to +0.8 V using differential pulse anodic stripping voltammetric technique. The best result was obtained at pH 6.0 with 0.1M HNO3 solution as stripping medium, allowing biosorption-accumulation time of 8 min using 5% P. cruentum biomass in graphite-mineral oil paste. Linear range for As(III) detection with the modified electrode-biosensor was observed between 2.5 and 20 µg L(-1). The FTIR spectrum of P. cruentum biomass confirmed the presence of active functional groups that participate in the binding of As(III). Scanning Electron Microscopy (SEM) indulged the surface morphology of modified electrode-biosensor before and after As(III) adsorption. Similarly, Atomic Force Microscopy (AFM) showed that the average roughness of the modified electrode decreased indicating the successful incorporation of P. cruentum biomass. Efficiency of the biosensor in the presence of different interfering metal (Na(+), K(+), Ca(2+), and Mg(2+)) ions were also evaluated. The application of P. cruentum modified biosensor was successfully used for the detection of As(III) in the binary metal (Fe(3+), Mn(2+), Cd(2+), Cu(2+), Ni(2+), Hg(2+), and Pb(2+)) contaminated system. The accuracy of application of biosorption based biosensor for the detection of As(III) is as low as 2.5 µg L(-1).

  19. Musical hallucinations treated with acetylcholinesterase inhibitors.

    PubMed

    Blom, Jan Dirk; Coebergh, Jan Adriaan F; Lauw, René; Sommer, Iris E C

    2015-01-01

    Musical hallucinations are relatively rare auditory percepts which, due to their intrusive nature and the accompanying fear of impending mental decline, tend to cause significant distress and impairment. Although their etiology and pathophysiology appear to be heterogeneous and no evidence-based treatment methods are available, case reports indicate that acetylcholinesterase inhibitors may yield positive results in patients with comorbid hearing loss. We present two female patients (aged 76 and 78 years) both of whom suffered from hearing impairment and practically incessant musical hallucinations. Both patients were successfully treated with the acetylcholinesterase inhibitor rivastigmine. Based on these two case descriptions and an overview of studies describing the use of acetylcholinesterase inhibitors in similar patients, we discuss possible mechanisms and propose further research on the use of acetylcholinesterase inhibitors for musical hallucinations experienced in concordance with hearing loss.

  20. Musical Hallucinations Treated with Acetylcholinesterase Inhibitors

    PubMed Central

    Blom, Jan Dirk; Coebergh, Jan Adriaan F.; Lauw, René; Sommer, Iris E. C.

    2015-01-01

    Musical hallucinations are relatively rare auditory percepts which, due to their intrusive nature and the accompanying fear of impending mental decline, tend to cause significant distress and impairment. Although their etiology and pathophysiology appear to be heterogeneous and no evidence-based treatment methods are available, case reports indicate that acetylcholinesterase inhibitors may yield positive results in patients with comorbid hearing loss. We present two female patients (aged 76 and 78 years) both of whom suffered from hearing impairment and practically incessant musical hallucinations. Both patients were successfully treated with the acetylcholinesterase inhibitor rivastigmine. Based on these two case descriptions and an overview of studies describing the use of acetylcholinesterase inhibitors in similar patients, we discuss possible mechanisms and propose further research on the use of acetylcholinesterase inhibitors for musical hallucinations experienced in concordance with hearing loss. PMID:25904872

  1. Quantitative detection of bovine and porcine gelatin difference using surface plasmon resonance based biosensor

    NASA Astrophysics Data System (ADS)

    Wardani, Devy P.; Arifin, Muhammad; Suharyadi, Edi; Abraha, Kamsul

    2015-05-01

    Gelatin is a biopolymer derived from collagen that is widely used in food and pharmaceutical products. Due to some religion restrictions and health issues regarding the gelatin consumption which is extracted from certain species, it is necessary to establish a robust, reliable, sensitive and simple quantitative method to detect gelatin from different parent collagen species. To the best of our knowledge, there has not been a gelatin differentiation method based on optical sensor that could detect gelatin from different species quantitatively. Surface plasmon resonance (SPR) based biosensor is known to be a sensitive, simple and label free optical method for detecting biomaterials that is able to do quantitative detection. Therefore, we have utilized SPR-based biosensor to detect the differentiation between bovine and porcine gelatin in various concentration, from 0% to 10% (w/w). Here, we report the ability of SPR-based biosensor to detect difference between both gelatins, its sensitivity toward the gelatin concentration change, its reliability and limit of detection (LOD) and limit of quantification (LOQ) of the sensor. The sensor's LOD and LOQ towards bovine gelatin concentration are 0.38% and 1.26% (w/w), while towards porcine gelatin concentration are 0.66% and 2.20% (w/w), respectively. The results show that SPR-based biosensor is a promising tool for detecting gelatin from different raw materials quantitatively.

  2. Fabrication of nanostructures and nanostructure based interfaces for biosensor application

    NASA Astrophysics Data System (ADS)

    Srivastava, Devesh

    Nanoparticles have applications from electronics, composites, drug-delivery, imaging and sensors etc. Fabricating and controlling shape and size of nanoparticles and also controlling the positioning of these particles in 1, 2 or 3-d structures is of most interest. The underlying theme of this study is to develop simple and efficient techniques to fabricate nanoparticles from polymers, and also achieve control in shape, size and functionalization of nanoparticles, while applying them in biosensor applications. First part of the dissertation studies the fabrication of nanostructures using anodized alumina membrane as template. It discusses the fabrication design for injecting polystyrene nanoparticles inside the pores of anodized alumina membranes and heating the membrane to coalesce the particles into tapered nanoparticles. Various parameters like temperature and amount of injected particles can vary the size and shape of fabricated nanoparticles. Later it focuses on the fabrication of metallic nanostructures using the alumina membranes without the aid of the injection system. It utilizes the difference in the functionality of the pore edges of cleaved alumina membrane with respect to the pore walls to first deposit charged polymers using layer-by-layer deposition followed by deposition of nickel. Second part of this study involves immobilization of enzymes for biosensor applications. It describes a biosensor interface developed by immobilization of tyrosinase using layer-by-layer (LBL) deposition process. The interface was modified with functional nanoparticles and their influence on the response of biosensor was studied. Tyrosinase sensor was further extended to develop a novel biosensor which was used to study real time inhibition of NEST, a subunit of the medically relevant membrane protein, neuropathy target esterase. The biosensor was developed to give real time monitoring of dose dependent decrease in activity of NEST. Final part of this study emphasizes on

  3. Double layer structure-based virtual screening reveals 3'-Hydroxy-A-Naphthoflavone as novel inhibitor candidate of human acetylcholinesterase

    NASA Astrophysics Data System (ADS)

    Ichsan, Mochammad; Pangastuti, Ardini; Habibi, Mohammad Wildan; Juliana, Kartika

    2016-03-01

    One of the most effective target for Alzheimer's disease's (AD) treatment is the inhibition of human acetylcholinesterase (hAChE) eventhough it has many side effects. So that, this study was aimed to discover a new candidate of hAChE's inhibitor that has more negative binding affinity than existing drugs. hAChE's 3D model used in this study has a good quality according to its number of residues in most favoured regions (92%), three bad contacts, >50 ERRAT's score (85,870) and successfully passed the VERIFY 3D threshold (>80%). Based on the first layer of SBVS againts more than 12.180.630 ligands, we discovered 11.806 hits and then we found 359 hits from the second layer of SBVS. Based on our previous steps, we found that 3'-Hydroxy-a-Naphthoflavone was the only one candidate, that directly interacted with Trp286 via hydrogen bond and hydrophobic interactions and also has the most negative binding affinity (-10,6 kcal/mol) and also has more negative than existing hAChE's inhibitors, such as tacrine, donepezil, etc. 3'-Hydroxy-a-Naphthoflavone is the best candidate of hAChE's inhibitor based on its binding affinity (-10,6 kcal/mol) that is more negative than existing hAChE's inhibitors, such as tacrine, donepezil, etc.

  4. Biosensor platform based on carbon nanotubes covalently modified with aptamers

    NASA Astrophysics Data System (ADS)

    Komarov, I. A.; Rubtsova, E. I.; Golovin, A. V.; Bobrinetskiy, I. I.

    2016-12-01

    We developed a new platform for biosensing applications. Aptamers as sensitive agents have a great potential and gives us possibility to have highest possible selectivity among other sensing agents like enzymes or antibodies. We covalently bound aptamers to the functional groups of c-CNTs and then put this system on the surface of polymer substrate. Thus we got high sensitive flexible transparent biological sensors. We also suggest that by varying aptamer type we can make set of biosensors for disease detection which can be integrated into self-healthcare systems and gadgets.

  5. A new PANI biosensor based on catalase for cyanide determination.

    PubMed

    Özcan, Hakkı Mevlüt; Aydin, Tuba

    2016-01-01

    Cyanide is one of the most widespread of compounds measured in environmental analysis due to their toxic effects on environment and health. We report a highly sensitive, reliable, selective amperometric sensor for determination of cyanide, using a polyaniline conductive polymer. The enzyme catalase was immobilized by electropolymerization. The steps during the immobilization were controlled by electrochemical impedance spectroscopy. Optimum pH, temperature, aniline concentration, enzyme concentration, and the number of scans obtained during electropolymerization, were investigated. In addition, the cyanide present in artificial waste water samples was determined. In the characterization studies of the biosensor, some parameters such as reproducibility and storage stability, were analyzed.

  6. Analysis of diazinon pesticide using potentiometric biosensor based on enzyme immobilized cellulose acetate membrane in gold electrode

    NASA Astrophysics Data System (ADS)

    Mashuni; Ramadhan, L. O. A. N.; Jahiding, M.; Herniati

    2016-02-01

    Biosensor for analysis of diazinon pesticide using Potentiometric transducer has been developed. The basic element of this biosensor was a gold electrode modified with an immobilized acetylcholinesterase enzyme layer formed by entrapment with glutaraldehyde crosslinked-cellulose acetate. The aim of the research is to determine the composition of glutaraldehyde crosslinked-cellulose acetate in the gold electrode which provide optimum performance of biosensors of diazinon pesticide analysis on characterization include a range of working concentration, sensitivity, and detection limit. The results showed the composition of the cellulose acetate 15% and glutaraldehyde 25% that obtain optimum performance in the measurement of diazinon pesticide with a range of working concentration of 10-6 ppm to 1 ppm, the value of sensitivity 20.275 mV/decade and detection limit 10-6 ppm. The use of cellulose acetate provides highly sensitive devices allowing the efficient analysis of pesticides. The response time of electrode is on the measurement of pesticide diazinon with concentration variation of 10-6 ppm to 1 ppm with response time is about 5 minutes.

  7. Fluorescence-based biosensor for monitoring of environmental pollutants: From concept to field application.

    PubMed

    Bidmanova, Sarka; Kotlanova, Marketa; Rataj, Tomas; Damborsky, Jiri; Trtilek, Martin; Prokop, Zbynek

    2016-10-15

    An advanced optical biosensor was developed based on the enzymatic reaction with halogenated aliphatic hydrocarbons that is accompanied by the fluorescence change of pH indicator. The device is applicable for the detection of halogenated contaminants in water samples with pH ranging from 4 to 10 and temperature ranging from 5 to 60°C. Main advantages of the developed biosensor are small size (60×30×190mm(3)) and portability, which together with short measurement time of 1min belong to crucial attributes of analytical technique useful for routine environmental monitoring. The biosensor was successfully applied for the detection of several important halogenated pollutants under laboratory conditions, e.g., 1,2-dichloroethane, 1,2,3-trichloropropane and γ-hexachlorocyclohexane, with the limits of detection of 2.7, 1.4 and 12.1mgL(-1), respectively. The continuous monitoring was demonstrated by repetitive injection of halogenated compound into measurement solution. Consequently, field trials under environmental settings were performed. The presence of 1,2-dichloroethane (10mgL(-1)) was proved unambiguously on one of three potentially contaminated sites in Czech Republic, and the same contaminant was monitored on contaminated locality in Serbia. Equipped by Global Positioning System, the biosensor was used for creation of a precise map of contamination. Concentrations determined by biosensor and by gas chromatograph coupled with mass spectrometer exhibited the correlation coefficient of 0.92, providing a good confidence for the routine use of the biosensor system in both field screening and monitoring.

  8. A Toolbox of Genetically Encoded FRET-Based Biosensors for Rapid l-Lysine Analysis.

    PubMed

    Steffen, Victoria; Otten, Julia; Engelmann, Susann; Radek, Andreas; Limberg, Michael; Koenig, Bernd W; Noack, Stephan; Wiechert, Wolfgang; Pohl, Martina

    2016-09-28

    Background: The fast development of microbial production strains for basic and fine chemicals is increasingly carried out in small scale cultivation systems to allow for higher throughput. Such parallelized systems create a need for new rapid online detection systems to quantify the respective target compound. In this regard, biosensors, especially genetically encoded Förster resonance energy transfer (FRET)-based biosensors, offer tremendous opportunities. As a proof-of-concept, we have created a toolbox of FRET-based biosensors for the ratiometric determination of l-lysine in fermentation broth. Methods: The sensor toolbox was constructed based on a sensor that consists of an optimized central lysine-/arginine-/ornithine-binding protein (LAO-BP) flanked by two fluorescent proteins (enhanced cyan fluorescent protein (ECFP), Citrine). Further sensor variants with altered affinity and sensitivity were obtained by circular permutation of the binding protein as well as the introduction of flexible and rigid linkers between the fluorescent proteins and the LAO-BP, respectively. Results: The sensor prototype was applied to monitor the extracellular l-lysine concentration of the l-lysine producing Corynebacterium glutamicum (C. glutamicum) strain DM1933 in a BioLector(®) microscale cultivation device. The results matched well with data obtained by HPLC analysis and the Ninhydrin assay, demonstrating the high potential of FRET-based biosensors for high-throughput microbial bioprocess optimization.

  9. A Toolbox of Genetically Encoded FRET-Based Biosensors for Rapid l-Lysine Analysis

    PubMed Central

    Steffen, Victoria; Otten, Julia; Engelmann, Susann; Radek, Andreas; Limberg, Michael; Koenig, Bernd W.; Noack, Stephan; Wiechert, Wolfgang; Pohl, Martina

    2016-01-01

    Background: The fast development of microbial production strains for basic and fine chemicals is increasingly carried out in small scale cultivation systems to allow for higher throughput. Such parallelized systems create a need for new rapid online detection systems to quantify the respective target compound. In this regard, biosensors, especially genetically encoded Förster resonance energy transfer (FRET)-based biosensors, offer tremendous opportunities. As a proof-of-concept, we have created a toolbox of FRET-based biosensors for the ratiometric determination of l-lysine in fermentation broth. Methods: The sensor toolbox was constructed based on a sensor that consists of an optimized central lysine-/arginine-/ornithine-binding protein (LAO-BP) flanked by two fluorescent proteins (enhanced cyan fluorescent protein (ECFP), Citrine). Further sensor variants with altered affinity and sensitivity were obtained by circular permutation of the binding protein as well as the introduction of flexible and rigid linkers between the fluorescent proteins and the LAO-BP, respectively. Results: The sensor prototype was applied to monitor the extracellular l-lysine concentration of the l-lysine producing Corynebacterium glutamicum (C. glutamicum) strain DM1933 in a BioLector® microscale cultivation device. The results matched well with data obtained by HPLC analysis and the Ninhydrin assay, demonstrating the high potential of FRET-based biosensors for high-throughput microbial bioprocess optimization. PMID:27690044

  10. Fabrication of an electrochemical DNA-based biosensor for Bacillus cereus detection in milk and infant formula.

    PubMed

    Izadi, Zahra; Sheikh-Zeinoddin, Mahmoud; Ensafi, Ali A; Soleimanian-Zad, Sabihe

    2016-06-15

    This paper describes fabrication of a DNA-based Au-nanoparticle modified pencil graphite electrode (PGE) biosensor for detection of Bacillus cereus, causative agent of two types of food-borne disease, i.e., emetic and diarrheal syndrome. The sensing element of the biosensor was comprised of gold nanoparticles (GNPs) self-assembled with single-stranded DNA (ssDNA) of nheA gene immobilized with thiol linker on the GNPs modified PGE. The size, shape and dispersion of the GNPs were characterized by field emission scanning electron microscope (FESEM). Detection of B. cereus was carried out based on an increase in the charge transfer resistance (Rct) of the biosensor due to hybridization of the ss-DNA with target DNA. An Atomic force microscope (AFM) was used to confirm the hybridization. The biosensor sensitivity in pure cultures of B. cereus was found to be 10(0) colony forming units per milliliter (CFU/mL) with a detection limit of 9.4 × 10(-12) mol L(-1). The biosensor could distinguish complementary from mismatch DNA sequence. The proposed biosensor exhibited a rapid detection, low cost, high sensitivity to bacterial contamination and could exclusively and specifically detect the target DNA sequence of B. cereus from other bacteria that can be found in dairy products. Moreover, the DNA biosensor exhibited high reproducibility and stability, thus it may be used as a suitable biosensor to detect B. cereus and to become a portable system for food quality control.

  11. Biosensor for dopamine based on stabilized lipid films with incorporated resorcin[4]arene receptor.

    PubMed

    Nikolelis, Dimitrios P; Theoharis, George

    2003-04-01

    This work reports a technique for the stabilization after storage in air of a lipid film with incorporated resorcin[4]arene receptor based biosensor for dopamine. Microporous filters composed of glass fibers (nominal pore sizes, 0.7 and 1.0 microm) were used as supports for the formation and stabilization of these devices and the lipid film is formed on the filter by polymerization prior its use. Methacrylic acid was the functional monomer, ethylene glycol dimethacrylate was the crosslinker and 2,2'-azobis-(2-methylpropionitrile) was the initiator. The stability of the lipid films by incorporation of a receptor for the preparation of stabilized lipid film biosensor is studied throughout this work. The response towards dopamine of the present stabilized for repetitive uses lipid membrane biosensor composed of dipalmitoyl phosphatidylcholine and dipalmitoyl phosphatidic acid was compared with planar freely suspended bilayer lipid membranes (BLMs). The stabilized lipid membranes provided similar artificial ion gating events as BLMs in the form of transient signals and can function for repetitive uses after storage in air. However, the response of the stabilized lipid films was slower than that of the freely suspended BLMs. This will allow the practical use of the techniques for chemical sensing based on lipid films and commercialization of these devices, because it is now possible to prepare stabilized lipid film based biosensors and store them in the air.

  12. Whole‐cell biosensors for detection of heavy metal ions in environmental samples based on metallothionein promoters from Tetrahymena thermophila

    PubMed Central

    Amaro, Francisco; Turkewitz, Aaron P.; Martín‐González, Ana; Gutiérrez, Juan‐Carlos

    2011-01-01

    Summary Heavy metals are among the most serious pollutants, and thus there is a need to develop sensitive and rapid biomonitoring methods for heavy metals in the environment. Critical parameters such as bioavailability, toxicity and genotoxicity cannot be tested using chemical analysis, but only can be assayed using living cells. A whole‐cell biosensor uses the whole cell as a single reporter incorporating both bioreceptor and transducer elements. In the present paper, we report results with two gene constructs using the Tetrahymena thermophila MTT1 and MTT5 metallothionein promoters linked with the eukaryotic luciferase gene as a reporter. This is the first report of a ciliated protozoan used as a heavy metal whole‐cell biosensor. T. thermophila transformed strains were created as heavy metal whole‐cell biosensors, and turn on bioassays were designed to detect, in about 2 h, the bioavailable heavy metals in polluted soil or aquatic samples. Validation of these whole‐cell biosensors was carried out using both artificial and natural samples, including methods for detecting false positives and negatives. Comparison with other published cell biosensors indicates that the Tetrahymena metallothionein promoter‐based biosensors appear to be the most sensitive eukaryotic metal biosensors and compare favourably with some prokaryotic biosensors as well. PMID:21366892

  13. A luminescent hybridoma-based biosensor for rapid detection of V. cholerae upon induction of calcium signaling pathway.

    PubMed

    Zamani, Parichehr; Sajedi, Reza H; Hosseinkhani, Saman; Zeinoddini, Mehdi; Bakhshi, Bita

    2016-05-15

    In this study, a hybridoma based biosensor was developed for rapid, sensitive and selective detection of Vibrio cholerae O1 which converts the antibody-antigen binding to bioluminescence light. After investigation on hybridoma performance, the biosensor was constructed by transfecting specific hybridoma cells with aequorin reporter gene and the bioluminescence activities of stable biosensor were measured. The sensitivity of biosensor was as few as 50 CFU/ml and it showed no responses to other entric bacteria. Moreover, the response time of biosensor was estimated in 7th second which means this method is considerably faster than many available detection assays. In addition, this biosensor was successfully applied to V. cholerae detection in environmental samples with no significant loss in sensitivity, demonstrating our proposed biosensor provides a sensitive and reliable method for detection of V. cholerae in natural samples. The application of whole hybridoma cell directly as a sensing element in biosensor construction which mentioned for the first time in present study suggests that hybridoma cells could provide a valuable tool for future studies in both basic and diagnostic sciences and could be considered as a fast and specific sensing element for detection of other pathogens in different applications.

  14. A Novel Conductometric Urea Biosensor with Improved Analytical Characteristic Based on Recombinant Urease Adsorbed on Nanoparticle of Silicalite

    NASA Astrophysics Data System (ADS)

    Velychko, T. P.; Soldatkin, O. O.; Melnyk, V. G.; Marchenko, S. V.; Kirdeciler, S. K.; Akata, B.; Soldatkin, A. P.; El'skaya, A. V.; Dzyadevych, S. V.

    2016-02-01

    Development of a conductometric biosensor for the urea detection has been reported. It was created using a non-typical method of the recombinant urease immobilization via adsorption on nanoporous particles of silicalite. It should be noted that this biosensor has a number of advantages, such as simple and fast performance, the absence of toxic compounds during biosensor preparation, and high reproducibility (RSD = 5.1 %). The linear range of urea determination by using the biosensor was 0.05-15 mM, and a lower limit of urea detection was 20 μM. The bioselective element was found to be stable for 19 days. The characteristics of recombinant urease-based biomembranes, such as dependence of responses on the protein and ion concentrations, were investigated. It is shown that the developed biosensor can be successfully used for the urea analysis during renal dialysis.

  15. A Novel Conductometric Urea Biosensor with Improved Analytical Characteristic Based on Recombinant Urease Adsorbed on Nanoparticle of Silicalite.

    PubMed

    Velychko, T P; Soldatkin, О О; Melnyk, V G; Marchenko, S V; Kirdeciler, S K; Akata, B; Soldatkin, A P; El'skaya, A V; Dzyadevych, S V

    2016-12-01

    Development of a conductometric biosensor for the urea detection has been reported. It was created using a non-typical method of the recombinant urease immobilization via adsorption on nanoporous particles of silicalite. It should be noted that this biosensor has a number of advantages, such as simple and fast performance, the absence of toxic compounds during biosensor preparation, and high reproducibility (RSD = 5.1 %). The linear range of urea determination by using the biosensor was 0.05-15 mM, and a lower limit of urea detection was 20 μM. The bioselective element was found to be stable for 19 days. The characteristics of recombinant urease-based biomembranes, such as dependence of responses on the protein and ion concentrations, were investigated. It is shown that the developed biosensor can be successfully used for the urea analysis during renal dialysis.

  16. Affinity and enzyme-based biosensors: recent advances and emerging applications in cell analysis and point-of-care testing.

    PubMed

    Liu, Ying; Matharu, Zimple; Howland, Michael C; Revzin, Alexander; Simonian, Aleksandr L

    2012-09-01

    The applications of biosensors range from environmental testing and biowarfare agent detection to clinical testing and cell analysis. In recent years, biosensors have become increasingly prevalent in clinical testing and point-of-care testing. This is driven in part by the desire to decrease the cost of health care, to shift some of the analytical tests from centralized facilities to "frontline" physicians and nurses, and to obtain more precise information more quickly about the health status of a patient. This article gives an overview of recent advances in the field of biosensors, focusing on biosensors based on enzymes, aptamers, antibodies, and phages. In addition, this article attempts to describe efforts to apply these biosensors to clinical testing and cell analysis.

  17. A fluorometric assay for acetylcholinesterase activity and inhibitor detection based on DNA-templated copper/silver nanoclusters.

    PubMed

    Li, Wenhua; Li, Wang; Hu, Yufang; Xia, Yalin; Shen, Qinpeng; Nie, Zhou; Huang, Yan; Yao, Shouzhuo

    2013-09-15

    A novel label-free, rapid, cost-effective, and highly sensitive fluorometric sensor has been constructed for the detection of acetylcholinesterase (AChE) activity and its inhibitor based on the fluorescence quenching of DNA-templated copper/silver nanoclusters (DNA-Cu/AgNCs). In this assay, AChE catalyzes the hydrolysis of acetylthiocholine (ATCh) to form thiocholine which induces fluorescence quenching of DNA-Cu/AgNCs. The AChE activity could be detected as low as 0.05mU/mL and with a linear range from 0.05 to 2.0mU/mL. This assay offers a very convenient "mix and detect" approach for AChE activity. On the other hand, tacrine and organophosphorus pesticides (OPPs) were employed to inhibit the hydrolysis of ATCh, which could eliminate the fluorescence quenching of DNA-Cu/AgNCs. The IC50 of tacrine and methamidophos were estimated to be 16.9nM and 0.075mg/L, respectively. This method was also used to detect spiked OPPs in agricultural products successfully. The present work may expand the use of DNA-Cu/AgNCs to the field of enzyme sensors.

  18. QSAR models for the reactivation of sarin inhibited acetylcholinesterase by quaternary pyridinium oximes based on Monte Carlo method.

    PubMed

    Veselinović, Aleksandar M; Veselinović, Jovana B; Toropov, Andrey A; Toropova, Alla P; Nikolić, Goran M

    2014-01-01

    Monte Carlo method has been used as a computational tool for building QSAR models for the reactivation of sarin inhibited acetylcholinesterase (AChE) by quaternary pyridinium oximes. Simplified molecular input line entry system (SMILES) together with hydrogen-suppressed graph (HSG) was used to represent molecular structure. Total number of considered oximes was 46 and activity was defined as logarithm of the AChE reactivation percentage by oximes with concentration of 0.001 M. One-variable models have been calculated with CORAL software for one data split into training, calibration and test set. Computational experiments indicated that this approach can satisfactorily predict the desired endpoint. Best QSAR model had the following statistical parameters: for training set r2=0.7096, s=0.177, MAE=0.148; calibration set: r2=0.6759, s=0.330, MAE=0.271 and test set: r2=0.8620, s=0.182, MAE=0.150. Structural indicators (SMILES based molecular fragments) for the increase and the decrease of the stated activity are defined. Using defined structural alerts computer aided design of new oxime derivatives with desired activity is presented.

  19. Effect of a glyphosate-based herbicide in Cyprinus carpio: assessment of acetylcholinesterase activity, hematological responses and serum biochemical parameters.

    PubMed

    Gholami-Seyedkolaei, Seyed Jalil; Mirvaghefi, Alireza; Farahmand, Hamid; Kosari, Ali Asghar

    2013-12-01

    The objective of this study was to investigate the toxicity effects of acute and sublethal of Roundup® as a glyphosate-based herbicide on acetylcholinesterase (AChE) activity and several hematological and biochemical parameters of Cyprinus carpio. The LC₅₀-96 h of Roundup® to C. carpio was found to be 22.19 ppm. Common carp was subjected to Roundup® at 0 (control), 3.5, 7 and 14 ppm for 16 days, and the AChE activity is verified in tissues of gill, muscle, brain and liver. After 5 days, a significant decrease was observed in the AChE activity of muscle, brain and liver tissues. Besides, a time- and dose-dependent increase in mean cell hemoglobin (MCH) and mean cell volume (MCV) was observed. In contrast, a significant decrease was found in the quantities of hemoglobin (Hb), hematocrit (HCT) and, red (RBC) and white (WBC) blood cell count. Also, the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) in Roundup® treated groups were significantly higher than the controlled group at experimental periods. However, the level of alkaline phosphatase (ALP) had a significant reduction behavior during the sampling days. It seems that the changes in hematological and biochemical parameters as well as AChE activity could be used as efficient biomarkers in order to determine Roundup® toxicity in aquatic environment.

  20. Elaborate ligand-based modeling coupled with QSAR analysis and in silico screening reveal new potent acetylcholinesterase inhibitors

    NASA Astrophysics Data System (ADS)

    Abuhamdah, Sawsan; Habash, Maha; Taha, Mutasem O.

    2013-12-01

    Inhibition of the enzyme acetylcholinesterase (AChE) has been shown to alleviate neurodegenerative diseases prompting several attempts to discover and optimize new AChE inhibitors. In this direction, we explored the pharmacophoric space of 85 AChE inhibitors to identify high quality pharmacophores. Subsequently, we implemented genetic algorithm-based quantitative structure-activity relationship (QSAR) modeling to select optimal combination of pharmacophoric models and 2D physicochemical descriptors capable of explaining bioactivity variation among training compounds ( {{r}}^{ 2}_{ 6 8} = 0. 9 4 , F-statistic = 125.8, {{r}}^{ 2}_{{LOO}} { = 0} . 9 2 , {{r}}^{ 2}_{{PRESS}} against 17 external test inhibitors = 0.84). Two orthogonal pharmacophores emerged in the QSAR equation suggesting the existence of at least two binding modes accessible to ligands within AChE binding pocket. The successful pharmacophores were comparable with crystallographically resolved AChE binding pocket. We employed the pharmacophoric models and associated QSAR equation to screen the national cancer institute list of compounds. Twenty-four low micromolar AChE inhibitors were identified. The most potent gave IC50 value of 1.0 μM.

  1. Detection of Salmonella Typhimurium on Spinach Using Phage-Based Magnetoelastic Biosensors.

    PubMed

    Wang, Fengen; Horikawa, Shin; Hu, Jiajia; Wikle, Howard C; Chen, I-Hsuan; Du, Songtao; Liu, Yuzhe; Chin, Bryan A

    2017-02-16

    Phage-based magnetoelastic (ME) biosensors have been studied as an in-situ, real-time, wireless, direct detection method of foodborne pathogens in recent years. This paper investigates an ME biosensor method for the detection of Salmonella Typhimurium on fresh spinach leaves. A procedure to obtain a concentrated suspension of Salmonella from contaminated spinach leaves is described that is based on methods outlined in the U.S. FDA Bacteriological Analytical Manual for the detection of Salmonella on leafy green vegetables. The effects of an alternative pre-enrichment broth (LB broth vs. lactose broth), incubation time on the detection performance and negative control were investigated. In addition, different blocking agents (BSA, Casein, and Superblock) were evaluated to minimize the effect of nonspecific binding. None of the blocking agents was found to be superior to the others, or even better than none. Unblocked ME biosensors were placed directly in a concentrated suspension and allowed to bind with Salmonella cells for 30 min before measuring the resonant frequency using a surface-scanning coil detector. It was found that 7 h incubation at 37 °C in LB broth was necessary to detect an initial spike of 100 cfu/25 g S. Typhimurium on spinach leaves with a confidence level of difference greater than 95% (p < 0.05). Thus, the ME biosensor method, on both partly and fully detection, was demonstrated to be a robust and competitive method for foodborne pathogens on fresh products.

  2. Synthesis of Polydopamine Functionalized Reduced Graphene Oxide-Palladium Nanocomposite for Laccase Based Biosensor

    PubMed Central

    Luo, Lei; Lv, Peng-Fei; Wang, Qing-Qing; Wei, An-Fang

    2016-01-01

    Graphene based 2D nanomaterials have attracted increasing attention in biosensing application due to the outstanding physicochemical properties of graphene. In this work, palladium nanoparticles (Pd) loaded reduced graphene oxide (rGO) hybrid (rGO-Pd) was synthesized through a facile method. Laccase (Lac) was immobilized on rGO-Pd by utilizing the self-polymerization of dopamine, which generated polydopamine (PDA). The PDA-Lac-rGO-Pd nanocomposites were further modified on electrode surface to construct novel biosensing platform. The obtained electrochemical biosensor was applied in the detection of catechol, achieving excellent analytic results. Under the optimum condition, this biosensor possessed a linear range from 0.1 µM to 263 µM for catechol detection, the sensitivity reached 18.4 µA mM−1, and the detection limit was as low as 0.03 µM. In addition, the biosensor also showed good repeatability, reproducibility, anti-interference, and stability. Moreover, the novel Lac based biosensor was successfully used in the trace detection of catechol existing in real water environment. PMID:27478426

  3. Carcinoembryonic antigen admittance biosensor based on Au and ZnO nanoparticles using FFT admittance voltammetry.

    PubMed

    Norouzi, Parviz; Gupta, Vinod Kumar; Faridbod, Farnoush; Pirali-Hamedani, Morteza; Larijani, Bagher; Ganjali, Mohammad Reza

    2011-03-01

    In this work, a highly sensitive carcinoembryonic antigen fast Fourier transform admittance biosensor is introduced. The proposed biosensor is based on bilayer films of ZnO/Au nanoparticles as an immobilization matrix. These layers are prepared by self-assembly and deposition method on a gold electrode surface, respectively. Carcinoembryonic antibody (anti-CEA) was immobilized on gold nanoparticles and positively charged horseradish peroxidase (HRP) was used to block sites against nonspecific binding. The admittance biosensor was developed based on fast Fourier transform continuous square wave voltammetry, which produces a sensitive, fast (less than 20 s) and reliable response for determination of carcinoembryonic antigen. The technique was applied as a detector in a flow injection system. The admittances reduction current of the biosensor decreases linearly in two concentrations ranges of CEA from 0.1 to 70 ng/mL and from 70 to 200 ng/mL with a detection limit of 0.01 ng/mL in presence of 0.5 mM H(2)O(2) as an eluent solution.

  4. Ultrasensitive Electrochemical Biosensor for HIV Gene Detection Based on Graphene Stabilized Gold Nanoclusters with Exonuclease Amplification.

    PubMed

    Wang, Yijia; Bai, Xiaoning; Wen, Wei; Zhang, Xiuhua; Wang, Shengfu

    2015-08-26

    Because human immunodeficiency virus (HIV) has been one of the most terrible viruses in recent decades, early diagnosis of the HIV gene is of great importance for all scientists around the world. In our work, we developed a novel electrochemical biosensor based on one-step ultrasonic synthesized graphene stabilized gold nanocluster (GR/AuNC) modified glassy carbon electrode (GCE) with an exonuclease III (Exo III)-assisted target recycling amplification strategy for the detection of HIV DNA. It is the first time that GR/AuNCs have been used as biosensor platform and aptamer with cytosine-rich base set as capture probe to construct the biosensor. With the combination of cytosine-rich capture probe, good conductivity and high surfaces of GR/AuNCs, and Exo III-assisted target recycling amplification, we realized high sensitivity and good selectivity detection of target HIV DNA with a detection limit of 30 aM (S/N = 3). Furthermore, the proposed biosensor has a promising potential application for target detection in human serum analysis.

  5. A Potentiometric Formaldehyde Biosensor Based on Immobilization of Alcohol Oxidase on Acryloxysuccinimide-modified Acrylic Microspheres

    PubMed Central

    Ling, Yew Pei; Heng, Lee Yook

    2010-01-01

    A new alcohol oxidase (AOX) enzyme-based formaldehyde biosensor based on acrylic microspheres has been developed. Hydrophobic poly(n-butyl acrylate-N-acryloxy-succinimide) [poly(nBA-NAS)] microspheres, an enzyme immobilization matrix, was synthesized using photopolymerization in an emulsion form. AOX-poly(nBA-NAS) microspheres were deposited on a pH transducer made from a layer of photocured and self-plasticized polyacrylate membrane with an entrapped pH ionophore coated on a Ag/AgCl screen printed electrode (SPE). Oxidation of formaldehyde by the immobilized AOX resulted in the production of protons, which can be determined via the pH transducer. Effects of buffer concentrations, pH and different amount of immobilization matrix towards the biosensor’s analytical performance were investigated. The formaldehyde biosensor exhibited a dynamic linear response range to formaldehyde from 0.3–316.2 mM and a sensitivity of 59.41 ± 0.66 mV/decade (R2 = 0.9776, n = 3). The lower detection limit of the biosensor was 0.3 mM, while reproducibility and repeatability were 3.16% RSD (relative standard deviation) and 1.11% RSD, respectively (n = 3). The use of acrylic microspheres in the potentiometric formaldehyde biosensor improved the biosensor’s performance in terms of response time, linear response range and long term stability when compared with thick film immobilization methods. PMID:22163450

  6. Detection of Salmonella Typhimurium on Spinach Using Phage-Based Magnetoelastic Biosensors

    PubMed Central

    Wang, Fengen; Horikawa, Shin; Hu, Jiajia; Wikle, Howard C.; Chen, I-Hsuan; Du, Songtao; Liu, Yuzhe; Chin, Bryan A.

    2017-01-01

    Phage-based magnetoelastic (ME) biosensors have been studied as an in-situ, real-time, wireless, direct detection method of foodborne pathogens in recent years. This paper investigates an ME biosensor method for the detection of Salmonella Typhimurium on fresh spinach leaves. A procedure to obtain a concentrated suspension of Salmonella from contaminated spinach leaves is described that is based on methods outlined in the U.S. FDA Bacteriological Analytical Manual for the detection of Salmonella on leafy green vegetables. The effects of an alternative pre-enrichment broth (LB broth vs. lactose broth), incubation time on the detection performance and negative control were investigated. In addition, different blocking agents (BSA, Casein, and Superblock) were evaluated to minimize the effect of nonspecific binding. None of the blocking agents was found to be superior to the others, or even better than none. Unblocked ME biosensors were placed directly in a concentrated suspension and allowed to bind with Salmonella cells for 30 min before measuring the resonant frequency using a surface-scanning coil detector. It was found that 7 h incubation at 37 °C in LB broth was necessary to detect an initial spike of 100 cfu/25 g S. Typhimurium on spinach leaves with a confidence level of difference greater than 95% (p < 0.05). Thus, the ME biosensor method, on both partly and fully detection, was demonstrated to be a robust and competitive method for foodborne pathogens on fresh products. PMID:28212322

  7. Third-generation biosensor for lactose based on newly discovered cellobiose dehydrogenase.

    PubMed

    Stoica, Leonard; Ludwig, Roland; Haltrich, Dietmar; Gorton, Lo

    2006-01-15

    The present paper describes the principle and characteristics of a biosensor for lactose based on a third-generation design involving cellobiose dehydrogenase. As resulted from a previous comparative study (submitted manuscript), the novelty of this lactose biosensor is based on highly efficient direct electron transfer between two newly discovered cellobiose dehydrogenases (CDH), from the white rot fungi Trametes villosa and Phanerochaete sordida, and a solid spectrographic graphite electrode. CDH was immobilized on the electrode surface (0.073 cm2) by simple physical adsorption, and the CDH-modified electrode was next inserted into a wall-jet amperometric cell connected on-line to a flow injection setup (0.5 mL x min(-1)). The P. sordida CDH-based lactose biosensor, proved to be the better one, has a detection limit for lactose of 1 microM, a sensitivity of 1100 microA x mM(-1) x cm(-2), a response time of 4 s (the time required to obtain the maximum peak current), and a linear range from 1 to 100 microM lactose (correlation coefficient 0.998). The simplicity of construction and analytical characteristics make this CDH-based lactose biosensor an excellent alternative to previous lactose biosensors reported in the literature or commercially available. The CDH-lactose sensor was used to quantify the content of lactose in pasteurized milk, buttermilk, and low-lactose milk, using the standard addition method. No effects of the samples matrixes were observed. The operational stability of the sensor was tested for 11 h by continuous injection of 100 microM lactose (290 injections). The final signal of the sensor was maintained at 98% of its initial signal, with a low standard deviation of 1.72 (RSD 2.41%).

  8. Research and fabrication of integrated bio-sensor for blood analysis based on µTAS

    NASA Astrophysics Data System (ADS)

    En, De; Wei, Jianxia; Tong, Zhengrong; Chen, Caihe; Cui, Yuming; Xu, Kexin; Si, Qin; Li, Chao; Liu, Jie

    2007-01-01

    For simultaneously detecting multi-parameters of blood in the clinical diagnosis, the analysis apparatus should be smaller in size, more reliable and sensitive. So a kind of integrated bio-sensor for blood analysis based on Micro Total Analysis System (μTAS) is presented. It provides modern bio-sensor prospect with a novel technology. A multi-parameters of blood analysis integration sensor is μTAS bio-sensor based on 4 groups of interdigital array (IDA)microelectrodes. The IDA microelectrodes are fabricated on glass substrates by photography, film deposition and other microfabrication techniques. Thin-film gold microelectrode with a thickness of 250nm is deposited on a chromium-adhesion layer. The finger microelectrode width and space are both 10μm. The work space is 2×2cm2. The concentration of Blood sugar, Total Cholesterol, Acetone body and Lactic acid is measured by detecting steady-state limiting currents in IDA microelectrodes modified with enzymes on the "generate-collect" mode. Blood distribution structure is designed and fabricated, to distribute blood and isolate reaction areas. By contrasting two kinds of process flow based on lift-off and etching, etching is adopted to preparation method of microelectrode. A multi-channel apparatus for current measurement is accompleted. The system characteristics of the bio-sensor are tested. The curve of the apparatus time to current response is achieved by testing on real-time. The relationships between parameter concentration and current are analyzed in detail. The experimental data indicates: current measurement dimension 0~40μA, certainty of measurement 0.1μA, the performances of the bio-sensor meets design requirement.

  9. Design of a macroalgae amperometric biosensor; application to the rapid monitoring of organophosphate insecticides in an agroecosystem.

    PubMed

    Nunes, G S; Lins, J A P; Silva, F G S; Araujo, L C; Silva, F E P S; Mendonça, C D; Badea, M; Hayat, A; Marty, J-L

    2014-09-01

    The immobilization of enzymes onto transducer support is a mature technology and has been successfully implemented to improve biocatalytic processes for diverse applications. However, there exists still need to design more sophisticated and specialized strategies to enhance the functional properties of the biosensors. In this work, a biosensor platform based on innovative fabrication strategy was designed, and employed for the detection of organophosphate (OP) in natural waters. The biosensor was prepared by incorporating acetylcholinesterase enzyme (AChE) to the graphite paste modified with tetracyanoquinodimethane (TCNQ) mediator, along with the use of a macroalgae (Cladaphropsis membranous) as a functional immobilization support. The novel immobilization design resulted in a synergic effect, and led to enhanced stability and sensitivity of the biosensor. The designed biosensor was used to analyze methyl parathion OP insecticide in water samples collected from a demonstrably contaminated lake of São Luis Island, Maranhão, Northeast of Brazil. Water analysis revealed that the aquatic ecosystem was polluted by sub-ppm concentrations of the OP insecticide, and a good correlation was found between values obtained through biosensor and GC-MS techniques. Our results demonstrated that macroalgae-biosensor could be used as a low-cost and sensitive screening method to detect target analyte.

  10. A FRET Biosensor for ROCK Based on a Consensus Substrate Sequence Identified by KISS Technology.

    PubMed

    Li, Chunjie; Imanishi, Ayako; Komatsu, Naoki; Terai, Kenta; Amano, Mutsuki; Kaibuchi, Kozo; Matsuda, Michiyuki

    2017-01-11

    Genetically-encoded biosensors based on Förster/fluorescence resonance energy transfer (FRET) are versatile tools for studying the spatio-temporal regulation of signaling molecules within not only the cells but also tissues. Perhaps the hardest task in the development of a FRET biosensor for protein kinases is to identify the kinase-specific substrate peptide to be used in the FRET biosensor. To solve this problem, we took advantage of kinase-interacting substrate screening (KISS) technology, which deduces a consensus substrate sequence for the protein kinase of interest. Here, we show that a consensus substrate sequence for ROCK identified by KISS yielded a FRET biosensor for ROCK, named Eevee-ROCK, with high sensitivity and specificity. By treating HeLa cells with inhibitors or siRNAs against ROCK, we show that a substantial part of the basal FRET signal of Eevee-ROCK was derived from the activities of ROCK1 and ROCK2. Eevee-ROCK readily detected ROCK activation by epidermal growth factor, lysophosphatidic acid, and serum. When cells stably-expressing Eevee-ROCK were time-lapse imaged for three days, ROCK activity was found to increase after the completion of cytokinesis, concomitant with the spreading of cells. Eevee-ROCK also revealed a gradual increase in ROCK activity during apoptosis. Thus, Eevee-ROCK, which was developed from a substrate sequence predicted by the KISS technology, will pave the way to a better understanding of the function of ROCK in a physiological context.

  11. Amperometric Glucose Biosensor Based on Self-Assembling Glucose Oxidase on Carbon Nanotubes

    SciTech Connect

    Liu, Guodong; Lin, Yuehe

    2006-01-01

    A flow injection amperometric glucose biosensor based on electrostatic self-assembling glucose oxidase (GOx) on a carbon nanotube (CNT)-modified glassy carbon transducer is described. GOx is immobilized on the negatively charged CNT surface by alternatively assembling a cationic polydiallyldimethylammonium chloride (PDDA) layer and a GOx layer. The unique sandwich-like layer structure (PDDA/GOx/PDDA/CNT) formed by self-assembling provides a favorable microenvironment to keep the bioactivity of GOx and to prevent enzyme molecule leakage. The direct electrochemistry behavior of GOx and electrocatalysis of H2O2 on the fabricated PDDA/GOx/PDDA/CNT electrode demonstrated that such a biosensor fabrication method preserves the activity of enzyme molecules and the mechanical and electrocatalytic properties of carbon nanotubes, enabling sensitive determination of glucose. Flow injection amperometric detection of glucose is carried out at -100 mV (vs Ag/AgCl) in 0.05 M phosphate buffer solution (pH 7.4) with wide linear response range of 15 uM- 6 mM and a detection limit of 7 uM. The PDDA/GOx/PDDA/CNT/GC biosensor showed excellent properties for the sensitive determination of glucose with good reproducibility, remarkable stability, and free of interference from other co-existing electroactive species. The present methods can be applied to assemble other enzyme molecules and biological molecules, such as antibody, antigen, and DNA, to the CNT surface for wide biosensor and bioassay applications.

  12. Graphene and tricobalt tetraoxide nanoparticles based biosensor for electrochemical glutamate sensing.

    PubMed

    Dalkıran, Berna; Erden, Pınar Esra; Kılıç, Esma

    2017-03-01

    An amperometric biosensor based on tricobalt tetraoxide nanoparticles (Co3O4), graphene (GR), and chitosan (CS) nanocomposite modified glassy carbon electrode (GCE) for sensitive determination of glutamate was fabricated. Scanning electron microscopy was implemented to characterize morphology of the nanocomposite. The biosensor showed optimum response within 25 s at pH 7.5 and 37 °C, at +0.70 V. The linear working range of biosensor for glutamate was from 4.0 × 10(-)(6) to 6.0 × 10(-)(4) M with a detection limit of 2.0 × 10(-)(6) M and sensitivity of 0.73 μA/mM or 7.37 μA/mMcm(2). The relatively low Michaelis-Menten constant (1.09 mM) suggested enhanced enzyme affinity to glutamate. The glutamate biosensor lost 45% of its initial activity after three weeks.

  13. Poly(neutral red) based hydrogen peroxide biosensor for chromium determination by inhibition measurements.

    PubMed

    Attar, Aisha; Emilia Ghica, M; Amine, Aziz; Brett, Christopher M A

    2014-08-30

    Amperometric hydrogen peroxide enzyme inhibition biosensors based on horseradish peroxidase (HRP) immobilised on electropolymerised neutral red (NR) or directly on the surface of carbon film electrodes (CFE) have been successfully applied to the determination of toxic Cr(III) and Cr(VI). Parameters influencing the performance of the biosensor including the enzyme immobilisation method, the amount of hydrogen peroxide, applied potential and electrolyte pH were optimised. The inhibition of horseradish peroxidase by the chromium species was studied under the optimised conditions. Results from the quantitative analysis of chromium ions are discussed in terms of detection limit, linear range and sensitivity. The HRP kinetic interactions reveal mixed binding of Cr(III) with I50=3.8μM and inhibition binding constant Ki=11.3μM at HRP/PNR/CFE biosensors and uncompetitive binding of Cr(VI) with I50=3.9μM and Ki=0.78μM at HRP/CFE biosensors in the presence of H2O2 substrate. Interferences from other heavy metal ions were studied and the inhibition show very good selectivity towards Cr(III) and Cr(VI).

  14. Fabrication of a glucose biosensor based on inserted barrel plating gold electrodes.

    PubMed

    Hsu, Cheng-Teng; Chung, Hsieh-Hsun; Tsai, Dong-Mung; Fang, Mei-Yen; Hsiao, Hung-Chan; Zen, Jyh-Myng

    2009-01-01

    We demonstrate here the application of barrel plating gold electrodes for fabricating a new type of disposable amperometric glucose biosensor. It is prepared by inserting two barrel plating gold electrodes onto an injection molding plastic base followed by immobilizing with a bioreagent layer and membrane on the electrode surface. The primary function of barrel plating is to provide an economical way to electroplate manufactured parts. The manufacture procedure is simple and can increase the fabrication precision for automation in mass production. At the two-electrode system, the detection of glucose is linear up to 800 mg/dL (i.e., 44.5 mM, r(2) > 0.99) in pH 7.4 PBS with a sensitivity of 0.71 microA/mM. Excellent sensor-to-sensor reproducibility shows coefficients of variation of only 0.8-1.4% for the detection of 56.5-561.0 mg/dL glucose. In laboratory trials 176 capillary blood samples with a range of 30-572 mg/dL glucose are used to evaluate the clinical application of the biosensor. A good linear correlation is observed between the measured values of the proposed biosensor and laboratory reference. Error grid analysis verifies that the proposed technique is promising in fabricating biosensor strips on a mass scale. As successfully demonstrated by using whole blood glucose as a model analyte, the fabrication technique can extend into other barrel plating noble metal electrodes for various applications.

  15. Superior long-term stability of a glucose biosensor based on inserted barrel plating gold electrodes.

    PubMed

    Hsu, Cheng-Teng; Hsiao, Hung-Chan; Fang, Mei-Yen; Zen, Jyh-Myng

    2009-10-15

    Disposable one shot usage blood glucose strips are routinely used in the diagnosis and management of diabetes mellitus and their performance can vary greatly. In this paper we critically evaluated the long-term stability of glucose strips made of barrel plating gold electrodes. Compared to other glucose biosensing platforms of vapor deposited palladium and screen printed carbon electrodes, the proposed glucose biosensor was found to show the best stability among the three biosensing platforms in thermal acceleration experiments at 40 degrees C for 6 months with an average bias of 3.4% at glucose concentrations of 5-20 mM. The precision test of this barrel plating gold glucose biosensor also showed the best performance (coefficients of variation in the range of 1.4-2.4%) in thermal acceleration experiments at 40 degrees C, 50 degrees C and 70 degrees C for 27 days. Error grid analysis revealed that all measurements fell in zone A and zone B. Regression analysis showed no significant difference between the proposed biosensor and the reference method at 99% confidence level. The amperometric glucose biosensor fabricated by inserting two barrel plating gold electrodes onto an injection-molding plastic base followed by immobilizing with a bio-reagent layer and membrane was very impressive with a long-term stability up to 2.5 years at 25 degrees C. Overall, these results indicated that the glucose oxidase/barrel plating gold biosensing platform is ideal for long-term accurate glycemic control.

  16. Characterization of an organic phase peroxide biosensor based on horseradish peroxidase immobilized in Eastman AQ.

    PubMed

    Konash, Anastassija; Magner, Edmond

    2006-07-15

    Due to their frequent occurrence in food, cosmetics and pharmaceutical products, and their poor solubility in water, the detection of peroxides in organic solvents has aroused significant interest. For diagnostics or on-site testing, a fast and specific experimental approach is required. Although aqueous peroxide biosensors are well known, they are usually not suitable for nonaqueous applications due to their instability. Here we describe an organic phase biosensor for hydrogen peroxide based on horseradish peroxidase immobilized in an Eastman AQ 55 polymer matrix. Rotating disc amperometry was used to examine the effect of the solvent properties, the amount and pH of added buffer, the concentration of peroxide and ferrocene dimethanol, and the amount of Eastman AQ 55 and of enzyme on the response of the biosensor to hydrogen peroxide. The response of the biosensor was limited by diffusion. Linear responses (with detection limits to hydrogen peroxide given in parentheses) were obtained in methanol (1.2 microM), ethanol (0.6 microM), 1-propanol (2.8 microM), acetone (1.4 microM), acetonitrile (2.6 microM), and ethylene glycol (13.6 microM). The rate of diffusion of ferrocene dimethanol was more constrained than the rate of diffusion of hydrogen peroxide, resulting in a comparatively narrow linear range. The main advantages of the sensor are its ease of use and a high degree of reproducibility, together with good operational and storage stability.

  17. Zirconia-poly(propylene imine) dendrimer nanocomposite based electrochemical urea biosensor.

    PubMed

    Shukla, Sudheesh K; Mishra, Ajay K; Mamba, Bhekie B; Arotiba, Omotayo A

    2014-11-01

    In this article we report a selective urea electrochemical biosensor based on electro-co-deposited zirconia-polypropylene imine dendrimer (ZrO2-PPI) nanocomposite modified screen printed carbon electrode (SPCE). ZrO2 nanoparticles, prepared by modified sol-gel method were dispersed in PPI solution, and electro-co-deposited by cyclic voltammetry onto a SPCE surface. The material and the modified electrodes were characterised using FTIR, electron microscopy and electrochemistry. The synergistic effect of the high active surface area of both materials, i.e. PPI and ZrO2 nanoparticles, gave rise to a remarkable improvement in the electrocatalytic properties of the biosensor and aided the immobilisation of the urease enzyme. The biosensor has an ampereometric response time of ∼4 s in urea concentration ranging from 0.01 mM to 2.99 mM with a correlation coefficient of 0.9985 and sensitivity of 3.89 μA mM(-1) cm(-2). The biosensor was selective in the presence of interferences. Photochemical study of the immobilised enzyme revealed high stability and reactivity.

  18. Enzyme biosensor based on the immobilization of HRP on SiO₂/BSA/Au composite nanoparticles.

    PubMed

    Yuan, Shirong; Yuan, Ruo; Chai, Yaqin; Zhuo, Ying; Yang, Xia; Yuan, Yali

    2010-12-01

    In this work, an enzyme biosensor based on the immobilization of horseradish peroxidase (HRP) on SiO₂/BSA/Au/thionine/nafion-modified gold electrode was fabricated successfully. Firstly, nafion was dropped on the surface of the gold electrode to form a nafion film followed by chemisorption of thionine (Thi) as an electron mediator via the ion-exchange interaction between the Thi and nafion. Subsequently, the SiO₂/BSA/Au composite nanoparticles were assembled onto Thi film through the covalent bounding with the amino groups of Thi. Finally, HRP was immobilized on the SiO₂/BSA/Au composite nanoparticles due to the covalent conjugation to construct an enzyme biosensor. The surface topographies of the SiO₂/BSA/Au composite nanoparticles were investigated by using scanning electronic microscopy. The stepwise self-assemble procedure of the biosensor was further characterized by means of cyclic voltammetry and chronoamperometry. The enzyme biosensor showed high sensitivity, good stability and selectivity, a wide linear response to hydrogen peroxide (H₂O₂) in the range of 8.0 x 10⁻⁶  ~3.72 x 10⁻³ mol/L, with a detection limit of 2.0 x 10⁻⁶ mol/L. The Michaelies-Menten constant K(app)(M) value was estimated to be 2.3 mM.

  19. A Novel Cell-Based Hybrid Acoustic Wave Biosensor with Impedimetric Sensing Capabilities

    PubMed Central

    Liu, Fei; Li, Fang; Nordin, Anis Nurashikin; Voiculescu, Ioana

    2013-01-01

    A novel multiparametric biosensor system based on living cells will be presented. The biosensor system includes two biosensing techniques on a single device: resonant frequency measurements and electric cell-substrate impedance sensing (ECIS). The multiparametric sensor system is based on the innovative use of the upper electrode of a quartz crystal microbalance (QCM) resonator as working electrode for the ECIS technique. The QCM acoustic wave sensor consists of a thin AT-cut quartz substrate with two gold electrodes on opposite sides. For integration of the QCM with the ECIS technique a semicircular counter electrode was fabricated near the upper electrode on the same side of the quartz crystal. Bovine aortic endothelial live cells (BAECs) were successfully cultured on this hybrid biosensor. Finite element modeling of the bulk acoustic wave resonator using COMSOL simulations was performed. Simultaneous gravimetric and impedimetric measurements performed over a period of time on the same cell culture were conducted to validate the device's sensitivity. The time necessary for the BAEC cells to attach and form a compact monolayer on the biosensor was 35∼45 minutes for 1.5 × 104 cells/cm2 BAECs; 60 minutes for 2.0 × 104 cells/cm2 BAECs; 70 minutes for 3.0 × 104 cells/cm2 BAECs; and 100 minutes for 5.0 × 104 cells/cm2 BAECs. It was demonstrated that this time is the same for both gravimetric and impedimetric measurements. This hybrid biosensor will be employed in the future for water toxicity detection. PMID:23459387

  20. Disposable L-lactate biosensor based on a screen-printed carbon electrode enhanced by graphene

    NASA Astrophysics Data System (ADS)

    Tu, Dandan; He, Yu; Rong, Yuanzhen; Wang, You; Li, Guang

    2016-04-01

    In this work, an amperometric L-lactate biosensor based on a graphene-modified screen-printed carbon electrode (SPCE) was constructed. First, the electrocatalytic performance of the SPCE modified with graphene by a one-step electrodeposition process (OerGO/SPCE) was investigated. The cyclic voltammogram of OerGO/SPCE, which showed a well-defined redox peak, had a smaller peak potential separation than that of SPCE, revealing the improvement in electron transfer speed brought about by modifying with graphene. Next, lactate oxidase and potassium ferricyanide were dropped on the OerGO/SPCE to construct a graphene-modified L-lactate biosensor (LOD/K3[Fe(CN)6]/OerGO/SPCE). The proposed biosensor, with a detection limit of 60 μM, had a high sensitivity (42.42 μA mM-1 cm-2) when working at a low working potential (0.15 V). The linear range was 0.5 mM-15 mM, covering the detecting range of L-lactate in clinical applications. The L-lactate biosensor had a short response time (10 s) and required only 10 μl of the sample. This L-lactate sensor modified with electrodeposited graphene had a larger sensitivity than that based on the bare SPCE. Thus, our low-cost and disposable L-lactate biosensor enhanced by graphene can perform as an attractive electrochemical device that can be manufactured for point-of-care testing (POCT) devices and be employed in POCT applications.

  1. High-efficient and high-content cytotoxic recording via dynamic and continuous cell-based impedance biosensor technology.

    PubMed

    Hu, Ning; Fang, Jiaru; Zou, Ling; Wan, Hao; Pan, Yuxiang; Su, Kaiqi; Zhang, Xi; Wang, Ping

    2016-10-01

    Cell-based bioassays were effective method to assess the compound toxicity by cell viability, and the traditional label-based methods missed much information of cell growth due to endpoint detection, while the higher throughputs were demanded to obtain dynamic information. Cell-based biosensor methods can dynamically and continuously monitor with cell viability, however, the dynamic information was often ignored or seldom utilized in the toxin and drug assessment. Here, we reported a high-efficient and high-content cytotoxic recording method via dynamic and continuous cell-based impedance biosensor technology. The dynamic cell viability, inhibition ratio and growth rate were derived from the dynamic response curves from the cell-based impedance biosensor. The results showed that the biosensors has the dose-dependent manners to diarrhetic shellfish toxin, okadiac acid based on the analysis of the dynamic cell viability and cell growth status. Moreover, the throughputs of dynamic cytotoxicity were compared between cell-based biosensor methods and label-based endpoint methods. This cell-based impedance biosensor can provide a flexible, cost and label-efficient platform of cell viability assessment in the shellfish toxin screening fields.

  2. Development of dual-fluorescence cell-based biosensors for detecting the influence of environmental factors on nanoparticle toxicity.

    PubMed

    Liang, Junting; Wang, Xuanyu; Li, Luzhi; Xu, Shengmin; Jiang, Jiang; Wu, Lijun; Zhao, Guoping; Chen, Shaopeng

    2017-03-01

    With the expanding use of engineered nanoparticles (NPs), development of a high-throughput, sensitive method for evaluating NP safety is important. In this study, we developed cell-based biosensors to efficiently and conveniently monitor NP toxicity. The biosensor cells were obtained by transiently transfecting human cells with biosensor plasmids containing a mCherry gene regulated by an inducible promoter [an activator protein 1 (AP-1) promoter, an interleukin 8 (IL8) promoter, or a B cell translocation gene 2 (BTG2) promoter], with an enhanced green-fluorescent protein gene driven by the cytomegalovirus promoter as the internal control. After optimizing flow cytometric analysis, these dual-fluorescence cell-based biosensors were capable of accurately and rapidly detecting NP toxicity. We found that the responses of AP-1, BTG2, and IL8 biosensors in assessing the toxicity of silver nanoparticles (Ag NPs) showed good dose-related increases after exposure to Ag NPs and were consistent with data acquired by conventional assays, such as western blot, real-time polymerase chain reaction, and immunofluorescence. Further investigation of the effects of environmental factors on Ag NP toxicity revealed that aging in water, co-exposure with fulvic acid, and irradiation with ultraviolet A light could affect Ag NP-induced biosensor responses. These results indicated that these novel dual-fluorescence biosensors can be applied to accurately and sensitively monitor NP toxicity.

  3. Electrochemical Quartz Crystal Nanobalance (EQCN) Based Biosensor for Sensitive Detection of Antibiotic Residues in Milk.

    PubMed

    Bhand, Sunil; Mishra, Geetesh K

    2017-01-01

    An electrochemical quartz crystal nanobalance (EQCN), which provides real-time analysis of dynamic surface events, is a valuable tool for analyzing biomolecular interactions. EQCN biosensors are based on mass-sensitive measurements that can detect small mass changes caused by chemical binding to small piezoelectric crystals. Among the various biosensors, the piezoelectric biosensor is considered one of the most sensitive analytical techniques, capable of detecting antigens at picogram levels. EQCN is an effective monitoring technique for regulation of the antibiotics below the maximum residual limit (MRL). The analysis of antibiotic residues requires high sensitivity, rapidity, reliability and cost effectiveness. For analytical purposes the general approach is to take advantage of the piezoelectric effect by immobilizing a biosensing layer on top of the piezoelectric crystal. The sensing layer usually comprises a biological material such as an antibody, enzymes, or aptamers having high specificity and selectivity for the target molecule to be detected. The biosensing layer is usually functionalized using surface chemistry modifications. When these bio-functionalized quartz crystals are exposed to a particular substance of interest (e.g., a substrate, inhibitor, antigen or protein), binding interaction occurs. This causes a frequency or mass change that can be used to determine the amount of material interacted or bound. EQCN biosensors can easily be automated by using a flow injection analysis (FIA) setup coupled through automated pumps and injection valves. Such FIA-EQCN biosensors have great potential for the detection of different analytes such as antibiotic residues in various matrices such as water, waste water, and milk.

  4. Analytical modeling of label free biosensor using charge plasma based gate underlap dielectric modulated MOSFET

    NASA Astrophysics Data System (ADS)

    Chanda, Manash; Das, Rahul; Kundu, Atanu; Sarkar, Chandan K.

    2017-04-01

    In this paper charge plasma based dielectric modulated four gated MOSFET (CP-GUDM-MOSFET) has been proposed for the efficacy of label free electrical detection of the biomolecules. To achieve low thermal budgeting, charge-plasma concept is employed using appropriate metal work function electrodes. Extensive simulations have been done using the Sentaurus TCAD to validate the proposed architecture. An analytical modeling has also been done on surface potential and drain current to consolidate the feasibility of the structure. Significant improvements in the on current (ION) and threshold voltage have been observed in presence of the charged biomolecules. The performance of proposed structure is found to be sensitive to gate-oxide thickness variations. High sensitivity of the proposed CP-GUDM-MOSFET based biosensor with low thermal budgeting scheme; simple structure and its compatibility with the existing CMOS processes make it an exciting alternative to the conventional FET-based biosensors.

  5. Protein-Based Graphene Biosensors: Optimizing Artificial Chemoreception in Bilayer Lipid Membranes

    PubMed Central

    Siontorou, Christina G.; Georgopoulos, Konstantinos N.; Nikoleli, Georgia-Paraskevi; Nikolelis, Dimitrios P.; Karapetis, Stefanos K.; Bratakou, Spyridoula

    2016-01-01

    Proteinaceous moieties are critical elements in most detection systems, including biosensing platforms. Their potential is undoubtedly vast, yet many issues regarding their full exploitation remain unsolved. On the other hand, the biosensor formats with the higher marketability probabilities are enzyme in nature and electrochemical in concept. To no surprise, alternative materials for hosting catalysis within an electrode casing have received much attention lately to demonstrate a catalysis-coated device. Graphene and ZnO are presented as ideal materials to modify electrodes and biosensor platforms, especially in protein-based detection. Our group developed electrochemical sensors based on these nanomaterials for the sensitive detection of cholesterol using cholesterol oxidase incorporated in stabilized lipid films. A comparison between the two platforms is provided and discussed. In a broader sense, the not-so-remote prospect of quickly assembling a protein-based flexible biosensing detector to fulfill site-specific requirements is appealing to both university researchers and industry developers. PMID:27618113

  6. A Critical Review of Glucose Biosensors Based on Carbon Nanomaterials: Carbon Nanotubes and Graphene

    PubMed Central

    Zhu, Zhigang; Garcia-Gancedo, Luis; Flewitt, Andrew J.; Xie, Huaqing; Moussy, Francis; Milne, William I.

    2012-01-01

    There has been an explosion of research into the physical and chemical properties of carbon-based nanomaterials, since the discovery of carbon nanotubes (CNTs) by Iijima in 1991. Carbon nanomaterials offer unique advantages in several areas, like high surface-volume ratio, high electrical conductivity, chemical stability and strong mechanical strength, and are thus frequently being incorporated into sensing elements. Carbon nanomaterial-based sensors generally have higher sensitivities and a lower detection limit than conventional ones. In this review, a brief history of glucose biosensors is firstly presented. The carbon nanotube and grapheme-based biosensors, are introduced in Sections 3 and 4, respectively, which cover synthesis methods, up-to-date sensing approaches and nonenzymatic hybrid sensors. Finally, we briefly outline the current status and future direction for carbon nanomaterials to be used in the sensing area. PMID:22778628

  7. Fabrication of polyimide based microfluidic channels for biosensor devices

    NASA Astrophysics Data System (ADS)

    Zulfiqar, Azeem; Pfreundt, Andrea; Svendsen, Winnie Edith; Dimaki, Maria

    2015-03-01

    The ever-increasing complexity of the fabrication process of Point-of-care (POC) devices, due to high demand of functional versatility, compact size and ease-of-use, emphasizes the need of multifunctional materials that can be used to simplify this process. Polymers, currently in use for the fabrication of the often needed microfluidic channels, have limitations in terms of their physicochemical properties. Therefore, the use of a multipurpose biocompatible material with better resistance to the chemical, thermal and electrical environment, along with capability of forming closed channel microfluidics is inevitable. This paper demonstrates a novel technique of fabricating microfluidic devices using polyimide (PI) which fulfills the aforementioned properties criteria. A fabrication process to pattern microfluidic channels, using partially cured PI, has been developed by using a dry etching method. The etching parameters are optimized and compared to those used for fully cured PI. Moreover, the formation of closed microfluidic channel on wafer level by bonding two partially cured PI layers or a partially cured PI to glass with high bond strength has been demonstrated. The reproducibility in uniformity of PI is also compared to the most commonly used SU8 polymer, which is a near UV sensitive epoxy resin. The potential applications of PI processing are POC and biosensor devices integrated with microelectronics.

  8. Electrochemical impedimetric biosensor based on a nanostructured polycarbonate substrate

    PubMed Central

    Chen, Yu-Shan; Wu, Chia-Che; Tsai, Jaw-Ji; Wang, Gou-Jen

    2012-01-01

    This study integrates the techniques of nanoelectroforming, hot-embossing, and electrochemical deposition to develop a disposable, low-cost, and high sensitivity nanostructure biosensor. A modified anodic aluminum oxide barrier-layer surface was used as the template for thin nickel film deposition. After etching the anodic aluminum oxide template off, a three-dimensional mold of the concave nanostructure array was created. The fabricated three-dimensional nickel mold was further used for replica molding of a nanostructure polycarbonate substrate by hot-embossing. A thin gold film was then sputtered onto the polycarbonate substrate to form the electrode, followed by deposition of an orderly and uniform gold nanoparticle layer on the three-dimensional gold electrode using electrochemical deposition. Finally, silver nanoparticles were deposited on the uniformly deposited gold nanoparticles to enhance the conductivity of the sensor. Electrochemical impedance spectroscopy analysis was then used to detect the concentration of the target element. The sensitivity of the proposed scheme on the detection of the dust mite antigen, Der p2, reached 0.1 pg/mL. PMID:22275829

  9. Transcription factor-based biosensors enlightened by the analyte

    PubMed Central

    Fernandez-López, Raul; Ruiz, Raul; de la Cruz, Fernando; Moncalián, Gabriel

    2015-01-01

    Whole cell biosensors (WCBs) have multiple applications for environmental monitoring, detecting a wide range of pollutants. WCBs depend critically on the sensitivity and specificity of the transcription factor (TF) used to detect the analyte. We describe the mechanism of regulation and the structural and biochemical properties of TF families that are used, or could be used, for the development of environmental WCBs. Focusing on the chemical nature of the analyte, we review TFs that respond to aromatic compounds (XylS-AraC, XylR-NtrC, and LysR), metal ions (MerR, ArsR, DtxR, Fur, and NikR) or antibiotics (TetR and MarR). Analyzing the structural domains involved in DNA recognition, we highlight the similitudes in the DNA binding domains (DBDs) of these TF families. Opposite to DBDs, the wide range of analytes detected by TFs results in a diversity of structures at the effector binding domain. The modular architecture of TFs opens the possibility of engineering TFs with hybrid DNA and effector specificities. Yet, the lack of a crisp correlation between structural domains and specific functions makes this a challenging task. PMID:26191047

  10. A Urea Potentiometric Biosensor Based on a Thiophene Copolymer.

    PubMed

    Lai, Cheng-Yuan Kevin; Foot, Peter J S; Brown, John W; Spearman, Peter

    2017-03-03

    A potentiometric enzyme biosensor is a convenient detector for quantification of urea concentrations in industrial processes, or for monitoring patients with diabetes, kidney damage or liver malfunction. In this work, poly(3-hexylthiophene-co-3-thiopheneacetic acid) (P(3HT-co-3TAA)) was chemically synthesized, characterized and spin-coated onto conductive indium tin oxide (ITO) glass electrodes. Urease (Urs) was covalently attached to the smooth surface of this copolymer via carbodiimide coupling. The electrochemical behavior and stability of the modified Urs/P(3HT-co-3TAA)/ITO glass electrode were investigated by cyclic voltammetry, and the bound enzyme activity was confirmed by spectrophotometry. Potentiometric response studies indicated that this electrode could determine the concentration of urea in aqueous solutions, with a quasi-Nernstian response up to about 5 mM. No attempt was made to optimize the response speed; full equilibration occurred after 10 min, but the half-time for response was typically <1 min.

  11. A Urea Potentiometric Biosensor Based on a Thiophene Copolymer

    PubMed Central

    Lai, Cheng-Yuan (Kevin); Foot, Peter J. S.; Brown, John W.; Spearman, Peter

    2017-01-01

    A potentiometric enzyme biosensor is a convenient detector for quantification of urea concentrations in industrial processes, or for monitoring patients with diabetes, kidney damage or liver malfunction. In this work, poly(3-hexylthiophene-co-3-thiopheneacetic acid) (P(3HT-co-3TAA)) was chemically synthesized, characterized and spin-coated onto conductive indium tin oxide (ITO) glass electrodes. Urease (Urs) was covalently attached to the smooth surface of this copolymer via carbodiimide coupling. The electrochemical behavior and stability of the modified Urs/P(3HT-co-3TAA)/ITO glass electrode were investigated by cyclic voltammetry, and the bound enzyme activity was confirmed by spectrophotometry. Potentiometric response studies indicated that this electrode could determine the concentration of urea in aqueous solutions, with a quasi-Nernstian response up to about 5 mM. No attempt was made to optimize the response speed; full equilibration occurred after 10 min, but the half-time for response was typically <1 min. PMID:28273816

  12. Efficient method for high-throughput virtual screening based on flexible docking: discovery of novel acetylcholinesterase inhibitors.

    PubMed

    Mizutani, Miho Yamada; Itai, Akiko

    2004-09-23

    A method of easily finding ligands, with a variety of core structures, for a given target macromolecule would greatly contribute to the rapid identification of novel lead compounds for drug development. We have developed an efficient method for discovering ligand candidates from a number of flexible compounds included in databases, when the three-dimensional (3D) structure of the drug target is available. The method, named ADAM&EVE, makes use of our automated docking method ADAM, which has already been reported. Like ADAM, ADAM&EVE takes account of the flexibility of each molecule in databases, by exploring the conformational space fully and continuously. Database screening has been made much faster than with ADAM through the tuning of parameters, so that computational screening of several hundred thousand compounds is possible in a practical time. Promising ligand candidates can be selected according to various criteria based on the docking results and characteristics of compounds. Furthermore, we have developed a new tool, EVE-MAKE, for automatically preparing the additional compound data necessary for flexible docking calculation, prior to 3D database screening. Among several successful cases of lead discovery by ADAM&EVE, the finding of novel acetylcholinesterase (AChE) inhibitors is presented here. We performed a virtual screening of about 160 000 commercially available compounds against the X-ray crystallographic structure of AChE. Among 114 compounds that could be purchased and assayed, 35 molecules with various core structures showed inhibitory activities with IC(50) values less than 100 microM. Thirteen compounds had IC(50) values between 0.5 and 10 microM, and almost all their core structures are very different from those of known inhibitors. The results demonstrate the effectiveness and validity of the ADAM&EVE approach and provide a starting point for development of novel drugs to treat Alzheimer's disease.

  13. A Comprehensive Review of Glucose Biosensors Based on Nanostructured Metal-Oxides

    PubMed Central

    Rahman, Md. Mahbubur; Saleh Ahammad, A. J.; Jin, Joon-Hyung; Ahn, Sang Jung; Lee, Jae-Joon

    2010-01-01

    Nanotechnology has opened new and exhilarating opportunities for exploring glucose biosensing applications of the newly prepared nanostructured materials. Nanostructured metal-oxides have been extensively explored to develop biosensors with high sensitivity, fast response times, and stability for the determination of glucose by electrochemical oxidation. This article concentrates mainly on the development of different nanostructured metal-oxide [such as ZnO, Cu(I)/(II) oxides, MnO2, TiO2, CeO2, SiO2, ZrO2, and other metal-oxides] based glucose biosensors. Additionally, we devote our attention to the operating principles (i.e., potentiometric, amperometric, impedimetric and conductometric) of these nanostructured metal-oxide based glucose sensors. Finally, this review concludes with a personal prospective and some challenges of these nanoscaled sensors. PMID:22399911

  14. Simple method of enzyme immobilization for pH-ISFET-based urea biosensors

    NASA Astrophysics Data System (ADS)

    Pijanowska, Dorota; Torbicz, Wladislaw

    1997-02-01

    In this paper, a simple chemical method of urease immobilization on silicon nitride surface is described. As a basic structure to construct urea-biosensor, a pH-sensitive Si3N4-gate ISFET was used. The developed method of chemical immobilization of urease is based on Schiff's base formation. The developed EnFET type urea biosensor are characterized by the following parameters: (1) maximum analytical signal: 120 divided by 140 mV in 10 mM phosphate buffer solution, (2) linear range of the (Delta) Ugs equals f(logCurea): pCurea(2 divided by 3.5) in 10 mM phosphate buffer, (3) response time: 80 s and (4) lifetime: 35 days with the stable analytical signal then after 52 days this signal decreased by at least 40%. The influence of the concentration as well as the pH of the buffer solution on EnFET response were investigated.

  15. Electrochemical DNA biosensors based on thin gold films sputtered on capacitive nanoporous niobium oxide.

    PubMed

    Rho, Sangchul; Jahng, Deokjin; Lim, Jae Hoon; Choi, Jinsub; Chang, Jeong Ho; Lee, Sang Cheon; Kim, Kyung Ja

    2008-01-18

    Electrochemical DNA biosensors based on a thin gold film sputtered on anodic porous niobium oxide (Au@Nb(2)O(5)) are studied in detail here. We found that the novel DNA biosensor based on Au@Nb(2)O(5) is superior to those based on the bulk gold electrode or niobium oxide electrode. For example, the novel method does not require any time-consuming cleaning step in order to obtain reproducible results. The adhesion of gold films on the substrate is very stable during electrochemical biosensing, when the thin gold films are deposited on anodically prepared nanoporous niobium oxide. In particular, the novel biosensor shows enhanced biosensing performance with a 2.4 times higher resolution and a three times higher sensitivity. The signal enhancement is in part attributed to capacitive interface between gold films and nanoporous niobium oxide, where charges are accumulated during the anodic and cathodic scanning, and is in part ascribed to the structural stability of DNA immobilized at the sputtered gold films. The method allows for the detection of single-base mismatch DNA as well as for the discrimination of mismatch positions.

  16. Biosensor-based microRNA detection: techniques, design, performance, and challenges.

    PubMed

    Johnson, Blake N; Mutharasan, Raj

    2014-04-07

    The current state of biosensor-based techniques for amplification-free microRNA (miRNA) detection is critically reviewed. Comparison with non-sensor and amplification-based molecular techniques (MTs), such as polymerase-based methods, is made in terms of transduction mechanism, associated protocol, and sensitivity. Challenges associated with miRNA hybridization thermodynamics which affect assay selectivity and amplification bias are briefly discussed. Electrochemical, electromechanical, and optical classes of miRNA biosensors are reviewed in terms of transduction mechanism, limit of detection (LOD), time-to-results (TTR), multiplexing potential, and measurement robustness. Current trends suggest that biosensor-based techniques (BTs) for miRNA assay will complement MTs due to the advantages of amplification-free detection, LOD being femtomolar (fM)-attomolar (aM), short TTR, multiplexing capability, and minimal sample preparation requirement. Areas of future importance in miRNA BT development are presented which include focus on achieving high measurement confidence and multiplexing capabilities.

  17. A modular cell-based biosensor using engineered genetic logic circuits to detect and integrate multiple environmental signals

    PubMed Central

    Wang, Baojun; Barahona, Mauricio; Buck, Martin

    2013-01-01

    Cells perceive a wide variety of cellular and environmental signals, which are often processed combinatorially to generate particular phenotypic responses. Here, we employ both single and mixed cell type populations, pre-programmed with engineered modular cell signalling and sensing circuits, as processing units to detect and integrate multiple environmental signals. Based on an engineered modular genetic AND logic gate, we report the construction of a set of scalable synthetic microbe-based biosensors comprising exchangeable sensory, signal processing and actuation modules. These cellular biosensors were engineered using distinct signalling sensory modules to precisely identify various chemical signals, and combinations thereof, with a quantitative fluorescent output. The genetic logic gate used can function as a biological filter and an amplifier to enhance the sensing selectivity and sensitivity of cell-based biosensors. In particular, an Escherichia coli consortium-based biosensor has been constructed that can detect and integrate three environmental signals (arsenic, mercury and copper ion levels) via either its native two-component signal transduction pathways or synthetic signalling sensors derived from other bacteria in combination with a cell-cell communication module. We demonstrate how a modular cell-based biosensor can be engineered predictably using exchangeable synthetic gene circuit modules to sense and integrate multiple-input signals. This study illustrates some of the key practical design principles required for the future application of these biosensors in broad environmental and healthcare areas. PMID:22981411

  18. A modular cell-based biosensor using engineered genetic logic circuits to detect and integrate multiple environmental signals.

    PubMed

    Wang, Baojun; Barahona, Mauricio; Buck, Martin

    2013-02-15

    Cells perceive a wide variety of cellular and environmental signals, which are often processed combinatorially to generate particular phenotypic responses. Here, we employ both single and mixed cell type populations, pre-programmed with engineered modular cell signalling and sensing circuits, as processing units to detect and integrate multiple environmental signals. Based on an engineered modular genetic AND logic gate, we report the construction of a set of scalable synthetic microbe-based biosensors comprising exchangeable sensory, signal processing and actuation modules. These cellular biosensors were engineered using distinct signalling sensory modules to precisely identify various chemical signals, and combinations thereof, with a quantitative fluorescent output. The genetic logic gate used can function as a biological filter and an amplifier to enhance the sensing selectivity and sensitivity of cell-based biosensors. In particular, an Escherichia coli consortium-based biosensor has been constructed that can detect and integrate three environmental signals (arsenic, mercury and copper ion levels) via either its native two-component signal transduction pathways or synthetic signalling sensors derived from other bacteria in combination with a cell-cell communication module. We demonstrate how a modular cell-based biosensor can be engineered predictably using exchangeable synthetic gene circuit modules to sense and integrate multiple-input signals. This study illustrates some of the key practical design principles required for the future application of these biosensors in broad environmental and healthcare areas.

  19. Clinical Application of Surface Plasmon Resonance-Based Biosensors for Fetal Fibronectin Detection

    PubMed Central

    Chen, Chen-Yu; Chang, Chia-Chen; Yu, Chun; Lin, Chii-Wann

    2012-01-01

    Preterm birth is the leading cause of perinatal morbidity and mortality. Fetal fibronectin (fFN), a glycoprotein in the extracellular matrix of the amniotic membranes, is the most powerful biomarker for predicting the risk of preterm birth. Biosensors using the surface plasmon resonance (SPR) response are potentially useful in quantitatively measuring molecules. We established a standard calibration curve of SPR intensity against fFN concentration and used the SPR-based biosensor to detect fFN concentrations in the cervicovaginal secretions of pregnant women between 22 and 34 weeks of gestation. The calibration curve extends from 0.5 ng/mL to 100 ng/mL with an excellent correlation (R2 = 0.985) based on standard fFN samples. A cutoff value of 50 ng/mL fFN concentration in commercial ELISA kits corresponds to a relative intensity of 17 arbitrary units (a.u.) in SPR. Thirty-two pregnant women were analyzed in our study. In 11 women, the SPR relative intensity was greater than or equal to 17 a.u., and in 21 women, the SPR relative intensity was less than 17 a.u. There were significant differences between the two groups in regular uterine contractions (p = 0.040), hospitalization for tocolysis (p = 0.049), and delivery weeks (p = 0.043). Our prospective study concluded that SPR-based biosensors can quantitatively measure fFN concentrations. These results reveal the potential utility of SPR-based biosensors in predicting the risk of preterm birth. PMID:22666007

  20. A paper-based nanomodified electrochemical biosensor for ethanol detection in beers.

    PubMed

    Cinti, Stefano; Basso, Mattia; Moscone, Danila; Arduini, Fabiana

    2017-04-01

    Herein, we report the first example of a paper-based screen-printed biosensor for the detection of ethanol in beer samples. Common office paper was adopted to fabricate the analytical device. The properties of this paper-based screen-printed electrode (SPE) were investigated by cyclic voltammetry, electrochemical impedance spectroscopy, and scanning electron microscopy, and they were compared with the well-established polyester-based SPEs as well. Paper demonstrated similar properties when compared with polyester, highlighting suitability towards its utilization in sensor development, with the advantages of low cost and simple disposal by incineration. A nanocomposite formed by Carbon Black (CB) and Prussian Blue nanoparticles (PBNPs), namely CB/PBNPs, was utilized as an electrocatalyst to detect the hydrogen peroxide generated by the enzymatic reaction between alcohol oxidase (AOx) and ethanol. After optimizing the analytical parameters, such as pH, enzyme, concentration, and working potential, the developed biosensor allowed a facile quantification of ethanol up to 10 mM (0.058 %vol), with a sensitivity of 9.13 μA/mM cm(2) (1574 μA/%vol cm(2)) and a detection limit equal to 0.52 mM (0.003%vol). These satisfactory performances rendered the realized paper-based biosensor reliable over the analysis of ethanol contained in four different types of beers, including Pilsner, Weiss, Lager, and alcohol-free. The proposed manufacturing approach offers an affordable and sustainable tool for food quality control and for the realization of different electrochemical sensors and biosensors as well.

  1. High-sensitive label-free biosensors based on single-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Maehashi, Kenzo; Matsumoto, Kazuhiko

    2006-02-01

    DNA hybridization has sensitively been detected using carbon nanotube field-effect transistors (CNTFETs) in real time. After full-complementary DNA introduction, the source-drain current gradually increased while monitoring in real time. Full-complementary DNA with concentration as low as 1 fmol/L solution could be effectively detected. Our CNTFET-based biochip is a promising candidate for the development of an integrated, high-throughput, multiplexed DNA biosensor for medical, forensic and environmental diagnostics.

  2. An absolute calibration method of an ethyl alcohol biosensor based on wavelength-modulated differential photothermal radiometry

    SciTech Connect

    Liu, Yi Jun; Mandelis, Andreas; Guo, Xinxin

    2015-11-15

    In this work, laser-based wavelength-modulated differential photothermal radiometry (WM-DPTR) is applied to develop a non-invasive in-vehicle alcohol biosensor. WM-DPTR features unprecedented ethanol-specificity and sensitivity by suppressing baseline variations through a differential measurement near the peak and baseline of the mid-infrared ethanol absorption spectrum. Biosensor signal calibration curves are obtained from WM-DPTR theory and from measurements in human blood serum and ethanol solutions diffused from skin. The results demonstrate that the WM-DPTR-based calibrated alcohol biosensor can achieve high precision and accuracy for the ethanol concentration range of 0-100 mg/dl. The high-performance alcohol biosensor can be incorporated into ignition interlocks that could be fitted as a universal accessory in vehicles in an effort to reduce incidents of drinking and driving.

  3. An absolute calibration method of an ethyl alcohol biosensor based on wavelength-modulated differential photothermal radiometry.

    PubMed

    Liu, Yi Jun; Mandelis, Andreas; Guo, Xinxin

    2015-11-01

    In this work, laser-based wavelength-modulated differential photothermal radiometry (WM-DPTR) is applied to develop a non-invasive in-vehicle alcohol biosensor. WM-DPTR features unprecedented ethanol-specificity and sensitivity by suppressing baseline variations through a differential measurement near the peak and baseline of the mid-infrared ethanol absorption spectrum. Biosensor signal calibration curves are obtained from WM-DPTR theory and from measurements in human blood serum and ethanol solutions diffused from skin. The results demonstrate that the WM-DPTR-based calibrated alcohol biosensor can achieve high precision and accuracy for the ethanol concentration range of 0-100 mg/dl. The high-performance alcohol biosensor can be incorporated into ignition interlocks that could be fitted as a universal accessory in vehicles in an effort to reduce incidents of drinking and driving.

  4. An absolute calibration method of an ethyl alcohol biosensor based on wavelength-modulated differential photothermal radiometry

    NASA Astrophysics Data System (ADS)

    Liu, Yi Jun; Mandelis, Andreas; Guo, Xinxin

    2015-11-01

    In this work, laser-based wavelength-modulated differential photothermal radiometry (WM-DPTR) is applied to develop a non-invasive in-vehicle alcohol biosensor. WM-DPTR features unprecedented ethanol-specificity and sensitivity by suppressing baseline variations through a differential measurement near the peak and baseline of the mid-infrared ethanol absorption spectrum. Biosensor signal calibration curves are obtained from WM-DPTR theory and from measurements in human blood serum and ethanol solutions diffused from skin. The results demonstrate that the WM-DPTR-based calibrated alcohol biosensor can achieve high precision and accuracy for the ethanol concentration range of 0-100 mg/dl. The high-performance alcohol biosensor can be incorporated into ignition interlocks that could be fitted as a universal accessory in vehicles in an effort to reduce incidents of drinking and driving.

  5. The development of a silica nanoparticle-based label-free DNA biosensor

    NASA Astrophysics Data System (ADS)

    Kell, Arnold J.; Pagé, Lilianne; Tan, Sophie; Charlebois, Isabelle; Boissinot, Maurice; Leclerc, Mario; Simard, Benoit

    2011-09-01

    A silica nanoparticle-based DNA biosensor capable of detecting Bacillus anthracis bacteria through the use of unlabelled ss-oligonucleotides has been developed. The biosensor makes use of the optical changes that accompany a nanoparticle-immobilized cationic conjugated polymer (polythiophene) interacting with single-stranded vs. hybridized oligonucleotides, where a fluorescence signal appears only when hybridized DNA is present (i.e. only when the ss-oligonucleotide interacting with the polymer has hybridized with its complement). In order to enhance the sensitivity of the biosensor, two different nanoparticle architectures were developed and used to elucidate how the presence of neighboring fluorophores on the nanoparticle surface affects Förster-resonant energy transfer (FRET) between the polythiophene/oligonucleotide complex (FRET donor) and the fluorophores (FRET acceptors). We demonstrate that the silica nanoparticle-based FRET platform lowers the limit of detection at least 10-fold in comparison to the polythiophene itself, and allows the detection of ~2 × 10-12 moles of ss-oligonucleotide in a 100 μL sample with a standard fluorimeter (i.e. has a limit of detection of ~2 nM ssDNA). Such nanoparticle-based biosensor platforms are beneficial because of the robustness and stability inherent to their covalent assembly and they provide a valuable new tool that may allow for the sensitive, label-free detection (the target DNA that produces the fluorescence signal is unlabelled) without the use of polymerase chain reaction.A silica nanoparticle-based DNA biosensor capable of detecting Bacillus anthracis bacteria through the use of unlabelled ss-oligonucleotides has been developed. The biosensor makes use of the optical changes that accompany a nanoparticle-immobilized cationic conjugated polymer (polythiophene) interacting with single-stranded vs. hybridized oligonucleotides, where a fluorescence signal appears only when hybridized DNA is present (i.e. only when

  6. Extended-Gate Metal Oxide Semiconductor Field Effect Transistor-Based Biosensor for Detection of Deoxynivalenol

    NASA Astrophysics Data System (ADS)

    Kwon, Insu; Lee, Hee-Ho; Choi, Jinhyeon; Shin, Jang-Kyoo; Seo, Sang-Ho; Choi, Sung-Wook; Chun, Hyang Sook

    2011-06-01

    In this work, we present an extended-gate metal oxide semiconductor field effect transistor (MOSFET)-based biosensor for the detection of deoxynivalenol using a null-balancing circuit. An extended-gate MOSFET-based biosensor was fabricated by a standard complementary metal oxide semiconductor (CMOS) process and its characteristics were measured. A null-balancing circuit was used to measure the output voltage of the sensor directly, instead of measuring the drain current of the sensor. Au was used as the gate metal, which has a chemical affinity with thiol, which leads to the immobilization of a self-assembled monolayer (SAM) of mercaptohexadecanoic acid (MHDA). The SAM was used to immobilize the anti-deoxynivalenol antibody. The carboxyl group of the SAM was bound to the anti-deoxynivalenol antibody. The anti-deoxynivalenol antibody and deoxynivalenol were bound by their antigen-antibody reaction. The measurements were performed in phosphate buffered saline (PBS; pH 7.4) solution. A standard Ag/AgCl electrode was employed as a reference electrode. The bindings of a SAM, anti-deoxynivalenol antibody, and deoxynivalenol caused a variation in the output voltage of the extended-gate MOSFET-based biosensor. Surface plasmon resonance (SPR) measurement was performed to verify the interaction among the SAM, deoxynivalenol-antibody, and deoxynivalenol.

  7. Transcription factor-based biosensors in biotechnology: current state and future prospects.

    PubMed

    Mahr, Regina; Frunzke, Julia

    2016-01-01

    Living organisms have evolved a plethora of sensing systems for the intra- and extracellular detection of small molecules, ions or physical parameters. Several recent studies have demonstrated that these principles can be exploited to devise synthetic regulatory circuits for metabolic engineering strategies. In this context, transcription factors (TFs) controlling microbial physiology at the level of transcription play a major role in biosensor design, since they can be implemented in synthetic circuits controlling gene expression in dependency of, for example, small molecule production. Here, we review recent progress on the utilization of TF-based biosensors in microbial biotechnology highlighting different areas of application. Recent advances in metabolic engineering reveal TF-based sensors to be versatile tools for strain and enzyme development using high-throughput (HT) screening strategies and adaptive laboratory evolution, the optimization of heterologous pathways via the implementation of dynamic control circuits and for the monitoring of single-cell productivity in live cell imaging studies. These examples underline the immense potential of TF-based biosensor circuits but also identify limitations and room for further optimization.

  8. Green fluorescent protein-based biosensor for detecting SOS-inducing activity of genotoxic compounds.

    PubMed

    Kostrzynska, Magdalena; Leung, Kam T; Lee, Hung; Trevors, Jack T

    2002-01-01

    Increasing levels of environmental pollution demand specific and sensitive methods for detection of genotoxic agents in water, food products and environmental samples. Tests for genotoxicity assessment are often based on biosensor strains that respond to DNA damage induced by chemicals. In the present study, fluorescent reporter Escherichia coli strains have been developed, which contain a plasmid-borne transcriptional fusion between the DNA-damage inducible recA promoter and the green fluorescent protein gene (gfp) or a gene encoding a red-shifted, higher intensity GFP variant (mutant 3). GFP-based biosensors allowed the detection of a dose-dependent response to genotoxic agents such as mitomycin C (MMC), N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and nalidixic acid (NA). A reporter strain carrying recA'-gfp mutant 3 fusion gave more dramatic and sensitive response than a strain containing the wild-type gfp. These results indicate that recA'-gfp mutant 3-based biosensor is potentially useful for detection of genotoxins.

  9. An electrochemical DNA biosensor based on Oracet Blue as a label for detection of Helicobacter pylori.

    PubMed

    Hajihosseini, Saeedeh; Nasirizadeh, Navid; Hejazi, Mohammad Saeid; Yaghmaei, Parichereh

    2016-10-01

    An innovative method of a DNA electrochemical biosensor based on Oracet Blue (OB) as an electroactive label and gold electrode (AuE) for detection of Helicobacter pylori, was offered. A single-stranded DNA probe with a thiol modification was covalently immobilized on the surface of the AuE by forming an Au-S bond. Differential pulse voltammetry (DPV) was used to monitor DNA hybridization by measuring the electrochemical signals of reduction of the OB binding to double-stranded DNA (ds-DNA). Our results showed that OB-based DNA biosensor has a decent potential for detection of single-base mismatch in target DNA. Selectivity of the proposed DNA biosensor was further confirmed in the presence of non-complementary and complementary DNA strands. Under optimum conditions, the electrochemical signal had a linear relationship with the concentration of the target DNA ranging from 0.3nmolL(-1) to 240.0nmolL(-1), and the detection limit was 0.17nmolL(-1), whit a promising reproducibility and repeatability.

  10. A cell-based biosensor for nanomaterials cytotoxicity assessment in three dimensional cell culture.

    PubMed

    Dubiak-Szepietowska, Monika; Karczmarczyk, Aleksandra; Winckler, Thomas; Feller, Karl-Heinz

    2016-08-31

    Nanoparticles (NPs) are widely used in consumer and medicinal products. The high prevalence of nanoparticles in the environment raises concerns regarding their effects on human health, but there is limited knowledge about how NPs interact with cells or tissues. Because the European Union has called for a substantial reduction of animal experiments for scientific purposes (Directive 2010/63), increased efforts are required to develop in vitro models to evaluate potentially hazardous agents. Here, we describe a new cell-based biosensor for the evaluation of NPs cytotoxicity. The new biosensor is based on transgenic human hepatoblastoma cells (HepG2) that express a secreted form of alkaline phosphatase (SEAP) as a reporter protein whose expression is induced upon activation of a stress response pathway controlled by the transcription regulator nuclear factor-κB (NF-κB). The NF-κB_HepG2 sensor cells were cultured in a Matrigel-based three dimensional environment to simulate the in vivo situation. The new biosensor cells offer the advantage of generating fast and reproducible readout at lower concentrations and shorter incubation time than conventional viability assays, avoid possible interaction between nanomaterials and assay compounds, therefore, minimize generation of false positive or negative results and indicate mechanism of toxicity through NF-κB signaling.

  11. ZnO nanorods array based field-effect transistor biosensor for phosphate detection.

    PubMed

    Ahmad, Rafiq; Ahn, Min-Sang; Hahn, Yoon-Bong

    2017-03-18

    A promising field-effect transistor (FET) biosensor has been fabricated based on pyruvate oxidase (PyO) functionalized ZnO nanorods (ZnO NRs) array grown on seeded SiO2/Si substrate. The direct and vertically grown ZnO NRs on the seeded SiO2/Si substrate offers high surface area for enhanced PyO immobilization, which further helps to detect phosphate with higher specificity. Under optimum conditions, the fabricated FET biosensor provided a convenient method for phosphate detection with high sensitivity (80.57μAmM(-1)cm(-2)) in a wide-linear range (0.1µM-7.0mM). Additionally, it also showed very low effect of electroactive species, stability and good reproducibility. Encouraging results suggest that this approach presents a promising method to be used for field measurements to detect phosphate.

  12. Lead-Free Piezoelectric Diaphragm Biosensors Based on Micro-Machining Technology and Chemical Solution Deposition

    PubMed Central

    Li, Xiaomeng; Wu, Xiaoqing; Shi, Peng; Ye, Zuo-Guang

    2016-01-01

    In this paper, we present a new approach to the fabrication of integrated silicon-based piezoelectric diaphragm-type biosensors by using sodium potassium niobate-silver niobate (0.82KNN-0.18AN) composite lead-free thin film as the piezoelectric layer. The piezoelectric diaphragms were designed and fabricated by micro-machining technology and chemical solution deposition. The fabricated device was very sensitive to the mass changes caused by various targets attached on the surface of diaphragm. The measured mass sensitivity value was about 931 Hz/μg. Its good performance shows that the piezoelectric diaphragm biosensor can be used as a cost-effective platform for nucleic acid testing. PMID:26771617

  13. Single-molecule electrical biosensors based on single-walled carbon nanotubes.

    PubMed

    Guo, Xuefeng

    2013-07-05

    Interactions between biological molecules are fundamental to biology. Probing the complex behaviors of biological systems at the molecular level provides new opportunities to uncover the wealth of molecular information that is usually hidden in conventional ensemble experiments and address the "unanswerable" questions in the physical, chemical and biological sciences. Nanometer-scale materials are particularly well matched with biomolecular interactions due to their biocompatibility, size comparability, and remarkable electrical properties, thus setting the basis for biological sensing with ultrahigh sensitivity. This brief review aims to highlight the recent progress of the burgeoning field of single-molecule electrical biosensors based on nanomaterials, with a particular focus on single-walled carbon nanotubes (SWNTs), for better understanding of the molecular structure, interacting dynamics, and molecular functions. The perspectives and key issues that will be critical to the success of next-generation single-molecule biosensors toward practical applications are also discussed, such as the device reproducibility, system integration, and theoretical simulation.

  14. Amperometric biosensor based on glassy carbon electrode modified with long-length carbon nanotube and enzyme

    NASA Astrophysics Data System (ADS)

    Furutaka, Hajime; Nemoto, Kentaro; Inoue, Yuki; Hidaka, Hiroki; Muguruma, Hitoshi; Inoue, Hitoshi; Ohsawa, Tatsuya

    2016-05-01

    An amperometric biosensor based on a glassy carbon electrode modified with long-length multiwalled carbon nanotubes (MWCNTs) and enzyme nicotinamide-adenine-dinucleotide-dependent glucose dehydrogenase (GDH) is presented. We demonstrate the effect of the MWCNT length on the amperometric response of the enzyme biosensor. The long length of MWCNT is 200 µm (average), whereas the normal length of MWCNT is 1 µm (average). The response of the long MWCNT-GDH electrode is 2 times more sensitive than that of the normal-length MWCNT-GDH electrode in the concentration range from 0.25-35 mM. The result of electrochemical impedance spectroscopy measurements suggest that the long-length MWCNT-GDH electrode formed a better electron transfer network than the normal-length one.

  15. Ultrasensitive cDNA Detection of Dengue Virus RNA Using Electrochemical Nanoporous Membrane-Based Biosensor

    PubMed Central

    Rai, Varun; Hapuarachchi, Hapuarachchige C.; Ng, Lee Ching; Soh, Siew Hwa; Leo, Yee Sin; Toh, Chee-Seng

    2012-01-01

    A nanoporous alumina membrane-based ultrasensitive DNA biosensor is constructed using 5′-aminated DNA probes immobilized onto the alumina channel walls. Alumina nanoporous membrane-like structure is carved over platinum wire electrode of 76 µm diameter dimension by electrochemical anodization. The hybridization of complementary target DNA with probe DNA molecules attached inside the pores influences the pore size and ionic conductivity. The biosensor demonstrates linear range over 6 order of magnitude with ultrasensitive detection limit of 9.55×10−12 M for the quantification of ss-31 mer DNA sequence. Its applicability is challenged against real time cDNA PCR sample of dengue virus serotype1 derived from asymmetric PCR. Excellent specificity down to one nucleotide mismatch in target DNA sample of DENV3 is also demonstrated. PMID:22927927

  16. Lead-Free Piezoelectric Diaphragm Biosensors Based on Micro-Machining Technology and Chemical Solution Deposition.

    PubMed

    Li, Xiaomeng; Wu, Xiaoqing; Shi, Peng; Ye, Zuo-Guang

    2016-01-12

    In this paper, we present a new approach to the fabrication of integrated silicon-based piezoelectric diaphragm-type biosensors by using sodium potassium niobate-silver niobate (0.82KNN-0.18AN) composite lead-free thin film as the piezoelectric layer. The piezoelectric diaphragms were designed and fabricated by micro-machining technology and chemical solution deposition. The fabricated device was very sensitive to the mass changes caused by various targets attached on the surface of diaphragm. The measured mass sensitivity value was about 931 Hz/μg. Its good performance shows that the piezoelectric diaphragm biosensor can be used as a cost-effective platform for nucleic acid testing.

  17. A biristor based on a floating-body silicon nanowire for biosensor applications

    NASA Astrophysics Data System (ADS)

    Moon, Dong-Il; Peycelon, Maxime; Kim, Jee-Yeon; Ahn, Jae-Hyuk; Jung Park, Tae; Choi, Yang-Kyu

    2013-01-01

    A silicon nanowire (SiNW), which has been named "biristor" (bistable resistor), is demonstrated for biosensor applications. The SiNW is composed of three segments: n-type (source), p-type (floating-body), and n-type (drain). Its structure is based on a metal-oxide-semiconductor field-effect transistor without a gate. The biristor uses the uncovered floating-body as a sensing site, and it is triggered by impact ionization. A charge effect arising from biomolecules influences the triggering voltage, which is a sensing metric and changes the resistance of the SiNW. The biristor can be a promising candidate for biosensors in terms of complementary metal-oxide-semiconductor compatibility, low-cost, and compact density.

  18. Nanomaterials-based biosensors for detection of microorganisms and microbial toxins.

    PubMed

    Sutarlie, Laura; Ow, Sian Yang; Su, Xiaodi

    2017-04-01

    Detection of microorganisms and microbial toxins is important for health and safety. Due to their unique physical and chemical properties, nanomaterials have been extensively used to develop biosensors for rapid detection of microorganisms with microbial cells and toxins as target analytes. In this paper, the design principles of nanomaterials-based biosensors for four selected analyte categories (bacteria cells, toxins, mycotoxins, and protozoa cells), closely associated with the target analytes' properties is reviewed. Five signal transducing methods that are less equipment intensive (colorimetric, fluorimetric, surface enhanced Raman scattering, electrochemical, and magnetic relaxometry methods) is described and compared for their sensory performance (in term oflimit of detection, dynamic range, and response time) for all analyte categories. In the end, the suitability of these five sensing principles for on-site or field applications is discussed. With a comprehensive coverage of nanomaterials, design principles, sensing principles, and assessment on the sensory performance and suitability for on-site application, this review offers valuable insight and perspective for designing suitable nanomaterials-based microorganism biosensors for a given application.

  19. Hydrogel Based Biosensors for In Vitro Diagnostics of Biochemicals, Proteins, and Genes.

    PubMed

    Jung, Il Young; Kim, Ji Su; Choi, Bo Ram; Lee, Kyuri; Lee, Hyukjin

    2017-03-31

    Hydrogel-based biosensors have drawn considerable attention due to their various advantages over conventional detection systems. Recent studies have shown that hydrogel biosensors can be excellent alternative systems to detect a wide range of biomolecules, including small biochemicals, pathogenic proteins, and disease specific genes. Due to the excellent physical properties of hydrogels such as the high water content and stimuli-responsive behavior of cross-linked network structures, this system can offer substantial improvement for the design of novel detection systems for various diagnostic applications. The other main advantage of hydrogels is the role of biomimetic three-dimensional (3D) matrix immobilizing enzymes and aptamers within the detection systems, which enhances their stability. This provides ideal reaction conditions for enzymes and aptamers to interact with substrates within the aqueous environment of the hydrogel. In this review, we have highlighted various novel detection approaches utilizing the outstanding properties of the hydrogel. This review summarizes the recent progress of hydrogel-based biosensors and discusses their future perspectives and clinical limitations to overcome.

  20. Electrochemical Affinity Biosensors Based on Disposable Screen-Printed Electrodes for Detection of Food Allergens

    PubMed Central

    Vasilescu, Alina; Nunes, Gilvanda; Hayat, Akhtar; Latif, Usman; Marty, Jean-Louis

    2016-01-01

    Food allergens are proteins from nuts and tree nuts, fish, shellfish, wheat, soy, eggs or milk which trigger severe adverse reactions in the human body, involving IgE-type antibodies. Sensitive detection of allergens in a large variety of food matrices has become increasingly important considering the emergence of functional foods and new food manufacturing technologies. For example, proteins such as casein from milk or lysozyme and ovalbumin from eggs are sometimes used as fining agents in the wine industry. Nonetheless, allergen detection in processed foods is a challenging endeavor, as allergen proteins are degraded during food processing steps involving heating or fermentation. Detection of food allergens was primarily achieved via Enzyme-Linked Immuno Assay (ELISA) or by chromatographic methods. With the advent of biosensors, electrochemical affinity-based biosensors such as those incorporating antibodies and aptamers as biorecognition elements were also reported in the literature. In this review paper, we highlight the success achieved in the design of electrochemical affinity biosensors based on disposable screen-printed electrodes towards detection of protein allergens. We will discuss the analytical figures of merit for various disposable screen-printed affinity sensors in relation to methodologies employed for immobilization of bioreceptors on transducer surface. PMID:27827963

  1. Zinc oxide nanowires-based electrochemical biosensor for L-lactic acid amperometric detection

    NASA Astrophysics Data System (ADS)

    Zhao, Yanguang; Yan, Xiaoqin; Kang, Zhuo; Fang, Xiaofei; Zheng, Xin; Zhao, Lanqing; Du, Hongwu; Zhang, Yue

    2014-05-01

    In this work, zinc oxide (ZnO) nanowires-based electrochemical biosensor is designed and fabricated for the detection of L-lactic acid. ZnO nanowires were successfully synthesized via the chemical vapor deposition method. The morphology and structure of the prepared products were characterized, and the average diameter of synthesized ZnO samples was 500 nm. The fluorescence characterization was performed to verify the immobilization of lactate oxidase onto the ZnO surface. Biosensors based on large-area ZnO nanowires were then constructed, and a series of electrochemical experiments showed that ZnO could provide the efficient electron transfer channel between the enzymic active sites and the electrode surface. The proposed electrochemical biosensor exhibited a sensitivity of 15.6 µA cm-2 mM-1, a wide linear range of 12 µM-1.2 mM with a low-detection limit of 12 µM for L-lactic acid detection. This study has indicated the potential applications for ZnO nanowires to construct the simple and economic nano-bio devices for the detection of biological species.

  2. A double-mediator based whole cell electrochemical biosensor for acute biotoxicity assessment of wastewater.

    PubMed

    Gao, Guanyue; Fang, Deyu; Yu, Yuan; Wu, Liangzhuan; Wang, Yu; Zhi, Jinfang

    2017-05-15

    This work investigates the feasibility and sensitivity of a double-mediator based whole cell electrochemical biosensor to detect the acute biotoxicity of wastewater. The lipophilic mediator menadione was used to mediate the intracellular metabolic activities whereas hydrophilic potassium ferricyanide was employed as extracellular electron acceptor to transport the electron from the menadiol to anode. A chitosan hydrogel polymer film with boron-doped nanocrystalline diamond (BND) particles was electrodeposited onto a glassy carbon (GC) electrode to immobilize Saccharomyces cerevisiae cells and the mediators. The feasibility of the as-prepared biosensor was verified by determine the acute biotoxicity of four heavy metal ions(Cu(2+), Cd(2+), Ni(2+), Pb(2+)), three phenol pollutants (3,5-dichlorophenol, 4-chlorophenol, phenol) and three real wastewater samples. The IC50 values for Cu(2+), Cd(2+), Ni(2+), Pb(2+) are 10.12mg/L,13.88mg/L, 17.06mg/L and 34.56mg/L. And the IC50 value is 16.48mg/L, 34.40mg/L and 44.55mg/L for 3,5-dichlorophenol, 4-chlorophenol and phenol, respectively. The results of this work indicate that the double-mediator based whole cell electrochemical biosensor could be applied into the acute toxicity assessment of real wastewater samples with excellent performance and highlight their merit as portable and sensitive, which may providing a reasonable and reliable way for wastewater toxicity online detection.

  3. A highly sensitive electrochemical biosensor based on zinc oxide nanotetrapods for l-lactic acid detection

    NASA Astrophysics Data System (ADS)

    Lei, Yang; Luo, Ning; Yan, Xiaoqin; Zhao, Yanguang; Zhang, Gong; Zhang, Yue

    2012-05-01

    An amperometric biosensor based on zinc oxide (ZnO) nanotetrapods was designed to detect l-lactic acid. The lactate oxidase was immobilized on the surface of ZnO nanotetrapods by electrostatic adsorption. Unlike traditional detectors, the special four-leg individual ZnO nanostructure, as an adsorption layer, provides multiterminal charge transfer channels. Furthermore, a large amount of ZnO tetrapods are randomly stacked to form a three-dimensional network naturally that facilitates the exchange of electrons and ions in the phosphate buffer solution. Utilizing amperometric response measurements, the prepared ZnO nanotetrapod l-lactic acid biosensor displayed a detection limit of 1.2 μM, a low apparent Michaelis-Menten constant of 0.58 mM, a high sensitivity of 28.0 μA cm-2 mM-1 and a good linear relationship in the range of 3.6 μM-0.6 mM for the l-lactic acid detection. This study shows that the biosensor based on ZnO tetrapod nanostructures is highly sensitive and able to respond rapidly in detecting lactic acid.

  4. Biosensors and bio-based methods for the separation and detection of foodborne pathogens.

    PubMed

    Bhunia, Arun K

    2008-01-01

    The safety of our food supply is always a major concern to consumers, food producers, and regulatory agencies. A safer food supply improves consumer confidence and brings economic stability. The safety of foods from farm-to-fork through the supply chain continuum must be established to protect consumers from debilitating, sometimes fatal episodes of pathogen outbreaks. The implementation of preventive strategies like hazard analysis critical control points (HACCP) assures safety but its full utility will not be realized unless supportive tools are fully developed. Rapid, sensitive, and accurate detection methods are such essential tools that, when integrated with HACCP, will improve safety of products. Traditional microbiological methods are powerful, error-proof, and dependable but these lengthy, cumbersome methods are often ineffective because they are not compatible with the speed at which the products are manufactured and the short shelf life of products. Automation in detection methods is highly desirable, but is not achievable with traditional methods. Therefore, biosensor-based tools offer the most promising solutions and address some of the modern-day needs for fast and sensitive detection of pathogens in real time or near real time. The application of several biosensor tools belonging to the categories of optical, electrochemical, and mass-based tools for detection of foodborne pathogens is reviewed in this chapter. Ironically, geometric growth in biosensor technology is fueled by the imminent threat of bioterrorism through food, water, and air and by the funding through various governmental agencies.

  5. Thiamine biosensor based on oxidative trapping of enzyme-substrate intermediate.

    PubMed

    Halma, Matilte; Doumèche, Bastien; Hecquet, Laurence; Prévot, Vanessa; Mousty, Christine; Charmantray, Franck

    2017-01-15

    In the present work, we describe a new thiamine amperometric biosensor based on thiamine pyrophosphate (ThDP)-dependent transketolase (TK)-catalyzed reaction, followed by the oxidative trapping of TK intermediate α,β-dihydroxyethylthiamine diphosphate (DHEThDP) within the enzymatic active site. For the biosensor design purpose, TK from Escherichia coli (TKec) was immobilized in Mg2Al-NO3 Layered Double Hydroxides (LDH) and the electrochemical detection was achieved with the TKec/LDH modified glassy carbon electrode (GCE). The transduction process was based on the ability of Fe(CN)6(3-) to oxidize DHEThDP to glycolic acid along with ThDP regeneration. The released Fe(CN)6(4-) was re-oxidized at +0.5V vs Ag-AgCl and the reaction was followed by chronoamperometry. The TKec/LDH/GCE biosensor was optimized using the best TK donor substrates, namely l-erythrulose and d-fructose-6-phosphate. ThDP was assayed with great sensitivity (3831mAM(-1)cm(-2)) over 20-400nM linear range.

  6. Nicking enzyme-assisted biosensor for Salmonella enteritidis detection based on fluorescence resonance energy transfer.

    PubMed

    Song, Yang; Li, Wenkai; Duan, Yingfen; Li, Zhongjie; Deng, Le

    2014-05-15

    Salmonella enteritidis (S. enteritidis) outbreaks continue to occur, and have increased public awareness of this pathogen. Nicking endonuclease Nb.BbvC I is widely used for the detection of biomolecules and displays activity for specific double-stranded DNA (dsDNA). In this study, we developed a biosensor to detect S. enteritidis based on fluorescence resonance energy transfer (FRET) using nicking enzyme and carbon nanoparticles (CNPs). Because of the quenching effect of black hole quencher 1 (BHQ 1), the CNPs do not fluoresce in the reaction system. When the target bacteria are added, the nicking enzyme recognizes and cleaves the dsDNA fabricated by the interaction between probe and target. As a result, the CNPs dissociate from BHQ 1 and emit strong fluorescence. Using the nicking enzyme, the fluorescence signals of the biosensor are greatly amplified. The biosensor exhibited a linear relationship with the concentration of S. enteritidis ranging from 10(2) to 3 × 10(3)CFU/mL in water and from 1.5 × 10(2) to 3 × 10(3)CFU/mL in milk. The present results indicate that our FRET-based detection system can be widely employed for the effective detection of pathogens.

  7. Rapid detection of urinary polyomavirus BK by heterodyne-based surface plasmon resonance biosensor

    NASA Astrophysics Data System (ADS)

    Su, Li-Chen; Tian, Ya-Chung; Chang, Ying-Feng; Chou, Chien; Lai, Chao-Sung

    2014-01-01

    In renal transplant patients, immunosuppressive therapy may result in the reactivation of polyomavirus BK (BKV), leading to polyomavirus-associated nephropathy (PVAN), which inevitably causes allograft failure. Since the treatment outcomes of PVAN remain unsatisfactory, early identification and continuous monitoring of BKV reactivation and reduction of immunosuppressants are essential to prevent PVAN development. The present study demonstrated that the developed dual-channel heterodyne-based surface plasmon resonance (SPR) biosensor is applicable for the rapid detection of urinary BKV. The use of a symmetrical reference channel integrated with the poly(ethylene glycol)-based low-fouling self-assembled monolayer to reduce the environmental variations and the nonspecific noise was proven to enhance the sensitivity in urinary BKV detection. Experimentally, the detection limit of the biosensor for BKV detection was estimated to be around 8500 copies/mL. In addition, urine samples from five renal transplant patients were tested to rapidly distinguish PVAN-positive and PVAN-negative renal transplant patients. By virtue of its simplicity, rapidity, and applicability, the SPR biosensor is a remarkable potential to be used for continuous clinical monitoring of BKV reactivation.

  8. RCA-Based Biosensor for Electrical and Colorimetric Detection of Pathogen DNA

    NASA Astrophysics Data System (ADS)

    Jeong, Jaepil; Kim, Hyejin; Lee, Dong Jun; Jung, Byung Jun; Lee, Jong Bum

    2016-05-01

    For the diagnosis and prevention of diseases, a range of strategies for the detection of pathogens have been developed. In this study, we synthesized the rolling circle amplification (RCA)-based biosensor that enables detection of pathogen DNA in two analytical modes. Only in the presence of the target DNA, the template DNA can be continuously polymerized by simply carrying out RCA, which gives rise to a change of surface structure of Au electrodes and the gap between the electrodes. Electrical signal was generated after introducing hydrogen tetrachloroaurate (HAuCl4) to the DNA-coated biosensor for the improvement of the conductivity of DNA, which indicates that the presence of the pathogen DNA can be detected in an electrical approach. Furthermore, the existence of the target DNA was readily detected by the naked eyes through change in colors of the electrodes from bright yellow to orange-red after RCA reaction. The RCA-based biosensor offers a new platform for monitoring of pathogenic DNA with two different detection modes in one system.

  9. Experimental demonstration of a Fresnel-reflection based optical fiber biosensor coated with polyelectrolyte multilayers

    NASA Astrophysics Data System (ADS)

    Yu, Wenjie; Lang, Tingting

    2014-11-01

    We report that the end facet of an optical fiber can be coated with polyelectrolyte multilayers (PEM) of polycation (diallyldimethyl ammonium chloride) and polyanion (styrenesulfonate sodium salt) (PDDA+PSS)n (n is the number of bilayers), which functions effectively as a Fresnel-reflection based biosensor. The experimental setup includes a broadband light source, a 3dB coupler, and an optical spectrum analyzer. Biotin and streptavidin are deposited onto the multilayers-coated end facet sequentially. The light intensity change due to variation of external refractive index is monitored. When the concentrations of streptavidin changes from 0.1mg/ml to 1mg/ml, a linear relationship between the concentration of streptavidin and the reflected optical power at the wavelength of 1530nm is observed. The sensitivity increases from -1.6262×10-3 dB/ppm to -4.7852 ×10-3 dB/ppm, when the number of PEM increases from 1 to 2. Then we confirm the optimized numbers of bilayers of PEM are 5 through experiment. Selectivity and repeatability of our proposed optical fiber biosensor are verified. When bovine serum albumin (BSA) is added instead of streptavidin, the obtained spectra overlaps with that of biotin's. The final end facet coated with PEM and biotin-streptavidin can be cleaned using microwave vibration or aqua regia. The microwave vibration method is utilized due to security concern. The optical spectra changes back to the initial one of the optical fiber in air. In conclusion, a Fresnel-reflection based optical fiber biosensor with good sensitivity, selectivity and repeatability is proposed. This biosensor has the advantages of simple structure, low cost and reliability.

  10. Chemical surface modifications for the development of silicon-based label-free integrated optical (IO) biosensors: a review.

    PubMed

    Bañuls, María-José; Puchades, Rosa; Maquieira, Ángel

    2013-05-13

    Increasing interest has been paid to label-free biosensors in recent years. Among them, refractive index (RI) optical biosensors enable high density and the chip-scale integration of optical components. This makes them more appealing to help develop lab-on-a-chip devices. Today, many RI integrated optical (IO) devices are made using silicon-based materials. A key issue in their development is the biofunctionalization of sensing surfaces because they provide a specific, sensitive response to the analyte of interest. This review critically discusses the biofunctionalization procedures, assay formats and characterization techniques employed in setting up IO biosensors. In addition, it provides the most relevant results obtained from using these devices for real sample biosensing. Finally, an overview of the most promising future developments in the fields of chemical surface modification and capture agent attachment for IO biosensors follows.

  11. ZnS nanoparticles electrodeposited onto ITO electrode as a platform for fabrication of enzyme-based biosensors of glucose.

    PubMed

    Du, Jian; Yu, Xiuping; Wu, Ying; Di, Junwei

    2013-05-01

    The electrochemical and photoelectrochemical biosensors based on glucose oxidase (GOD) and ZnS nanoparticles modified indium tin oxide (ITO) electrode were investigated. The ZnS nanoparticles were electrodeposited directly on the surface of ITO electrode. The enzyme was immobilized on ZnS/ITO electrode surface by sol-gel method to fabricate glucose biosensor. GOD could electrocatalyze the reduction of dissolved oxygen, which resulted in a great increase of the reduction peak current. The reduction peak current decreased linearly with the addition of glucose, which could be used for glucose detection. Moreover, ZnS nanoparticles deposited on ITO electrode surface showed good photocurrent response under illumination. A photoelectrochemical biosensor for the detection of glucose was also developed by monitoring the decreases in the cathodic peak photocurrent. The results indicated that ZnS nanoparticles deposited on ITO substrate were a good candidate material for the immobilization of enzyme in glucose biosensor construction.

  12. Label-free detection of glycated haemoglobin in human blood using silicon-based photonic crystal nanocavity biosensor

    NASA Astrophysics Data System (ADS)

    Olyaee, Saeed; Seifouri, Mahmood; Mohsenirad, Hamideh

    2016-07-01

    In this paper, we describe a two-dimensional photonic crystal-based biosensor that consists of a waveguide and a nanocavity with high sensitivity. A new method is employed for increasing sensitivity of the biosensor. The simulation results show that biosensor is highly sensitive to the refractive index (RI) variations due to injected biomaterials, like glycated haemoglobin, into the sensing surface. The proposed biosensor is designed for the wavelength range of 1514.4-1896.3 nm. The sensitivity and the quality factor are calculated to be 3000 and 272.43 nm/RIU, respectively. The designed structure can detect a 0.002 change in the RI via resonant wavelength shift of 0.9 nm. The band diagram and transmission spectra are computed using plane wave expansion and finite difference time domain methods.

  13. Fabrication of Ultrasensitive Field-Effect Transistor DNA Biosensors by a Directional Transfer Technique Based on CVD-Grown Graphene.

    PubMed

    Zheng, Chao; Huang, Le; Zhang, Hong; Sun, Zhongyue; Zhang, Zhiyong; Zhang, Guo-Jun

    2015-08-12

    Most graphene field-effect transistor (G-FET) biosensors are fabricated through a routine process, in which graphene is transferred onto a Si/SiO2 substrate and then devices are subsequently produced by micromanufacture processes. However, such a fabrication approach can introduce contamination onto the graphene surface during the lithographic process, resulting in interference for the subsequent biosensing. In this work, we have developed a novel directional transfer technique to fabricate G-FET biosensors based on chemical-vapor-deposition- (CVD-) grown single-layer graphene (SLG) and applied this biosensor for the sensitive detection of DNA. A FET device with six individual array sensors was first fabricated, and SLG obtained by the CVD-growth method was transferred onto the sensor surface in a directional manner. Afterward, peptide nucleic acid (PNA) was covalently immobilized on the graphene surface, and DNA detection was realized by applying specific target DNA to the PNA-functionalized G-FET biosensor. The developed G-FET biosensor was able to detect target DNA at concentrations as low as 10 fM, which is 1 order of magnitude lower than those reported in a previous work. In addition, the biosensor was capable of distinguishing the complementary DNA from one-base-mismatched DNA and noncomplementary DNA. The directional transfer technique for the fabrication of G-FET biosensors is simple, and the as-constructed G-FET DNA biosensor shows ultrasensitivity and high specificity, indicating its potential application in disease diagnostics as a point-of-care tool.

  14. Optical detection of different phenolic compounds by means of a novel biosensor based on sol-gel immobilized laccase.

    PubMed

    Lepore, Maria; Portaccio, Marianna

    2016-12-16

    A novel sol-gel based biosensor exploiting the optical absorption properties of sol-gel immobilized laccase has been constructed in the attempt to increase enzyme specificity towards different phenolic substrates. Laccase from Trametes versicolor has been immobilized in optically transparent sol-gel matrices. Using Fourier transform infrared spectroscopy and data analysis based on a wavelet algorithm the successful enzyme immobilization has been evidenced. The changes in the optical absorption spectra of laccase reaction products at 425 nm, 375 nm and 400 nm have been used for hydroquinone, resorcinol and catechol concentration determination, respectively. Due to the slow response time of hydroquinone-laccase reaction, our optical biosensor has been tested with resorcinol and catechol. Linear ranges up to 1.4 mM and 0.2 mM, limit-of-detection (LOD) of 4.5 μM and 0.6 μΜ have been evidenced for resorcinol and catechol, respectively. Data for resorcinol concentration determination have been particularly interesting since no other biosensor device has been reported in literature. In comparison with other biosensors using laccase from the same native source our biosensor has been characterized by larger linear ranges, significant sensitivities and good LODs. To challenge our biosensor with real samples, tap water samples spiked with known amount of catechol and resorcinol have been employed. This article is protected by copyright. All rights reserved.

  15. Conducting polymer based DNA biosensor for the detection of the Bacillus cereus group species

    NASA Astrophysics Data System (ADS)

    Velusamy, Vijayalakshmi; Arshak, Khalil; Korostynska, Olga; Oliwa, Kamila; Adley, Catherine

    2009-05-01

    Biosensor designs are emerging at a significant rate and play an increasingly important role in foodborne pathogen detection. Conducting polymers are excellent tools for the fabrication of biosensors and polypyrrole has been used in the detection of biomolecules due to its unique properties. The prime intention of this paper was to pioneer the design and fabrication of a single-strand (ss) DNA biosensor for the detection of the Bacillus cereus (B.cereus) group species. Growth of B. cereus, results in production of several highly active toxins. Therefore, consumption of food containing >106 bacteria/gm may results in emetic and diarrhoeal syndromes. The most common source of this bacterium is found in liquid food products, milk powder, mixed food products and is of particular concern in the baby formula industry. The electrochemical deposition technique, such as cyclic voltammetry, was used to develop and test a model DNA-based biosensor on a gold electrode electropolymerized with polypyrrole. The electrically conducting polymer, polypyrrole is used as a platform for immobilizing DNA (1μg) on the gold electrode surface, since it can be more easily deposited from neutral pH aqueous solutions of pyrrolemonomers. The average current peak during the electrodeposition event is 288μA. There is a clear change in the current after hybridization of the complementary oligonucleotide (6.35μA) and for the noncomplementary oligonucleotide (5.77μA). The drop in current after each event was clearly noticeable and it proved to be effective.

  16. An amperometric uric acid biosensor based on chitosan-carbon nanotubes electrospun nanofiber on silver nanoparticles.

    PubMed

    Numnuam, Apon; Thavarungkul, Panote; Kanatharana, Proespichaya

    2014-06-01

    A novel amperometric uric acid biosensor was fabricated by immobilizing uricase on an electrospun nanocomposite of chitosan-carbon nanotubes nanofiber (Chi-CNTsNF) covering an electrodeposited layer of silver nanoparticles (AgNPs) on a gold electrode (uricase/Chi-CNTsNF/AgNPs/Au). The uric acid response was determined at an optimum applied potential of -0.35 V vs Ag/AgCl in a flow-injection system based on the change of the reduction current for dissolved oxygen during oxidation of uric acid by the immobilized uricase. The response was directly proportional to the uric acid concentration. Under the optimum conditions, the fabricated uric acid biosensor had a very wide linear range, 1.0-400 μmol L(-1), with a very low limit of detection of 1.0 μmol L(-1) (s/n = 3). The operational stability of the uricase/Chi-CNTsNF/AgNPs/Au biosensor (up to 205 injections) was excellent and the storage life was more than six weeks. A low Michaelis-Menten constant of 0.21 mmol L(-1) indicated that the immobilized uricase had high affinity for uric acid. The presence of potential common interfering substances, for example ascorbic acid, glucose, and lactic acid, had negligible effects on the performance of the biosensor. When used for analysis of uric acid in serum samples, the results agreed well with those obtained by use of the standard enzymatic colorimetric method (P > 0.05).

  17. Disposable urea biosensor based on nanoporous ZnO film fabricated from omissible polymeric substrate.

    PubMed

    Rahmanian, Reza; Mozaffari, Sayed Ahmad; Abedi, Mohammad

    2015-12-01

    In the present study, a facile and simple fabrication method of a semiconductor based urea biosensor was reported via three steps: (i) producing a ZnO-PVA composite film by means of a polymer assisted electrodeposition of zinc oxide (ZnO) on the F-doped SnO2 conducting glass (FTO) using water soluble polyvinyl alcohol (PVA), (ii) obtaining a nanoporous ZnO film by PVA omission via a subsequent post-treatment by annealing of the ZnO-PVA film, and (iii) preparation of a FTO/ZnO/Urs biosensor by exploiting a nanoporous ZnO film as an efficient and excellent platform area for electrostatic immobilization of urease enzyme (Urs) which was forced by the difference in their isoelectric point (IEP). The characterization techniques focused on the analysis of the ZnO-PVA film surfaces before and after annealing, which had a prominent effect on the porosity of the prepared ZnO film. The surface characterization of the nanostructured ZnO film by a field emission-scanning electron microscopy (FE-SEM), exhibited a film surface area as an effective bio-sensing matrix for enzyme immobilization. The structural characterization and monitoring of the biosensor fabrication was performed using UV-Vis, Fourier Transform Infrared (FT-IR), Raman Spectroscopy, Thermogravimetric Analysis (TGA), Cyclic Voltammetry (CV), and Electrochemical Impedance Spectroscopy (EIS) techniques. The impedimetric results of the FTO/ZnO/Urs biosensor showed a high sensitivity for urea detection within 8.0-110.0mg dL(-1) with the limit of detection as 5.0mg dL(-1).

  18. RNA aptamer based electrochemical biosensor for sensitive and selective detection of cAMP.

    PubMed

    Zhao, Fulin; Xie, Qingyun; Xu, Mingfei; Wang, Shouyu; Zhou, Jiyong; Liu, Fei

    2015-04-15

    Cyclic adenosine monophosphate (cAMP) is an important small biological molecule associated with the healthy state of living organism. In order to realize highly sensitive and specific detection of cAMP, here an RNA aptamer and electrochemical impedance spectroscopy (EIS) based biosensor enhanced by gold nanoparticles electrodeposited on the surface of gold electrode is designed. The designed aptasensor has a wide effective measuring range from 50pM to 250pM with a detection limit of 50pM in PBS buffer, and an effective measuring range from 50nM to 1μM with a detection limit of 50nM in serum. The designed biosensor is also able to detect cAMP with high sensitivity, specificity, and stability. Since the biosensor can be easily fabricated with low cost and repeatedly used for at least two times, it owns great potential in wide application fields such as clinical test and food inspection, etc.

  19. Fresh broad (Vicia faba) tissue homogenate-based biosensor for determination of phenolic compounds.

    PubMed

    Ozcan, Hakki Mevlut; Sagiroglu, Ayten

    2014-08-01

    In this study, a novel fresh broad (Vicia faba) tissue homogenate-based biosensor for determination of phenolic compounds was developed. The biosensor was constructed by immobilizing tissue homogenate of fresh broad (Vicia faba) on to glassy carbon electrode. For the stability of the biosensor, general immobilization techniques were used to secure the fresh broad tissue homogenate in gelatin-glutaraldehyde cross-linking matrix. In the optimization and characterization studies, the amount of fresh broad tissue homogenate and gelatin, glutaraldehyde percentage, optimum pH, optimum temperature and optimum buffer concentration, thermal stability, interference effects, linear range, storage stability, repeatability and sample applications (Wine, beer, fruit juices) were also investigated. Besides, the detection ranges of thirteen phenolic compounds were obtained with the help of the calibration graphs. A typical calibration curve for the sensor revealed a linear range of 5-60 μM catechol. In reproducibility studies, variation coefficient (CV) and standard deviation (SD) were calculated as 1.59%, 0.64×10(-3) μM, respectively.

  20. Giant Magnetoresistance-based Biosensor for Detection of Influenza A Virus

    PubMed Central

    Krishna, Venkatramana D.; Wu, Kai; Perez, Andres M.; Wang, Jian-Ping

    2016-01-01

    We have developed a simple and sensitive method for the detection of influenza A virus based on giant magnetoresistance (GMR) biosensor. This assay employs monoclonal antibodies to viral nucleoprotein (NP) in combination with magnetic nanoparticles (MNPs). Presence of influenza virus allows the binding of MNPs to the GMR sensor and the binding is proportional to the concentration of virus. Binding of MNPs onto the GMR sensor causes change in the resistance of sensor, which is measured in a real time electrical readout. GMR biosensor detected as low as 1.5 × 102 TCID50/mL virus and the signal intensity increased with increasing concentration of virus up to 1.0 × 105 TCID50/mL. This study showed that the GMR biosensor assay is relevant for diagnostic application since the virus concentration in nasal samples of influenza virus infected swine was reported to be in the range of 103 to 105 TCID50/mL. PMID:27065967

  1. An Fe3O4-nanoparticles-based amperometric biosensor for creatine determination.

    PubMed

    Kaçar, Ceren; Erden, Pinar Esra; Pekyardimci, Sule; Kiliç, Esma

    2013-02-01

    An amperometric biosensor for the detection of creatine was designed, based on carbon paste electrode modified with Fe(3)O(4) nanoparticles. Electron transfer properties of unmodified and Fe(3)O(4)-nanoparticles-modified carbon paste electrodes were investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) methods. Fe(3)O(4) nanoparticles increased the surface area and electric conductivity of the electrode, thus enhancing the sensitivity of the electrode. Optimum pH, buffer concentration, working potential and enzyme loading were selected as 7.0; 0.05 mol L(-1); +0.30 V and 2.0 Unit creatinase (CI), 1.0 Unit sarcosine oxidase (SO), respectively. The purposed biosensor exhibited linear response from 2.0 × 10(-7) mol L(-1) to 3.8 × 10(-6) mol L(-1) and from 9.0 × 10(-6) mol L(-1) to 1.2 × 10(-4) mol L(-1) with a detection limit of 2.0 × 10(-7) mol L(-1). Biosensor was used for determination of creatine in commercial creatine powder samples and showed a good sensing performance.

  2. "Off-On"switching electrochemiluminescence biosensor for mercury(II) detection based on molecular recognition technology.

    PubMed

    Cheng, Lin; Wei, BingGuo; He, Ling Ling; Mao, Ling; Zhang, Jie; Ceng, JinXiang; Kong, DeRong; Chen, ChaDan; Cui, HanFeng; Hong, Nian; Fan, Hao

    2017-02-01

    A novel "off-On" electrogenerated chemiluminescence (ECL) biosensor has been developed for the detection of mercury(II) based on molecular recognition technology. The ECL mercury(II) biosensor comprises two main parts: an ECL substrate and an ECL intensity switch. The ECL substrate was made by modifying the complex of Ruthenium(II) tris-(bipyridine)(Ru(bpy)3(2+))/Cyclodextrins-Au nanoparticles(CD-AuNps)/Nafion on the surface of glass carbon electrode (GCE), and the ECL intensity switch is the single hairpin DNA probe designed according to the "molecular recognition" strategy which was functionalized with ferrocene tag at one end and attached to Cyclodextrins (CD) on modified GCE through supramolecular noncovalent interaction. We demonstrated that, in the absence of Hg(II) ion, the probe keeps single hairpin structure and resulted in a quenching of ECL of Ru(bpy)3(2+). Whereas, in the presence of Hg(II) ion, the probe prefers to form the T-Hg(II)-T complex and lead to an obvious recovery of ECL of Ru(bpy)3(2+), which provided a sensing platform for the detection of Hg(II) ion. Using this sensing platform, a simple, rapid and selective "off-On" ECL biosensor for the detection of mercury(II) with a detection limit of 0.1 nM has been developed.

  3. A heparin-functionalized carbon nanotube-based affinity biosensor for dengue virus.

    PubMed

    Wasik, Daniel; Mulchandani, Ashok; Yates, Marylynn V

    2017-05-15

    Dengue virus is an arthropod-borne virus transmitted primarily by Aedes mosquitos and is major cause of disease in tropical and subtropical regions. Colloquially known as Dengue Fever, infection can cause hemorrhagic disorders and death in humans and non-human primates. We report a novel electronic biosensor based on a single-walled carbon nanotube network chemiresistive transducer that is functionalized with heparin for low-cost, label-free, ultra-sensitive, and rapid detection of whole dengue virus (DENV). Heparin, an analog of the heparan sulfate proteoglycans that are receptors for dengue virus during infection of Vero cells and hepatocytes, was used for the first time in a biosensor as a biorecognition element instead of traditional antibody. Detection of DENV in viral culture supernatant has similar sensitivity as the corresponding viral titer in phosphate buffer despite the presence of growth media and Vero cell lysate. The biosensor demonstrated sensitivity within the clinically relevant range for humans and infected Aedes aegypti. It has potential application in clinical diagnosis and can improve point-of-care diagnostics of dengue infection.

  4. Development of tyrosinase biosensor based on quantum dots/chitosan nanocomposite for detection of phenolic compounds.

    PubMed

    Han, En; Yang, Yi; He, Zheng; Cai, Jianrong; Zhang, Xinai; Dong, Xiaoya

    2015-10-01

    A sensitive and simple amperometric biosensor for phenols was developed based on the immobilization of tyrosinase into CdS quantum dots/chitosan nanocomposite matrix. The nanocomposite film with porous nanostructure, excellent hydrophilicity and biocompatibility resulted in high enzyme loading, and the tyrosinase (Tyr) immobilized in this novel matrix retained its activity to a large extent. The CdS quantum dots/chitosan nanocomposite film was characterized by scanning electron microscopy and electrochemical impedance spectroscopy, and the parameters of the various experimental variables for the biosensor were optimized. Under the optimal conditions, the designed biosensor displayed a wide linear response to catechol over a concentration range of 1.0×10(-9) to 2.0×10(-5)M with a high sensitivity of 561±9.7mAM(-1) and a low detection limit down to 0.3 nM at a signal-to-noise ratio of 3. The CdS quantum dots/chitosan nanocomposites could provide a novel matrix for enzyme immobilization to promote the development of biosensing and biocatalysis.

  5. Interdigitated microelectrode based impedance biosensor for detection of salmonella enteritidis in food samples

    NASA Astrophysics Data System (ADS)

    Kim, G.; Morgan, M.; Hahm, B. K.; Bhunia, A.; Mun, J. H.; Om, A. S.

    2008-03-01

    Salmonella enteritidis outbreaks continue to occur, and S. enteritidis-related outbreaks from various food sources have increased public awareness of this pathogen. Conventional methods for pathogens detection and identification are labor-intensive and take days to complete. Some immunological rapid assays are developed, but these assays still require prolonged enrichment steps. Recently developed biosensors have shown great potential for the rapid detection of foodborne pathogens. To develop the biosensor, an interdigitated microelectrode (IME) was fabricated by using semiconductor fabrication process. Anti-Salmonella antibodies were immobilized based on avidin-biotin binding on the surface of the IME to form an active sensing layer. To increase the sensitivity of the sensor, three types of sensors that have different electrode gap sizes (2 μm, 5 μm, 10 μm) were fabricated and tested. The impedimetric biosensor could detect 103 CFU/mL of Salmonella in pork meat extract with an incubation time of 5 minutes. This method may provide a simple, rapid and sensitive method to detect foodborne pathogens.

  6. Urea potentiometric enzymatic biosensor based on charged biopolymers and electrodeposited polyaniline.

    PubMed

    Lakard, Boris; Magnin, Delphine; Deschaume, Olivier; Vanlancker, Guilhem; Glinel, Karine; Demoustier-Champagne, Sophie; Nysten, Bernard; Jonas, Alain M; Bertrand, Patrick; Yunus, Sami

    2011-06-15

    A potentiometric biosensor based on urease was developed for the quantitative determination of urea concentration in aqueous solutions for biomedical applications. The urease was either physisorbed onto an electrodeposited polyaniline film (PANI), or immobilized on a layer-by-layer film (LbL) assembled over the PANI film, that was obtained by the alternate deposition of charged polysaccharides (carboxymethylpullulan (CMP) and chitosan (CHI)). In the latter case, the urease (Urs) enzyme was either physically adsorbed or covalently grafted to the LbL film using carbodiimide coupling reaction. Potentiometric responses of the enzymatic biosensors were measured as a function of the urea concentration in aqueous solutions (from 10(-6) to 10(-1) mol L(-1) urea). Very high sensitivity and short response time were observed for the present biosensor. Moreover, a stability study showed a higher stability over time for the potentiometric response of the sensor with the enzyme-grafted LbL film, testifying for the protective nature of the polysaccharide coating and the interest of covalent grafting.

  7. Natural polyhydroxyalkanoate-gold nanocomposite based biosensor for detection of antimalarial drug artemisinin.

    PubMed

    Phukon, Pinkee; Radhapyari, Keisham; Konwar, Bolin Kumar; Khan, Raju

    2014-04-01

    The worrisome trend of antimalarial resistance has already highlighted the importance of artemisinin as a potent antimalarial agent. The current investigation aimed at fabricating a biosensor based on natural polymer polyhydroxyalkanoate-gold nanoparticle composite mounting on an indium-tin oxide glass plate for the analysis of artemisinin. The biosensor was fabricated using an adsorbing horse-radish peroxidase enzyme on the electrode surface for which cyclic voltammetry was used to monitor the electro-catalytic reduction of artemisinin under diffusion controlled conditions. Electrochemical interfacial properties and immobilization of enzyme onto a polyhydroxyalkanoate-gold nanoparticle film were evaluated, and confirmed by cyclic voltammetry, electrochemical impedance spectroscopy and scanning electron microscopy. The differential pulse voltammetric peak current for artemisinin was increased linearly (concentration range of 0.01-0.08μg mL(-1)) with sensitivity of 0.26μAμg mL(-1). The greater sensitivity of the fabricated biosensor to artemisinin (optimum limits of detection were 0.0035μg mL(-1) and 0.0036μg mL(-1) in bulk and spiked human serum, respectively) could be of much aid in medical diagnosis.

  8. Electrochemical DNA biosensor based on the proximity-dependent surface hybridization assay.

    PubMed

    Zhang, Yanli; Wang, Ying; Wang, Haibo; Jiang, Jian-Hui; Shen, Guo-Li; Yu, Ru-Qin; Li, Jinghong

    2009-03-01

    This paper describes a novel electrochemical DNA (E-DNA) biosensor for simple, rapid, and specific detection of nucleic acids based on the proximity-dependent surface hybridization assay. This E-DNA biosensor was constructed by self-assembly of a 3' short thiolated capture probe on the gold electrode. DNA detection was realized by outputting a remarkable redox current of the 5' ferrocene (Fc) tail labeled probe. When the target DNA was introduced into the system, it was complementary to the 5' Fc labeled probe at the one-half-segment and complementary to the 3' short thiolated capture probe at the other half-segment, resulting in forming a stable duplex complex. As a result, the Fc probe was proximate to the electrode surface, and the Faradaic current was observed. This E-DNA biosensor was proved to have a low detection limit (1 fM) and a wide dynamic range (from 1 fM to 1 nM) due to the stable hybridization mode. In addition, the sensing system could discriminate the complementary sequence from mismatch sequences, with high sensitivity, stability, and reusability.

  9. Development of urease based amperometric biosensors for the inhibitive determination of Hg (II).

    PubMed

    Domínguez-Renedo, O; Alonso-Lomillo, M A; Ferreira-Gonçalves, L; Arcos-Martínez, M J

    2009-10-15

    Enzymatic amperometric procedures for measurement of Hg (II), based on the inhibitive action of this metal on urease enzyme activity, were developed. Screen-printed carbon electrodes (SPCEs) and gold nanoparticles modified screen-printed carbon electrodes (AuNPs/SPCEs) were used as supports for the cross-linking inmobilization of the enzyme urease. The amperometric response of urea was affected by the presence of Hg (II) ions which caused a decreasing in the current intensity. The optimum working conditions were found using experimental design methodology. Under these conditions, repeatability and reproducibility for both types of biosensors were determined, reaching values below 6% in terms of residual standard deviation. The detection limit obtained for Hg (II) was 4.2x10(-6)M for urease/SPCE biosensor and 5.6x10(-8)M for urease/AuNPs/SPCE biosensor. Analysis of the possible effect of the presence of foreign ions in the solution was performed. The method was applied to determine levels of Hg (II) in spiked human plasma samples.

  10. Determination of total creatine kinase activity in blood serum using an amperometric biosensor based on glucose oxidase and hexokinase.

    PubMed

    Kucherenko, I S; Soldatkin, O O; Lagarde, F; Jaffrezic-Renault, N; Dzyadevych, S V; Soldatkin, A P

    2015-11-01

    Creatine kinase (CK: adenosine-5-triphosphate-creatine phosphotransferase) is an important enzyme of muscle cells; the presence of a large amount of the enzyme in blood serum is a biomarker of muscular injuries, such as acute myocardial infarction. This work describes a bi-enzyme (glucose oxidase and hexokinase based) biosensor for rapid and convenient determination of CK activity by measuring the rate of ATP production by this enzyme. Simultaneously the biosensor determines glucose concentration in the sample. Platinum disk electrodes were used as amperometric transducers. Glucose oxidase and hexokinase were co-immobilized via cross-linking with BSA by glutaraldehyde and served as a biorecognition element of the biosensor. The biosensor work at different concentrations of CK substrates (ADP and creatine phosphate) was investigated; optimal concentration of ADP was 1mM, and creatine phosphate - 10 mM. The reproducibility of the biosensor responses to glucose, ATP and CK during a day was tested (relative standard deviation of 15 responses to glucose was 2%, to ATP - 6%, to CK - 7-18% depending on concentration of the CK). Total time of CK analysis was 10 min. The measurements of creatine kinase in blood serum samples were carried out (at 20-fold sample dilution). Twentyfold dilution of serum samples was chosen as optimal for CK determination. The biosensor could distinguish healthy and ill people and evaluate the level of CK increase. Thus, the biosensor can be used as a test-system for CK analysis in blood serum or serve as a component of multibiosensors for determination of important blood substances. Determination of activity of other kinases by the developed biosensor is also possible for research purposes.

  11. Porous Silicon-Based Biosensors: Towards Real-Time Optical Detection of Target Bacteria in the Food Industry.

    PubMed

    Massad-Ivanir, Naama; Shtenberg, Giorgi; Raz, Nitzan; Gazenbeek, Christel; Budding, Dries; Bos, Martine P; Segal, Ester

    2016-11-30

    Rapid detection of target bacteria is crucial to provide a safe food supply and to prevent foodborne diseases. Herein, we present an optical biosensor for identification and quantification of Escherichia coli (E. coli, used as a model indicator bacteria species) in complex food industry process water. The biosensor is based on a nanostructured, oxidized porous silicon (PSi) thin film which is functionalized with specific antibodies against E. coli. The biosensors were exposed to water samples collected directly from process lines of fresh-cut produce and their reflectivity spectra were collected in real time. Process water were characterized by complex natural micro-flora (microbial load of >10(7) cell/mL), in addition to soil particles and plant cell debris. We show that process water spiked with culture-grown E. coli, induces robust and predictable changes in the thin-film optical interference spectrum of the biosensor. The latter is ascribed to highly specific capture of the target cells onto the biosensor surface, as confirmed by real-time polymerase chain reaction (PCR). The biosensors were capable of selectively identifying and quantifying the target cells, while the target cell concentration is orders of magnitude lower than that of other bacterial species, without any pre-enrichment or prior processing steps.

  12. Porous Silicon-Based Biosensors: Towards Real-Time Optical Detection of Target Bacteria in the Food Industry

    PubMed Central

    Massad-Ivanir, Naama; Shtenberg, Giorgi; Raz, Nitzan; Gazenbeek, Christel; Budding, Dries; Bos, Martine P.; Segal, Ester

    2016-01-01

    Rapid detection of target bacteria is crucial to provide a safe food supply and to prevent foodborne diseases. Herein, we present an optical biosensor for identification and quantification of Escherichia coli (E. coli, used as a model indicator bacteria species) in complex food industry process water. The biosensor is based on a nanostructured, oxidized porous silicon (PSi) thin film which is functionalized with specific antibodies against E. coli. The biosensors were exposed to water samples collected directly from process lines of fresh-cut produce and their reflectivity spectra were collected in real time. Process water were characterized by complex natural micro-flora (microbial load of >107 cell/mL), in addition to soil particles and plant cell debris. We show that process water spiked with culture-grown E. coli, induces robust and predictable changes in the thin-film optical interference spectrum of the biosensor. The latter is ascribed to highly specific capture of the target cells onto the biosensor surface, as confirmed by real-time polymerase chain reaction (PCR). The biosensors were capable of selectively identifying and quantifying the target cells, while the target cell concentration is orders of magnitude lower than that of other bacterial species, without any pre-enrichment or prior processing steps. PMID:27901131

  13. Porous Silicon-Based Biosensors: Towards Real-Time Optical Detection of Target Bacteria in the Food Industry

    NASA Astrophysics Data System (ADS)

    Massad-Ivanir, Naama; Shtenberg, Giorgi; Raz, Nitzan; Gazenbeek, Christel; Budding, Dries; Bos, Martine P.; Segal, Ester

    2016-11-01

    Rapid detection of target bacteria is crucial to provide a safe food supply and to prevent foodborne diseases. Herein, we present an optical biosensor for identification and quantification of Escherichia coli (E. coli, used as a model indicator bacteria species) in complex food industry process water. The biosensor is based on a nanostructured, oxidized porous silicon (PSi) thin film which is functionalized with specific antibodies against E. coli. The biosensors were exposed to water samples collected directly from process lines of fresh-cut produce and their reflectivity spectra were collected in real time. Process water were characterized by complex natural micro-flora (microbial load of >107 cell/mL), in addition to soil particles and plant cell debris. We show that process water spiked with culture-grown E. coli, induces robust and predictable changes in the thin-film optical interference spectrum of the biosensor. The latter is ascribed to highly specific capture of the target cells onto the biosensor surface, as confirmed by real-time polymerase chain reaction (PCR). The biosensors were capable of selectively identifying and quantifying the target cells, while the target cell concentration is orders of magnitude lower than that of other bacterial species, without any pre-enrichment or prior processing steps.

  14. Mesoporous carbon nitride based biosensor for highly sensitive and selective analysis of phenol and catechol in compost bioremediation.

    PubMed

    Zhou, Yaoyu; Tang, Lin; Zeng, Guangming; Chen, Jun; Cai, Ye; Zhang, Yi; Yang, Guide; Liu, Yuanyuan; Zhang, Chen; Tang, Wangwang

    2014-11-15

    Herein, we reported here a promising biosensor by taking advantage of the unique ordered mesoporous carbon nitride material (MCN) to convert the recognition information into a detectable signal with enzyme firstly, which could realize the sensitive, especially, selective detection of catechol and phenol in compost bioremediation samples. The mechanism including the MCN based on electrochemical, biosensor assembly, enzyme immobilization, and enzyme kinetics (elucidating the lower detection limit, different linear range and sensitivity) was discussed in detail. Under optimal conditions, GCE/MCN/Tyr biosensor was evaluated by chronoamperometry measurements and the reduction current of phenol and catechol was proportional to their concentration in the range of 5.00 × 10(-8)-9.50 × 10(-6)M and 5.00 × 10(-8)-1.25 × 10(-5)M with a correlation coefficient of 0.9991 and 0.9881, respectively. The detection limits of catechol and phenol were 10.24 nM and 15.00 nM (S/N=3), respectively. Besides, the data obtained from interference experiments indicated that the biosensor had good specificity. All the results showed that this material is suitable for load enzyme and applied to the biosensor due to the proposed biosensor exhibited improved analytical performances in terms of the detection limit and specificity, provided a powerful tool for rapid, sensitive, especially, selective monitoring of catechol and phenol simultaneously. Moreover, the obtained results may open the way to other MCN-enzyme applications in the environmental field.

  15. Immobilization free electrochemical biosensor for folate receptor in cancer cells based on terminal protection.

    PubMed

    Ni, Jiancong; Wang, Qingxiang; Yang, Weiqiang; Zhao, Mengmeng; Zhang, Ying; Guo, Longhua; Qiu, Bin; Lin, Zhenyu; Yang, Huang-Hao

    2016-12-15

    The determination of folate receptor (FR) that over expressed in vast quantity of cancerous cells frequently is significant for the clinical diagnosis and treatment of cancers. Many DNA-based electrochemical biosensors have been developed for FR detection with high selectivity and sensitivity, but most of them need complicated immobilization of DNA on the electrode surface firstly, which is tedious and therefore results in the poor reproducibility. In this study, a simple, sensitive, and selective electrochemical FR biosensor in cancer cells has been proposed, which combines the advantages of the convenient immobilization-free homogeneous indium tin oxide (ITO)-based electrochemical detection strategy and the high selectivity of the terminal protection of small molecule linked DNA. The small molecule of folic acid (FA) and an electroactive molecule of ferrocence (Fc) were tethered to 3'- and 5'-end of an arbitrary single-stranded DNA (ssDNA), respectively, forming the FA-ssDNA-Fc complex. In the absence of the target FR, the FA-ssDNA-Fc was degraded by exonuclease I (Exo I) from 3'-end and produced a free Fc, diffusing freely to the ITO electrode surface and resulting in strong electrochemical signal. When the target FR was present, the FA-ssDNA-Fc was bound to FR through specific interaction with FA anchored at the 3'-end, effectively protecting the ssDNA strand from hydrolysis by Exo I. The FR-FA-ssDNA-Fc could not diffuse easily to the negatively charged ITO electrode surface due to the electrostatic repulsion between the DNA strand and the negatively charged ITO electrode, so electrochemical signal reduced. The decreased electrochemical signal has a linear relationship with the logarithm of FR concentration in range of 10fM to 10nM with a detection limit of 3.8fM (S/N=3). The proposed biosensor has been applied to detect FR in HeLa cancer cells, and the decreased electrochemical signal has a linear relationship with the logarithm of cell concentration ranging

  16. Aptamer-Based Microfluidic Electrochemical Biosensor for Monitoring Cell-Secreted Trace Cardiac Biomarkers.

    PubMed

    Shin, Su Ryon; Zhang, Yu Shrike; Kim, Duck-Jin; Manbohi, Ahmad; Avci, Huseyin; Silvestri, Antonia; Aleman, Julio; Hu, Ning; Kilic, Tugba; Keung, Wendy; Righi, Martina; Assawes, Pribpandao; Alhadrami, Hani A; Li, Ronald A; Dokmeci, Mehmet R; Khademhosseini, Ali

    2016-10-04

    Continual monitoring of secreted biomarkers from organ-on-a-chip models is desired to understand their responses to drug exposure in a noninvasive manner. To achieve this goal, analytical methods capable of monitoring trace amounts of secreted biomarkers are of particular interest. However, a majority of existing biosensing techniques suffer from limited sensitivity, selectivity, stability, and require large working volumes, especially when cell culture medium is involved, which usually contains a plethora of nonspecific binding proteins and interfering compounds. Hence, novel analytical platforms are needed to provide noninvasive, accurate information on the status of organoids at low working volumes. Here, we report a novel microfluidic aptamer-based electrochemical biosensing platform for monitoring damage to cardiac organoids. The system is scalable, low-cost, and compatible with microfluidic platforms easing its integration with microfluidic bioreactors. To create the creatine kinase (CK)-MB biosensor, the microelectrode was functionalized with aptamers that are specific to CK-MB biomarker secreted from a damaged cardiac tissue. Compared to antibody-based sensors, the proposed aptamer-based system was highly sensitive, selective, and stable. The performance of the sensors was assessed using a heart-on-a-chip system constructed from human embryonic stem cell-derived cardiomyocytes following exposure to a cardiotoxic drug, doxorubicin. The aptamer-based biosensor was capable of measuring trace amounts of CK-MB secreted by the cardiac organoids upon drug treatments in a dose-dependent manner, which was in agreement with the beating behavior and cell viability analyses. We believe that, our microfluidic electrochemical biosensor using aptamer-based capture mechanism will find widespread applications in integration with organ-on-a-chip platforms for in situ detection of biomarkers at low abundance and high sensitivity.

  17. Kinetics of Antibody Binding to Membranes of Living Bacteria Measured by a Photonic Crystal-Based Biosensor

    PubMed Central

    Rostova, Ekaterina; Ben Adiba, Carine; Dietler, Giovanni; Sekatskii, Sergey K.

    2016-01-01

    Optical biosensors based on photonic crystal surface waves (PC SWs) offer a possibility to study binding interactions with living cells, overcoming the limitation of rather small evanescent field penetration depth into a sample medium that is characteristic for typical optical biosensors. Besides this, simultaneous excitation of s- and p-polarized surface waves with different penetration depths is realized here, permitting unambiguous separation of surface and volume contributions to the measured signal. PC-based biosensors do not require a bulk signal correction, compared to widely used surface plasmon resonance-based devices. We developed a chitosan-based protocol of PC chip functionalization for bacterial attachment and performed experiments on antibody binding to living bacteria measured in real time by the PCSW-based biosensor. Data analysis reveals specific binding and gives the value of the dissociation constant for monoclonal antibodies (IgG2b) against bacterial lipopolysaccharides equal to KD = 6.2 ± 3.4 nM. To our knowledge, this is a first demonstration of antibody-binding kinetics to living bacteria by a label-free optical biosensor. PMID:27727183

  18. An improved sensitive assay for the detection of PSP toxins with neuroblastoma cell-based impedance biosensor.

    PubMed

    Zou, Ling; Wu, Chunsheng; Wang, Qin; Zhou, Jie; Su, Kaiqi; Li, Hongbo; Hu, Ning; Wang, Ping

    2015-05-15

    Paralytic shellfish poisoning (PSP) toxins are well-known sodium channel-blocking marine toxins, which block the conduction of nerve impulses and lead to a series of neurological disorders symptoms. However, PSP toxins can inhibit the cytotoxicity effect of compounds (e.g., ouabain and veratridine). Under the treatment of ouabain and veratridine, neuroblastoma cell will swell and die gradually, since veratridine causes the persistent inflow of Na(+) and ouabain inhibits the activity of Na(+)/K(+)-ATPases. Therefore, PSP toxins with antagonism effect can raise the chance of cell survival by blocking inflow of Na(+). Based on the antagonism effect of PSP toxins, we designed an improved cell-based assay to detect PSP toxins using a neuroblastoma cell-based impedance biosensor. The results demonstrated that this biosensor showed high sensitivity and good specificity for saxitoxins detection. The detection limit of this biosensor was as low as 0.03 ng/ml, which was lower than previous reported cell-based assays and mouse bioassays. With the improvement of biosensor performance, the neuroblastoma cell-based impedance biosensor has great potential to be a universal PSP screening method.

  19. Facile Fabrication of 3D Layer-by-layer Graphene-gold Nanorod Hybrid Architecture for Hydrogen Peroxide Based Electrochemical Biosensor

    DTIC Science & Technology

    2015-01-01

    Facile fabrication of 3D layer-by-layer graphene-gold nanorod hybrid architecture for hydrogen peroxide based electrochemical biosensor Chenming Xue...the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/). 1. Introduction Electrochemical biosensors are highly effective in...measurement techniques such as radioisotope tracing, NMR spectroscopy, and microfluorometry assay [12,25,18]. In recent years, electrochemical biosensors

  20. Paper-based colorimetric biosensor for antibiotics inhibiting bacterial protein synthesis.

    PubMed

    Duyen, Tran Thi My; Matsuura, Hideyuki; Ujiie, Kazuki; Muraoka, Misa; Harada, Kazuo; Hirata, Kazumasa

    2017-01-01

    Due to the presence of antibiotics in environmental water and their potential influence on the occurrence of antibiotic-resistant bacteria, development of a detection method suitable for the screening of environmental water for antibiotics is required. In this study, we developed a simple colorimetric paper-based biosensor based on a novel principle for the detection of antibiotics inhibiting bacterial protein synthesis, including aminoglycosides, tetracycline, chloramphenicol, and macrolides. This biosensor is based on the detection of a color change induced by β-galactosidase, which is synthesized on freeze-dried paper discs containing an in vitro transcription/translation system. When a water sample without antibiotics is applied to the paper discs, β-galactosidase can be synthesized, and it hydrolyzes a colorimetric substrate, resulting in a color change from yellow to purple. By contrast, in the presence of antibiotics, the color change can be hampered due to an inhibition of β-galactosidase synthesis. We investigated the effect of the incubation temperature and pH of water samples and confirmed that the paper discs showed the color change to purple in the ranges of 15-37°C and pH 6-10. We observed concentration-dependent color variations of the paper discs by the naked eye and further estimated detection limits to be 0.5, 2.1, 0.8, and 6.1 μg/mL for paromomycin, tetracycline, chloramphenicol, and erythromycin, respectively, using digitized pictures. The paper-based biosensor proved to detect 0.5 μg/mL paromomycin, spiked in real environmental water samples, by the naked eye.

  1. Electrochemical paper-based peptide nucleic acid biosensor for detecting human papillomavirus.

    PubMed

    Teengam, Prinjaporn; Siangproh, Weena; Tuantranont, Adisorn; Henry, Charles S; Vilaivan, Tirayut; Chailapakul, Orawon

    2017-02-01

    A novel paper-based electrochemical biosensor was developed using an anthraquinone-labeled pyrrolidinyl peptide nucleic acid (acpcPNA) probe (AQ-PNA) and graphene-polyaniline (G-PANI) modified electrode to detect human papillomavirus (HPV). An inkjet printing technique was employed to prepare the paper-based G-PANI-modified working electrode. The AQ-PNA probe baring a negatively charged amino acid at the N-terminus was immobilized onto the electrode surface through electrostatic attraction. Electrochemical impedance spectroscopy (EIS) was used to verify the AQ-PNA immobilization. The paper-based electrochemical DNA biosensor was used to detect a synthetic 14-base oligonucleotide target with a sequence corresponding to human papillomavirus (HPV) type 16 DNA by measuring the electrochemical signal response of the AQ label using square-wave voltammetry before and after hybridization. It was determined that the current signal significantly decreased after the addition of target DNA. This phenomenon is explained by the rigidity of PNA-DNA duplexes, which obstructs the accessibility of electron transfer from the AQ label to the electrode surface. Under optimal conditions, the detection limit of HPV type 16 DNA was found to be 2.3 nM with a linear range of 10-200 nM. The performance of this biosensor on real DNA samples was tested with the detection of PCR-amplified DNA samples from the SiHa cell line. The new method employs an inexpensive and disposable device, which easily incinerated after use and is promising for the screening and monitoring of the amount of HPV-DNA type 16 to identify the primary stages of cervical cancer.

  2. Biological evaluation of synthetic α,β-unsaturated carbonyl based cyclohexanone derivatives as neuroprotective novel inhibitors of acetylcholinesterase, butyrylcholinesterase and amyloid-β aggregation.

    PubMed

    Zha, Gao-Feng; Zhang, Cheng-Pan; Qin, Hua-Li; Jantan, Ibrahim; Sher, Muhammad; Amjad, Muhammad Wahab; Hussain, Muhammad Ajaz; Hussain, Zahid; Bukhari, Syed Nasir Abbas

    2016-05-15

    A series of new α,β-unsaturated carbonyl-based cyclohexanone derivatives was synthesized by simple condensation method and all compounds were characterized by using various spectroscopic techniques. New compounds were evaluated for their effects on acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). These compounds were also screened for in vitro cytotoxicity and for inhibitory activity for self-induced Aβ1-42 aggregation. The effect of these compounds against amyloid β-induced cytotoxicity was also investigated. The findings of in vitro experiment revealed that most of these compounds exhibited potent inhibitory activity against AChE and self-induced Aβ1-42 aggregation. The compound 3o exhibited best AChE (IC50=0.037μM) inhibitory potential. Furthermore, compound 3o disassembled the Aβ fibrils produced by self-induced Aβ aggregation by 76.6%. Compounds containing N-methyl-4-piperidone linker, showed high acetylcholinesterase and self-induced Aβ aggregation inhibitory activities as compared to reference drug donepezil. The pre-treatment of cells with synthetic compounds protected them against Aβ-induced cell death by up to 92%. Collectively, these findings suggest that some compounds from this series have potential to be promising multifunctional agents for AD treatment and our study suggest the cyclohexanone derivatives as promising new inhibitors for AChE and BuChE, potentially useful to treat neurodegenerative diseases.

  3. Photoelectrochemical enzymatic biosensors.

    PubMed

    Zhao, Wei-Wei; Xu, Jing-Juan; Chen, Hong-Yuan

    2017-06-15

    Enzymatic biosensors have been valuable bioanalytical devices for analysis of diverse targets in disease diagnosis, biological and biomedical research, etc. Photoelectrochemical (PEC) bioanalysis is a recently emerged method that promptly becoming a subject of new research interests due to its attractive potential for future bioanalysis with high sensitivity and specificity. PEC enzymatic biosensors integrate the inherent sensitivities of PEC bioanalysis and the selectivity of enzymes and thus share their both advantages. Currently, PEC enzymatic biosensors have become a hot topic of significant research and the recent impetus has grown rapidly as demonstrated by increased research papers. Given the pace of advances in this area, this review will make a thorough discussion and survey on the fundamentals, sensing strategies, applications and the state of the art in PEC enzymatic biosensors, followed by future prospects based on our own opinions. We hope this work could provide an accessible introduction to PEC enzymatic biosensors for any scientist.

  4. Fabrication and characterization of spiral interdigitated electrodes based biosensor for salivary glucose detection

    NASA Astrophysics Data System (ADS)

    Adelyn, P. Y. P.; Hashim, U.; Arshad, M. K. Md; Voon, C. H.; Liu, Wei-Wen; Kahar, S. M.; Huda, A. R. N.; Lee, H. Cheun

    2017-03-01

    This work introduces the non-invasive glucose monitoring technique by using the Complementary Metal Oxide Semiconductor (CMOS) technologically fabricated spiral Interdigitated Electrodes (IDE) based biosensor. Scanning Electron Microscopy (SEM) image explores the morphology of spiral IDE while Energy Dispersive X-Ray (EDX) determines the elements induced in spiral IDE. Oral saliva of two patients are collected and tested on the spiral IDE sensor with electrical characterization as glucose detection results. However, both patients exhibit their glucose level characteristics inconsistently. Therefore, this work could be extended and enhanced by adding Glutaraldehyde in between 3-Aminoproply)triethoxysilane (APTES) modified and glucose oxidase (GOD) enzyme immobilized layer with FTIR validation for bonding attachment.

  5. Detection of mercury compounds using invertase-glucose oxidase-based biosensor

    SciTech Connect

    Amine, A.; Cremisini, C.; Palleschi, G.

    1995-12-31

    Mercury compounds have been determined with an electrochemical biosensor based on invertase inhibition. When invertase is in presence of mercury its activity decreases; this causes a decrease of glucose production which is monitored by the glucose sensor and correlated to the concentration of mercury in solution. Parameters as pH, enzyme concentration, substrate concentration, and reaction and incubation time were optimized. Mercury compounds determination using soluble or immobilized invertase were reported. Results showed that the inhibition was competitive and reversible. Mercury compounds can be detected directly in aqueous solution in the range 2--10 ppb.

  6. Detection of mercury compounds using invertase-glucose oxidase-based biosensor

    NASA Astrophysics Data System (ADS)

    Amine, A.; Cremisini, C.; Palleschi, G.

    1995-10-01

    Mercury compounds have been determined with an electrochemical biosensor based on invertase inhibition. When invertase is in the presence of mercury its activity decreases; this causes a decrease of glucose production which is monitored by the glucose sensor and correlated to the concentration of mercury in solution. Parameters as pH, enzyme concentration, substrate concentration, and reaction and incubation time were optimized. Mercury compounds determination using soluble or immobilized invertase were reported. Results show that the inhibition was competitive and reversible. Mercury compounds can be detected directly in aqueous solution in the range 2 - 10 ppb.

  7. Thin-Film Transistor-Based Biosensors for Determining Stoichiometry of Biochemical Reactions.

    PubMed

    Wang, Yi-Wen; Chen, Ting-Yang; Yang, Tsung-Han; Chang, Cheng-Chung; Yang, Tsung-Lin; Lo, Yu-Hwa; Huang, Jian-Jang

    2016-01-01

    The enzyme kinetic in a biochemical reaction is critical to scientific research and drug discovery but can hardly be determined experimentally from enzyme assays. In this work, a charge-current transducer (a transistor) is proposed to evaluate the status of biochemical reaction by monitoring the electrical charge changes. Using the malate-aspartate shuttle as an example, a thin-film transistor (TFT)-based biosensor with an extended gold pad is demonstrated to detect the biochemical reaction between NADH and NAD+. The drain current change indicates the status of chemical equilibrium and stoichiometry.

  8. Thin-Film Transistor-Based Biosensors for Determining Stoichiometry of Biochemical Reactions

    PubMed Central

    Wang, Yi-Wen; Chen, Ting-Yang; Yang, Tsung-Han; Chang, Cheng-Chung; Yang, Tsung-Lin; Lo, Yu-Hwa

    2016-01-01

    The enzyme kinetic in a biochemical reaction is critical to scientific research and drug discovery but can hardly be determined experimentally from enzyme assays. In this work, a charge-current transducer (a transistor) is proposed to evaluate the status of biochemical reaction by monitoring the electrical charge changes. Using the malate-aspartate shuttle as an example, a thin-film transistor (TFT)-based biosensor with an extended gold pad is demonstrated to detect the biochemical reaction between NADH and NAD+. The drain current change indicates the status of chemical equilibrium and stoichiometry. PMID:28033412

  9. Asymmetric Mach-Zehnder Interferometer Based Biosensors for Aflatoxin M1 Detection.

    PubMed

    Chalyan, Tatevik; Guider, Romain; Pasquardini, Laura; Zanetti, Manuela; Falke, Floris; Schreuder, Erik; Heideman, Rene G; Pederzolli, Cecilia; Pavesi, Lorenzo

    2016-01-06

    In this work, we present a study of Aflatoxin M1 detection by photonic biosensors based on Si₃N₄ Asymmetric Mach-Zehnder Interferometer (aMZI) functionalized with antibodies fragments (Fab'). We measured a best volumetric sensitivity of 10⁴ rad/RIU, leading to a Limit of Detection below 5 × 10(-7) RIU. On sensors functionalized with Fab', we performed specific and non-specific sensing measurements at various toxin concentrations. Reproducibility of the measurements and re-usability of the sensor were also investigated.

  10. A Fluorescent, Reagentless Biosensor for ATP, Based on Malonyl-Coenzyme A Synthetase

    PubMed Central

    2015-01-01

    A fluorescent reagentless biosensor for ATP has been developed, based on malonyl-coenzyme A synthetase from Rhodopseudomonas palustris as the protein scaffold and recognition element. Two 5-iodoacetamidotetramethylrhodamines were covalently bound to this protein to provide the readout. This adduct couples ATP binding to a 3.7-fold increase in fluorescence intensity with excitation at 553 nm and emission at 575 nm. It measures ATP concentrations with micromolar sensitivity and is highly selective for ATP relative to ADP. Its ability to monitor enzymatic ATP production or depletion was demonstrated in steady-state kinetic assays in which ATP is a product or substrate, respectively. PMID:26355992

  11. Electrical percolation-based biosensor for real-time direct detection of staphylococcal enterotoxin B (SEB).

    PubMed

    Yang, Minghui; Sun, Steven; Bruck, Hugh Alan; Kostov, Yordan; Rasooly, Avraham

    2010-08-15

    Electrical percolation-based biosensing is a new technology. This is the first report of an electrical percolation-based biosensor for real-time detection. The label-free biosensor is based on electrical percolation through a single-walled carbon nanotubes (SWNTs)-antibody complex that forms a network functioning as a "Biological Semiconductor" (BSC). The conductivity of a BSC is directly related to the number of contacts facilitated by the antibody-antigen "connectors" within the SWNT network. BSCs are fabricated by immobilizing a pre-functionalized SWNTs-antibody complex directly on a poly(methyl methacrylate) (PMMA) and polycarbonate (PC) surface. Each BSC is connected via silver electrodes to a computerized ohmmeter, thereby enabling a continuous electronic measurement of molecular interactions (e.g. antibody-antigen binding) via the change in resistance. Using anti-staphylococcal enterotoxin B (SEB) IgG to functionalize the BSC, we demonstrate that the biosensor was able to detect SEB at concentrations as low as 5 ng/mL at a signal to baseline (S/B) ratio of 2. Such measurements were performed on the chip in wet conditions. The actuation of the chip by SEB is immediate, permitting real-time signal measurements. In addition to this "direct" label-free detection mode, a secondary antibody can be used to "label" the target molecule bound to the BSC in a manner analogous to an immunological sandwich "indirect" detection-type assay. Although a secondary antibody is not needed for direct detection, the indirect mode of detection may be useful as an additional measurement to verify or amplify signals from direct detection in clinical, food safety and other critical assays. The BSC was used to measure SEB both in buffer and in milk, a complex matrix, demonstrating the potential of electrical percolation-based biosensors for real-time label-free multi-analyte detection in clinical and complex samples. Assembly of BSCs is simple enough that multiple sensors can be

  12. Novel fluorescent biosensor for α-glucosidase inhibitor screening based on cationic conjugated polymers.

    PubMed

    Cao, Ali; Tang, Yanli; Liu, Yue

    2012-08-01

    A new fluorescent biosensor has been designed to screen α-glucosidase inhibitors (AGIs) sensitively by utilizing signal amplification effect of conjugated polymers. The fluorescence of cationic poly(fluorenylene phenylene) (PFP) was quenched in the presence of para-nitrophenyl-α-d-glucopyranoside and α-glucosidase, and turned on upon addition of AGIs. Thus, a new method was developed for AGIs screening based on the fluorescence turn-off/turn-on. The IC(50) values obtained for inhibitors were compared with that reported using absorption spectroscopy. All results present the new method is more sensitive and promising in screening AGIs and inhibitors of other enzymes whose hydrolysis product is 4-nitrophenol.

  13. Optical biosensor based on liquid crystal droplets for detection of cholic acid

    NASA Astrophysics Data System (ADS)

    Niu, Xiaofang; Luo, Dan; Chen, Rui; Wang, Fei; Sun, Xiaowei; Dai, Haitao

    2016-12-01

    A highly sensitive cholic acid biosensor based on 4-cyano-4‧-penthlbiphenyl (5CB) Liquid crystal droplets in phosphate buffer saline solution was reported. A radial-to-bipolar transition of 5CB droplet would be triggered during competitive reaction of CA at the sodium dodecyl sulfate surfactant-laden 5CB droplet surface. Our liquid crystal droplet sensor is a low-cost, simple and fast method for CA detection. The detection limit (5 μM) of our method is 2.4 times lower than previously report by using liquid crystal film to detection of CA.

  14. Measuring and Imaging Metal Ions With Fluorescence-Based Biosensors: Speciation, Selectivity, Kinetics, and Other Issues.

    PubMed

    Thompson, Richard B; Fierke, Carol A

    2017-01-01

    Fluorescence-based biosensors have shown themselves to be a powerful tool for the study of a variety of chemical species in biological systems, notably including metal ions. This chapter provides an overview of several important issues in using such sensors to study metallobiochemistry. These issues include selectivity for the analyte over potential interferents, including those that do not themselves induce a signal, the different forms in which metal ions are found (speciation), the utility of metal ion buffers, and the importance of kinetics in studying metal ion binding reactions. Finally, the chapter briefly discusses some of the issues in understanding whole-organism distribution of metal ions and its control.

  15. Homo-FRET Based Biosensors and Their Application to Multiplexed Imaging of Signalling Events in Live Cells

    PubMed Central

    Warren, Sean C.; Margineanu, Anca; Katan, Matilda; Dunsby, Chris; French, Paul M. W.

    2015-01-01

    Multiplexed imaging of Förster Resonance Energy Transfer (FRET)-based biosensors potentially presents a powerful approach to monitoring the spatio-temporal correlation of signalling pathways within a single live cell. Here, we discuss the potential of homo-FRET based biosensors to facilitate multiplexed imaging. We demonstrate that the homo-FRET between pleckstrin homology domains of Akt (Akt-PH) labelled with mCherry may be used to monitor 3′-phosphoinositide accumulation in live cells and show how global analysis of time resolved fluorescence anisotropy measurements can be used to quantify this accumulation. We further present multiplexed imaging readouts of calcium concentration, using fluorescence lifetime measurements of TN-L15-a CFP/YFP based hetero-FRET calcium biosensor-with 3′-phosphoinositide accumulation. PMID:26133241

  16. Graphene oxide-based SPR biosensor chip for immunoassay applications

    NASA Astrophysics Data System (ADS)

    Chiu, Nan-Fu; Huang, Teng-Yi; Lai, Hsin-Chih; Liu, Kou-Chen

    2014-08-01

    This work develops a highly sensitive immunoassay sensor for use in graphene oxide sheet (GOS)-based surface plasmon resonance (SPR) chips. This sensing film, which is formed by chemically modifying a GOS surface, has covalent bonds that strongly interact with the bovine serum albumin (BSA), explaining why it has a higher sensitivity. This GOS film-based SPR chip has a BSA concentration detection limit that is 100 times higher than that of the conventional Au-film-based sensor. The affinity constants ( K A) on the GOS film-based SPR chip and the conventional SPR chip for 100 μg/ml BSA are 80.82 × 106 M-1 and 15.67 × 106 M-1, respectively. Therefore, the affinity constant of the GOS film-based SPR chip is 5.2 times higher than that of the conventional chip. With respect to the protein-protein interaction, the SPR sensor capability to detect angle changes at a low concentration anti-BSA of 75.75 nM on the GOS film-based SPR chip and the conventional SPR chip is 36.1867 and 26.1759 mdeg, respectively. At a high concentration, anti-BSA of 378.78 nM on the GOS film-based SPR chip and the conventional SPR chip reveals two times increases in the SPR angle shift. Above results demonstrate that the GOS film is promising for highly sensitive clinical diagnostic applications.

  17. Graphene oxide-based electrochemical label-free detection of glycoproteins down to aM level using a lectin biosensor.

    PubMed

    Klukova, L; Filip, J; Belicky, S; Vikartovska, A; Tkac, J

    2016-07-21

    A label-free ultrasensitive impedimetric biosensor with lectin immobilised on graphene oxide (GO) for the detection of glycoproteins from 1 aM is shown here. This is the first time a functional lectin biosensor with lectin directly immobilised on a graphene-based interface without any polymer modifier has been described. The study also shows that hydrophilic oxidative debris present on GO has a beneficial effect on the sensitivity of (8.46 ± 0.20)% per decade for the lectin biosensor compared to the sensitivity of (4.52 ± 0.23)% per decade for the lectin biosensor built up from GO with the oxidative debris washed out.

  18. Sol-Gel-Based Titania-Silica Thin Film Overlay for Long Period Fiber Grating-Based Biosensors.

    PubMed

    Chiavaioli, Francesco; Biswas, Palas; Trono, Cosimo; Jana, Sunirmal; Bandyopadhyay, Somnath; Basumallick, Nandini; Giannetti, Ambra; Tombelli, Sara; Bera, Susanta; Mallick, Aparajita; Baldini, Francesco

    2015-12-15

    An evanescent wave optical fiber biosensor based on titania-silica-coated long period grating (LPG) is presented. The chemical overlay, which increases the refractive index (RI) sensitivity of the sensor, consists of a sol-gel-based titania-silica thin film, deposited along the sensing portion of the fiber by means of the dip-coating technique. Changing both the sol viscosity and the withdrawal speed during the dip-coating made it possible to adjust the thickness of the film overlay, which is a crucial parameter for the sensor performance. After the functionalization of the fiber surface using a methacrylic acid/methacrylate copolymer, an antibody/antigen (IgG/anti-IgG) assay was carried out to assess the performance of sol-gel based titania-silica-coated LPGs as biosensors. The analyte concentration was determined from the wavelength shift at the end of the binding process and from the initial binding rate. This is the first time that a sol-gel based titania-silica-coated LPG is proposed as an effective and feasible label-free biosensor. The specificity of the sensor was validated by performing the same model assay after spiking anti-IgG into human serum. With this structured LPG, detection limits of the order of tens of micrograms per liter (10(-11) M) are attained.

  19. Stimulus-response mesoporous silica nanoparticle-based chemiluminescence biosensor for cocaine determination.

    PubMed

    Chen, Zhonghui; Tan, Yue; Xu, Kefeng; Zhang, Lan; Qiu, Bin; Guo, Longhua; Lin, Zhenyu; Chen, Guonan

    2016-01-15

    Mesoporous silica nanoparticles (MSN) based controlled release system had been coupled with diverse detection technologies to establish biosensors for different targets. Chemiluminescence (CL) system of luminol/H2O2 owns the characters of simplicity, low cost and high sensitivity, but the targets of which are mostly focused on some oxidants or which can participate in a chemical reaction that yields a product with a role in the CL reaction. In this study, chemiluminescent detection technique had been coupled with mesoporous silica-based controlled released system for the first time to develop a sensitive biosensor for the target which does not cause effect to the CL system itself. Cocaine had been chosen a model target, the MSN support was firstly loaded with glucose, then the positively charged MSN interacted with negatively charged oligonucleotides (the aptamer cocaine) to close the mesopores of MSN. At the present of target, cocaine binds with its aptamer with high affinity; the flexible linear aptamer structured will become stems structured through currently well-defined non-Waston-Crick interactions and causes the releasing of entrapped glucose into the solution. With the assistant of glucose oxidase (GOx), the released glucose can react with the dissolved oxgen to produce gluconic acid and H2O2, the latter can enhance the CL of luminol in the NaOH solution. The enhanced CL intensity has a relationship with the cocaine concentration in the range of 5.0-60μM with the detection limit of 1.43μM. The proposed method had been successfully applied to detect cocaine in serum samples with high selectivity. The same strategy can be applied to develop biosensors for different targets.

  20. An ultrasensitive electrochemical DNA biosensor based on a copper oxide nanowires/single-walled carbon nanotubes nanocomposite

    NASA Astrophysics Data System (ADS)

    Chen, Mei; Hou, Changjun; Huo, Danqun; Yang, Mei; Fa, Huanbao

    2016-02-01

    Here, we developed a novel and sensitive electrochemical biosensor to detect specific-sequence target DNA. The biosensor was based on a hybrid nanocomposite consisting of copper oxide nanowires (CuO NWs) and carboxyl-functionalized single-walled carbon nanotubes (SWCNTs-COOH). The resulting CuO NWs/SWCNTs layers exhibited a good differential pulse voltammetry (DPV) current response for the target DNA sequences, which we attributed to the properties of CuO NWs and SWCNTs. CuO NWs and SWCNTs hybrid composites with highly conductive and biocompatible nanostructure were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and cyclic voltammetry (CV). Immobilization of the probe DNA on the electrode surface was largely improved due to the unique synergetic effect of CuO NWs and SWCNTs. DPV was applied to monitor the DNA hybridization event, using adriamycin as an electrochemical indicator. Under optimal conditions, the peak currents of adriamycin were linear with the logarithm of target DNA concentrations (ranging from 1.0 × 10-14 to 1.0 × 10-8 M), with a detection limit of 3.5 × 10-15 M (signal/noise ratio of 3). The biosensor also showed high selectivity to single-base mismatched target DNA. Compared with other electrochemical DNA biosensors, we showed that the proposed biosensor is simple to implement, with good stability and high sensitivity.

  1. Nanomembrane-Based, Thermal-Transport Biosensor for Living Cells.

    PubMed

    ElAfandy, Rami T; AbuElela, Ayman F; Mishra, Pawan; Janjua, Bilal; Oubei, Hassan M; Büttner, Ulrich; Majid, Mohammed A; Ng, Tien Khee; Merzaban, Jasmeen S; Ooi, Boon S

    2017-02-01

    Knowledge of materials' thermal-transport properties, conductivity and diffusivity, is crucial for several applications within areas of biology, material science and engineering. Specifically, a microsized, flexible, biologically integrated thermal transport sensor is beneficial to a plethora of applications, ranging across plants physiological ecology and thermal imaging and treatment of cancerous cells, to thermal dissipation in flexible semiconductors and thermoelectrics. Living cells pose extra challenges, due to their small volumes and irregular curvilinear shapes. Here a novel approach of simultaneously measuring thermal conductivity and diffusivity of different materials and its applicability to single cells is demonstrated. This technique is based on increasing phonon-boundary-scattering rate in nanomembranes, having extremely low flexural rigidities, to induce a considerable spectral dependence of the bandgap-emission over excitation-laser intensity. It is demonstrated that once in contact with organic or inorganic materials, the nanomembranes' emission spectrally shift based on the material's thermal diffusivity and conductivity. This NM-based technique is further applied to differentiate between different types and subtypes of cancer cells, based on their thermal-transport properties. It is anticipated that this novel technique to enable an efficient single-cell thermal targeting, allow better modeling of cellular thermal distribution and enable novel diagnostic techniques based on variations of single-cell thermal-transport properties.

  2. Highly sensitive biosensors based on all-dielectric nanoresonators.

    PubMed

    Bontempi, Nicolò; Chong, Katie E; Orton, Henry W; Staude, Isabelle; Choi, Duk-Yong; Alessandri, Ivano; Kivshar, Yuri S; Neshev, Dragomir N

    2017-04-13

    Biosensing based on nanophotonic structures has shown a great potential for cost-efficient, high-speed and compact personal medical diagnostics. While plasmonic nanosensors offer high sensitivity, their intrinsically restricted resonance quality factors and strong heating due to metal absorption impose severe limitations on real life applications. Here, we demonstrate an all-dielectric sensing platform based on silicon nanodisks with strong optically-induced magnetic resonances, which are able to detect a concentration of streptavidin of as low as 10(-10) M (mol L(-1)) or 5 ng mL(-1), thus pushing the current detection limit by at least two orders of magnitudes. Our study suggests a new direction in biosensing based on bio-compatible, non-toxic, robust and low-loss dielectric nanoresonators with potential applications in medicine, including disease diagnosis and drug detection.

  3. A surface-acoustic-wave-based cantilever bio-sensor.

    PubMed

    De Simoni, Giorgio; Signore, Giovanni; Agostini, Matteo; Beltram, Fabio; Piazza, Vincenzo

    2015-06-15

    A scalable surface-acoustic-wave- (SAW-) based cantilevered device for portable bio-chemical sensing applications is presented. Even in the current, proof-of-principle implementation this architecture is shown to outperform commercial quartz-crystal microbalances in terms of sensitivity. Adhesion of analytes on a functionalized surface of the cantilever shifts the resonant frequency of a SAW-generating transducer due to the stress-induced variation of the speed of surface acoustic modes. We discuss the relevance of this approach for diagnostics applications based on miniaturized devices.

  4. Gold and aluminum based surface plasmon resonance biosensors: sensitivity enhancement

    NASA Astrophysics Data System (ADS)

    Biednov, Mykola; Lebyedyeva, Tetyana; Shpylovyy, Pavlo

    2015-05-01

    In this work we considered Gold and Aluminum thin films coated with additional dielectric layers as sensing platforms. Operation of these sensors is based on measuring shift in the position of the reflectivity dip in angular reflectivity spectrum of the sample. Shift can be caused by changes in the refraction index of either liquid that interacts with sensors surface (refractometric measurements) or thin adjacent biolayer on top of the sensor due to immobilization of the target molecules (biosensing). Calculations based on Fresnel equations and transfer matrix formalism allowed us to make comprehensive analysis of the angular sensitivity, shape of the reflectivity dip and dynamic range of the sensors with different dielectric coatings. Calculations were performed for both cases of bio and refractometric sensing. Results showed different dependence of the sensitivity of Au an Al based sensors upon refraction index of the dielectric coating. For Au-based surface Plasmon resonance sensor up to two times increased sensitivity can be achieved using dielectric coating with high refraction index 2.3 of proper thickness. For sensors based on aluminum we were able to achieve 50% increased angular sensitivity. At the same time width of the reflectivity dip increased proportionally to the optical thickness of the dielectric coating. For estimating sensors quality we analyzed ratio of the angular sensitivity to the width of the reflectivity dip. This ratio decreased with increase in optical thickness of the dielectric, however angular sensitivity of the sensor increased significantly. Deposition of the additional dielectric layer with high refraction index such as Niobium Oxide can also improve chemical and mechanical stability of the sensor.

  5. Potential for Development of an Escherichia coli—Based Biosensor for Assessing Bioavailable Methionine: A Review

    PubMed Central

    Chalova, Vesela I.; Froelich, Clifford A.; Ricke, Steven C.

    2010-01-01

    Methionine is an essential amino acid for animals and is typically considered one of the first limiting amino acids in animal feed formulations. Methionine deficiency or excess in animal diets can lead to sub-optimal animal performance and increased environmental pollution, which necessitates its accurate quantification and proper dosage in animal rations. Animal bioassays are the current industry standard to quantify methionine bioavailability. However, animal-based assays are not only time consuming, but expensive and are becoming more scrutinized by governmental regulations. In addition, a variety of artifacts can hinder the variability and time efficacy of these assays. Microbiological assays, which are based on a microbial response to external supplementation of a particular nutrient such as methionine, appear to be attractive potential alternatives to the already established standards. They are rapid and inexpensive in vitro assays which are characterized with relatively accurate and consistent estimation of digestible methionine in feeds and feed ingredients. The current review discusses the potential to develop Escherichia coli-based microbial biosensors for methionine bioavailability quantification. Methionine biosynthesis and regulation pathways are overviewed in relation to genetic manipulation required for the generation of a respective methionine auxotroph that could be practical for a routine bioassay. A prospective utilization of Escherichia coli methionine biosensor would allow for inexpensive and rapid methionine quantification and ultimately enable timely assessment of nutritional profiles of feedstuffs. PMID:22319312

  6. Electrochemical sensors and biosensors based on redox polymer/carbon nanotube modified electrodes: a review.

    PubMed

    Barsan, Madalina M; Ghica, M Emilia; Brett, Christopher M A

    2015-06-30

    The aim of this review is to present the contributions to the development of electrochemical sensors and biosensors based on polyphenazine or polytriphenylmethane redox polymers together with carbon nanotubes (CNT) during recent years. Phenazine polymers have been widely used in analytical applications due to their inherent charge transport properties and electrocatalytic effects. At the same time, since the first report on a CNT-based sensor, their application in the electroanalytical chemistry field has demonstrated that the unique structure and properties of CNT are ideal for the design of electrochemical (bio)sensors. We describe here that the specific combination of phenazine/triphenylmethane polymers with CNT leads to an improved performance of the resulting sensing devices, because of their complementary electrical, electrochemical and mechanical properties, and also due to synergistic effects. The preparation of polymer/CNT modified electrodes will be presented together with their electrochemical and surface characterization, with emphasis on the contribution of each component on the overall properties of the modified electrodes. Their importance in analytical chemistry is demonstrated by the numerous applications based on polymer/CNT-driven electrocatalytic effects, and their analytical performance as (bio) sensors is discussed.

  7. Electrochemical lectin based biosensors as a label-free tool in glycomics

    PubMed Central

    Bertók, Tomáš; Katrlík, Jaroslav; Gemeiner, Peter; Tkac, Jan

    2016-01-01

    Glycans and other saccharide moieties attached to proteins and lipids, or present on the surface of a cell, are actively involved in numerous physiological or pathological processes. Their structural flexibility (that is based on the formation of various kinds of linkages between saccharides) is making glycans superb “identity cards”. In fact, glycans can form more “words” or “codes” (i.e., unique sequences) from the same number of “letters” (building blocks) than DNA or proteins. Glycans are physicochemically similar and it is not a trivial task to identify their sequence, or - even more challenging - to link a given glycan to a particular physiological or pathological process. Lectins can recognise differences in glycan compositions even in their bound state and therefore are most useful tools in the task to decipher the “glycocode”. Thus, lectin-based biosensors working in a label-free mode can effectively complement the current weaponry of analytical tools in glycomics. This review gives an introduction into the area of glycomics and then focuses on the design, analytical performance, and practical utility of lectin-based electrochemical label-free biosensors for the detection of isolated glycoproteins or intact cells. PMID:27239071

  8. Novel charge plasma based dielectric modulated impact ionization MOSFET as a biosensor for label-free detection

    NASA Astrophysics Data System (ADS)

    Chanda, Manash; Dey, Prithu; De, Swapnadip; Sarkar, Chandan Kumar

    2015-10-01

    In this paper a charge plasma based dielectric modulated impact ionization MOSFET (CP-DIMOSFET) has been proposed for the first time to ease the label free detection of biomolecules. The concept of CP-DIMOSFET is proposed and analyzed on basis of simulated data using SILVACO ATLAS. Low thermal budgeting and thin silicon layer without any dopant implantations make the proposed structure advantageous compared to the existing MOSFET based biosensors. The results show that the proposed device is capable to detect the presence of biomolecules. Simple fabrication schemes, miniaturization, high sensitivity, dominance of dielectric modulation make the proposed biosensor a promising one that could one day revolutionize the healthcare industry.

  9. Electrochemical biosensors for hormone analyses.

    PubMed

    Bahadır, Elif Burcu; Sezgintürk, Mustafa Kemal

    2015-06-15

    Electrochemical biosensors have a unique place in determination of hormones due to simplicity, sensitivity, portability and ease of operation. Unlike chromatographic techniques, electrochemical techniques used do not require pre-treatment. Electrochemical biosensors are based on amperometric, potentiometric, impedimetric, and conductometric principle. Amperometric technique is a commonly used one. Although electrochemical biosensors offer a great selectivity and sensitivity for early clinical analysis, the poor reproducible results, difficult regeneration steps remain primary challenges to the commercialization of these biosensors. This review summarizes electrochemical (amperometric, potentiometric, impedimetric and conductometric) biosensors for hormone detection for the first time in the literature. After a brief description of the hormones, the immobilization steps and analytical performance of these biosensors are summarized. Linear ranges, LODs, reproducibilities, regenerations of developed biosensors are compared. Future outlooks in this area are also discussed.

  10. The performance of a multi-sensor detection system based on phage-coated magnetoelastic biosensors

    NASA Astrophysics Data System (ADS)

    Huang, S.; Yang, H.; Lakshmanan, R.; Li, S.; Chen, I.; Petrenko, V. A.; Barbaree, J. M.; Chin, B. A.

    2009-05-01

    In this paper the performance of a magnetoelastic biosensor detection system for the simultaneous identification of B. anthracis spores and S. typhimurium was investigated. This system was also designed for selective in-situ detection of B. anthracis spores in the presence a mixed microbial population. The system was composed of a reference sensor (devoid of phage), an E2 phage sensor (coated with phage specific to S. typhimurium) and a JRB7 phage sensor (coated with phage specific to B. anthracis spores). When cells/spores are bound to the specific phage-based ME biosensor surface, only the resonance frequency of the specific sensor changed. The instantaneous response of the multiple sensor system was studied by exposing the system to B. anthracis spores and S. typhimurium suspensions sequentially. A detection limit of 1.6×103 cfu/mL and 1.1×103 cfu/m was observed for JRB7 phage sensor and E2 phage sensor, respectively. Additionally, the performance of the system was also evaluated by exposure to a flowing mixture of B. anthracis spores (5×101-5×108 cfu/ml) in the presence of B. cereus spores (5×107 cfu/ml). Only the JRB7 phage biosensor responded to the B. anthracis spores. Moreover, there was no appreciable frequency change due to non-specific binding when other microorganisms (spores) were in the mixture. A detection limit of 3×102 cfu/mL was observed for JRB7 phage sensor. The results show that the multi-sensor detection system offers good performance, including good sensitivity, selectivity and rapid detection.

  11. An amperometric hydrogen peroxide biosensor based on Co3O4 nanoparticles and multiwalled carbon nanotube modified glassy carbon electrode

    NASA Astrophysics Data System (ADS)

    Kaçar, Ceren; Dalkiran, Berna; Erden, Pınar Esra; Kiliç, Esma

    2014-08-01

    In this work a new type of hydrogen peroxide biosensor was fabricated based on the immobilization of horseradish peroxidase (HRP) by cross-linking on a glassy carbon electrode (GCE) modified with Co3O4 nanoparticles, multiwall carbon nanotubes (MWCNTs) and gelatin. The introduction of MWCNTs and Co3O4 nanoparticles not only enhanced the surface area of the modified electrode for enzyme immobilization but also facilitated the electron transfer rate, resulting in a high sensitivity of the biosensor. The fabrication process of the sensing surface was characterized by scanning electron microscopy (SEM), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Amperometric detection of hydrogen peroxide was investigated by holding the modified electrode at -0.30 V (vs. Ag/AgCl). The biosensor showed optimum response within 5 s at pH 7.0. The optimized biosensor showed linear response range of 7.4 × 10-7-1.9 × 10-5 M with a detection limit of 7.4 × 10-7. The applicability of the purposed biosensor was tested by detecting hydrogen peroxide in disinfector samples. The average recovery was calculated as 100.78 ± 0.89.

  12. Sensitivity Enhancement of Bead-based Electrochemical Impedance Spectroscopy (BEIS) biosensor by electric field-focusing in microwells.

    PubMed

    Shin, Kyeong-Sik; Ji, Jae Hoon; Hwang, Kyo Seon; Jun, Seong Chan; Kang, Ji Yoon

    2016-11-15

    This paper reports a novel electrochemical impedance spectroscopy (EIS) biosensors that uses magnetic beads trapped in a microwell array to improve the sensitivity of conventional bead-based EIS (BEIS) biosensors. Unloading the previously measured beads by removing the magnetic bar enables the BEIS sensor to be used repeatedly by reloading it with new beads. Despite its recyclability, the sensitivity of conventional BEIS biosensors is so low that it has not attracted much attentions from the biosensor industry. We significantly improved the sensitivity of the BEIS system by introducing of a microwell array that contains two electrodes (a working electrode and a counter electrode) to concentrate the electric field on the surfaces of the beads. We confirmed that the performance of the BEIS sensor in a microwell array using an immunoassay of prostate specific antigen (PSA) in PBS buffer and human plasma. The experimental results showed that a low concentration of PSA (a few tens or hundreds of fg/mL) were detectable as a ratio of the changes in the impedance of the PBS buffer or in human plasma. Therefore, our BEIS sensor with a microwell array could be a promising platform for low cost, high-performance biosensors for applications that require high sensitivity and recyclability.

  13. A comparison of three amperometric phenoloxidase-Sonogel-Carbon based biosensors for determination of polyphenols in beers.

    PubMed

    ElKaoutit, Mohammed; Naranjo-Rodriguez, Ignacio; Temsamani, Khalid Riffi; Hernández-Artiga, Maria P; Bellido-Milla, Dolores; Cisneros, Jose Luis Hidalgo-Hidalgo de

    2008-10-15

    Three phenoloxidases based biosensors were successfully developed using as electrochemical transducer a new type of electrode recently developed by our group: the "Sonogel-Carbon electrode". The employed enzymes were Trametes versicolor laccase (Lac), Mushroom tyrosinase (Tyr), and Horseradish peroxidase (HRP). Immobilization step was accomplished by doping the electrode surface with a mixture of the individual enzyme and Nafion ion exchanger as additive-protective. The biosensor responses, optimized in beer real samples, were evaluated for five individual polyphenols. It was found that the developed biosensors were sensitive to nanomolar concentrations of the tested polyphenols. As example, the limit of detection, sensitivity, and response linear range for caffeic acid for Nafion-Lac/Sonogel-Carbon biosensor were 0.06μmolL(-1), 99.6nAμmol(-1)L, and 0.04-2μmolL(-1), respectively. The stability and reproducibility of the biosensors were evaluated by applying them directly to beer real samples. It has been demonstrated that the Nafion-Lac/Sonogel-Carbon system is the more stable with a relative standard deviation of 3.3% (n=10), maintaining 84% of its stable response for at least three weeks. Estimation of polyphenol index in eight lager beers and a comparison of the results with those obtained by a classical method was carried out.

  14. Highly sensitive amperometric biosensor based on electrochemically-reduced graphene oxide-chitosan/hemoglobin nanocomposite for nitromethane determination.

    PubMed

    Wen, Yunping; Wen, Wei; Zhang, Xiuhua; Wang, Shengfu

    2016-05-15

    Nitromethane (CH3NO2) is an important organic chemical raw material with a wide variety of applications as well as one of the most common pollutants. Therefore it is pretty important to establish a simple and sensitive detection method for CH3NO2. In our study, a novel amperometric biosensor for nitromethane (CH3NO2) based on immobilization of electrochemically-reduced graphene oxide (rGO), chitosan (CS) and hemoglobin (Hb) on a glassy carbon electrode (GCE) was constructed. Scanning electron microscopy, infrared spectroscopy and electrochemical methods were used to characterize the Hb-CS/rGO-CS composite film. The effects of scan rate and pH of phosphate buffer on the biosensor have been studied in detail and optimized. Due to the graphene and chitosan nanocomposite, the developed biosensor demonstrating direct electrochemistry with faster electron-transfer rate (6.48s(-1)) and excellent catalytic activity towards CH3NO2. Under optimal conditions, the proposed biosensor exhibited fast amperometric response (<5s) to CH3NO2 with a wide linear range of 5 μM~1.46 mM (R=0.999) and a low detection limit of 1.5 μM (S/N=3). In addition, the biosensor had high selectivity, reproducibility and stability, providing the possibility for monitoring CH3NO2 in complex real samples.

  15. DNA-based biosensors for Hg(2+) determination by polythymine-methylene blue modified electrodes.

    PubMed

    Tortolini, Cristina; Bollella, Paolo; Antonelli, Marta Letizia; Antiochia, Riccarda; Mazzei, Franco; Favero, Gabriele

    2015-05-15

    In this work we have developed a new electrochemical DNA-based biosensor for the selective determination of the Hg(2+) ion by the use of different electrodes modified with polythymine, bearing methylene blue, as redox probe, in 3' position. The determination of Hg(2+) can be employed with an excellent degree of selectivity by the use of DNA biosensors through the formation of the complex Thymine-Hg-Thymine (T-Hg-T): in fact, Hg(2+) tends to bind two thymines, generating a T-Hg-T complex with a formation constant higher than that one of the coupling Adenine-Thymine, which can be employed for a selective, fast and cost-effective Hg(2+) detection. The presence of the Hg(2+) in solution leads to the formation of T-Hg-T complex thus causing the "hairpin-like" folding of oligonucleotide, leading to an improved electronic exchange of methylene blue with the electrode surface due to the reduced distance and thus to an increase of the faradic current which is detected by means of square wave voltammetry (SWV). To test the feasibility of this kind of biosensor to be applied to the analysis of Hg(2+) we have developed several biosensors configuration by modifying the electrochemical sensor transducer: (a) Au electrode; (b) Au screen-printed electrode (SPE). The proposed system, allows the determination of Hg(2+) in the range 0.2-100 nM (0.05-20 ppb), with a sensitivity 0.327 µA/nM, LOD 0.1 nM (0.02 ppb), LOQ 0.2 nM (0.05 ppb) and RSD ≤4.3% when Au electrode is used as electrochemical transducer; on the other hand, in the case of Au SPE the linear range is 0.2-50 nM (0.05-10 ppb), with a sensitivity 0.285 µA/nM, while LOD and LOQ are the same as previously and RSD is ≤3.8%. This enabled the detection of mercury in real samples (waters and fishes) with good accuracy (recoveries 92-101% on waters and 92-107% on fishes, respectively) and reproducibility (RSD ≤9.6% for measurements on waters and ≤8.8% on fishes, respectively).

  16. Biosensors based on Si3N4 asymmetric Mach-Zehnder interferometers

    NASA Astrophysics Data System (ADS)

    Chalyan, Tatevik; Pasquardini, Laura; Falke, Floris; Zanetti, Manuela; Guider, Romain; Gandolfi, Davide; Schreuder, Eric; Pederzolli, Cecilia; Heideman, René G.; Pavesi, Lorenzo

    2016-04-01

    In this work, we present a study on photonic biosensors based on Si3N4 asymmetric Mach-Zehnder Interferometers (aMZI) for Aflatoxin M1 (AFM1) detection. AFM1 is an hepatotoxic and a carcinogenic toxin present in milk. The biosensor is based on an array of four Si3N4 aMZI that are optimized for 850nm wavelength. We measure the bulk Sensitivity (S) and the Limit of Detection (LOD) of our devices. In the array, three devices are exposed and have very similar sensitivities. The fourth aMZI, which is covered by SiO2, is used as an internal reference for laser (a VCSEL) and temperature fluctuations. We measured a phase sensitivity of 14300+/-400 rad/RIU. To characterize the LOD of the sensors, we measure the uncertainty of the experimental readout system. From the measurements on three aMZI, we observe the same value of LOD, which is ≍ 4.5×10-7 RIU. After the sensor characterization on homogeneous sensing, we test the surface sensing performances by flowing specific Aflatoxin M1 and non-specific Ochratoxin in 50 mM MES pH 6.6 buffer on the top of the sensors functionalized with Antigen-Recognising Fragments (Fab'). The difference between specific and non-specific signals shows the specificity of our sensors. A moderate regeneration of the sensors is obtained by using glycine solution.

  17. [Study of immobilization and properties of urease for creation of a biosensor based on semiconductor structures].

    PubMed

    Bubriak, O A; Khustochka, L N; Soldatkin, A P; Starodub, N F

    1992-01-01

    Many-sided investigations of urease immobilization methods were carried out to create the biosensor devices on the base of semiconductor structures. Special attention was concentrated on the biomembrane formation by means of urease and bovine serum albumin (BSA) cross-linking by gaseous glutaraldehyde. Optimal conditions for the formation process were selected which preserve about 20% of total urease activity after the cross-linking. The properties of enzyme immobilized by the above-mentioned method have been comprehensively studied. They included the urease activity dependence on pH, ionic strength, incubation buffer capacity as well as the enzyme stability during its functioning, storing and thermoinactivation. As was shown, for immobilized ureas Km value for urea at pH 7.0 and 20 degrees C is 1.65 time less than for free enzyme. In the presence of EDTA (1 mM) the enzyme activity in the biomembrane is practically unchanged under a month storing. Biomembrane possesses good adhesion to silicon surface and its swelling level under different conditions does not exceed 35%. The conclusion is made about the prospects of the used method of biomembrane formation for biosensor technology based on semiconductor structures.

  18. Glycoprofiling of cancer biomarkers: Label-free electrochemical lectin-based biosensors

    PubMed Central

    Pihíková, Dominika; Kasák, Peter

    2016-01-01

    Glycosylation of biomolecules is one of the most prevalent post- and co-translational modification in a human body, with more than half of all human proteins being glycosylated. Malignant transformation of cells influences glycosylation machinery resulting in subtle changes of the glycosylation pattern within the cell populations as a result of cancer. Thus, an altered terminal glycan motif on glycoproteins could provide a warning signal about disease development and progression and could be applied as a reliable biomarker in cancer diagnostics. Among all highly effective glycoprofiling tools, label-free electrochemical impedance spectroscopy (EIS)-based biosensors have emerged as especially suitable tool for point-of-care early-stage cancer detection. Herein, we highlight the current challenges in glycoprofiling of various cancer biomarkers by ultrasensitive impedimetric-based biosensors with low sample consumption, low cost fabrication and simple miniaturization. Additionally, this review provides a short introduction to the field of glycomics and lectinomics and gives a brief overview of glycan alterations in different types of cancer. PMID:27275016

  19. ZnO nano-array-based EGFET biosensor for glucose detection

    NASA Astrophysics Data System (ADS)

    Qi, Junjie; Zhang, Huihui; Ji, Zhaoxia; Xu, Minxuan; Zhang, Yue

    2015-06-01

    Electrochemical biosensors are normally based on enzymatic catalysis of a reaction that produces or consumes electrons and the sensing membranes dominate the performance. In this work, ZnO nano-array-based EGFETs were fabricated for pH and glucose detection. The ZnO nano-arrays prepared via low-temperature hydrothermal method were well-aligned, with an average length of 2 μm and diameter of 100-150 nm, and have a typical hexagonal wurtzite structure. The sensor performed with a sensitivity of 45 mV/pH and response time of about 6-7 s from pH = 4-12. UV irradiation can improve the Vref response as a result of the formation of a depletion region at the surface of ZnO nanomaterials. Due to its high specific surface area, the ZnO nano-array EGFET sensor showed a sensitivity of -0.395 mV/μM to the glucose detection in a concentration range between 20 and 100 μM. These EGFET glucose biosensors demonstrate a low detectable concentration (20 μM) with good linearity, therefore may be used to detect glucose in saliva and tears at much lower concentrations than that in blood.

  20. Amperometric inhibitive biosensor based on horseradish peroxidase-nanoporous gold for sulfide determination

    NASA Astrophysics Data System (ADS)

    Sun, Huihui; Liu, Zhuang; Wu, Chao; Xu, Ping; Wang, Xia

    2016-08-01

    As a well-known toxic pollutant, sulfide is harmful to human health. In this study, a simple and sensitive amperometric inhibitive biosensor was developed for the determination of sulfide in the environment. By immobilizing nanoporous gold (NPG) on glassy carbon electrode (GCE), and encapsulating horseradish peroxidase (HRP) onto NPG, a HRP/NPG/GCE bioelectrode for sulfide detection was successfully constructed based on the inhibition of sulfide on HRP activity with o-Phenylenediamine (OPD) as a substrate. The resulted HRP/NPG/GCE bioelectrode achieved a wide linear range of 0.1–40 μM in sulfide detection with a high sensitivity of 1720 μA mM‑1 cm‑2 and a low detection limit of 0.027 μM. Additionally, the inhibition of sulfide on HRP is competitive inhibition with OPD as a substrate by Michaelis-Menten analysis. Notably, the recovery of HRP activity was quickly achieved by washing the HRP/NPG/GCE bioelectrode using differential pulse voltammetry (DPV) technique in deaerated PBS (50 mM, pH 7.0) for only 60 s. Furthermore, the real sample analysis of sulfide by the HRP/NPG/GCE bioelectrode was achieved. Based on above results, the HRP/NPG/GCE bioelectrode could be a better choice for the real determination of sulfide compared to inhibitive biosensors previously reported.

  1. Non-enzymatic Fluorescent Biosensor for Glucose Sensing Based on ZnO Nanorods

    NASA Astrophysics Data System (ADS)

    Mai, Hong Hanh; Pham, Van Thanh; Nguyen, Viet Tuyen; Sai, Cong Doanh; Hoang, Chi Hieu; Nguyen, The Binh

    2017-02-01

    We have developed a non-enzymatic fluorescent biosensor for glucose sensing based on ZnO nanorods. ZnO nanorods of high density, high crystallinity, and good alignment were grown on low-cost industrial copper substrates at low temperature. To grow them directly on the substrates without using a seed layer, we utilized a simple one-step seedless hydrothermal method, which is based on galvanic cell structure. Herein, the glucose-treated ZnO nanorods together with the ultraviolet (UV) irradiation of the sample during the photoluminescent measurement played the role of a catalyst. They decomposed glucose into hydrogen peroxide (H2O2) and gluconic acid, which is similar to the glucose oxidase enzyme (GOx) used in enzymatic sensors. Due to the formation of H2O2, the photoluminescence intensity of the UV emission peak of ZnO nanorods decreased as the glucose concentration increased from 1 mM to 100 mM. In comparison with glucose concentration of a normal human serum, which is in the range of 4.4-6.6 mM, the obtained results show potential of non-enzymatic fluorescent biosensors in medical applications.

  2. Development of swine-specific DNA markers for biosensor-based halal authentication.

    PubMed

    Ali, M E; Hashim, U; Kashif, M; Mustafa, S; Che Man, Y B; Abd Hamid, S B

    2012-06-29

    The pig (Sus scrofa) mitochondrial genome was targeted to design short (15-30 nucleotides) DNA markers that would be suitable for biosensor-based hybridization detection of target DNA. Short DNA markers are reported to survive harsh conditions in which longer ones are degraded into smaller fragments. The whole swine mitochondrial-genome was in silico digested with AluI restriction enzyme. Among 66 AluI fragments, five were selected as potential markers because of their convenient lengths, high degree of interspecies polymorphism and intraspecies conservatism. These were confirmed by NCBI blast analysis and ClustalW alignment analysis with 11 different meat-providing animal and fish species. Finally, we integrated a tetramethyl rhodamine-labeled 18-nucleotide AluI fragment into a 3-nm diameter citrate-tannate coated gold nanoparticle to develop a swine-specific hybrid nanobioprobe for the determination of pork adulteration in 2.5-h autoclaved pork-beef binary mixtures. This hybrid probe detected as low as 1% pork in deliberately contaminated autoclaved pork-beef binary mixtures and no cross-species detection was recorded, demonstrating the feasibility of this type of probe for biosensor-based detection of pork adulteration of halal and kosher foods.

  3. Label-free measurements on cell apoptosis using a terahertz metamaterial-based biosensor

    NASA Astrophysics Data System (ADS)

    Zhang, Caihong; Liang, Lanju; Ding, Liang; Jin, Biaobing; Hou, Yayi; Li, Chun; Jiang, Ling; Liu, Weiwei; Hu, Wei; Lu, Yanqing; Kang, Lin; Xu, Weiwei; Chen, Jian; Wu, Peiheng

    2016-06-01

    Label-free, real-time, and in-situ measurement on cell apoptosis is highly desirable in cell biology. We propose here a design of terahertz (THz) metamaterial-based biosensor for meeting this requirement. This metamaterial consists of a planar array of five concentric subwavelength gold ring resonators on a 10 μm-thick polyimide substrate, which can sense the change of dielectric environment above the metamaterial. We employ this sensor to an oral cancer cell (SCC4) with and without cisplatin, a chemotherapy drug for cancer treatment, and find a linear relation between cell apoptosis measured by Flow Cytometry and the relative change of resonant frequencies of the metamaterial measured by THz time-domain spectroscopy. This implies that we can determine the cell apoptosis in a label-free manner. We believe that this metamaterial-based biosensor can be developed into a cheap, label-free, real-time, and in-situ detection tool, which is of significant impact on the study of cell biology.

  4. A silicon-based peptide biosensor for label-free detection of cancer cells

    NASA Astrophysics Data System (ADS)

    Martucci, Nicola M.; Rea, Ilaria; Ruggiero, Immacolata; Terracciano, Monica; De Stefano, Luca; Migliaccio, Nunzia; Dardano, Principia; Arcari, Paolo; Rendina, Ivo; Lamberti, Annalisa

    2015-05-01

    Sensitive and accurate detection of cancer cells plays a crucial role in diagnosis of cancer and minimal residual disease, so being one of the most hopeful approaches to reduce cancer death rates. In this paper, a strategy for highly selective and sensitive detection of lymphoma cells on planar silicon-based biosensor has been evaluated. In this setting an Idiotype peptide, able to specifically bind the B-cell receptor (BCR) of A20 cells in mice engrafted with A20 lymphoma, has been covalently linked to the sensor active surface and used as molecular probe. The biochip here presented showed a coverage efficiency of 85% with a detection efficiency of 8.5×10-3 cells/μm2. The results obtained suggested an efficient way for specific label-free cell detection by using a silicon-based peptide biosensor. In addition, the present recognition strategy, besides being useful for the development of sensing devices capable of monitoring minimal residual disease, could be used to find and characterize new specific receptor-ligand interactions through the screening of a recombinant phage library.

  5. Tissue-based standoff biosensors for detecting chemical warfare agents

    DOEpatents

    Greenbaum, Elias; Sanders, Charlene A.

    2003-11-18

    A tissue-based, deployable, standoff air quality sensor for detecting the presence of at least one chemical or biological warfare agent, includes: a cell containing entrapped photosynthetic tissue, the cell adapted for analyzing photosynthetic activity of the entrapped photosynthetic tissue; means for introducing an air sample into the cell and contacting the air sample with the entrapped photosynthetic tissue; a fluorometer in operable relationship with the cell for measuring photosynthetic activity of the entrapped photosynthetic tissue; and transmitting means for transmitting analytical data generated by the fluorometer relating to the presence of at least one chemical or biological warfare agent in the air sample, the sensor adapted for deployment into a selected area.

  6. Biosensors for EVA: Improved Instrumentation for Ground-based Studies

    NASA Technical Reports Server (NTRS)

    Soller, B.; Ellerby, G.; Zou, F.; Scott, P.; Jin, C.; Lee, S. M. C.; Coates, J.

    2010-01-01

    During lunar excursions in the EVA suit, real-time measurement of metabolic rate is required to manage consumables and guide activities to ensure safe return to the base. Metabolic rate, or oxygen consumption (VO2), is normally measured from pulmonary parameters but cannot be determined with standard techniques in the oxygen-rich environment of a spacesuit. Our group has developed novel near infrared spectroscopic (NIRS) methods to calculate muscle oxygen saturation (SmO 2), hematocrit, and pH, and we recently demonstrated that we can use our NIRS sensor to measure VO 2 on the leg during cycling. Our NSBRI project has 4 objectives: (1) increase the accuracy of the metabolic rate calculation through improved prediction of stroke volume; (2) investigate the relative contributions of calf and thigh oxygen consumption to metabolic rate calculation for walking and running; (3) demonstrate that the NIRS-based noninvasive metabolic rate methodology is sensitive enough to detect decrement in VO 2 in a space analog; and (4) improve instrumentation to allow testing within a spacesuit. Over the past year we have made progress on all four objectives, but the most significant progress was made in improving the instrumentation. The NIRS system currently in use at JSC is based on fiber optics technology. Optical fiber bundles are used to deliver light from a light source in the monitor to the patient, and light reflected back from the patient s muscle to the monitor for spectroscopic analysis. The fiber optic cables are large and fragile, and there is no way to get them in and out of the test spacesuit used for ground-based studies. With complimentary funding from the US Army, we undertook a complete redesign of the sensor and control electronics to build a novel system small enough to be used within the spacesuit and portable enough to be used by a combat medic. In the new system the filament lamp used in the fiber optic system was replaced with a novel broadband near infrared

  7. Genomagnetic Electrochemical Biosensors

    NASA Astrophysics Data System (ADS)

    Wang, Joseph; Erdem, Arzum

    The use of nucleic acid technologies has significantly improved preparation and diagnostic procedures in life sciences. Nucleic acid layers combined with electrochemical or optical transducers produce a new kind of affinity biosensors as DNA Biosensor for small molecular weight molecules. Electrochemical DNA biosensors are attractive devices for converting the hybridization event into an analytical signal for obtaining sequence-specific information in connection with clinical, environmental or forensic investigations. DNA hybridization biosensors, based on electrochemical transduction of hybridization, couple the high specificity of hybridization reactions with the excellent sensitivity and portability of electrochemical transducers. The main goal in all researches is to design DNA biosensors for preparing a basis for the future DNA microarray system. DNA chip has now become a powerful tool in biological research, however the real clinic assay is still under development. Recently, there has been a great interest to the magnetic beads and/or nanoparticles labelled with metals such as gold, cadmium, silver, etc. for designing of novel electrochemical DNA biosensor approaches resulting in efficient separation. The attractive features of this technology include simple approach, rapid results, multi-analyte detection, low-cost per measurument, stable, and non-hazardous reagents, and reduced waste handling. Some of these new approaches and applications of the electrochemical DNA biosensors based on magnetic beads and its combining with nanoparticles labelled with metals are described and discussed.

  8. Fluorogenic Cell-Based Biosensors for Monitoring Microbes

    NASA Technical Reports Server (NTRS)

    Curtis, Theresa; Salazar, Noe; Tabb, Joel; Chase, Chris

    2010-01-01

    Fluorogenic cell-based sensor systems for detecting microbes (especially pathogenic ones) and some toxins and allergens are undergoing development. These systems harness the natural signaltransduction and amplification cascades that occur in mast cells upon activation with antigens. These systems include (1) fluidic biochips for automated containment of samples, reagents, and wastes and (2) sensitive, compact fluorometers for monitoring the fluorescent responses of mast cells engineered to contain fluorescent dyes. It should be possible to observe responses within minutes of adding immune complexes. The systems have been shown to work when utilizing either immunoglobulin E (IgE) antibodies or traditionally generated rat antibodies - a promising result in that it indicates that the systems could be developed to detect many target microbes. Chimeric IgE antibodies and rat immunoglobulin G (IgG) antibodies could be genetically engineered for recognizing biological and chemical warfare agents and airborne and food-borne allergens. Genetic engineering efforts thus far have yielded (1) CD14 chimeric antibodies that recognize both Grampositive and Gram-negative bacteria and bind to the surfaces of mast cells, eliciting a degranulation response and (2) rat IgG2a antibodies that act similarly in response to low levels of canine parvovirus.

  9. A novel bio-sensor based on DNA strand displacement.

    PubMed

    Shi, Xiaolong; Wang, Zhiyu; Deng, Chenyan; Song, Tao; Pan, Linqiang; Chen, Zhihua

    2014-01-01

    DNA strand displacement technology performs well in sensing and programming DNA segments. In this work, we construct DNA molecular systems based on DNA strand displacement performing computation of logic gates. Specifically, a class of so-called "DNA neurons" are achieved, in which a "smart" way inspired by biological neurons encoding information is developed to encode and deliver information using DNA molecules. The "DNA neuron" is bistable, that is, it can sense DNA molecules as input signals, and release "negative" or "positive" signals DNA molecules. We design intelligent DNA molecular systems that are constructed by cascading some particularly organized "DNA neurons", which could perform logic computation, including AND, OR, XOR logic gates, automatically. Both simulation results using visual DSD (DNA strand displacement) software and experimental results are obtained, which shows that the proposed systems can detect DNA signals with high sensitivity and accretion; moreover, the systems can process input signals automatically with complex nonlinear logic. The method proposed in this work may provide a new way to construct a sensitive molecular signal detection system with neurons spiking behavior in vitro, and can be used to develop intelligent molecular processing systems in vivo.

  10. Nine-analyte detection using an array-based biosensor

    NASA Technical Reports Server (NTRS)

    Taitt, Chris Rowe; Anderson, George P.; Lingerfelt, Brian M.; Feldstein, s. Mark. J.; Ligler, Frances S.

    2002-01-01

    A fluorescence-based multianalyte immunosensor has been developed for simultaneous analysis of multiple samples. While the standard 6 x 6 format of the array sensor has been used to analyze six samples for six different analytes, this same format has the potential to allow a single sample to be tested for 36 different agents. The method described herein demonstrates proof of principle that the number of analytes detectable using a single array can be increased simply by using complementary mixtures of capture and tracer antibodies. Mixtures were optimized to allow detection of closely related analytes without significant cross-reactivity. Following this facile modification of patterning and assay procedures, the following nine targets could be detected in a single 3 x 3 array: Staphylococcal enterotoxin B, ricin, cholera toxin, Bacillus anthracis Sterne, Bacillus globigii, Francisella tularensis LVS, Yersiniapestis F1 antigen, MS2 coliphage, and Salmonella typhimurium. This work maximizes the efficiency and utility of the described array technology, increasing only reagent usage and cost; production and fabrication costs are not affected.

  11. Nanopore-based instruments as biosensors for future planetary missions.

    PubMed

    Rezzonico, Fabio

    2014-04-01

    Data from automated orbiters and landers have dashed humankind's hopes of finding complex life-forms elsewhere in the Solar System. The focus of exobiological research was thus forced to shift from the detection of life through simple visual imaging to complex biochemical experiments aimed at the detection of microbial activity. Searching for biosignatures over interplanetary distances is a formidable task and poses the dilemma of what are the proper experiments that can be performed on-site to maximize the chances of success if extraterrestrial life is present but not evident. Despite their astonishing morphological diversity, all known organisms on Earth share the same basic molecular architecture; thus the vast majority of our detection and identification techniques are b(i)ased on Terran biochemistry. There is, however, a distinct possibility that life may have emerged elsewhere by using other molecular building blocks, a fact that is likely to make the outcome of most of the current molecular biological and biochemical life-detection protocols difficult to interpret if not completely ineffective. Nanopore-based sensing devices allow the analysis of single molecules, including the sequence of informational biopolymers such as DNA or RNA, by measuring current changes across an electrically resistant membrane when the analyte flows through an embedded transmembrane protein or a solid-state nanopore. Under certain basic assumptions about their physical properties, this technology has the potential to discriminate and possibly analyze biopolymers, in particular genetic information carriers, without prior detailed knowledge of their fundamental chemistry and is sufficiently portable to be used for automated analysis in planetary exploration, all of which makes it the ideal candidate for the search for life signatures in remote watery environments such as Mars, Europa, or Enceladus.

  12. A novel amperometric catechol biosensor based on α-Fe2O3 nanocrystals-modified carbon paste electrode.

    PubMed

    Sarika, C; Shivakumar, M S; Shivakumara, C; Krishnamurthy, G; Narasimha Murthy, B; Lekshmi, I C

    2017-05-01

    In this work, we designed an amperometric catechol biosensor based on α-Fe2O3 nanocrystals (NCs) incorporated carbon-paste electrode. Laccase enzyme is then assembled onto the modified electrode surface to form a nanobiocomposite enhancing the electron transfer reactions at the enzyme's active metal centers for catechol oxidation. The biosensor gave good sensitivity with a linear detection response in the range of 8-800 μM with limit of detection 4.28 μM. We successfully employed the sensor for real water sample analysis. The results illustrate that the metal oxide NCs have enormous potential in the construction of biosensors for sensitive determination of phenol derivatives.

  13. Biosensors Based on Nano-Gold/Zeolite-Modified Ion Selective Field-Effect Transistors for Creatinine Detection

    NASA Astrophysics Data System (ADS)

    Ozansoy Kasap, Berna; Marchenko, Svitlana V.; Soldatkin, Oleksandr O.; Dzyadevych, Sergei V.; Akata Kurc, Burcu

    2017-03-01

    The combination of advantages of using zeolites and gold nanoparticles were aimed to be used for the first time to improve the characteristic properties of ion selective field-effect transistor (ISFET)-based creatinine biosensors. The biosensors with covalently cross-linked creatinine deiminase using glutaraldehyde (GA) were used as a control group, and the effect of different types of zeolites on biosensor responses was investigated in detail by using silicalite, zeolite beta (BEA), nano-sized zeolite beta (Nano BEA) and zeolite BEA including gold nanoparticle (BEA-Gold). The presence of gold nanoparticles was investigated by ICP, STEM-EDX and XPS analysis. The chosen zeolite types allowed investigating the effect of aluminium in the zeolite framework, particle size and the presence of gold nanoparticles in the zeolitic framework.

  14. Fluorescence biosensor based on CdTe quantum dots for specific detection of H5N1 avian influenza virus

    NASA Astrophysics Data System (ADS)

    Hoa Nguyen, Thi; Dieu Thuy Ung, Thi; Hien Vu, Thi; Tran, Thi Kim Chi; Quyen Dong, Van; Khang Dinh, Duy; Liem Nguyen, Quang

    2012-09-01

    This report highlights the fabrication of fluorescence biosensors based on CdTe quantum dots (QDs) for specific detection of H5N1 avian influenza virus. The core biosensor was composed of (i) the highly luminescent CdTe/CdS QDs, (ii) chromatophores extracted from bacteria Rhodospirillum rubrum, and (iii) the antibody of β-subunit. This core part was linked to the peripheral part of the biosensor via a biotin-streptavidin-biotin bridge and finally connected to the H5N1 antibody to make it ready for detecting H5N1 avian influenza virus. Detailed studies of each constituent were performed showing the image of QDs-labeled chromatophores under optical microscope, proper photoluminescence (PL) spectra of CdTe/CdS QDs, chromatophores and the H5N1 avian influenza viruses.

  15. A Simple Metallothionein-Based Biosensor for Enhanced Detection of Arsenic and Mercury

    PubMed Central

    Irvine, Gordon W.; Tan, Swee Ngin; Stillman, Martin J.

    2017-01-01

    Metallothioneins (MTs) are a family of cysteine-rich proteins whose biological roles include the regulation of essential metal ions and protection against the harmful effects of toxic metals. Due to its high affinity for many toxic, soft metals, recombinant human MT isoform 1a was incorporated into an electrochemical-based biosensor for the detection of As3+ and Hg2+. A simple design was chosen to maximize its potential in environmental monitoring and MT was physically adsorbed onto paper discs placed on screen-printed carbon electrodes (SPCEs). This system was tested with concentrations of arsenic and mercury typical of contaminated water sources ranging from 5 to 1000 ppb. The analytical performance of the MT-adsorbed paper discs on SPCEs demonstrated a greater than three-fold signal enhancement and a lower detection limit compared to blank SPCEs, 13 ppb for As3+ and 45 ppb for Hg2+. While not being as low as some of the recommended drinking water limits, the sensitivity of the simple MT-biosensor would be potentially useful in monitoring of areas of concern with a known contamination problem. This paper describes the ability of the metal binding protein metallothionein to enhance the effectiveness of a simple, low-cost electrochemical sensor. PMID:28335390

  16. Whole cell based microcontact imprinted capacitive biosensor for the detection of Escherichia coli.

    PubMed

    Idil, Neslihan; Hedström, Martin; Denizli, Adil; Mattiasson, Bo

    2017-01-15

    In this study, a label-free, selective and sensitive microcontact imprinted capacitive biosensor was developed for the detection of Escherichia coli. The recognition of E. coli was successfully performed by this sensor prepared with the combination of microcontact imprinting method and capacitive biosensor technology. After preparation of bacterial stamps, microcontact-E. coli imprinted gold electrodes were generated using an amino acid based recognition element, N-methacryloyl-L-histidine methylester (MAH), 2-Hydroxyethyl methacrylate (HEMA) as monomers and ethyleneglycol dimethacrylate (EGDMA) as crosslinker under UV-polymerization. Real-time E. coli detection experiments were carried out within the range of 1.0×10(2)-1.0×10(7)CFU/mL. The unique combination of these two techniques provides selective detection with a detection limit of 70CFU/mL. The designed capacitive sensor has high selectivity and was able to distinguish E. coli when present together with competing bacterial strains which are known to have similar shape. In addition, the prepared sensor has the ability to detect E. coli with a recovery of 81-97% in e.g. river water.

  17. A Simple Metallothionein-Based Biosensor for Enhanced Detection of Arsenic and Mercury.

    PubMed

    Irvine, Gordon W; Tan, Swee Ngin; Stillman, Martin J

    2017-03-13

    Metallothioneins (MTs) are a family of cysteine-rich proteins whose biological roles include the regulation of essential metal ions and protection against the harmful effects of toxic metals. Due to its high affinity for many toxic, soft metals, recombinant human MT isoform 1a was incorporated into an electrochemical-based biosensor for the detection of As(3+) and Hg(2+). A simple design was chosen to maximize its potential in environmental monitoring and MT was physically adsorbed onto paper discs placed on screen-printed carbon electrodes (SPCEs). This system was tested with concentrations of arsenic and mercury typical of contaminated water sources ranging from 5 to 1000 ppb. The analytical performance of the MT-adsorbed paper discs on SPCEs demonstrated a greater than three-fold signal enhancement and a lower detection limit compared to blank SPCEs, 13 ppb for As(3+) and 45 ppb for Hg(2+). While not being as low as some of the recommended drinking water limits, the sensitivity of the simple MT-biosensor would be potentially useful in monitoring of areas of concern with a known contamination problem. This paper describes the ability of the metal binding protein metallothionein to enhance the effectiveness of a simple, low-cost electrochemical sensor.

  18. Resonant-energy-transfer-based biosensor for detection of multivalent proteins

    NASA Astrophysics Data System (ADS)

    Song, Xuedong; Swanson, Basil I.

    1999-12-01

    We have developed a new fluorescence-based biosensor for sensitive detection of species involved in a multivalent interaction. The biosensor system utilizes specific interactions between proteins and cell surface receptors, which trigger a receptor aggregation process. Distance- dependent fluorescence self-quenching and resonant fluorescence energy transfer mechanisms were coupled with a multivalent interaction to probe the receptor aggregation process, providing a sensitive and specific signal transduction method for such a binding event. The fluorescence change induced by the aggregation process can be monitored by different instrument platforms, e.g. fluorimetry and flow cytometry. In this article, a sensitive detection of pentavalent cholera toxin which recognizes ganglioside GMI has been demonstrated through the resonant energy transfer scheme, which can achieve a double color change simultaneously. A detection sensitivity as high as 10 pM has been achieved within a few minutes (c.a. 5 minutes). The simultaneous double color change (an increase of acceptor fluorescence and a decrease of donor fluorescence intensity) of two similar fluorescent probes provides particularly high detection reliability owing to the fact that they act as each other's internal reference. Any external perturbation such as environmental temperature change causes no significant change in signal generation. Besides the application for biological sensing, the method also provides a useful tool for investigation of kinetics and thermodynamics of a multivalent interaction.

  19. Low-concentration mechanical biosensor based on a photonic crystal nanowire array.

    PubMed

    Lu, Yuerui; Peng, Songming; Luo, Dan; Lal, Amit

    2011-12-06

    The challenge for new biosensors is to achieve detection of biomolecules at low concentrations, which is useful for early-stage disease detection. Nanomechanical biosensors are promising in medical diagnostic applications. For nanomechanical biosensing at low concentrations, a sufficient resonator device surface area is necessary for molecules to bind to. Here we present a low-concentration (500 aM sensitivity) DNA sensor, which uses a novel nanomechanical resonator with ordered vertical nanowire arrays on top of a Si/SiO(2) bilayer thin membrane. The high sensitivity is achieved by the strongly enhanced total surface area-to-volume ratio of the resonator (10(8) m(-1)) and the state-of-the-art mass-per-area resolution (1.8×10(-12) kg m(-2)). Moreover, the nanowire array forms a photonic crystal that shows strong light trapping and absorption over broad-band optical wavelengths, enabling high-efficiency broad-band opto-thermo-mechanical remote device actuation and biosensing on a chip. This method represents a mass-based platform technology that can sense molecules at low concentrations.

  20. A high efficiency label-free photonic biosensor based on vertically stacked ring resonators

    NASA Astrophysics Data System (ADS)

    Campanella, C. E.; Campanella, C. M.; De Leonardis, F.; Passaro, V. M. N.

    2014-09-01

    In this paper we propose an optical biosensor based on two vertically stacked Silicon on Insulator (SOI) micro-ring resonators interacting with a microfluidic ring channel. This device behaves as a resonant optical coupler and it is very sensitive to the variation of the coupling coefficient between the two vertically stacked ring resonators. A ring microfluidic channel is proposed in the coupling region between the two vertically stacked ring resonators. The inner walls of the channel are funzionalized in order to the trap a specific biological species. Assuming a biotin-streptavidin system, the straptividin trapping gives rise to a change of the biological thickness of about 3 nm. This thickness increase of the deposited layer leads to a consequent change in the coupling strength between the two rings. These theoretical predictions have been validated by using both 3D Finite-Difference Time-Domain (FDTD) and 3D full-vectorial Finite Element Method (FEM) approaches. Moreover, by appropriately choosing the design parameters of the micro-resonant structure, we evaluate a sensitivity of the spectral response to the streptavidin adlayer variation of about 20% nm-1 for TE polarization and 34% nm-1 for TM polarization, which represents an important achievement to obtain selective SOI bio-sensors with ultra-high resolution.

  1. Detection of Bacillus anthracis spores in water using biosensors based on magnetostrictive microcantilever coated with phage

    NASA Astrophysics Data System (ADS)

    Fu, Liling; Li, Suiqiong; Zhang, Kewei; Cheng, Z.-Y.; Barbaree, J. M.

    2007-04-01

    Microcantilevers (MCs) as state-of-art sensor platforms have been widely investigated. We recently introduced a new type of MC, magnetostrictive microcantilever (MSMC), as high performance sensor platform. The MSMC is a remote/wireless sensor platform and exhibits a high quality merit factor in liquid. In this paper, a MSMC-based biosensor is developed for detecting B. anthracis spores in liquid, a potential biothreaten agent. The results demonstrated the advantages of MSMCs as a sensor platform. MSMCs with different sizes were fabricated and utilized in the experiments. The MSMCs were coated with the filamentous phage as a bio-recognition element to capture the B. anthracis spores. The phage-coated MSMCs as biosensors were exposed to cultures containing target spores with concentrations ranging from 5 * 10 4 spores/mL to 5 * 10 8 spores/mL. The resonance frequency of the MSMC sensors in cultures was monitored in a real-time manner. The results showed that for MSMCs of 2.8 mm * 1.0 mm * 35 μm and with 1.4 mm * 0.8 mm * 35 μm have a detection limit of 10 5 and 10 4 spores/mL, respectively.

  2. Detection of Myoglobin with an Open-Cavity-Based Label-Free Photonic Crystal Biosensor.

    PubMed

    Zhang, Bailin; Tamez-Vela, Juan Manuel; Solis, Steven; Bustamante, Gilbert; Peterson, Ralph; Rahman, Shafiqur; Morales, Andres; Tang, Liang; Ye, Jing Yong

    2013-01-01

    The label-free detection of one of the cardiac biomarkers, myoglobin, using a photonic-crystal-based biosensor in a total-internal-reflection configuration (PC-TIR) is presented in this paper. The PC-TIR sensor possesses a unique open optical microcavity that allows for several key advantages in biomolecular assays. In contrast to a conventional closed microcavity, the open configuration allows easy functionalization of the sensing surface for rapid biomolecular binding assays. Moreover, the properties of PC structures make it easy to be designed and engineered for operating at any optical wavelength. Through fine design of the photonic crystal structure, biochemical modification of the sensor surface, and integration with a microfluidic system, we have demonstrated that the detection sensitivity of the sensor for myoglobin has reached the clinically significant concentration range, enabling potential usage of this biosensor for diagnosis of acute myocardial infarction. The real-time response of the sensor to the myoglobin binding may potentially provide point-of-care monitoring of patients and treatment effects.

  3. Fabrication LSPR sensor chip of Ag NPs and their biosensor application based on interparticle coupling

    NASA Astrophysics Data System (ADS)

    Ghodselahi, T.; Neishaboorynejad, T.; Arsalani, S.

    2015-07-01

    We introduce a simple method to synthesize localized surface plasmon resonance (LSPR) sensor chip of Ag NPs on the hydrogenated amorphous carbon by co-deposition of RF-Sputtering and RF-PECVD. The X-ray photoelectron spectroscopy revealed the content of Ag and C atoms. X-ray diffraction profile and atomic force microscopy indicate that the Ag NPs have fcc crystal structure and spherical shape and by increasing deposition time, particle sizes do not vary and only Ag NPs aggregation occurs, resulting in LSPR wavelength shift. Firstly, by increasing Ag NPs content, in-plan interparticles coupling is dominant and causes redshift in LSPR. At the early stage of agglomeration, out-plane coupling occurs and in-plane coupling is reduced, resulting a blueshift in the LSPR. By further increasing of Ag NPs content, agglomeration is completed on the substrate and in-plan coupling rises, resulting significant redshift in the LSPR. Results were used to implement biosensor application of chips. Detection of DNA primer at fM concentration was achieved based on breaking interparticles coupling of Ag NPs. A significant wavelength shift sensitivity of 30 nm and a short response time of 30 min were obtained, where both of these are prerequisite for biosensor applications.

  4. A novel glutamine biosensor based on zinc oxide nanorod and glutaminase enzyme from Hypocria jecorina.

    PubMed

    Albayrak, Dilruba; Karakuş, Emine

    2016-01-01

    A novel biosensor for determination of L-glutamine in pharmaceutical glutamine powder was developed via immobilizing our produced glutaminase enzyme from Hypocria jecorina onto our prepared zinc oxide (ZnO) nanorod and chitosan. ZnO nanorods were prepared as surface-dependent and surface-independent and both were used. The biosensor is specific for L-glutamine and the peculiar analytical properties (linearity range, reproducibility, and accuracy) of it were experimentally determined. The optimum operating conditions of the biosensor such as buffer concentration, buffer pH, and medium temperature effect on the response of biosensor were studied. Km and Vmax values for the our-producing glutaminase enzyme from Hypocria jecorina immobilized on the biosensor were also determined as 0.29 mM and 208.33 mV/min., respectively, from Lineweaver-Burk plot. The biosensor was then used for the determination of glutamine contained in pharmaceutical formulations.

  5. Online electrochemical systems for continuous neurochemical measurements with low-potential mediator-based electrochemical biosensors as selective detectors.

    PubMed

    Zhang, Zipin; Hao, Jie; Xiao, Tongfang; Yu, Ping; Mao, Lanqun

    2015-08-07

    This study demonstrates a new strategy to develop online electrochemical systems (OECSs) for continuously monitoring neurochemicals by efficiently integrating in vivo microdialysis with an oxidase-based electrochemical biosensor with low-potential electron mediators to shuttle the electron transfer of the oxidases. By using thionine and xanthine oxidase (XOD) as examples of low-potential mediators and oxidases, respectively, we demonstrate that the use of low-potential mediators to shuttle the electron transfer of oxidases would offer a new approach to the development of oxidase-based biosensors with theoretical and technical simplicity. To construct the XOD-based biosensor, thionine was adsorbed onto carbon nanotubes and used to shuttle the electron transfer of XOD. The XOD-based biosensor was positioned into an electrochemical cell that was directly coupled with in vivo microdialysis to form an online electrochemical system (OECS) for continuous and selective measurements of the substrate of XOD (with hypoxanthine as an example). The OECS based on the low-potential mediators is highly selective against the species endogenously existing in the brain system, which is attributed to the low operation potential benefited from the low redox potentials of the mediators. Moreover, the OECS demonstrated here is stable and reproducible and could thus be envisaged to find some interesting applications in physiological and pathological investigations. This study essentially offers a new strategy to develop online electrochemical systems, which is of great importance in understanding the molecular basis of physiological and pathological events.

  6. A plastic total internal reflection-based photoluminescence device for enzymatic biosensors

    NASA Astrophysics Data System (ADS)

    Thakkar, Ishan G.

    Growing concerns for quality of water, food and beverages in developing and developed countries drive sizeable markets for mass-producible, low cost devices that can measure the concentration of contaminant chemicals in water, food, and beverages rapidly and accurately. Several fiber-optic enzymatic biosensors have been reported for these applications, but they exhibit very strong presence of scattered excitation light in the signal for sensing, requiring expensive thin-film filters, and their non-planar structure makes them challenging to mass-produce. Several other planar optical waveguide-based biosensors prove to be relatively costly and more fragile due to constituent materials and the techniques involved in their fabrication. So, a plastic total internal reflection (TIR)-based low cost, low scatter, field-portable device for enzymatic biosensors is fabricated and demonstrated. The design concept of the TIR-based photoluminescent enzymatic biosensor device is explained. An analysis of economical materials with appropriate optical and chemical properties is presented. PMMA and PDMS are found to be appropriate due to their high chemical resistance, low cost, high optical transmittance and low auto-fluorescence. The techniques and procedures used for device fabrication are discussed. The device incorporated a PMMA-based optical waveguide core and PDMS-based fluid cell with simple multi-mode fiber-optics using cost-effective fabrication techniques like molding and surface modification. Several techniques of robustly depositing photoluminescent dyes on PMMA core surface are discussed. A pH-sensitive fluorescent dye, fluoresceinamine, and an O2-sensitive phosphorescent dye, Ru(dpp) both are successfully deposited using Si-adhesive gel-based as well as HydroThane-based deposition methods. Two different types of pH-sensors using two different techniques of depositing fluoresceinamine are demonstrated. Also, the effect of concentration of fluoresceinamine-dye molecules

  7. Novel creatine biosensors based on all solid-state contact ammonium-selective membrane electrodes.

    PubMed

    Altikatoglu, Melda; Karakus, Emine; Erci, Vildan; Pekyardımcı, Sule; Isildak, Ibrahim

    2013-04-01

    Novel creatine bienzymatic potentiometric biosensors were prepared by immobilizing urease and creatinase on all solid-state contact PVC-containing palmitic acid and carboxylated PVC matrix membrane ammonium-selective electrodes without inner reference solution. Potentiometric characteristics of biosensors were examined in physiological model solutions at different creatine concentrations. The linear working range and long-term sensitivity of the biosensors were also determined. The creatine biosensors prepared by using the carboxylated PVC membrane electrodes showed more effective performance than those of the PVC containing palmitic acid membrane electrodes. Creatine assay in serum samples was successfully carried out by using the standard addition method.

  8. Immobilization techniques in the fabrication of nanomaterial-based electrochemical biosensors: a review.

    PubMed

    Putzbach, William; Ronkainen, Niina J

    2013-04-11

    The evolution of 1st to 3rd generation electrochemical biosensors reflects a simplification and enhancement of the transduction pathway. However, in recent years, modification of the transducer with nanomaterials has become increasingly studied and imparts many advantages. The sensitivity and overall performance of enzymatic biosensors has improved tremendously as a result of incorporating nanomaterials in their fabrication. Given the unique and favorable qualities of gold nanoparticles, graphene and carbon nanotubes as applied to electrochemical biosensors, a consolidated survey of the different methods of nanomaterial immobilization on transducer surfaces and enzyme immobilization on these species is beneficial and timely. This review encompasses modification of enzymatic biosensors with gold nanoparticles, carbon nanotubes, and graphene.

  9. Sensitive detection of maltose and glucose based on dual enzyme-displayed bacteria electrochemical biosensor.

    PubMed

    Liu, Aihua; Lang, Qiaolin; Liang, Bo; Shi, Jianguo

    2017-01-15

    Glucoamylase-displayed bacteria (GA-bacteria) and glucose dehydrogenase-displayed bacteria (GDH-bacteria) were co-immobilized on multi-walled carbon nanotubes (MWNTs) modified glassy carbon electrode (GCE) to construct GA-bacteria/GDH-bacteria/MWNTs/GCE biosensor. The biosensor was developed by optimizing the loading amount and the ratio of GA-bacteria to GDH-bacteria. The as-prepared biosensor exhibited a wide dynamic range of 0.2-10mM and a low detection limit of 0.1mM maltose (S/N=3). The biosensor also had a linear response to glucose in the range of 0.1-2.0mM and a low detection limit of 0.04mM glucose (S/N=3). Interestingly, at the same concentration, glucose was 3.75-fold sensitive than that of maltose at the proposed biosensor. No interferences were observed for other possible mono- and disaccharides. The biosensor also demonstrated good long-term storage stability and repeatability. Further, using both GDH-bacteria/MWNTs/GCE biosensor and GA-bacteria/GDH-bacteria/MWNTs/GCE biosensor, glucose and maltose in real samples can be detected. Therefore, the proposed biosensor is capable of monitoring the food manufacturing and fermentation process.

  10. Biosensors Based on Nano-Gold/Zeolite-Modified Ion Selective Field-Effect Transistors for Creatinine Detection.

    PubMed

    Ozansoy Kasap, Berna; Marchenko, Svitlana V; Soldatkin, Oleksandr O; Dzyadevych, Sergei V; Akata Kurc, Burcu

    2017-12-01

    The combination of advantages of using zeolites and gold nanoparticles were aimed to be used for the first time to improve the characteristic properties of ion selective field-effect transistor (ISFET)-based creatinine biosensors. The biosensors with covalently cross-linked creatinine deiminase using glutaraldehyde (GA) were used as a control group, and the effect of different types of zeolites on biosensor responses was investigated in detail by using silicalite, zeolite beta (BEA), nano-sized zeolite beta (Nano BEA) and zeolite BEA including gold nanoparticle (BEA-Gold). The presence of gold nanoparticles was investigated by ICP, STEM-EDX and XPS analysis. The chosen zeolite types allowed investigating the effect of aluminium in the zeolite framework, particle size and the presence of gold nanoparticles in the zeolitic framework.After the synthesis of different types of zeolites in powder form, bare biosensor surfaces were modified by drop-coating of zeolites and creatinine deiminase (CD) was adsorbed on this layer. The sensitivities of the obtained biosensors to 1 mM creatinine decreased in the order of BEA-Gold > BEA > Nano BEA > Silicalite > GA. The highest sensitivity belongs to BEA-Gold, having threefold increase compared to GA, which can be attributed to the presence of gold nanoparticle causing favourable microenvironment for CD to avoid denaturation as well as increased surface area. BEA zeolites, having aluminium in their framework, regardless of particle size, gave higher responses than silicalite, which has no aluminium in its structure. These results suggest that ISFET biosensor responses to creatinine can be tailored and enhanced upon carefully controlled alteration of zeolite parameters used to modify electrode surfaces.

  11. Self assembled monolayer based liquid crystal biosensor for free cholesterol detection

    SciTech Connect

    Tyagi, Mukta; Agrawal, V. V.; Chandran, Achu; Joshi, Tilak; Prakash, Jai; Biradar, A. M.

    2014-04-14

    A unique cholesterol oxidase (ChOx) liquid crystal (LC) biosensor, based on the disruption of orientation in LCs, is developed for cholesterol detection. A self-assembled monolayer (SAM) of Dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride (DMOAP) and (3-Aminopropyl)trimethoxy-silane (APTMS) is prepared on a glass plate by adsorption. The enzyme (ChOx) is immobilized on SAM surface for 12 h before utilizing the film for biosensing purpose. LC based biosensing study is conducted on SAM/ChOx/LC (5CB) cells for cholesterol concentrations ranging from 10 mg/dl to 250 mg/dl. The sensing mechanism has been verified through polarizing optical microscopy, scanning electron microscopy, and spectrometric techniques.

  12. Self assembled monolayer based liquid crystal biosensor for free cholesterol detection

    NASA Astrophysics Data System (ADS)

    Tyagi, Mukta; Chandran, Achu; Joshi, Tilak; Prakash, Jai; Agrawal, V. V.; Biradar, A. M.

    2014-04-01

    A unique cholesterol oxidase (ChOx) liquid crystal (LC) biosensor, based on the disruption of orientation in LCs, is developed for cholesterol detection. A self-assembled monolayer (SAM) of Dimethyloctadecyl[3-(trimethoxysilyl)propyl]ammonium chloride (DMOAP) and (3-Aminopropyl)trimethoxy-silane (APTMS) is prepared on a glass plate by adsorption. The enzyme (ChOx) is immobilized on SAM surface for 12 h before utilizing the film for biosensing purpose. LC based biosensing study is conducted on SAM/ChOx/LC (5CB) cells for cholesterol concentrations ranging from 10 mg/dl to 250 mg/dl. The sensing mechanism has been verified through polarizing optical microscopy, scanning electron microscopy, and spectrometric techniques.

  13. Smartphone-based enzymatic biosensor for oral fluid L-lactate detection in one minute using confined multilayer paper reflectometry.

    PubMed

    Calabria, Donato; Caliceti, Cristiana; Zangheri, Martina; Mirasoli, Mara; Simoni, Patrizia; Roda, Aldo

    2017-03-01

    The development of smartphone-based biosensors for point-of-care testing (POCT) applications allows realizing "all in one" instruments, with large potential distribution among the general population. With this respect, paper color-based detection performed by reflectance measurement is the most popular, simple, inexpensive and straightforward method. Despite the large number of scientific publications related to these biosensors, they still suffer from a poor detectability and reproducibility related to inhomogeneity of color development, which leads to low assay reproducibility. To overcome these problems, we propose a smartphone paper-based biosensor, in which all the reagents necessary to complete the analysis are co-entrapped on paper in a "wafer"-like bilayer film of polyelectrolytes (Poly (allyl amine hydrochloride/poly(sodium 4-styrene sulfonate)). Using a 3D printing low-cost technology we fabricated the smartphone-based device that consists in a cover accessory attached to the smartphone and incorporating a light diffuser over the flash to improve the image quality, a mini dark box and a disposable analytical cartridge containing all the reagents necessary for the complete analysis. The biosensor was developed exploiting coupled enzyme reactions for quantifying L-lactate in oral fluid, which is considered a biomarker of poor tissue perfusion, a key element in the management of severe sepsis, septic shock and in sports performance evaluation. The developed method is sensitive, rapid, and it allows detecting L-lactate in oral fluid in the relevant physiological range, with a limit of detection of 0.1mmolL(-1). The extreme simplicity of assay execution (no reagents need to be added) and flexibility of fabrication of the device, together with the high assay versatility (any oxidase can be coupled with HRP-based color change reaction) make our approach suitable for the realization of smartphone-based biosensors able to non-invasively detect a large variety of

  14. Development of novel acoustic wave biosensor platforms based on magnetostriction and fabrication of magnetostrictive nanowires

    NASA Astrophysics Data System (ADS)

    Li, Suiqiong

    There is an urgent need for biosensors that are able to detect and quantify the presence of a small amount of biological threat agents in a real-time manner. Acoustic wave (AW) devices, whose performance is defined by mass sensitivity (Sm) and merit quality factor (Q value), have been extensively studied as high performance biosensor platforms. However, current AW devices face some challenges in practical applications. In this research, two types of AW devices---magnetostrictive microcantilever (MSMC) and completely free-standing magnetostrictive particle (MSP)---were developed. The research consists of two parts: (1) Design and the feasibility study of MSMC and MSP based sensor technology; (2) Fabrication and characterization of micro/nano MSPs made of amorphous Fe-B alloy. Both MSMC and MSP based sensors are wireless/remote and work well in liquid, which makes the sensors good candidates for in-situ detection. The performance of MSMC was simulated and compared with the state of art AW devices: microcantilevers. The MSMC exhibits the following advantages: (1) remote/wireless driving and sensing; (2) ease of fabrication; (3) works well in liquid; (4) exhibits a high Q value (> 500 in air); (5) well suited for sensor array development. MSMCs in milli/micro sizes were fabricated and their performance was characterized in air and liquid. The experimental results confirm the advantages of MSMC mentioned above. The in situ detection of the yeast cells and Bacillus anthracis spores in water were performed using MSMC biosensors. MSPs in the shape of strip and bar were investigated. Strip-shape MSPs in milli/micro sizes were fabricated. The resonance behaviors of MSPs at the even and odd vibration modes were analyzed. MSP exhibits a Sm about 100 times greater, and a Q value about 10 times greater, than MCs. A multiple-sensor and a multiple-target approach were developed to further enhance the performance of MSP-based sensors. A unique methodology was created to detect the

  15. Urea biosensors based on immobilization of urease into two oppositely charged clays (laponite and Zn-Al layered double hydroxides).

    PubMed

    de Melo, J V; Cosnier, S; Mousty, C; Martelet, C; Jaffrezic-Renault, N

    2002-08-15

    Enzyme-based field effect transistors (ENFETs) for urea determination were developed based on the immobilization of urease within two different clay matrixes, one cationic (Laponite) and the other anionic (layered double hydroxide (LDH)), cross-linked with glutaraldehyde. The biosensor based on the enzyme immobilized in Laponite shows a greater sensitivity and smaller dynamic linear range, because the enzymatic reaction is protected from the effect of the buffer capacity of the outer medium. The apparent Michaelis-Menten constant, Km(app), is quite similar for both biosensors. Inhibition of the enzyme by sodium tetraborate was investigated. Tetraborate acts as a competitive inhibitor for urease in the two different types of clay, the inhibitor effect being stronger for the LDH/urease biosensor. In particular, the maximum limit of the dynamic linear range extends from 1.4 mM in the absence of the inhibitor to 12 mM in the presence of 0.5 mM tetraborate. The Km(app) values in the presence of 0.5 mM tetraborate for Laponite and LDH biomembranes were 10 and 62 mM, respectively. Comparison of the inhibition constant values, Ki 0.16 and 0.05 mM for Laponite and LDH biosensors, respectively, clearly indicates a stronger enzyme-inhibitor interaction in the LDH/urease biomembrane.

  16. Biosensor commercialization strategy - a theoretical approach.

    PubMed

    Lin, Chin-Tsai; Wang, Su-Man

    2005-01-01

    Biosensors are analytical devices, which use biological interactions to provide either qualitative or quantitative results. They are extensively employed in many fields such as clinical diagnosis and biomedicine, military applications, anti-terrorism, farm, garden and veterinary analysis, process control, fermentation control and analysis, pharmaceutical and drug analysis, food and drink production and analysis, pollution control and monitoring, microbiology, bacterial and viral analysis, mining, and industrial and toxic gases. The biosensor market has significantly increased and will be mushrooming in the next decade. The total biosensor market is estimated to be 10.8 billion dollars by 2007. The emerging biosensor market presents both opportunities and obstacles to start-up biosensor entrepreneurs. The major challenge and threat for these entrepreneurs is how to predict the biosensor market and how to convert promising biosensor technology into commercialized biosensors. By adopting a simple commercialization strategy framework, we identify two key elements of biosensor commercialization strategy: excludability and complementary asset. We further divide biosensor commercialization environments into four distinct sub-environments: the Attacker's Advantage, Reputation-Based Idea Trading, Greenfield Competition and Ideas Factories. This paper explains how the interaction between these two key elements shapes biosensor commercialization strategy and biosensor industry dynamics. This paper also discusses alternative commercialization strategies for each specific commercialization environment and how to choose from these alternatives. The analysis of this study further provides a good reference for start-up biosensor entrepreneurs to formulate effective biosensor commercialization strategy.

  17. Biosensors in clinical chemistry.

    PubMed

    D'Orazio, Paul

    2003-08-01

    Biosensors are analytical devices composed of a recognition element of biological origin and a physico-chemical transducer. The biological element is capable of sensing the presence, activity or concentration of a chemical analyte in solution. The sensing takes place either as a binding event or a biocatalytical event. These interactions produce a measurable change in a solution property, which the transducer converts into a quantifiable electrical signal. Present-day applications of biosensors to clinical chemistry are reviewed, including basic and applied research, commercial applications and fabrication techniques. Recognition elements include enzymes as biocatalytic recognition elements and immunoagents and DNA segments as affinity ligand recognition elements, coupled to electrochemical and optical modes of transduction. The future will include biosensors based on synthetic recognition elements to allow broad applicability to different classes of analytes and modes of transduction extending lower limits of sensitivity. Microfabrication will permit biosensors to be constructed as arrays and incorporated into lab-on-a-chip devices.

  18. Biosensors Incorporating Bimetallic Nanoparticles

    PubMed Central

    Rick, John; Tsai, Meng-Che; Hwang, Bing Joe

    2015-01-01

    This article presents a review of electrochemical bio-sensing for target analytes based on the use of electrocatalytic bimetallic nanoparticles (NPs), which can improve both the sensitivity and selectivity of biosensors. The review moves quickly from an introduction to the field of bio-sensing, to the importance of biosensors in today’s society, the nature of the electrochemical methods employed and the attendant problems encountered. The role of electrocatalysts is introduced with reference to the three generations of biosensors. The contributions made by previous workers using bimetallic constructs, grouped by target analyte, are then examined in detail; following which, the synthesis and characterization of the catalytic particles is examined prior to a summary of the current state of endeavor. Finally, some perspectives for the future of bimetallic NPs in biosensors are given. PMID:28344262

  19. A biosensor based on zucchini (Cucurbita pepo L.) homogenate as a biorecognition layer for ascorbic acid determination.

    PubMed

    Sezgintürk, Mustafa Kemal; Koca, Halit Buğra; Ozben, Yavuz Selim; Dinçkaya, Erhan

    2010-08-01

    An amperometric biosensor based on zucchini (Cucurbita pepo) tissue homogenate is presented. The zucchini tissue homogenate was crosslinked with gelatine using glutaraldehyde and fixed on a pretreated teflon membrane. The zucchini tissue contained the enzyme ascorbate oxidase and this enzyme catalyzed the oxidation of ascorbic acid in the presence of dissolved oxygen. The principle of the measurements was based on the determination of the decrease in the dissolved oxygen level. Determinations were carried out by standard curves, which were obtained by the measurement of the decrease in the oxygen level related to ascorbic acid concentration. Optimization and characterization studies of the biosensor were carried out in detail. First of all, the amounts of zucchini tissue homogenate, gelatin, and glutaraldehyde percentage were optimized. Experimental parameters such as buffer system, pH, buffer concentration, and temperature were also optimized carefully. Thermal stability, storage stability, and repeatability of the biosensor were investigated. A linear response was observed from 5x10(-6) M to 1.2x10(-3) M ascorbic acid. Finally, the results of some plant and drug samples analyzed with the presented biosensor compared with the spectrophotometric method (Tillman reagent) used as a reference.

  20. A practical method for monitoring FRET-based biosensors in living animals using two-photon microscopy

    PubMed Central

    Tao, Wen; Rubart, Michael; Ryan, Jennifer; Xiao, Xiao; Qiao, Chunping; Hato, Takashi; Davidson, Michael W.; Dunn, Kenneth W.

    2015-01-01

    The commercial availability of multiphoton microscope systems has nurtured the growth of intravital microscopy as a powerful technique for evaluating cell biology in the relevant context of living animals. In parallel, new fluorescent protein (FP) biosensors have become available that enable studies of the function of a wide range of proteins in living cells. Biosensor probes that exploit Förster resonance energy transfer (FRET) are among the most sensitive indicators of an array of cellular processes. However, differences between one-photon and two-photon excitation (2PE) microscopy are such that measuring FRET by 2PE in the intravital setting remains challenging. Here, we describe an approach that simplifies the use of FRET-based biosensors in intravital 2PE microscopy. Based on a systematic comparison of many different FPs, we identified the monomeric (m) FPs mTurquoise and mVenus as particularly well suited for intravital 2PE FRET studies, enabling the ratiometric measurements from linked FRET probes using a pair of experimental images collected simultaneously. The behavior of the FPs is validated by fluorescence lifetime and sensitized emission measurements of a set of FRET standards. The approach is demonstrated using a modified version of the AKAR protein kinase A biosensor, first in cells in culture, and then in hepatocytes in the liver of living mice. The approach is compatible with the most common 2PE microscope configurations and should be applicable to a variety of different FRET probes. PMID:26333599