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. Copyright © 2011 Elsevier B.V. All rights reserved.

Permanganate-bromide-silver nanoparticles as a new chemiluminescence system and its application to captopril determination.

PubMed

Amjadi, Mohammad; Manzoori, Jamshid L; Hassanzadeh, Javad; Sorouraddin, Mohammad H

2013-10-15

A novel chemiluminescence (CL) system based on the oxidation of bromide by permanganate in sulfuric acid medium is introduced. The enhancing effect of silver nanoparticles (NPs), synthesized by chemical reduction method, on this reaction was studied. It was demonstrated that spherical silver nanoparticles with average size of 18 nm had a most remarkable catalytic effect on this reaction. CL emission wavelengths and UV-vis spectra were used to characterize the system and propose a possible mechanism. Furthermore, it was found that captopril inhibits the action of NPs and decreases the intensity of CL. Based on this phenomenon, a new CL method was developed for the determination of captopril in the 3.0 × 10(-10) to 1.0 × 10(-7) mol L(-1) concentration range with a detection limit (3s) of 0.12 nmol L(-1). The method was successfully applied to the determination of captopril in pharmaceutical formulations, human urine and serum samples. Copyright © 2013 Elsevier B.V. All rights reserved.

Chemiluminescent detection of cell apoptosis enzyme by gold nanoparticle-based resonance energy transfer assay.

PubMed

Huang, Xiangyi; Liang, Yiran; Ruan, Lingao; Ren, Jicun

2014-09-01

We report a new chemiluminescence resonance energy transfer (CRET) technique, using gold nanoparticles (AuNPs) as efficient energy acceptor, for homogeneous measurement of cell apoptosis enzyme with high sensitivity. In the design of the CRET system, we chose the highly sensitive chemiluminescence (CL) reaction between luminol and hydrogen peroxide catalysed by horseradish peroxidase (HRP) because the CL spectrum of luminol (λ max 425 nm) partially overlaps the visible absorption bands of AuNPs. In this system, the peptide substrate (DEVD) of caspase 3 was linked to the AuNP surface by Au-S linkage. HRP was attached to the AuNP surface by means of a bridge formed by the streptavidin-biotin reaction. CRET occurred as a result of formation of AuNP-peptide-biotin-streptavidin-HRP complexes. The CL of luminol was significantly reduced, because of the quenching effect of AuNPs. The quenched CL was recovered after cleavage of DEVD by caspase 3, an enzyme involved in the apoptotic process. Experimental conditions were systematically investigated. Under the optimum conditions the increase of the CL signal was linearly dependent on caspase 3 concentration within the concentration range 25 pmol L(-1) to 800 pmol L(-1) and the detection limit of caspase 3 was as low as 20 pmol L(-1), one order of magnitude lower than for FRET sensors based on graphene oxides. Our method was successfully used to detect drug-induced apoptosis of cells. This approach is expected to be extended to other assays, i.e., using other enzymes, analytes, CL substances, and even other nanoparticles (e.g., quantum dots and graphene).

Enhancement effect on the chemiluminescence of acridinium esters under neutral conditions.

PubMed

Nakazono, Manabu; Nanbu, Shinkoh

2018-03-01

Enhancement effect on the chemiluminescence of acridinium ester derivatives under neutral conditions was investigated. Additions of phenols did not enhance the chemiluminescence intensities of acridinium ester derivatives in the presence of horseradish peroxidase and hydrogen peroxide. Additions of cetyltrimethylammonium bromide apparently enhanced the chemiluminescence intensities of phenyl 10-methyl-10λ 4 -acridine-9-carboxylate derivatives with electron-withdrawing groups at the 4-position of the phenyl group. In particular, the chemiluminescence intensity of 4-(trifluoromethyl)phenyl 10-methyl-10λ 4 -acridine-9-carboxylate trifluoromethanesulfonate salt was 5.5 times stronger in the presence of cetyltrimethylammonium bromide than in its absence at pH 7. The chemiluminescence intensity of 3,4-dicyano-phenyl 10-methyl-10λ 4 -acridine-9-carboxylate trifluoromethanesulfonate salt was 46 times stronger in the presence of cetyltrimethylammonium bromide at pH 7 than in its absence at pH 10. Copyright © 2017 John Wiley & Sons, Ltd.

A sensitive gold nanoparticles sensing platform based on resonance energy transfer for chemiluminescence light on detection of biomolecules.

PubMed

Qin, Guoxing; Zhao, Shulin; Huang, Yong; Jiang, Jing; Liu, Yi-Ming

2013-08-15

In this article, we report a gold nanoparticles (AuNPs) sensing platform based on chemiluminescence resonance energy transfer (CRET) for light on detection of biomolecules. In designing such a CRET-based biosensing platform, the aptamer was first covalently labeled with a chemiluminescent reagent, N-(4-aminobutyl)-N-ethylisoluminol (ABEI). The ABEI labeled aptamer was then hybridized with AuNPs functionalized ssDNA which was complementary to the aptamer, obtaining the aptasensor. The CRET between ABEI and AuNPs in the aptasensor led to the CL quenching of ABEI. In the presence of a target analyte, it formed a complex with aptamer, and released ABEI-aptamer from AuNPs surface that resulted in CL recovery of ABEI. To test this design, a thrombin (used as a model analyte) aptasensor was prepared and evaluated. The results indicate that the proposed approach is simple and provided a linear range of 50-550 pM for thrombin detection with a detection limit of 15 pM. This new methodology can be easily extended to assay other biomolecules by simply changing the recognition sequence with the substrate aptamer. Copyright © 2013 Elsevier B.V. All rights reserved.

A validated silver-nanoparticle-enhanced chemiluminescence method for the determination of citalopram in pharmaceutical preparations and human plasma.

PubMed

Khan, Muhammad Naeem; Jan, Muhammad Rasul; Shah, Jasmin; Lee, Sang Hak

2014-05-01

A simple and sensitive chemiluminescence (CL) method was developed for the determination of citalopram in pharmaceutical preparations and human plasma. The method is based on the enhancement of the weak CL signal of the luminol-H2 O2 system. It was found that the CL signal arising from the reaction between alkaline luminol and H2 O2 was greatly increased by the addition of silver nanoparticles in the presence of citalopram. Prepared silver nanoparticles (AgNPs) were characterized by UV-visible spectroscopy and transmission electron microscopy (TEM). Various experimental parameters affecting CL intensity were studied and optimized for the determination of citalopram. Under optimized experimental conditions, CL intensity was found to be proportional to the concentration of citalopram in the range 40-2500 ng/mL, with a correlation coefficient of 0.9997. The limit of detection (LOD) and limit of quantification (LOQ) of the devised method were 3.78 and 12.62 ng/mL, respectively. Furthermore, the developed method was found to have excellent reproducibility with a relative standard deviation (RSD) of 3.65% (n = 7). Potential interference by common excipients was also studied. The method was validated statistically using recovery studies and was successfully applied to the determination of citalopram in the pure form, in pharmaceutical preparations and in spiked human plasma samples. Percentage recoveries were found to range from 97.71 to 101.99% for the pure form, from 97.84 to 102.78% for pharmaceutical preparations and from 95.65 to 100.35% for spiked human plasma. Copyright © 2013 John Wiley & Sons, Ltd.

Flow-injection chemiluminescence determination of acetylsalicylic acid based on its enhancing effect on the lucigenin–hydrogen peroxide system.

PubMed

Wabaidur, S M; Alam, S M; Alothmana, Z A; Eldesokya, Gaber

2014-09-01

A sensitive flow-injection chemiluminescence method for the determination of acetylsalicylic acid is described. It is based on the enhanced chemiluminescent emission of the alkaline lucigenin–H2O2 system by acetylsalicylic acid. The difference in chemiluminescent intensity of alkaline lucigenin–H2O2 in the presence of acetylsalicylic acid from that in the absence of acetylsalicylic acid was linear at acetylsalicylic acid concentrations in the range of 0.0029–47.37 μg/mL, with detection and quantification limits of 0.0011 and 0.0029 μg/mL, respectively. The correlation coefficient of the working curve was 0.9983. The relative standard deviation (n = 10) for 25 μg/mL acetylsalicylic acid is 1.95%. All experimental parameters were optimized. The method was successfully applied to the determination of acetylsalicylic acid in pharmaceutical preparations. The recovery results obtained by the method were satisfactory.

Sensitive and selective determination of fluvoxamine maleate using a sensitive chemiluminescence system based on the alkaline permanganate-Rhodamine B-gold nanoparticles reaction.

PubMed

Hassanzadeh, Javad; Amjadi, Mohammad

2015-06-01

A high-yield chemiluminescence (CL) system based on the alkaline permanganate-Rhodamine B reaction was developed for the sensitive determination of fluvoxamine maleate (Flu). Rhodamine B is oxidized by alkaline KMnO4 and a weak CL emission is produced. It was demonstrated that gold nanoparticles greatly enhance this CL emission due to their interaction with Rhodamine B molecules. It is also observed that sodium dodecyl sulfate, an anionic surfactant, can strongly increase this enhancement. In addition, it was demonstrated that a notable decrease in the CL intensity is observed in the presence of Flu. This may be related to Flu oxidation with KMnO4 . There is a linear relationship between the decrease in CL intensity and the Flu concentration over a range of 2-300 µg/L. A new simple, rapid and sensitive CL method was developed for the determination of Flu with a detection limit (3s) of 1.35 µg/L. The proposed method was used for the determination of Flu in pharmaceutical and urine samples. Copyright © 2014 John Wiley & Sons, Ltd.

A novel luminol chemiluminescent method catalyzed by silver/gold alloy nanoparticles for determination of anticancer drug flutamide.

PubMed

Chaichi, Mohammad Javad; Azizi, Seyed Naser; Heidarpour, Maryam

2013-12-01

It was found that silver/gold alloy nanoparticles enhance the chemiluminescence (CL) of the luminol-H2O2 system in alkaline solution. The studies of UV-Vis spectra, CL spectra, effects of concentrations luminol, hydrogen peroxide and silver/gold alloy nanoparticles solutions were carried out to explore the CL enhancement mechanism. Flutamide was found to quench the CL signals of the luminol-H2O2 reaction catalyzed by silver/gold alloy nanoparticles, which made it applicable for the determination of flutamide. Under the optimum conditions, the CL intensity is proportional to the concentration of the flutamide in solution over the range 5.0 × 10(-7) to 1.0 × 10(-4)mol L(-1). Detection limit was obtained 1.2 × 10(-8)mol L(-1)and the relative standard deviation (RSD) γ5%. This work is introduced as a new method for the determination of flutamide in commercial tablets. Box-Behnken experimental design is applied to investigate and validate the CL measurement parameters. Copyright © 2013 Elsevier B.V. All rights reserved.

CdS/MoS2 heterojunction-based photoelectrochemical DNA biosensor via enhanced chemiluminescence excitation.

PubMed

Zang, Yang; Lei, Jianping; Hao, Qing; Ju, Huangxian

2016-03-15

This work developed a CdS/MoS2 heterojunction-based photoelectrochemical biosensor for sensitive detection of DNA under the enhanced chemiluminescence excitation of luminol catalyzed by hemin-DNA complex. The CdS/MoS2 photocathode was prepared by the stepwise assembly of MoS2 and CdS quantum dots (QDs) on indium tin oxide (ITO), and achieved about 280% increasing of photocurrent compared to pure CdS QDs electrode due to the formation of heterostructure. High photoconversion efficiency in the photoelectrochemical system was identified to be the rapid spatial charge separation of electron-hole pairs by the extension of electron transport time and electron lifetime. In the presence of target DNA, the catalytic hairpin assembly was triggered, and simultaneously the dual hemin-labeled DNA probe was introduced to capture DNA/CdS/MoS2 modified ITO electrode. Thus the chemiluminescence emission of luminol was enhanced via hemin-induced mimetic catalysis, leading to the physical light-free photoelectrochemical strategy. Under optimized conditions, the resulting photoelectrode was proportional to the logarithm of target DNA concentration in the range from 1 fM to 100 pM with a detection limit of 0.39 fM. Moreover, the cascade amplification biosensor demonstrated high selectivity, desirable stability and good reproducibility, showing great prospect in molecular diagnosis and bioanalysis. Copyright © 2015 Elsevier B.V. All rights reserved.

Chemiluminescence determination of terbutaline sulfate in bovine urine and pharmaceutical preparations based on enhancement of the 2-phenyl-4, 5-di (2-furyl) imidazole-potassium ferricyanide system.

PubMed

Han, Lu; Zhang, Yumin; Kang, Jing; Tang, Jieli; Zhang, Yihua

2012-01-25

In this paper, a novel chemiluminescence (CL) system, 2-phenyl-4, 5-di (2-furyl) imidazole (PDFI)-potassium ferricyanide, for the determination of terbutaline sulfate was described. The method was based on enhancement of CL emission of PDFI-potassium ferricyanide system in the presence of terbutaline sulfate. Under the optimum conditions, the enhanced chemiluminescence intensity is linearly related to the concentration of terbutaline sulfate. The proposed method has been successfully applied to the determination of terbutaline sulfate in bovine urine and pharmaceutical preparations with satisfactory results. Furthermore, the possible mechanism of chemiluminescence reaction was also discussed briefly. Copyright © 2011 Elsevier B.V. All rights reserved.

An enhanced chemiluminescence resonance energy transfer aptasensor based on rolling circle amplification and WS2 nanosheet for Staphylococcus aureus detection.

PubMed

Hao, Liling; Gu, Huajie; Duan, Nuo; Wu, Shijia; Ma, Xiaoyuan; Xia, Yu; Tao, Zui; Wang, Zhouping

2017-03-22

A chemiluminescence resonance energy transfer aptasensor was fabricated for the detection of Staphylococcus aureus (S. aureus) with Co 2+ enhanced N-(aminobutyl)-N-(ethylisoluminol) (ABEI) functional flowerlike gold nanoparticles (Co 2+ /ABEI-AuNFs) as donor and WS 2 nanosheet as acceptor. In the presence of S. aureus, rolling circle amplification (RCA) can be started. Partially complementary sequence of RCA product functional ABEI-AuNFs (cDNA-ABEI-AuNFs) were then annealed to multiple sites of the RCA product to form duplex complex. This complex is less adsorbed onto the WS 2 nanosheet, thus attenuating the quenching of ABEI-AuNFs chemiluminescence by WS 2 nanosheet. In the absence of target S. aureus (and hence the absence of RCA and duplex formation), the free cDNA-ABEI-AuNFs is completely adsorbed onto the WS 2 nanosheet and chemiluminescence quenching ensues. Under optimal conditions, the logarithmic correlation between the concentration of S. aureus and the CL signal was found to be linear within the range of 50 cfu/mL to 1.5 × 10 5  cfu/mL (R 2  = 0.9913). The limits of detection of the developed method were found to be 15 cfu/mL for S. aureus. The selectivity and the capability of the biosensor in meat samples were also studied. Therefore, this simple and easy operation method can be used to detect S. aureus with high sensitivity and specificity. Copyright © 2017 Elsevier B.V. All rights reserved.

Highly sensitive chemiluminescent aptasensor for detecting HBV infection based on rapid magnetic separation and double-functionalized gold nanoparticles.

PubMed

Xi, Zhijiang; Gong, Quan; Wang, Chao; Zheng, Bing

2018-06-21

Hepatitis B virus (HBV) infection is a major global public health problem and one of the leading causes of chronic liver disease. HBsAg is the first serological marker to appear in the blood and is the most important marker of HBV infection. Detection of HBsAg in serum samples is commonly carried out using an immunoassay such as an enzyme-linked immunosorbent assay (ELISA), which is complex to perform, time-consuming, and unsatisfactory for testing sensitivity. Therefore, new methods for highly sensitive detection of HBV infection are urgently needed. Aptamers are specific recognition molecules with high affinity and specificity toward their targets. Biosensors that employ aptamers as biorecognition elements are known as aptasensors. In this study, we select an HBsAg-specific aptamer and use it to develop a new chemiluminescent aptasensor based on rapid magnetic separation and double-functionalized gold nanoparticles. This sensor enables rapid magnetic separation and highly sensitive detection of HBsAg in HBV-positive serum. The detection limit of this HBsAg-detecting chemiluminescent aptasensor is as low as 0.05 ng/mL, which is much lower than the 0.5 ng/mL limit of a typical ELISA used in hospitals. Furthermore, this aptasensor works well and is highly specific to HBV infection.

A novel on-line gold nanoparticle-catalyzed luminol chemiluminescence detector for high-performance liquid chromatography.

PubMed

Zhang, Qun Lin; Wu, Liang; Lv, Chen; Zhang, Xiao Yue

2012-06-15

A novel on-line gold nanoparticle-catalyzed luminol-H(2)O(2) chemiluminescence (CL) detector for high-performance liquid chromatography (HPLC) was established, in which gold nanoparticles were produced by the on-line reaction of H(2)O(2), NaHCO(3)-Na(2)CO(3) (buffer solution of luminol), and HAuCl(4). Eight phenolic compounds (gallic acid, protocatechuic acid, protocatechuic aldehyde, 2,5-dihydroxybenzoic acid, caffeic acid, 2,3-dihydroxybenzoic acid, (+)-catechin, and (-)-epicatechin) were chosen as the model compounds. Every separated phenolic compound in the column eluent strongly enhanced the CL signal of on-line gold nanoparticle-catalyzed luminol system. The CL and UV-visible absorption spectra and transmission electron microscopy studies were carried out, and the CL enhancement mechanism was ascribed to that the presence of phenolic compound promoted the on-line formation of 38-nm-diameter gold nanoparticles, which better catalyzed the luminol-H(2)O(2) CL reaction. The effects of methanol and phosphoric acid in the proposed HPLC configuration were performed by two gradient elution programs, and the baseline profile revealed that on-line gold nanoparticle-catalyzed luminol-H(2)O(2) CL detector had better compatibility than 38 nm gold colloids-luminol-H(2)O(2) CL detector. The proposed CL detector exhibits excellent analytical performance with the low detection limit (S/N=3) of 0.53-0.97 ng/mL (10.6-19.4 pg) phenolic compounds, and offers a new strategy for developing on-line nanoparticle-catalyzed CL detector for HPLC with sensitive analysis. Copyright © 2012 Elsevier B.V. All rights reserved.

Enzyme immunoassays for IgG and IgM antibodies to Toxoplasma gondii based on enhanced chemiluminescence.

PubMed Central

Crouch, C F

1995-01-01

AIMS--To evaluate the clinical performance of enzyme immunoassays for IgG and IgM antibodies to Toxoplasma gondii based on enhanced chemiluminescence. METHODS--Classification of routine clinical samples from the originating laboratories was compared with that obtained using the chemiluminescence based assays. Resolution of discordant results was achieved by testing in alternative enzyme immunoassays (IgM) or by an independent laboratory using the dye test (IgG). RESULTS--Compared with resolved data, the IgM assay was found to be highly specific (100%) with a cut off selected to give optimal performance with respect to both the early detection of specific IgM and the detection of persistent levels of specific IgM (sensitivity 98%). Compared with resolved data, the IgG assay was shown to have a sensitivity and a specificity of 99.4%. CONCLUSIONS--The Amerlite Toxo IgM assay possesses high levels of sensitivity and specificity. Assay interference due to rheumatoid factor like substances is not a problem. The Amerlite Toxo IgG assay possesses good sensitivity and specificity, but is less sensitive for the detection of seroconversion than methods detecting both IgG and IgM. PMID:7560174

Chemiluminescent Diagnostics of Free-Radical Processes in an Abiotic System and in Liver Cells in the Presence of Nanoparticles Based on Rare-Earth Elements nReVO4:Eu3+ (Re = Gd, Y, La) and CeO2

NASA Astrophysics Data System (ADS)

Averchenko, E. A.; Kavok, N. S.; Klochkov, V. K.; Malyukin, Yu. V.

2014-11-01

We have used luminol-dependent chemiluminescence with Fenton's reagent to study the effect of nanoparticles based on rare-earth elements of different sizes and shapes on free-radical processes in abiotic and biotic cell-free systems, and also in isolated cells in vitro. We have estimated the effects of rare-earth orthovanadate nanoparticles of spherical (GdYVO4:Eu3+, 1-2 nm), spindle-shaped (GdVO4:Eu3+, 25 ×8 nm), and rod-shaped (LaVO4:Eu3+, 57 × (6-8) nm) nanoparticles and spherical CeO2 nanoparticles (sizes 1-2 nm and 8-10 nm). We have shown that in contrast to the abiotic system, in which all types of nanoparticles exhibit antiradical activity, in the presence of biological material, extra-small spherical (1-2 nm) nanoparticles of both types exhibit pro-oxidant activity, and also enhance pro-oxidant induced oxidative stress (for the pro-oxidants hydrogen peroxide and tert-butyl hydroperoxide). The effect of rare-earth orthovanadate spindle and rod shaped nanoparticles in this system was neutral; a moderate antioxidant effect was exhibited by 8-10 nm CeO2 nanoparticles.

Introducing novel amorphous carbon nanoparticles as energy acceptors into a chemiluminescence resonance energy transfer immunoassay system.

PubMed

Wang, Zhenxing; Gao, Hongfei; Fu, Zhifeng

2013-11-21

A novel chemiluminescence resonance energy transfer (CRET) system for competitive immunoassay of biomolecules was developed by using novel amorphous carbon nanoparticles (CNPs) prepared from candle soot as energy acceptors. The CNPs were firstly prepared to bind with the antigen (Ag) for obtaining the nanocomposite CNP-Ag, and this obtained CNP-Ag was then reacted with the horseradish peroxidase-labeled antibody (HRP-Ab) to assemble the CRET system. The luminol catalyzed by HRP serving as the energy donor for CNPs triggered the CRET phenomenon between luminol and CNPs, which led to the chemiluminescence signal decrease. Due to the competitive immunoreaction of the target antigen and the CNP-Ag, a part of the CNP-Ag was replaced from the HRP-Ab, and then resulted in a weaker interaction between luminol and CNPs. Thus the competitive immunoreaction led to a higher chemiluminescence emission. This CNP-based CRET system was successfully applied to detect the human IgG as a model analyte, and a linear range of 10-200 ng mL(-1) and a detection limit of 1.9 ng mL(-1) (S/N = 3) were obtained. The results for real sample analysis demonstrated its application potential in some important areas such as clinical diagnosis.

The investigation of photo-induced chemiluminescence on Co2+-doped TiO2 nanoparticles and its analytical application.

PubMed

Li, Guixin; Nan, Hongyan; Zheng, Xingwang

2009-07-01

A novel space- and time-resolved photo-induced chemiluminescence (PICL) analytical method was developed based on the photocatalysis of the Co2+-doped TiO2 nanoparticles. The PICL reaction procedure under the photocatalysis of Co2+-doped TiO2 nanoparticles was investigated using cyclic voltammetry and potentiometry. Meanwhile, the effect of the electrical double layer outside the Co2+-doped TiO2 nanoparticles on the PICL was investigated by contrasting with the Co2+-doped TiO2-SiO2 core-shell nanoparticles. Significantly, the CL intensity increased apparently and the time of the CL was prolonged in the presence of procaterol hydrochloride because the mechanism of the enhanced PICL reaction may be modified. The route of the PICL was changed due to the participation of the procaterol hydrochloride enriched at the surface of the Co2+-doped TiO2-SiO2 in the PICL reaction, which prolonged the time of the CL reaction and resulted in the long-term PICL. The analytical characteristics of the proposed in-situ PICL method were investigated using the procaterol hydrochloride as the model analyte. The investigation results showed that this new PICL analytical method offered higher sensitivity to the analysis of the procaterol hydrochloride and the PICL intensity was linear with the concentration of the procaterol hydrochloride in the range from ca. 2.0 x 10(-10) to 1.0 x 10(-8) g mL(-1).

Study on Enhancement Principle and Stabilization for the Luminol-H2O2-HRP Chemiluminescence System

PubMed Central

Yang, Lihua; Jin, Maojun; Du, Pengfei; Chen, Ge; Zhang, Chan; Wang, Jian; Jin, Fen; Shao, Hua; She, Yongxin; Wang, Shanshan; Zheng, Lufei; Wang, Jing

2015-01-01

A luminol-H2O2-HRP chemiluminescence system with high relative luminescent intensity (RLU) and long stabilization time was investigated. First, the comparative study on the enhancement effect of ten compounds as enhancers to the luminol-H2O2-HRP chemiluminescence system was carried out, and the results showed that 4-(imidazol-1-yl)phenol (4-IMP), 4-iodophenol (4-IOP), 4-bromophenol (4-BOP) and 4-hydroxy-4’-iodobiphenyl (HIOP) had the best performance. Based on the experiment, the four enhancers were dissolved in acetone, acetonitrile, methanol, and dimethylformamide (DMF) with various concentrations, the results indicated that 4-IMP, 4-IOP, 4-BOP and HIOP dissolved in DMF with the concentrations of 0.2%, 3.2%, 1.6% and 3.2% could get the highest RLU values. Subsequently, the influences of pH, ionic strength, HRP, 4-IMP, 4-IOP, 4-BOP, HIOP, H2O2 and luminol on the stabilization of the luminol-H2O2-HRP chemiluminescence system were studied, and we found that pH value, ionic strength, 4-IMP, 4-IOP, 4-BOP, HIOP, H2O2 and luminol have little influence on luminescent stabilization, while HRP has a great influence. In different ranges of HRP concentration, different enhancers should be selected. When the concentration is within the range of 0~6 ng/mL, 4-IMP should be selected. When the concentration of HRP ranges from 6 to 25ng/mL, 4-IOP was the best choice. And when the concentration is within the range of 25~80 ng/mL, HIOP should be selected as the enhancer. Finally, the three well-performing chemiluminescent enhanced solutions (CESs) have been further optimized according to the three enhancers (4-IMP, 4-IOP and HIOP) in their utilized HRP concentration ranges. PMID:26154162

Study on Enhancement Principle and Stabilization for the Luminol-H2O2-HRP Chemiluminescence System.

PubMed

Yang, Lihua; Jin, Maojun; Du, Pengfei; Chen, Ge; Zhang, Chan; Wang, Jian; Jin, Fen; Shao, Hua; She, Yongxin; Wang, Shanshan; Zheng, Lufei; Wang, Jing

2015-01-01

A luminol-H2O2-HRP chemiluminescence system with high relative luminescent intensity (RLU) and long stabilization time was investigated. First, the comparative study on the enhancement effect of ten compounds as enhancers to the luminol-H2O2-HRP chemiluminescence system was carried out, and the results showed that 4-(imidazol-1-yl)phenol (4-IMP), 4-iodophenol (4-IOP), 4-bromophenol (4-BOP) and 4-hydroxy-4'-iodobiphenyl (HIOP) had the best performance. Based on the experiment, the four enhancers were dissolved in acetone, acetonitrile, methanol, and dimethylformamide (DMF) with various concentrations, the results indicated that 4-IMP, 4-IOP, 4-BOP and HIOP dissolved in DMF with the concentrations of 0.2%, 3.2%, 1.6% and 3.2% could get the highest RLU values. Subsequently, the influences of pH, ionic strength, HRP, 4-IMP, 4-IOP, 4-BOP, HIOP, H2O2 and luminol on the stabilization of the luminol-H2O2-HRP chemiluminescence system were studied, and we found that pH value, ionic strength, 4-IMP, 4-IOP, 4-BOP, HIOP, H2O2 and luminol have little influence on luminescent stabilization, while HRP has a great influence. In different ranges of HRP concentration, different enhancers should be selected. When the concentration is within the range of 0~6 ng/mL, 4-IMP should be selected. When the concentration of HRP ranges from 6 to 25 ng/mL, 4-IOP was the best choice. And when the concentration is within the range of 25~80 ng/mL, HIOP should be selected as the enhancer. Finally, the three well-performing chemiluminescent enhanced solutions (CESs) have been further optimized according to the three enhancers (4-IMP, 4-IOP and HIOP) in their utilized HRP concentration ranges.

Enhancing and inhibiting effects of aromatic compounds on luminol-dimethylsulfoxide-OH(-) chemiluminescence and determination of intermediates in oxidative hair dyes by HPLC with chemiluminescence detection.

PubMed

Zhou, Jian; Xu, Hong; Wan, Guo-Hui; Duan, Chun-Feng; Cui, Hua

2004-10-08

The effect of 36 aromatic compounds on the luminol-dimethylsulfoxide-OH(-) chemiluminescence (CL) was systematically studied. It was found that dihydroxybenzenes, and ortho- and para-substituted aminophenols and phenylenediamines inhibited the CL and phenols with three or more than three hydroxyls except phloroglucin tended to enhance the CL. The CL inhibition and enhancement was proposed to be dependent on whether superoxide anion radical (O(2)(-)) was competitively consumed by compounds in the CL system. Trihydroxybenzenes were capable of generating superoxide anion radical, leading to the CL enhancement, whereas dihydroxybenzenes were superoxide anion radical scavenger, causing the CL inhibition. Based on the inhibited CL, a novel method for the simultaneous determination of p-phenylenediamine, o-phenylenediamine, p-aminophenol, o-aminophenol, resorcinol and hydroquinone by high-performance liquid chromatography coupled with chemiluminescence detection was developed. The method has been successfully applied to determine intermediates in oxidative hair dyes and wastewater of shampooing after hair dyed.

Chemiluminescence behaviour of CdTe-potassium permanganate enhanced by sodium hexametaphosphate and sensitized sensing of L-ascorbic acid.

PubMed

Chen, Hongqi; Ling, Bo; Yuan, Fei; Zhou, Cailing; Chen, Jingguo; Wang, Lun

2012-01-01

A highly sensitive flow-injection chemiluminescence (FIA-CL) method based on the CdTe nanocrystals and potassium permanganate chemiluminescence system was developed for the determination of L-ascorbic acid. It was found that sodium hexametaphosphate (SP), as an enhancer, could increase the chemiluminescence (CL) emission from the redox reaction of CdTe quantum dots with potassium permanganate in near-neutral pH conditions. L-ascorbic acid is suggested as a sensitive enhancer for use in the above energy-transfer excitation process. Under optimal conditions, the calibration graph of emission intensity against logarithmic l-ascorbic acid concentration was linear in the range 1.0 × 10(-9)-5.0 × 10(-6)  mol/L, with a correlation coefficient of 0.9969 and relative standard deviation (RSD) of 2.3% (n = 7) at 5.0 × 10(-7)  mol/L. The method was successfully used to determine L-ascorbic acid in vitamin C tablets. The possible mechanism of the chemiluminescence in the system is also discussed. Copyright © 2012 John Wiley & Sons, Ltd.

Determination of Montelukast in Plasma Using β - Cyclodextrins Coated on CoFe2O4 Magnetic Nanoparticles in Luminol-H2O2 Chemiluminescence System Optimized by Doehlert Design.

PubMed

Samadi-Maybodi, Abdolraouf; Bakhtiar, Alireza; Fatemi, Mohammad Hossein

2016-05-01

A novel chemiluminescence method using β - cyclodextrins coated on CoFe2O4 magnetic nanoparticles is proposed for the chemiluminometric determination of montelukast in plasma. The effect of coated β - cyclodexterinon CoFe2O4 magnetic nanoparticles in the chemiluminescence of luminol-H2O2 system was investigated. It was found that β - cyclodexterin coated on CoFe2O4 magnetic nanoparticles could greatly enhance the chemiluminescence of the luminol-H2O2 system. Doehlert design was applied in order to optimize the number of experiments to be carried out to ascertain the possible interactions between the parameters and their effects on the chemiluminescence emission intensity. This design was selected because the levels of each variable may vary in a very efficient way with few experiments. Doehlert design and response surface methodology have been employed for optimization pH and concentrations of the components. Results showed under the optimized experimental conditions, the relative CL intensity (ΔI) is increased linearly in the concentration range of 0.003-0.586 μgml(-1) of montelukast with limit of detection (LOD) 1.09 × 10(-4) μgml(-1) at S/N ratio of 3, limit of quantitative (LOQ) 3.59 × 10(-4) μgml(-1) and the relative standard deviation 2.63 %. The method has been successfully applied to the determination of montelukast in plasma of human body. Results specified that relative chemiluminescence intensity (ΔI) has good proportional with the montelukast concentration with R(2) = 0.99979. The test of the recovery efficiency for known amounts of montelukast was also performed, the recoveries range obtained from 98.2 to 103.3 %, with RSDs of <4 % indicated that the proposed method was reliable.

Improved sensitivity via layered-double-hydroxide-uniformity-dependent chemiluminescence.

PubMed

Li, Zenghe; Wang, Dan; Yuan, Zhiqin; Lu, Chao

2016-12-01

In the last two decades nanoparticles have been widely applied to enhance chemiluminescence (CL). The morphology of nanoparticles has an important influence on nanoparticle-amplified CL. However, studies of nanoparticle-amplified CL focus mainly on the size and shape effects, and no attempt has been made to explore the influence of uniformity in nanoparticle-amplified CL processes. In this study we have investigated nanoparticle uniformity in the luminol-H 2 O 2 CL system using layered double hydroxides (LDHs) as a model material. The results demonstrated that the uniformity of LDHs played a key role in CL amplification. A possible mechanism is that LDHs with high uniformity possess abundant catalytic active sites, which results in high CL intensity. Meanwhile, the sensitivity for H 2 O 2 detection was increased by one order of magnitude (1.0 nM). Moreover, the uniform-LDH-amplified luminol CL could be applied to selective detection of glucose in human plasma samples. Furthermore, such a uniformity-dependent CL enhancement effect could adapted to other redox CL systems-for example, the peroxynitrous acid (ONOOH) CL system.

Synthesis of dendritic platinum nanoparticles/lucigenin/reduced graphene oxide hybrid with chemiluminescence activity.

PubMed

He, Yi; Cui, Hua

2012-04-16

Multifunctional hybrid: A dendritic platinum nanoparticle/lucigenin/reduced graphene oxide (RGO) hybrid with chemiluminescence (CL) activity was prepared for the first time by using lucigenin as a linker through simultaneous reduction of H(2) PtCl(4) and a lucigenin-functionalized graphene oxide composite by sodium borohydride (see scheme). The hybrid may have potential applications as a CL sensor, in catalysis, energy conversion, and opto-electronic systems. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Application of silver nanoparticles to the chemiluminescence determination of cefditoren pivoxil using the luminol-ferricyanide system.

PubMed

Alarfaj, Nawal A; Aly, Fatma A; El-Tohamy, Maha F

2015-02-01

A new simple, accurate and sensitive sequential injection analysis chemiluminescence (CL) detection method for the determination of cefditoren pivoxil (CTP) has been developed. The developed method was based on the enhancement effect of silver nanoparticles on the CL signal arising from a luminol-potassium ferricyanide reaction in the presence of CTP. The optimum conditions relevant to the effect of luminol, potassium ferricyanide and silver nanoparticle concentrations were investigated. The proposed method showed linear relationships between relative CL intensity and the investigated drug concentration at the range 0.001-5000 ng/mL, (r = 0.9998, n = 12) with a detection limit of 0.5 pg/mL and quantification limit of 0.001 ng/mL. The relative standard deviation was 1.6%. The proposed method was employed for the determination of CTP in bulk drug, in its pharmaceutical dosage forms and biological fluids such as human serum and urine. The interference of some common additive compounds such as glucose, lactose, starch, talc and magnesium stearate was investigated. In addition, the interference of some related cephalosporins was tested. No interference was recorded. The obtained sequential injection analysis-CL results were statistically compared with those from a reported method and did not show any significant differences. Copyright © 2014 John Wiley & Sons, Ltd.

A highly sensitive detection of chloramphenicol based on chemiluminescence immunoassays with the cheap functionalized Fe3 O4 @SiO2 magnetic nanoparticles.

PubMed

Linyu, Wang; Manwen, Yao; Chengzhi, Fang; Xi, Yao

2017-09-01

A strategy has been applied to chloramphenicol (CAP) detection with chemiluminescence immunoassays (CLIA) based on cheap functionalized Fe 3 O 4 @SiO 2 magnetic nanoparticles (Fe-MNPs). The strategy that bovine serum albumin (BSA) was immobilized on cheap functionalized Fe-MNPs and that the CAP molecules were then immobilized on BSA, avoided the long process of dialysis for preparation of the BSA-CAP conjugates. The samples were detected for both methods that utilized two different kinds of functionalized Fe-MNPs (amine-functionalized Fe 3 O 4 @SiO 2 and carboxylic acid-functionalized Fe 3 O 4 @SiO 2 ). The sensitivities and limits of detection (LODs) of the two methods were obtained and compared based on inhibition curves. The 50% inhibition concentrations (IC 50 ) values of the two methods were about 0.024 ng ml -1 and 0.046 ng ml -1 respectively and LODs were approximately 0.0002 ng ml -1 and 0.001 ng ml -1 respectively. These methods were much more sensitive than that of any traditional enzyme-linked immunosorbent assay (ELISA) previously reported. Therefore, such chemiluminescence methods could be easily adapted for small molecule detection in a variety of foods using Fe-MNPs. Copyright © 2017 John Wiley & Sons, Ltd.

An ultrasensitive chemiluminescence immunoassay for fumonisin B1 detection in cereals based on gold-coated magnetic nanoparticles.

PubMed

Jie, Mingsha; Yu, Songcheng; Yu, Fei; Liu, Lie; He, Leiliang; Li, Yanqiang; Zhang, Hongquan; Qu, Lingbo; Harrington, Peter de B; Wu, Yongjun

2018-07-01

In the present study, a novel highly sensitive magnetic enzyme chemiluminescence immunoassay (MECLIA) was developed to detect fumonisin B 1 (FB 1 ) in cereal samples. The gold-coated magnetic nanoparticles (Fe 3 O 4 @Au, GoldMag) were used as solid phase carrier to develop a competitive CLIA for detecting FB 1 , in which FB 1 in samples would compete with FB 1 -ovalbumin coated on the surface of Fe 3 O 4 @Au nanoparticles for binding with FB 1 antibodies. Successively, horseradish peroxidase labeled goat anti-rabbit IgG (HRP-IgG) was conjugated with FB 1 antibodies on the microplate. In substrate solution containing luminol and H 2 O 2 , HRP-IgG catalyzed luminol oxidation by H 2 O 2 , generating a high chemiluminescence signal. The FB 1 immune GoldMag particles were characterized by Fourier transform infrared spectroscopy, scanning electron microscope and zeta potential analysis, etc. RESULTS: The concentrations and the reaction times of these immunoreagents were optimized to improve the performances of this method. The established method could detect as low as 0.027 ng mL -1 FB 1 from 0.05 ng mL -1 to 25 ng mL -1 , demonstrating little cross-reaction (less than 2.4%) with other structurally related compounds. The average intrassay relative SD (RSD) (n = 6) was 3.4% and the average interassay RSD (n = 6) was 5.4%. This method was successfully applied for the determination of FB 1 in corn and wheat and gave recoveries of between 98-110% and 91-105%, respectively. The results of the present study suggest that the MECLIA approach has potential application for high-throughput fumonisin screening in cereals. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

Amorphous carbon nanoparticle used as novel resonance energy transfer acceptor for chemiluminescent immunoassay of transferrin.

PubMed

Gao, Hongfei; Wang, Wenwen; Wang, Zhenxing; Han, Jing; Fu, Zhifeng

2014-03-28

Amorphous carbon nanoparticles (ACNPs) showing highly efficient quenching of chemiluminescence (CL) were prepared from candle soot with a very simple protocol. The prepared ACNP was employed as the novel energy acceptor for a chemiluminescence resonance energy transfer (CRET)-based immunoassay. In this work, ACNP was linked with transferrin (TRF), and horseradish peroxidase (HRP) was conjugated to TRF antibody (HRP-anti-TRF). The immunoreaction rendered the distance between the ACNP acceptor and the HRP-catalyzed CL emitter to be short enough for CRET occurring. In the presence of TRF, this antigen competed with ACNP-TRF for HRP-anti-TRF, thus led to the decreased occurrence of CRET. A linear range of 20-400 ng mL(-1) and a limit of detection of 20 ng mL(-1) were obtained in this immunoassay. The proposed method was successfully applied for detection of TRF levels in human sera, and the results were in good agreement with ELISA method. Moreover, the ACNPs show higher energy transfer efficiency than other conventional nano-scaled energy acceptors such as graphene oxide in CRET assay. It is anticipated that this approach can be developed for determination of other analytes with low cost, simple manipulation and high specificity. Copyright © 2014 Elsevier Ltd. All rights reserved.

Graphene-based chemiluminescence resonance energy transfer for homogeneous immunoassay.

PubMed

Lee, Joon Seok; Joung, Hyou-Arm; Kim, Min-Gon; Park, Chan Beum

2012-04-24

We report on chemiluminescence resonance energy transfer (CRET) between graphene nanosheets and chemiluminescent donors. In contrast to fluorescence resonance energy transfer, CRET occurs via nonradiative dipole-dipole transfer of energy from a chemiluminescent donor to a suitable acceptor molecule without an external excitation source. We designed a graphene-based CRET platform for homogeneous immunoassay of C-reactive protein (CRP), a key marker for human inflammation and cardiovascular diseases, using a luminol/hydrogen peroxide chemiluminescence (CL) reaction catalyzed by horseradish peroxidase. According to our results, anti-CRP antibody conjugated to graphene nanosheets enabled the capture of CRP at the concentration above 1.6 ng mL(-1). In the CRET platform, graphene played a key role as an energy acceptor, which was more efficient than graphene oxide, while luminol served as a donor to graphene, triggering the CRET phenomenon between luminol and graphene. The graphene-based CRET platform was successfully applied to the detection of CRP in human serum samples in the range observed during acute inflammatory stress.

A kinetic study of the enhancement of solution chemiluminescence of glyoxylic acid oxidation by manganese species.

PubMed

Otamonga, Jean-Paul; Abdel-Mageed, Amal; Agater, Irena B; Jewsbury, Roger A

2015-08-01

In order to study the mechanism of the enhancement of solution chemiluminescence, the kinetics of the decay of the oxidant and the chemiluminescence emission were followed for oxidations by permanganate, manganese dioxide sol and Mn(3+) (aq) of glyoxylic acid, using stopped-flow spectrophotometry. Results are reported for the glyoxylic acid oxidized under pseudo first-order conditions and in an acidic medium at 25 °C. For permanganate under these conditions, the decay is sigmoidal, consistent with autocatalysis, and for manganese dioxide sol and Mn(3+) it is pseudo first order. The effects of the presence of aqueous formaldehyde and Mn(2+) were observed and a fit to a simple mechanism is discussed. It is concluded that chemiluminescent enhancement in these systems is best explained by reaction kinetics. Copyright © 2014 John Wiley & Sons, Ltd.

Subnanogram determination of aniracetam in pharmaceutical preparations and biofluids by flow injection analysis with chemiluminescence detection based on its enhancement of the myoglobin-luminol reaction.

PubMed

Shao, Xiaodong; Li, Ying; Li, Fagen; Liu, Yangqin; Song, Zhenghua

2011-01-01

A novel flow injection chemiluminescence method with a myoglobin-luminol system is described for determining aniracetam. Myoglobin-bound aniracetam produced a complex that catalyzed the chemiluminescence reaction between luminol and myoglobin, leading to fast chemiluminescence. The chemiluminescence intensity in the presence of aniracetam was remarkably enhanced compared with that in the absence of aniracetam. Under the optimum reaction conditions the chemiluminescence increment produced was proportional to the concentration of aniracetam in the range of 0.1-1000.0 ng/mL (R2 = 0.9992), with a detection limit of 0.03 ng/mL (3delta). At a flow rate of 2.0 mL/min, the whole process, including sampling and washing, could be completed in 0.5 min, offering a sampling efficiency of 120/h; the RSD was less than 3.0% (n = 5). The method was satisfactory for determination of aniracetam in pharmaceutical preparations and human urine and serum samples. A possible mechanism of the reaction is also discussed.

Chemiluminescence microfluidic system of gold nanoparticles enhanced luminol-silver nitrate for the determination of vitamin B12.

PubMed

Kamruzzaman, Mohammad; Alam, Al-Mahmnur; Kim, Kyung Min; Lee, Sang Hak; Kim, Young Ho; Kabir, A N M Hamidul; Kim, Gyu-Man; Dang, Trung Dung

2013-02-01

A rapid and sensitive chemiluminescence (CL) system coupled with a microfluidic chip has been presented to determine vitamin B12 (VB12) based on the reaction of luminol and silver nitrate (AgNO(3)) in the presence of gold nanoparticles (AuNPs). A microfluidic chip was fabricated by a soft-lithographic procedure using polydimethyl siloxane (PDMS) having four inlets and one outlet with a 200 μm wide, 250 μm deep, and 100 mm long microchannel. Ag(+) was used as a chemiluminogenic oxidant in this CL reaction which oxidized luminol to produce strong CL signal in the presence of AuNPs. Luminol reacted with AgNO(3) under the catalysis of AuNPs to produce luminol radicals which reacted with dissolved oxygen and emitted CL light. The proposed CL system was applied to determine the amount of VB12 in VB12 tablets and multivitamin. Under the optimum conditions, the CL intensity of the system was increased with the concentration of VB12 in the range of 0.25-100 ng mL(-1) with the correlation coefficient of 0.9982. The limit of detection was found to be 0.04 ng mL(-1) with the relative standard deviation of 1.56 % for five replicate determinations of 25 ng mL(-1) of VB12. The CL reaction mechanism was demonstrated by UV-visible spectra and CL emission spectra.

Effect of gold nanoparticle as a novel nanocatalyst on luminol-hydrazine chemiluminescence system and its analytical application.

PubMed

Safavi, A; Absalan, G; Bamdad, F

2008-03-10

In this work the catalytic role of unsupported gold nanoparticles on the luminol-hydrazine reaction is investigated. Gold nanoparticles catalyze the reaction of hydrazine and dissolved oxygen to generate hydrogen peroxide and also catalyze the oxidation of luminol by the produced hydrogen peroxide. The result is an intense chemiluminescence (CL) due to the excited 3-aminophthalate anion. In the absence of gold nanoparticles no detectable CL was observed by the reaction of luminol and hydrazine unless an external oxidant is present in the system. The size effect of gold nanoparticles on the CL intensity was investigated. The most intensive CL signals were obtained with 15-nm gold nanoparticles. UV-vis spectra and transmission electron microscopy studies were used to investigate the CL mechanism. The luminol and hydroxide ion concentration, gold nanoparticles size and flow rate were optimized. The proposed method was successfully applied to the determination of hydrazine in boiler feed water samples. Between 0.1 and 30 microM of hydrazine could be determined with a detection limit of 30 nM.

Metal-enhanced chemiluminescence from chromium, copper, nickel, and zinc nanodeposits: Evidence for a second enhancement mechanism in metal-enhanced fluorescence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weisenberg, Micah; Zhang Yongxia; Geddes, Chris D.

Over the past decade metal-fluorophore interactions, metal-enhanced fluorescence, have attracted significant research attention, with the technology now becoming common place in life science applications. In this paper, we address the underlying mechanisms of metal-enhanced fluorescence (MEF) and experimentally show using chemiluminescence solutions that MEF is indeed underpinned by two complimentary mechanisms, consistent with the recent reports by Geddes and co-workers [Zhang et al., J. Phys. Chem. C 113, 12095 (2009)] and their enhanced fluorescence hypothesis.

Developments and Applications of Electrogenerated Chemiluminescence Sensors Based on Micro- and Nanomaterials

PubMed Central

Hazelton, Sandra G.; Zheng, Xingwang; Zhao, Julia Xiaojun; Pierce, David T.

2008-01-01

A variety of recent developments and applications of electrogenerated chemiluminescence (ECL) for sensors are described. While tris(2,2′-bipyridyl)-ruthenium(II) and luminol have dominated and continue to pervade the field of ECL-based sensors, recent work has focused on use of these lumophores with micro- and nanomaterials. It has also extended to inherently luminescent nanomaterials, such as quantum dots. Sensor configurations including microelectrode arrays and microfluidics are reviewed and, with the recent trend toward increased use of nanomaterials, special attention has been given to sensors which include thin films, nanoparticles and nanotubes. Applications of ECL labels and examples of label-free sensing that incorporate nanomaterials are also discussed. PMID:27873850

Flow-based analysis using microfluidics-chemiluminescence systems.

PubMed

Al Lawati, Haider A J

2013-01-01

This review will discuss various approaches and techniques in which analysis using microfluidics-chemiluminescence systems (MF-CL) has been reported. A variety of applications is examined, including environmental, pharmaceutical, biological, food and herbal analysis. Reported uses of CL reagents, sample introduction techniques, sample pretreatment methods, CL signal enhancement and detection systems are discussed. A hydrodynamic pumping system is predominately used for these applications. However, several reports are available in which electro-osmotic (EO) pumping has been implemented. Various sample pretreatment methods have been used, including liquid-liquid extraction, solid-phase extraction and molecularly imprinted polymers. A wide range of innovative techniques has been reported for CL signal enhancement. Most of these techniques are based on enhancement of the mixing process in the microfluidics channels, which leads to enhancement of the CL signal. However, other techniques are also reported, such as mirror reaction, liquid core waveguide, on-line pre-derivatization and the use of an opaque white chip with a thin transparent seal. Photodetectors are the most commonly used detectors; however, other detection systems have also been used, including integrated electrochemiluminescence (ECL) and organic photodiodes (OPDs). Copyright © 2012 John Wiley & Sons, Ltd.

Label-free immunosensor based on gold nanoparticle silver enhancement.

PubMed

Yang, Minghui; Wang, Cunchang

2009-02-01

A label-free immunosensor for the sensitive detection of human immunoglobulin G (IgG) was prepared based on gold nanoparticle-silver enhancement detection with a simple charge-coupled device (CCD) detector. The gold nanoparticles, which were used as nuclei for the deposit of metallic silver and also for the adsorption of antibodies, were immobilized into wells of a 9-well chip. With the addition of silver enhancement buffer, metallic silver will deposit onto gold nanoparticles, causing darkness that can be optically measured by the CCD camera and quantified using ImageJ software. When antibody was immobilized onto the gold nanoparticles and antigen was captured, the formed immunocomplex resulted in a decrease of the darkness and the intensity of the darkness was in line with IgG concentrations from 0.05 to 10 ng/ml. The CCD detector is simple and portable, and the reported method has many desirable merits such as sensitivity and accuracy, making it a promising technique for protein detection.

Recent advances and developments on integrating nanotechnology with chemiluminescence assays.

PubMed

Tiwari, Ashish; Dhoble, S J

2018-04-01

Chemiluminescence (CL) techniques are extensively utilized for detection of analytes due to their high sensitivity, rapidity and selectivity. With the advent of nanotechnology and incorporation of the nanoparticles in the CL system has revolutionized the assays due to their unique optical and mechanical properties. Several CL-based reactions have been developed where these nanoparticle based CL sensors have evolved as excellent prospects for sensing in various analytical applications. This review article addresses the nanoparticles based CL detection system that are recently developed, the mechanisms has been summarized and the role of luminophors have been discussed. This article critically analyzes the optimal conditions for the CL detection along with quantitative assessment of the analytes. We have included the use of semiconductor nanoparticles, metal nanoparticles, graphene based nanostructures, mesoporous nanospheres, layered double hydroxides, clays for CL detection. The scope and application of these nanoscale material based CL system in various branches of science and technology including chemistry, biomedical applications, pharmaceutics, food, environmental and toxicological applications has been critically summarized. Copyright © 2017 Elsevier B.V. All rights reserved.

Enhanced chemiluminescence of cerium(IV)-Tween 85 system and the analytical application.

PubMed

Li, Shifeng; Qian, Li; Zhu, Yan; Liu, Manman; Gao, Yinping; Ni, Yonghong

2013-01-01

The oxidation reaction between cerium(IV) and Tween 85 in sulfuric acid medium produced weak chemiluminescence (CL). In this paper, it was found that citrate could strongly enhance the CL of cerium(IV)-Tween 85-polyphenol system. Based on studies of ultraviolet-visible spectra and CL spectra, the CL enhancement mechanism had been proposed. It was surmised that the light emission was from an excited oxygen molecular pair O2((1)Δg)O2((1)∑g(-)). The maximum emission wavelength was about 478 nm. The effects of 17 amino acids and 29 organic compounds on cerium(IV)-Tween 85-citrate CL were investigated by a flow injection procedure. This study showed the present system had a wide application for the determination of these compounds. Copyright © 2012 John Wiley & Sons, Ltd.

Simultaneous Determination of Size and Quantification of Gold Nanoparticles by Direct Coupling Thin layer Chromatography with Catalyzed Luminol Chemiluminescence

PubMed Central

Yan, Neng; Zhu, Zhenli; He, Dong; Jin, Lanlan; Zheng, Hongtao; Hu, Shenghong

2016-01-01

The increasing use of metal-based nanoparticle products has raised concerns in particular for the aquatic environment and thus the quantification of such nanomaterials released from products should be determined to assess their environmental risks. In this study, a simple, rapid and sensitive method for the determination of size and mass concentration of gold nanoparticles (AuNPs) in aqueous suspension was established by direct coupling of thin layer chromatography (TLC) with catalyzed luminol-H2O2 chemiluminescence (CL) detection. For this purpose, a moving stage was constructed to scan the chemiluminescence signal from TLC separated AuNPs. The proposed TLC-CL method allows the quantification of differently sized AuNPs (13 nm, 41 nm and 100 nm) contained in a mixture. Various experimental parameters affecting the characterization of AuNPs, such as the concentration of H2O2, the concentration and pH of the luminol solution, and the size of the spectrometer aperture were investigated. Under optimal conditions, the detection limits for AuNP size fractions of 13 nm, 41 nm and 100 nm were 38.4 μg L−1, 35.9 μg L−1 and 39.6 μg L−1, with repeatabilities (RSD, n = 7) of 7.3%, 6.9% and 8.1% respectively for 10 mg L−1 samples. The proposed method was successfully applied to the characterization of AuNP size and concentration in aqueous test samples. PMID:27080702

Chemiluminescent Detection for Estimating Relative Copy Numbers of Porcine Endogenous Retrovirus Proviruses from Chinese Minipigs Based on Magnetic Nanoparticles.

PubMed

Yang, Haowen; Liu, Ming; Zhou, Bingcong; Deng, Yan; He, Nongyue; Jiang, Hesheng; Guo, Yafen; Lan, Ganqiu; Jiang, Qinyang; Yang, Xiurong; Li, Zhiyang

2016-06-01

Chinese Bama minipigs could be potential donors for the supply of xenografts because they are genetically stable, highly inbred, and inexpensive. However, porcine endogenous retrovirus (PERV) is commonly integrated in pig genomes and could cause a cross-species infection by xenotransplantation. For screening out the pigs with low copy numbers of PERV proviruses, we have developed a novel semiquantitative analysis approach based on magnetic nanoparticles (MNPs) and chemiluminescence (CL) for estimating relative copy numbers (RCNs) of PERV proviruses in Chinese Bama minipigs. The CL intensities of PERV proviruses and the housekeeping gene glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were respectively determined with this method, and the RCNs of PERV proviruses were calculated by the equation: RCN of PERV provirus = CL intensity of PERV provirus/CL intensity of GAPDH. The results showed that PERVs were integrated in the genomes of Bama minipigs at different copy numbers, and the copy numbers of PERV-C subtype were greatly low. Two Bama minipigs with low copy numbers of PERV proviruses were detected out and could be considered as xenograft donor candidates. Although only semiquantitation can be achieved, this approach has potential for screening out safe and suitable pig donors for xenotransplantation.

A simple and sensitive immunoassay for the determination of human chorionic gonadotropin by graphene-based chemiluminescence resonance energy transfer.

PubMed

Lei, Jiuqian; Jing, Tao; Zhou, Tingting; Zhou, Yusun; Wu, Wei; Mei, Surong; Zhou, Yikai

2014-04-15

In this study, we report a strategy of chemiluminescence resonance energy transfer (CRET) using graphene as an efficient long-range energy acceptor. Magnetic nanoparticles were also used in CRET for simple magnetic separation and immobilization of horseradish peroxidase (HRP)-labeled anti-HCG antibody. In the design of CRET system, the sandwich-type immunocomplex was formed between human chorionic gonadotropin (HCG, antigen) and two different antibodies bridged the magnetic nanoparticles and graphene (acceptors), which led to the occurrence of CRET from chemiluminescence light source to graphene. After optimizing the experimental conditions, the quenching of chemiluminescence signal depended linearly on the concentration of HCG in the range of 0.1 mIU mL(-1)-10 mIU mL(-1) and the detection limit was 0.06 mIU mL(-1). The proposed method was successfully applied for the determination of HCG levels in saliva and serum samples, and the results were in good agreement with the plate ELISA with colorimetric detection. It could also be developed for detection of other antigen-antibody immune complexes by using the corresponding antigens and respective antibodies. © 2013 Published by Elsevier B.V.

Stable and general-purpose chemiluminescent detection system for horseradish peroxidase employing a thiazole compound enhancer and some additives.

PubMed

Iwata, R; Ito, H; Hayashi, T; Sekine, Y; Koyama, N; Yamaki, M

1995-10-10

A stable and highly sensitive chemiluminescent detection system for horseradish peroxidase (HRP)/luminol/hydrogen peroxide using a newly designed thiazole compound enhancer has been established. Some additives for the chemiluminescent reaction were explored to overcome some defects of the reaction such as rapid decay and high background of light emission. Recrystallization of luminol and the addition of several detergents into the reacting solution were effective to increase specific light emissions. The addition of skim milk into the reacting solution reduced the background. Consequently, skim milk combined with a detergent increased the signal to noise ratio about 20 times compared with the reactions in the absence of both additives. The optimal concentration of enhancer and the addition of egg albumin stabilized the emission. In the new method, 6x 10(-18) mol of HRP was detectable. This would be the most sensitive enhanced chemiluminescent detection system for HRP. Furthermore, we could detect picogram per milliliter (10(-17) mol) concentrations of a trace component in biological materials such as endothelin-1 by employing this reaction.

Enhanced chemiluminescence for trazodone trace analysis based on acidic permanganate oxidation in concurrent presence of rhodamine 6G.

PubMed

Fujimori, Keiichi; Sakata, Yuta; Moriuchi-Kawakami, Takayo; Shibutani, Yasuhiko

2017-11-01

A new sensitized chemiluminescence method by acidic permanganate oxidation was developed for the sensitive determination of trazodone. A fluorescent dye as used rhodamine 6G to increase a chemiluminescence intensity. Under optimum conditions, the liner range of the calibration curve was obtained for 1-5000 nmol/L. The limit of detection was calculated from 3σ of a blank was 0.23 nmol/L. The coexistent ions and substances had no interference with the chemiluminescence measurement. The chemiluminescence spectra were measured to elucidate a possible mechanism for the system. The present method was satisfactorily used in the determination of the drugs in pharmaceutical samples and animal serums. Copyright © 2017 John Wiley & Sons, Ltd.

Luminol-Based Chemiluminescent Signals: Clinical and Non-clinical Application and Future Uses

PubMed Central

Khan, Parvez; Idrees, Danish; Moxley, Michael A.; Corbett, John A.; Ahmad, Faizan; von Figura, Guido; Sly, William S.; Waheed, Abdul

2015-01-01

Chemiluminescence (CL) is an important method for quantification and analysis of various macromolecules. A wide range of CL agents such as luminol, hydrogen peroxide, fluorescein, dioxetanes and derivatives of oxalate, and acridinium dyes are used according to their biological specificity and utility. This review describes the application of luminol chemiluminescence (LCL) in forensic, biomedical, and clinical sciences. LCL is a very useful detection method due to its selectivity, simplicity, low cost, and high sensitivity. LCL has a dynamic range of applications, including quantification and detection of macro and micromolecules such as proteins, carbohydrates, DNA, and RNA. Luminol-based methods are used in environmental monitoring as biosensors, in the pharmaceutical industry for cellular localization and as biological tracers, and in reporter gene-based assays and several other immunoassays. Here, we also provide information about different compounds that may enhance or inhibit the LCL along with the effect of pH and concentration on LCL. This review covers most of the significant information related to the applications of luminol in different fields. PMID:24752935

The importance of chain length for the polyphosphate enhancement of acidic potassium permanganate chemiluminescence.

PubMed

Holland, Brendan J; Adcock, Jacqui L; Nesterenko, Pavel N; Peristyy, Anton; Stevenson, Paul G; Barnett, Neil W; Conlan, Xavier A; Francis, Paul S

2014-09-09

Sodium polyphosphate is commonly used to enhance chemiluminescence reactions with acidic potassium permanganate through a dual enhancement mechanism, but commercially available polyphosphates vary greatly in composition. We have examined the influence of polyphosphate composition and concentration on both the dual enhancement mechanism of chemiluminescence intensity and the stability of the reagent under analytically useful conditions. The average chain length (n) provides a convenient characterisation, but materials with similar values can exhibit markedly different distributions of phosphate oligomers. There is a minimum polyphosphate chain length (∼6) required for a large enhancement of the emission intensity, but no further advantage was obtained using polyphosphate materials with much longer average chain lengths. Providing there is a sufficient average chain length, the optimum concentration of polyphosphate is dependent on the analyte and in some cases, may be lower than the quantities previously used in routine detection. However, the concentration of polyphosphate should not be lowered in permanganate reagents that have been partially reduced to form high concentrations of the key manganese(III) co-reactant, as this intermediate needs to be stabilised to prevent formation of insoluble manganese(IV). Copyright © 2014 Elsevier B.V. All rights reserved.

Mechanism-Based Enhanced Delivery of Drug-Loaded Targeted Nanoparticles for Breast Cancer Therapy

DTIC Science & Technology

2014-02-01

Based Enhanced Delivery of Drug-Loaded Targeted Nanoparticles for Breast Cancer Therapy” 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-11-1-0167 5c... Nanotechnologies in Living Systems”, Moscow Region, Russia, September, 2011. 3. “Ionic nanogels for drug delivery in cancer ”. NanoDDS’12; Atlantic City, New...AD Award Number: W81XWH-11-1-0167 TITLE: Mechanism-Based Enhanced Delivery of Drug-Loaded Targeted Nanoparticles for Breast

Rational design for enhancing inflammation-responsive in vivo chemiluminescence via nanophotonic energy relay to near-infrared AIE-active conjugated polymer.

PubMed

Seo, Young Hun; Singh, Ajay; Cho, Hong-Jun; Kim, Youngsun; Heo, Jeongyun; Lim, Chang-Keun; Park, Soo Young; Jang, Woo-Dong; Kim, Sehoon

2016-04-01

H2O2-specific peroxalate chemiluminescence is recognized as a potential signal for sensitive in vivo imaging of inflammation but the effect of underlying peroxalate-emitter energetics on its efficiency has rarely been understood. Here we report a simple nanophotonic way of boosting near-infrared chemiluminescence with no need of complicated structural design and synthesis of an energetically favored emitter. The signal enhancement was attained from the construction of a nanoparticle imaging probe (∼26 nm in size) by dense nanointegration of multiple molecules possessing unique photonic features, i.e., i) a peroxalate as a chemical fuel generating electronic excitation energy in response to inflammatory H2O2, ii) a low-bandgap conjugated polymer as a bright near-infrared emitter showing aggregation-induced emission (AIE), and iii) an energy gap-bridging photonic molecule that relays the chemically generated excitation energy to the emitter for its efficient excitation. From static and kinetic spectroscopic studies, a green-emissive BODIPY dye has proven to be an efficient relay molecule to bridge the energy gap between the AIE polymer and the chemically generated excited intermediate of H2O2-reacted peroxalates. The energy-relayed nanointegration of AIE polymer and peroxalate in water showed a 50-times boosted sensing signal compared to their dissolved mixture in THF. Besides the high H2O2 detectability down to 10(-9) M, the boosted chemiluminescence presented a fairly high tissue penetration depth (>12 mm) in an ex vivo condition, which enabled deep imaging of inflammatory H2O2 in a hair-covered mouse model of peritonitis. Copyright © 2016 Elsevier Ltd. All rights reserved.

Novel and versatile solid-state chemiluminescence sensor based on TiO2-Ru(bpy)32+ nanoparticles for pharmaceutical drugs detection

NASA Astrophysics Data System (ADS)

Al-Hetlani, Entesar; Amin, Mohamed O.; Madkour, Metwally

2018-02-01

This work describes a novel and versatile solid-state chemiluminescence sensor for analyte detection using TiO2-Ru(bpy)32+-Ce(IV). Herein, we report the synthesis, characterization, optimization and application of a new type of hybrid nanoparticles (NPs). Mesoporous TiO2-Ru(bpy)32+ NPs were prepared using a modified sol-gel method by incorporating Ru(bpy)32+ into the initial reaction mixture at various concentrations. The resultant bright orange precipitate was characterized via transmission electron microscopy, N2 sorpometry, inductively coupled plasma-optical emission spectrometer (ICP-OES), Raman and UV-Vis spectroscopy techniques. The concentration of Ru(bpy)32+ complex in the NPs was quantified using ICP-OES, and its chemiluminescence (CL) response was measured and compared with the same concentration in the liquid phase using oxalate as model analyte. The results showed that this type of hybrid material exhibited a higher CL signal compared with the liquid phase due to the enlarged surface area of the hybrid NPs ( 149.6 m2/g). The amount of TiO2-Ru(bpy)32+ NPs and the effect of the analyte flow rate were also investigated to optimize the CL signal. The optimized system was further used to detect oxalate and two pharmaceutical drugs, namely, imipramine and promazine. The linear range for both drugs was 1-100 pm with limits of detection (LOD) of 0.1 and 0.5 pm, respectively. This approach is considered to be simple, low cost and facile and can be applied to a wide range of analytes.

Opening a Gateway for Chemiluminescence Cell Imaging: Distinctive Methodology for Design of Bright Chemiluminescent Dioxetane Probes

PubMed Central

2017-01-01

Chemiluminescence probes are considered to be among the most sensitive diagnostic tools that provide high signal-to-noise ratio for various applications such as DNA detection and immunoassays. We have developed a new molecular methodology to design and foresee light-emission properties of turn-ON chemiluminescence dioxetane probes suitable for use under physiological conditions. The methodology is based on incorporation of a substituent on the benzoate species obtained during the chemiexcitation pathway of Schaap’s adamantylidene–dioxetane probe. The substituent effect was initially evaluated on the fluorescence emission generated by the benzoate species and then on the chemiluminescence of the dioxetane luminophores. A striking substituent effect on the chemiluminescence efficiency of the probes was obtained when acrylate and acrylonitrile electron-withdrawing groups were installed. The chemiluminescence quantum yield of the best probe was more than 3 orders of magnitude higher than that of a standard, commercially available adamantylidene–dioxetane probe. These are the most powerful chemiluminescence dioxetane probes synthesized to date that are suitable for use under aqueous conditions. One of our probes was capable of providing high-quality chemiluminescence cell images based on endogenous activity of β-galactosidase. This is the first demonstration of cell imaging achieved by a non-luciferin small-molecule probe with direct chemiluminescence mode of emission. We anticipate that the strategy presented here will lead to development of efficient chemiluminescence probes for various applications in the field of sensing and imaging. PMID:28470053

Ultrasensitive detection of lysozyme in droplet-based microfluidic devices.

PubMed

Giuffrida, Maria Chiara; Cigliana, Giovanni; Spoto, Giuseppe

2018-05-01

Lysozyme (LYS) is a bacteriolytic enzyme, available in secretions such as saliva, tears and human milk. LYS is an important defence molecule of the innate immune system, and its overexpression can be a consequence of diseases such as leukemia, kidney disease and sarcoidosis. This paper reports on a digital microfluidic-based approach that combines the gold nanoparticle-enhanced chemiluminescence with aptamer interaction to detect human lysozyme into droplets 20 nanoliters in volume. The described method allows identifying LYS with a 44.6 femtomolar limit of detection, using sample volume as low as 1μL and detection time in the range of 10min. We used luminol to generate the chemiluminescence and demonstrated that the compartmentalization of LYS in droplets also comprising gold nanoparticles provided enhanced luminescence. We functionalized the gold nanoparticles with a thiolated aptamer to achieve the required selectivity that allowed us to detect LYS in human serum. Copyright © 2017 Elsevier B.V. All rights reserved.

A flow injection chemiluminescence system for the determination of isoniazid.

PubMed

Huang, Y; Zhang, Z; Zhang, D; Lv, J

2000-10-01

A chemiluminescence (CL) flow system is described for the determination of isoniazid based on its enhancement on the chemiluminescence (CL) emission produced upon mixing a hexacyanoferrate(III) solution with an alkaline luminol solution. The system responds linearly to isoniazid concentration in the range 0-1 mg/L with a detection limit (3sigma) of 0.03 microg/L, relative standard deviation (RSD) of 1.2% for 0.1 mg/L isoniazid (n = 11). The system has been successfully applied to the determination of isoniazid in pharmaceutical preparations.

Determination of ampicillin sodium using the cupric oxide nanoparticles-luminol-H2 O2 chemiluminescence reaction.

PubMed

Iranifam, Mortaza; Kharameh, Merhnaz Khabbaz

2014-09-01

A simple and sensitive chemiluminescence (CL) method has been developed for the determination of ampicillin sodium at submicromolar levels. The method is based on the inhibitory effect of ampicillin sodium on the cupric oxide nanoparticles (CuO NPs)-luminol-H2 O2 CL reaction. Experimental parameters affecting CL inhibition including concentrations of CuO NPs, luminol, H2 O2 and NaOH were optimized. Under optimum conditions, the calibration plot was linear in the analyte concentration range 4.0 × 10(-7) -4.0 × 10(-6) mol/L. The limit of detection was 2.6 × 10(-7) mol/L and the relative standard deviation (RSD) for six replicate determinations of 1 × 10(-6) mol/L ampicillin sodium was 4.71%. Also, X-ray diffraction (XRD) and transmission electron microscopy (TEM) analysis were employed to characterize the CuO NPs. The utility of the proposed method was demonstrated by determining ampicillin sodium in pharmaceutical preparation. Copyright © 2013 John Wiley & Sons, Ltd.

Highly sensitive chemiluminescence immunoassay on chitosan membrane modified paper platform using TiO2 nanoparticles/multiwalled carbon nanotubes as label.

PubMed

Li, Weiping; Ge, Shenguang; Wang, Shoumei; Yan, Mei; Ge, Lei; Yu, Jinghua

2013-01-01

A highly sensitive chemiluminescence (CL) immunoassay was incorporated into a low-cost microfluidic paper-based analytical device (μ-PAD) to fabricate a facile paper-based CL immunodevice (denoted as μ-PCLI). This μ-PCLI was constructed by covalently immobilizing capture antibody on a chitosan membrane modified μ-PADs, which was developed by simple wax printing methodology. TiO2 nanoparticles coated multiwalled carbon nanotubes (TiO2/MWCNTs) were synthesized as an amplification catalyst tag to label signal antibody (Ab2). After sandwich-type immunoreactions, the TiO2/MWCNTs were captured on the surface of μ-PADs to catalyze the luminol-p-iodophenol-H2O2 CL system, which produced an enhanced CL emission. Using prostate-specific antigen as a model analyte, the approach provided a good linear response range from 0.001 to 20 ng/mL with a low detection limit of 0.8 pg/mL under optimal conditions. This μ-PCLI showed good reproducibility, selectivity and stability. The assay results of prostate-specific antigen in clinical serum samples were in good agreement with that obtained by commercially used electrochemiluminescence methods at the Cancer Research Center of Shandong Tumor Hospital (Jinan, Shandong Province, China). This μ-PCLI could be very useful to realize highly sensitive, qualitative point-of-care testing in developing or developed countries. Copyright © 2013 John Wiley & Sons, Ltd.

Bifunctional nanoparticles for surface-enhanced Raman spectroscopy-based leukemia biomarker detection

NASA Astrophysics Data System (ADS)

Mehn, Dora; Morasso, Carlo; Vanna, Renzo; Schiumarini, Domitilla; Bedoni, Marzia; Ciceri, Fabio; Gramatica, Furio

2014-03-01

The Wilms tumor gene (WT1) is a biomarker overexpressed in more than 90% of acute myeloid leukemia patients. Fast and sensitive detection of the WT1 in blood samples would allow monitoring of the minimal residual disease during clinical remission and would permit early detection of a potential relapse in acute myeloid leukemia. In this work, Surface Enhanced Raman Spectroscopy (SERS) based detection of the WT1 sequence using bifunctional, magnetic core - gold shell nanoparticles is presented. The classical co-precipitation method was applied to generate magnetic nanoparticles which were coated with a gold shell after modification with aminopropyltriethoxy silane and subsequent deposition of gold nanoparticle seeds. Simple hydroquinone based reduction procedure was applied for the shell growing in water based reaction mixture at room temperature. Thiolated ssDNA probes of the WT1 sequence were immobilized as capture oligonucleotides on the gold surface. Malachite green was applied both for testing the amplification performance of the core-shell colloidal SERS substrate and also as label dye of the target DNA sequence. The SERS enhancer efficacy of the core-shell nanomaterial was compared with the efficacy of classical spherical gold particles produced using the conventional citrate reduction method. The core-shell particles were found not only to provide an opportunity for facile separation in a heterogeneous reaction system but also to be superior regarding robustness as SERS enhancers.

Renewable chemiluminescence optosensors based on implementation of bead injection principle with multicommutation.

PubMed

Domínguez-Romero, Juan C; Gilbert-López, Bienvenida; Beneito-Cambra, Miriam; Molina-Díaz, Antonio

2018-05-15

In this work, the implementation of Bead Injection with multicommutation-based flow systems is reported. A surface renewable chemiluminescence (CL) flow sensor is presented based on the use of CL reaction of luminol with H 2 O 2 . Dowex 1 × 8 beads with immobilized luminol onto them were injected in the flow system by means of a six-port rotary valve and were accommodated into a 1 mm optical glass flow cell placed just in front of the rectangular photosensor window with the same size than the cell wall. Automatic computer-controlled manipulation of both reagents and sample solutions was undertaken using a multicommutated flow system which comprises five three-way solenoid valves, a home-made electronic interface and a Java-written software. Once the chemiluminescence signal was registered, sensing beads were automatically discarded out with a six-port rotary valve without needing to reverse or stop the flow. As a proof of concept and example, the enhancement of the chemiluminescence signal produced by Co(II) on the luminol-H 2 O 2 reaction in alkaline medium was used for illustrating this implementation determining vitamin B 12 in pharmaceutical preparations (after mineralization for releasing Co(II)). The analytical performance of the approach was satisfactory, showing a linear dynamic range from 1.7 to 50 µg L -1 , a detection limit of 0.5 µg L -1 , RSD (%) of 5.3%, with a sampling frequency of 11 h -1 . The proposed approach was applied to different samples and the results were consistent with those obtained with a reference method based on ICP-MS. Based on the same reaction (or re-configuring the system to accommodate it to reaction requirements) the approach can also be applied to the determination of other metal ions such as Cr(III) and Fe(II) and appropriately extended to molecules of bioanalytical interest based e.g. in CL immunoassays, given its versatility. Copyright © 2018 Elsevier B.V. All rights reserved.

Mechanism-Based Enhanced Delivery of Drug-Loaded Targeted Nanoparticles for Breast Cancer Therapy

DTIC Science & Technology

2014-02-01

Enhanced Delivery of Drug-Loaded Targeted Nanoparticles for Breast Cancer Therapy” 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-11-1-0166 5c... Nanotechnologies in Living Systems”, Moscow Region, Russia, September, 2011. 3. “Ionic nanogels for drug delivery in cancer ”. NanoDDS’12; Atlantic City, New...AD Award Number: W81XWH-11-1-0166 TITLE: Mechanism-Based Enhanced Delivery of Drug-Loaded Targeted Nanoparticles for Breast

A sensitive and selective chemiluminescence sensor for the determination of dopamine based on silanized magnetic graphene oxide-molecularly imprinted polymer

NASA Astrophysics Data System (ADS)

Duan, Huimin; Li, Leilei; Wang, Xiaojiao; Wang, Yanhui; Li, Jianbo; Luo, Chuannan

2015-03-01

Based on silanized magnetic graphene oxide-molecularly imprinted polymer (Si-MG-MIP), a sensitive and selective chemiluminescence sensor for dopamine measurement was developed. Si-MG-MIP, in which silanes was introduced to improve the mass transfer, graphene oxide was employed to improve absorption capacity, Fe3O4 nanoparticles were applied for separation easily and molecularly imprinted polymer was used to improve selectivity, demonstrated the advantages of the sensor. All the composites were confirmed by SEM, TEM, XRD and FTIR. Under the optimal conditions of chemiluminescence, dopamine could be assayed in the range of 8.0-200.0 ng/mL with a correlation coefficient of linear regression of 0.9970. The detection limit was 1.5 ng/mL (3δ) and the precision for 11 replicate detections of 80.0 ng/mL dopamine was 3.4% (RSD). When the sensor was applied in determining dopamine in actual samples, recovery ranged from 94% to 110%, which revealed that the results were satisfactory.

Plant Chemiluminescence

PubMed Central

Abeles, Fred B.; Leather, Gerald R.; Forrence, Leonard E.

1978-01-01

Light production by plants was confirmed by measuring chemiluminescence from root and stem tissue of peas (Pisum sativum), beans (Phaseolus vulgaris), and corn (Zea mays) in a modified scintillation spectrophotometer. Chemiluminescence was inhibited by treating pea roots with boiling ethanol or by placing them in a N2 gas phase. Chemiluminescence was increased by an O2 gas phase or by the addition of luminol. NaN3 and NaCN blocked both in vitro and in vivo chemiluminescence. It is postulated that the source of light is the hydrogen peroxide-peroxidase enzyme system. It is known that this system is responsible for chemiluminescence in leukocytes and it seems likely that a similar system occurs in plants. PMID:16660587

Detecting free radicals in sunscreens exposed to UVA radiation using chemiluminescence.

PubMed

Millington, Keith R; Osmond, Megan J; McCall, Maxine J

2014-04-05

One of the current concerns with the application of nanoparticles in sunscreens, and in particular nano-TiO2 and ZnO, is their potential to photogenerate free radicals and reactive oxygen species (ROS) when they absorb ultraviolet wavelengths from sunlight. Free radicals and ROS are known to be associated with UV-induced skin damage and oxidative stress, from which sunscreens are expected to offer significant protection. Here we describe a simple method, based on chemiluminescence emission, for detecting free radicals generated in commercial sunscreens alone, and when applied to various substrates, following exposure to UVA (320-400nm) radiation. This photo-induced chemiluminescence (PICL) technique could be used to optimise sunscreen formulations so as to minimise free radical photogeneration during exposure to sunlight. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

Chemiluminescence of Acanthamoeba castellanii.

PubMed Central

Lloyd, D; Boveris, A; Reiter, R; Filipkowski, M; Chance, B

1979-01-01

1. Chemiluminescence of Acanthomoeba castellanii in the presence of O2 was of similar intensity in organisms harvested early or late during exponential growth [when cyanide (1 mM) stimulates or inhibits respiration respectively]. 2. Cyanide (up to 1.5 mM) stimulated photoemission in both types of organism by 250--300 photons/s per 10(7) cells above the value observed under aerobic conditions. 3. 'Dibromothymoquinone' (2,5-dibromo-6-isopropyl-3-methyl-p-benzoquinone) (up to 80 microM) further increased chemiluminescence. 4. Similar responses were also demonstrated in whole homogenates and in subcellular fractions; 36% of the chemiluminescence was provided by a fraction sedimenting at 100000g-min, and 20% in that fraction that was non-sedimentable at 200000g-min. 5. Mitochondrial substrates (succinate, 2-oxoglutarate, NADH) in the presence or absence of ADP and Pi or peroxisomal substrates (glycollate, urate or ethanol) gave no increases in light emission by whole homogenates or in any of the fractions. 6. It is suggested that reactions responsible for production of chemiluminescence are those primarily producing superoxide anions and leading to lipid peroxidation and singlet-oxygen formation. Photoemission enhancement and superoxide dismutase inhibition showed similar cyanide concentration-dependencies. PMID:534514

Nanoparticle Delivery Enhancement With Acoustically Activated Microbubbles

PubMed Central

Mullin, Lee B; Phillips, Linsey C; Dayton, Paul A

2013-01-01

The application of microbubbles and ultrasound to deliver nanoparticle carriers for drug and gene delivery is an area that has expanded greatly in recent years. Under ultrasound exposure, microbubbles can enhance nanoparticle delivery by increasing cellular and vascular permeability. In this review, the underlying mechanisms of enhanced nanoparticle delivery with ultrasound and microbubbles and various proposed delivery techniques are discussed. Additionally, types of nanoparticles currently being investigated in preclinical studies, as well as the general limitations and benefits of a microbubble-based approach to nanoparticle delivery are reviewed. PMID:23287914

Recent advances in nanoparticle based aptasensors for food contaminants.

PubMed

Sharma, Richa; Ragavan, K V; Thakur, M S; Raghavarao, K S M S

2015-12-15

Food safety and hazard analysis is a prime concern of human life, thus quality assessment of food and water is the need of the day. Recent advances in nano-biotechnology play a significant role in providing possible solutions for developing highly sensitive and affordable detection tools for food analysis. Nanomaterials based aptasensors hold great potential to overcome the drawbacks of conventional analytical techniques. Aptamers comprise a novel class of highly specific bio-recognition elements which are produced by SELEX (systematic evolution of ligands by exponential enrichment) process. They bind to target molecules by folding into 3D structures that can discriminate different chiral compounds. The flexibility in making modifications in aptamers contribute to the design of biosensors, enabling the generation of bio-recognition elements for a wide variety of target molecules. Nanomaterials such as metal nanoparticles, metal nanoclusters, metal oxide nanoparticles, metal and carbon quantum dots, graphene, carbon nanotubes and nanocomposites enable higher sensitivity by signal amplification and introduce several novel transduction principles such as enhanced chemiluminescence, fluorescence, Raman signals, electrochemical signals, enhanced catalytic activity, and super-paramagnetic properties to the biosensor. Although there are a few reviews published recently which deal with the potential of aptamers in various fields, none are devoted exclusively to the potential of aptasensors based on nanomaterials for the analysis of food contaminants. Hence, the current review discusses several transduction systems and their principles used in aptamer based nanosensors which have been developed in the past five years, the challenges faced in their designing, along with their strengths and limitations. Copyright © 2015 Elsevier B.V. All rights reserved.

Chemiluminescence of off-line and on-line gold nanoparticle-catalyzed luminol system in the presence of flavonoid.

PubMed

Wu, Dong; Zhang, Xiaoyue; Liu, Yong; Ma, Yan; Wang, Xiaowu; Wang, Xiaojuan; Xu, Liuxin

2017-06-01

It was found that flavonoids could remarkably inhibit the chemiluminescence (CL) intensity of an off-line gold nanoparticle (AuNP)-catalyzed luminol-H 2 O 2 CL system. By contrast, flavonoids enhanced the CL intensity of an on-line AuNP-catalyzed luminol-H 2 O 2 CL system. In the off-line system, the AuNPs were prepared beforehand, whereas in the on-line system, AuNPs were produced by on-line mixing of luminol prepared in a buffer solution of NaHCO 3  - Na 2 CO 3 and HAuCl 4 with no need for the preliminary preparation of AuNPs. The on-line system had prominent advantages over the off-line system, namely a lowering of the background noise and improvements in the stability of the CL system. The results show that differences in the signal suppression effect of flavonoids on the off-line AuNP-catalyzed CL system are influenced by the combined action of a free radical scavenging effect and occupy-sites function; the latter was proved to be predominant using controlled experiments. Enhancement of the on-line system was ascribed to the presence of flavonoids promoting the on-line formation of AuNPs, which better catalyzed the luminol-H 2 O 2 CL reaction, and the enhancement activity of the six flavonoids increased with the increase in reducibility. This work broadens the scope of practical applications of an AuNP-catalyzed CL system. Copyright © 2016 John Wiley & Sons, Ltd.

Infrared chemiluminescence study of the reaction Cl + HI yielding HCl + I at enhanced collision energies.

NASA Technical Reports Server (NTRS)

Cowley, L. T.; Horne, D. S.; Polanyi, J. C.

1971-01-01

Performed chemiluminescence and beam experiments show a markedly increased efficiency of conversion of the reaction energy into vibration and a markedly enhanced tendency for forward scattering in the reaction Cl + HI yields HCl + I as compared with H + Cl2 yields HCl + Cl. These differences appear to be due predominantly to the difference in the masses involved.

Optimal energy for cell radiosensitivity enhancement by gold nanoparticles using synchrotron-based monoenergetic photon beams

PubMed Central

Rahman, Wan Nordiana; Corde, Stéphanie; Yagi, Naoto; Abdul Aziz, Siti Aishah; Annabell, Nathan; Geso, Moshi

2014-01-01

Gold nanoparticles have been shown to enhance radiation doses delivered to biological targets due to the high absorption coefficient of gold atoms, stemming from their high atomic number (Z) and physical density. These properties significantly increase the likelihood of photoelectric effects and Compton scattering interactions. Gold nanoparticles are a novel radiosensitizing agent that can potentially be used to increase the effectiveness of current radiation therapy techniques and improve the diagnosis and treatment of cancer. However, the optimum radiosensitization effect of gold nanoparticles is strongly dependent on photon energy, which theoretically is predicted to occur in the kilovoltage range of energy. In this research, synchrotron-generated monoenergetic X-rays in the 30–100 keV range were used to investigate the energy dependence of radiosensitization by gold nanoparticles and also to determine the photon energy that produces optimum effects. This investigation was conducted using cells in culture to measure dose enhancement. Bovine aortic endothelial cells with and without gold nanoparticles were irradiated with X-rays at energies of 30, 40, 50, 60, 70, 81, and 100 keV. Trypan blue exclusion assays were performed after irradiation to determine cell viability. Cell radiosensitivity enhancement was indicated by the dose enhancement factor which was found to be maximum at 40 keV with a value of 3.47. The dose enhancement factor obtained at other energy levels followed the same direction as the theoretical calculations based on the ratio of the mass energy absorption coefficients of gold and water. This experimental evidence shows that the radiosensitization effect of gold nanoparticles varies with photon energy as predicted from theoretical calculations. However, prediction based on theoretical assumptions is sometimes difficult due to the complexity of biological systems, so further study at the cellular level is required to fully characterize the

Optimal energy for cell radiosensitivity enhancement by gold nanoparticles using synchrotron-based monoenergetic photon beams.

PubMed

Rahman, Wan Nordiana; Corde, Stéphanie; Yagi, Naoto; Abdul Aziz, Siti Aishah; Annabell, Nathan; Geso, Moshi

2014-01-01

Gold nanoparticles have been shown to enhance radiation doses delivered to biological targets due to the high absorption coefficient of gold atoms, stemming from their high atomic number (Z) and physical density. These properties significantly increase the likelihood of photoelectric effects and Compton scattering interactions. Gold nanoparticles are a novel radiosensitizing agent that can potentially be used to increase the effectiveness of current radiation therapy techniques and improve the diagnosis and treatment of cancer. However, the optimum radiosensitization effect of gold nanoparticles is strongly dependent on photon energy, which theoretically is predicted to occur in the kilovoltage range of energy. In this research, synchrotron-generated monoenergetic X-rays in the 30-100 keV range were used to investigate the energy dependence of radiosensitization by gold nanoparticles and also to determine the photon energy that produces optimum effects. This investigation was conducted using cells in culture to measure dose enhancement. Bovine aortic endothelial cells with and without gold nanoparticles were irradiated with X-rays at energies of 30, 40, 50, 60, 70, 81, and 100 keV. Trypan blue exclusion assays were performed after irradiation to determine cell viability. Cell radiosensitivity enhancement was indicated by the dose enhancement factor which was found to be maximum at 40 keV with a value of 3.47. The dose enhancement factor obtained at other energy levels followed the same direction as the theoretical calculations based on the ratio of the mass energy absorption coefficients of gold and water. This experimental evidence shows that the radiosensitization effect of gold nanoparticles varies with photon energy as predicted from theoretical calculations. However, prediction based on theoretical assumptions is sometimes difficult due to the complexity of biological systems, so further study at the cellular level is required to fully characterize the effects

A sensitive and selective chemiluminescence sensor for the determination of dopamine based on silanized magnetic graphene oxide-molecularly imprinted polymer.

PubMed

Duan, Huimin; Li, Leilei; Wang, Xiaojiao; Wang, Yanhui; Li, Jianbo; Luo, Chuannan

2015-03-15

Based on silanized magnetic graphene oxide-molecularly imprinted polymer (Si-MG-MIP), a sensitive and selective chemiluminescence sensor for dopamine measurement was developed. Si-MG-MIP, in which silanes was introduced to improve the mass transfer, graphene oxide was employed to improve absorption capacity, Fe3O4 nanoparticles were applied for separation easily and molecularly imprinted polymer was used to improve selectivity, demonstrated the advantages of the sensor. All the composites were confirmed by SEM, TEM, XRD and FTIR. Under the optimal conditions of chemiluminescence, dopamine could be assayed in the range of 8.0-200.0 ng/mL with a correlation coefficient of linear regression of 0.9970. The detection limit was 1.5 ng/mL (3δ) and the precision for 11 replicate detections of 80.0 ng/mL dopamine was 3.4% (RSD). When the sensor was applied in determining dopamine in actual samples, recovery ranged from 94% to 110%, which revealed that the results were satisfactory. Copyright © 2014 Elsevier B.V. All rights reserved.

Flow-injection chemiluminescence method for the determination of chloramphenicol based on luminol-sodium periodate order-transform second-chemiluminescence reaction.

PubMed

Zhuang, Ya-Feng; Zhu, Sheng-Nan; Wei, Wei; Li, Jie-Li

2011-01-01

A new chemiluminescence (CL) reaction was observed when chloramphenicol solution was injected into the mixture after the end of the reaction of alkaline luminol and sodium periodate or sodium periodate was injected into the reaction mixture of chloramphenicol and alkaline luminol. This reaction is described as an order-transform second-chemiluminescence (OTSCL) reaction. The OTSCL method combined with a flow-injection technique was applied to the determination of chloramphenicol. The optimum conditions for the order-transform second-chemiluminescence emission were investigated. A mechanism for OTSCL has been proposed on the basis of the chemiluminescence kinetic characteristics, the UV-visible spectra and the chemiluminescent spectra. Under optimal experimental conditions, the CL response is proportional to the concentration of chloramphenicol over the range 5.0 × 10(-7)-5.0 × 10(-5) mol/L with a correlation coefficient of 0.9969 and a detection limit of 6.0 × 10(-8) mol/L (3σ). The relative standard deviation (RSD) for 11 repeated determinations of 5.0 × 10(-6) mol/L chloramphenicol is 1.7%. The method has been applied to the determination of chloramphenicol in pharmaceutical samples with satisfactory results. Copyright © 2011 John Wiley & Sons, Ltd.

A cascade amplification strategy based on rolling circle amplification and hydroxylamine amplified gold nanoparticles enables chemiluminescence detection of adenosine triphosphate.

PubMed

Wang, Ping; Zhang, Tonghuan; Yang, Taoyi; Jin, Nan; Zhao, Yanjun; Fan, Aiping

2014-08-07

A highly sensitive and selective chemiluminescent (CL) biosensor for adenosine triphosphate (ATP) was developed by taking advantage of the ATP-dependent enzymatic reaction (ATP-DER), the powerful signal amplification capability of rolling circle amplification (RCA), and hydroxylamine-amplified gold nanoparticles (Au NPs). The strategy relies on the ability of ATP, a cofactor of T4 DNA ligase, to trigger the ligation-RCA reaction. In the presence of ATP, the T4 DNA ligase catalyzes the ligation reaction between the two ends of the padlock probe, producing a closed circular DNA template that initiates the RCA reaction with phi29 DNA polymerase and dNTP. Therein, many complementary copies of the circular template can be generated. The ATP-DER is eventually converted into a detectable CL signal after a series of processes, including gold probe hybridization, hydroxylamine amplification, and oxidative gold metal dissolution coupled with a simple and sensitive luminol CL reaction. The CL signal is directly proportional to the ATP level. The results showed that the detection limit of the assay is 100 pM of ATP, which compares favorably with those of other ATP detection techniques. In addition, by taking advantage of ATP-DER, the proposed CL sensing system exhibits extraordinary specificity towards ATP and could distinguish the target molecule ATP from its analogues. The proposed method provides a new and versatile platform for the design of novel DNA ligation reaction-based CL sensing systems for other cofactors. This novel ATP-DER based CL sensing system may find wide applications in clinical diagnosis as well as in environmental and biomedical fields.

Highly sensitive glucose biosensor based on the effective immobilization of glucose oxidase/carbon-nanotube and gold nanoparticle in nafion film and peroxyoxalate chemiluminescence reaction of a new fluorophore.

PubMed

Zargoosh, Kiomars; Chaichi, Mohammad Javad; Shamsipur, Mojtaba; Hossienkhani, Saman; Asghari, Sakineh; Qandalee, Mohammad

2012-05-15

A novel glucose biosensor based on the chemiluminescence (CL) detection of enzymatically generated H(2)O(2) was constructed by the effective immobilization of glucose oxidase (GOD)/carbon-nanotubes (CNTs)/gold nanoparticles (GNPs) in nafion film on graphite support. The influences of various experimental parameters such as solution pH, the action time of the enzyme, interferents and the concentration of CL reagents were investigated. Carbon nanotubes and gold nanoparticles offer excellent catalytic activity toward hydrogen peroxide generation in enzymatic reaction between glucose oxidase and glucose, which would enable sensitive determination of glucose. Under the optimum condition, the linear response range of glucose was found to be 2.25 × 10(-6) to 1.75 × 10(-4 ) mol L(-1), and the detection limit (defined as the concentration that could be detected at the signal-to-noise ratio of 3) was 1.00 × 10(-6) mol L(-1). The CL biosensor exhibited good storage stability, i.e., 80% of its initial response was retained after 10 days storage at pH 7.0. The present CL biosensor has been used to determine the glucose concentrations in real serum and urine samples with satisfactory results. Copyright © 2011 Elsevier B.V. All rights reserved.

Nanosensors based on functionalized nanoparticles and surface enhanced raman scattering

DOEpatents

Talley, Chad E.; Huser, Thomas R.; Hollars, Christopher W.; Lane, Stephen M.; Satcher, Jr., Joe H.; Hart, Bradley R.; Laurence, Ted A.

2007-11-27

Surface-Enhanced Raman Spectroscopy (SERS) is a vibrational spectroscopic technique that utilizes metal surfaces to provide enhanced signals of several orders of magnitude. When molecules of interest are attached to designed metal nanoparticles, a SERS signal is attainable with single molecule detection limits. This provides an ultrasensitive means of detecting the presence of molecules. By using selective chemistries, metal nanoparticles can be functionalized to provide a unique signal upon analyte binding. Moreover, by using measurement techniques, such as, ratiometric received SERS spectra, such metal nanoparticles can be used to monitor dynamic processes in addition to static binding events. Accordingly, such nanoparticles can be used as nanosensors for a wide range of chemicals in fluid, gaseous and solid form, environmental sensors for pH, ion concentration, temperature, etc., and biological sensors for proteins, DNA, RNA, etc.

Amino acids as novel nucleophiles for silver nanoparticle-luminol chemiluminescence.

PubMed

Li, Na; Ni, Shubiao

2014-12-01

The use of noble metal nanoparticles (NPs) as reductants in chemiluminescence (CL) has been reported only rarely owing to their high oxidation potentials. Interestingly, nucleophiles could dramatically lower the oxidation potential of Ag NPs, such that in the presence of nucleophiles Ag NPS could be used as reductants to induce the CL emission of luminol, an important CL reagent widely used in forensic analysis for the detection of trace amounts of blood. Although nucleophiles are indispensible in Ag NP-luminol CL, only inorganic nucleophiles such as Cl(-), Br(-), I(-) and S2O3 (2-) have been shown to be efficient. The effects of organic nucleophiles on CL remain unexplored. In this study, 20 standard amino acids were evaluated as novel organic nucleophiles in Ag NP-luminol CL. Histidine, lysine and arginine could initiate CL emission; the others could not. It is proposed that the different behaviors of 20 standard amino acids in the CL reactions derive from the interface chemistry between Ag NPs and these amino acids. UV/vis absorption spectra were studied to validate the interface chemistry. In addition, imidazole and histidine were chosen as a model pair to compare the behavior of the monodentate nucleophile with that of the corresponding multidentate nucleophile in Ag NP-luminol CL. Copyright © 2014 John Wiley & Sons, Ltd.

Mechanism of alcohol-enhanced lucigenin chemiluminescence in alkaline solution.

PubMed

Chi, Quan; Chen, Wanying; He, Zhike

2015-11-01

The chemiluminescence (CL) of lucigenin (Luc(2+)) can be enhanced by different alcohols in alkaline solution. The effect of different fatty alcohols on the CL of lucigenin was related to the carbon chain length and the number of hydroxyl groups. Glycerol provides the greatest enhancement. UV/Vis absorption spectra and fluorescence spectra showed that N-methylacridone (NMA) was produced in the CL reaction in the presence of different alcohols. The peak of the CL spectrum was located at 470 nm in all cases, indicating that the luminophore was always the excited-state NMA. The quenching of lucigenin CL by superoxide dismutase (SOD) and the electron spin resonance (ESR) results with the spin trap of 5,5-dimethyl-1-pyrroline N-oxide (DMPO) demonstrated that superoxide anions (O2 (•-)) were generated from dissolved oxygen in the CL reaction and that glycerol and dihydroxyacetone (DHA) can promote O2 (•-) production by the reduction of dissolved oxygen in alkaline solution. It was assumed that the enhancement provided by different alcohols was related to the solvent effect and reducing capacity. Glycerol and DHA can also reduce Luc(2+) into lucigenin cation radicals (Luc(•+) ), which react with O2 (•-) to produce CL, and glycerol can slowly transform into DHA, which is oxidized quickly in alkaline solution. Copyright © 2015 John Wiley & Sons, Ltd.

Passive micromixer for luminol-peroxide chemiluminescence detection.

PubMed

Lok, Khoi Seng; Kwok, Yien Chian; Nguyen, Nam-Trung

2011-06-21

This paper reports a microchip with an integrated passive micromixer based on chaotic advection. The micromixer with staggered herringbone structures was used for luminol-peroxide chemiluminescence detection. The micromixer was examined to assess its suitability for chemiluminescence reaction. The relationship between the flow rate and the location of maximum chemiluminescence intensity was investigated. The light intensity was detected using an optical fiber attached along the mixing channel and a photon detector. A linear correlation between chemiluminescence intensity and the concentration of cobalt(ii) ions or hydrogen peroxide was observed. This microchip has a potential application in environmental monitoring for industries involved in heavy metals and in medical diagnostics.

Peroxyoxalate chemiluminescence enhanced by oligophenylenevinylene fluorophores in the presence of various surfactants.

PubMed

Motoyoshiya, Jiro; Takigawa, Setsuko

2014-11-01

The effect of several surfactants on peroxyoxalate chemiluminescence (PO-CL) using oligophenylenevinylene fluorophores was investigated. Among several oligophenylenevinylenes consisting of stilbene units, linearly conjugated ones, such as distyrylbenzene and distyrylstilbene, effectively enhanced PO-CL efficiency. Various effects of anionic, cationic, amphoteric and non-ionic surfactants on the CL efficiency of PO-CL were determined using three oxalates and the distyrylbenzene fluorophore. Anionic and non-ionic surfactants effectively enhanced CL efficiency, in contrast to the negative effect of cationic and amphoteric surfactants. Non-ionic surfactants were also effective in CL reactions of oxalates bearing dodecyl ester groups by the hydrophobic interaction between their alkyl chains. Considering these results, the surfactants not only increase the concentrations of water-insoluble interacting species in the hydrophobic micelle cores, but also control rapid degradation of the oxalates by alkaline hydrolysis. Copyright © 2014 John Wiley & Sons, Ltd.

A chemiluminescence method to detect hydroquinone with water-soluble sulphonato-(salen)manganese(III) complex as catalyst.

PubMed

Zhang, Guangbin; Tang, Yuhai; Sun, Yang; Yu, Hua; Du, Wei; Fu, Qiang

2016-02-01

A water-soluble sulphonato-(salen)manganese(III) complex with excellent catalytic properties was synthesized and demonstrated to greatly enhance the chemiluminescence signal of the hydrogen peroxide - luminol reaction. Coupled with flow-injection technique, a simple and sensitive chemiluminescence method was first developed to detect hydroquinone based on the chemiluminescence system of the hydrogen peroxide-luminol-sulphonato-(salen)manganese(III) complex. Under optimal conditions, the assay exhibited a wide linear range from 0.1 to 10 ng mL(-1) with a detection limit of 0.05 ng mL(-1) for hydroquinone. The method was applied successfully to detect hydroquinone in tap-water and mineral-water, with a sampling frequency of 120 times per hour. The relative standard deviation for determination of hydroquinone was less than 5.6%, and the recoveries ranged from 96.8 to 103.0%. The ultraviolet spectra, chemiluminescence spectra, and the reaction kinetics for the peroxide-luminol-sulphonato-(salen)manganese(III) complex system were employed to study the possible chemiluminescence mechanism. The proposed chemiluminescence analysis technique is rapid and sensitive, with low cost, and could be easily extended and applied to other compounds. Copyright © 2015 John Wiley & Sons, Ltd.

Projection model for flame chemiluminescence tomography based on lens imaging

NASA Astrophysics Data System (ADS)

Wan, Minggang; Zhuang, Jihui

2018-04-01

For flame chemiluminescence tomography (FCT) based on lens imaging, the projection model is essential because it formulates the mathematical relation between the flame projections captured by cameras and the chemiluminescence field, and, through this relation, the field is reconstructed. This work proposed the blurry-spot (BS) model, which takes more universal assumptions and has higher accuracy than the widely applied line-of-sight model. By combining the geometrical camera model and the thin-lens equation, the BS model takes into account perspective effect of the camera lens; by combining ray-tracing technique and Monte Carlo simulation, it also considers inhomogeneous distribution of captured radiance on the image plane. Performance of these two models in FCT was numerically compared, and results showed that using the BS model could lead to better reconstruction quality in wider application ranges.

Sulfide chemiluminescence detection

DOEpatents

Spurlin, Stanford R.; Yeung, Edward S.

1985-01-01

A method of chemiluminescently determining a sulfide which is either hydrogen sulfide or methyl mercaptan by reacting the sulfide with chlorine dioxide at low pressure and under conditions which allow a longer reaction time in emission of a single photon for every two sulfide containing species, and thereafter, chemiluminescently detecting and determining the sulfide. The invention also relates not only to the detection method, but the novel chemical reaction and a specifically designed chemiluminescence detection cell for the reaction.

Applications of chemiluminescence to bacterial analysis

NASA Technical Reports Server (NTRS)

Searle, N. D.

1975-01-01

Luminol chemiluminescence method for detecting bacteria was based on microbial activation of the oxidation of the luminol monoanion by hydrogen peroxide. Elimination of the prior lysing step, previously used in the chemiluminescence technique, was shown to improve considerably the reproducibility and accuracy of the method in addition to simplifying it. An inexpensive, portable photomultiplier detector was used to measure the maximum light intensity produced when the sample is added to the reagent. Studies of cooling tower water show that the luminol chemiluminescence technique can be used to monitor changes in viable cell population both under normal conditions and during chlorine treatment. Good correlation between chemiluminescence and plate counts was also obtained in the analysis of process water used in paper mills. This method showed good potential for monitoring the viable bacteria populations in activated sludge used in waste treatment plants to digest organic matter.

Sulfide chemiluminescence detection

DOEpatents

Spurlin, S.R.; Yeung, E.S.

1985-11-26

A method is described for chemiluminescently determining a sulfide which is either hydrogen sulfide or methyl mercaptan by reacting the sulfide with chlorine dioxide at low pressure and under conditions which allow a longer reaction time in emission of a single photon for every two sulfide containing species, and thereafter, chemiluminescently detecting and determining the sulfide. The invention also relates not only to the detection method, but the novel chemical reaction and a specifically designed chemiluminescence detection cell for the reaction. 4 figs.

A flexible and miniaturized hair dye based photodetector via chemiluminescence pathway.

PubMed

Lin, Ching-Chang; Sun, Da-Shiuan; Lin, Ya-Lin; Tsai, Tsung-Tso; Cheng, Chieh; Sun, Wen-Hsien; Ko, Fu-Hsiang

2017-04-15

A flexible and miniaturized metal semiconductor metal (MSM) biomolecular photodetector was developed as the core photocurrent system through chemiluminescence for hydrogen peroxide sensing. The flexible photocurrent sensing system was manufactured on a 30-µm-thick crystalline silicon chip by chemical etching process, which produced a flexible silicon chip. A surface texturization design on the flexible device enhanced the light-trapping effect and minimized reflectivity losses from the incident light. The model protein streptavidin bound to horseradish peroxidase (HRP) was successfully immobilized onto the sensor surface through high-affinity conjugation with biotin. The luminescence reaction occurred with luminol, hydrogen peroxide and HRP enzyme, and the emission of light from the catalytic reaction was detected by underlying flexible photodetector. The chemiluminescence in the miniaturized photocurrent sensing system was successfully used to determine the hydrogen peroxide concentration in real-time analyses. The hydrogen peroxide detection limit of the flexible MSM photodetector was 2.47mM. The performance of the flexible MSM photodetector maintained high stability under bending at various bending radii. Moreover, for concave bending, a significant improvement in detection signal intensity (14.5% enhancement compared with a flat configuration) was observed because of the increased photocurrent, which was attributed to enhancement of light trapping. Additionally, this detector was used to detect hydrogen peroxide concentrations in commercial hair dye products, which is a significant issue in the healthcare field. The development of this novel, flexible and miniaturized MSM biomolecular photodetector with excellent mechanical flexibility and high sensitivity demonstrates the applicability of this approach to future wearable sensor development efforts. Copyright © 2016 Elsevier B.V. All rights reserved.

Luminol functionalized gold nanoparticles as colorimetric and chemiluminescent probes for visual, label free, highly sensitive and selective detection of minocycline

NASA Astrophysics Data System (ADS)

He, Yi; Peng, Rufang

2014-11-01

In this work, luminol functionalized gold nanoparticles (LuAuNPs) were used as colorimetric and chemiluminescent probes for visual, label free, sensitive and selective detection of minocycline (MC). The LuAuNPs were prepared by simple one-pot reduction of HAuCl4 with luminol, which exhibited a good chemiluminescence (CL) activity owing to the presence of luminol molecules on their surface and surface plasmon resonance absorption. In the absence of MC, the color of LuAuNPs was wine red and their size was relatively small (˜25 nm), which could react with silver nitrate, producing a strong CL emission. Upon the addition of MC at acidic buffer solutions, the electrostatic interaction between positively charged MC and negatively charged LuAuNPs caused the aggregation of LuAuNPs, generating a purple or blue color. Simultaneously, the aggregated LuAuNPs did not effectively react with silver nitrate, producing a weak CL emission. The signal change was linearly dependent on the logarithm of MC concentration in the range from 30 ng to 1.0 μg for colorimetric detection and from 10 ng to 1.0 μg for CL detection. With colorimetry, a detection limit of 22 ng was achieved, while the detection limit for CL detection modality was 9.7 ng.

Post-chemiluminescence determination of chloramphenicol based on luminol-potassium periodate system.

PubMed

Yang, Xiao Feng; Li, Nian Bing; Luo, Hong Qun

2012-01-01

A post-chemiluminescence (PCL) phenomenon was observed when chloramphenicol was injected into a mixture of luminol and potassium periodate after the chemiluminescence (CL) reaction of luminol-potassium periodate had finished. The possible reaction mechanism was proposed based on studies of the CL kinetic characteristics, the CL spectra, the fluorescence spectra and the UV-vis absorption spectra of the related substances. Based on the PCL reaction, a rapid and sensitive method for the determination of chloramphenicol was established. The linear response range was 6.0 × 10(-7) -1.0 × 10(-5) mol/L, with a correlation coefficient of 0.9986. The relative standard deviation (RSD) for 5.0 × 10(-6) mol/L chloramphenicol was 2.3% (n = 11). The detection limit was 1.6 × 10(-7) mol/L. The method has been applied to the determination of chloramphenicol in pharmaceutical samples with satisfactory results. Copyright © 2011 John Wiley & Sons, Ltd.

Rapid and simple G-quadruplex DNA aptasensor with guanine chemiluminescence detection.

PubMed

Cho, Sandy; Park, Lucienne; Chong, Richard; Kim, Young Teck; Lee, Ji Hoon

2014-02-15

Cost-effective and sensitive aptasensor with guanine chemiluminescence detection capable of simply quantifying thrombin in human serum was developed using thrombin aptamer (TBA), one of the G-quadruplex DNA aptamers, without expensive nanoparticles and complicated procedures. Guanines of G-quadruplex TBA-conjugated carboxyfluorescein (6-FAM) bound with thrombin do not react with 3,4,5-trimethoxylphenylglyoxal (TMPG) in the presence of tetra-n-propylammonium hydroxide (TPA), whereas guanines of free TBA- and TBA-conjugated 6-FAM immobilized on the surface of graphene oxide rapidly react with TMPG to emit light. Thus, guanine chemiluminescence in 5% human serum with thrombin was lower than that without thrombin when TBA-conjugated 6-FAM was added in two samples and incubated for 20 min. In other words, the brightness of guanine chemiluminescence was quenched due to the formation of G-quadruplex TBA-conjugated 6-FAM bound with thrombin in a sample. High-energy intermediate, capable of emitting dim light by itself, formed from the reaction between guanines of TBA and TMPG in the presence of TPA, transfers energy to 6-FAM to emit bright light based on the principle of chemiluminescence energy transfer (CRET). G-quadruplex TBA aptasensor devised using the rapid interaction between TBA-conjugated 6-FAM and thrombin quantified trace levels of thrombin without complicated procedures. The limit of detection (LOD = background + 3 × standard deviation) of G-quadruplex TBA aptasensor with good linear calibration curve, accuracy, precision, and recovery was as low as 12.3 nM in 5% human serum. Using the technology reported in this research, we expect that various types of G-quadruplex DNA aptasensors capable of specifically sensing a target molecule such as ATP, HIV, ochratoxin, potassium ions, and thrombin can be developed. © 2013 Elsevier B.V. All rights reserved.

Copper nanocluster-enhanced luminol chemiluminescence for high-selectivity sensing of tryptophan and phenylalanine.

PubMed

Borghei, Yasaman-Sadat; Hosseini, Morteza; Khoobi, Mehdi; Ganjali, Mohammad Reza

2017-09-01

A remarkable method for the highly sensitive detection of phenylalanine and tryptophan based on a chemiluminescence (CL) assay was reported. It was found that fluorescent copper nanoclusters capped with cysteine (Cys-CuNCs) strongly enhance the weak CL signal resulting from the reaction between luminol and H 2 O 2 . Of the amino acids tested, phenylalanine and tryptophan could enhance the above CL system sensitively. Under optimum conditions, this method was satisfactorily described by a linear calibration curve over a range of 1.0 × 10 -6 to 2.7 × 10 -5  M for phenylalanine and 1.0 × 10 -7 to 3.0 × 10 -5  M for tryptophan, respectively. The effect of various parameters such as Cys-CuNC concentration, H 2 O 2 concentration and pH on the intensity of the CL system were also studied. The main experimental advantage of the proposed method was its selectivity for two amino acids compared with others. To evaluate the applicability of the method to the analysis of a real biological sample it was used to determine tryptophan and phenylalanine in human serum and remarkable results were obtained. Copyright © 2017 John Wiley & Sons, Ltd.

Spatial and temporal control of microwave triggered chemiluminescence: a protein detection platform.

PubMed

Previte, Michael J R; Aslan, Kadir; Geddes, Chris D

2007-09-15

We have combined the principles of microwave circuitry and antenna design and our recent work in microwave-triggered metal-enhanced chemiluminescence to now "trigger" chemically and enzyme-catalyzed chemiluminescent reactions with spatial and temporal control. With this technology platform, we achieve spatial and temporal control of enzyme and chemically catalyzed chemiluminescence reactions to achieve more than 500-fold increases in "on-demand" photon flux from chemically catalyzed chemiluminescent reactions. We also report a 6-fold increase in photon flux from HRP-catalyzed assays on disposable coverslips functionalized with HRP and placed proximal to the substrates modified with thin-film aluminum triangle disjointed "bow-tie" structures. In addition, we demonstrate the applicability of this technology to develop multiplexed or high-throughput chemiluminescent assays. We also demonstrate the clinical and biological relevance of this technology platform by affixing aluminum structures in proximity to HRP protein immobilized on nitrocellulose to improve the sensitivity for this model Western blot scheme by 50-fold. We believe analytical applications that rely on enzyme-catalyzed chemiluminescence, such as immunoassays, may greatly benefit from this new platform technology.

Flow injection chemiluminescent determination of tetracycline using a tris(2,2'-bipyridine)ruthenium(II)-cerium(IV) sulphate system.

PubMed

Guo, Liangqia; Xie, Zenghong; Lin, Xucong; Liu, Xiaohua; Zhang, Weilin; Chen, Guonan

2004-01-01

A flow-injection chemiluminescence method for the determination of tetracycline was developed. The method is based on an enhancement by tetracycline of the chemiluminescence light emission of tris(2,2'-bipyridine)ruthenium(II). In sulphuric acid medium, the chemiluminescence is generated by the continuous oxidation of tris(2,2'-bipyridine)ruthenium(II) by cerium (IV) sulphate. The light-emission intensity is greatly enhanced in the presence of tetracycline. Under the optimum conditions, the calibration curve is linear over the range 3.75 x 10(-8) g/mL-1.5 x 10(-5) g/mL for tetracycline with the linear equation: deltaINT = 205.898 x C - 20.442 (R2 = 0.9974). The detection limit is 3.27 x 10(-8) g/mL. The proposed method was also successfully used to determine tetracycline in pharmaceutical formulation (mean recovery of tetracycline, 100.7%). Copyright 2004 John Wiley & Sons, Ltd.

40 CFR 1065.270 - Chemiluminescent detector.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Chemiluminescent detector. 1065.270... Chemiluminescent detector. (a) Application. You may use a chemiluminescent detector (CLD) to measure NOX... chemiluminescent detector for comparison with any proposed alternate measurement procedure under § 1065.10. (b...

Customizable radiotherapy enhancement (CuRE) for prostate cancer using platinum based nanoparticles

NASA Astrophysics Data System (ADS)

Cifter, Gizem

New approach to prostate cancer (PCa) therapy titled "Customizable Radiotherapy Enhancement (CuRE)" employs cisplatin (C), carboplatin (Ca) and oxaliplatin (O) nanoparticles (CNPs, CaNPs and ONPs) as adjuvants to brachytherapy and external beam radiation therapy (EBRT), with the CNPs/CaNPs/ONPs released in situ from either brachytherapy spacers or fudicials loaded with the nanoparticles. The chemotherapy dose from the nanoparticles released in situ from within the prostate capsule, is enhanced by the physical dose due to photon interactions with the nanoparticles. The physical dose enhancement is due to low energy photons from the brachytherapy and EBRT sources interacting with the high-Z platinum component of the nanoparticles, causing emission of short-range photoelectrons to boost dose to the tumor. By varying the nanoparticle parameters, such as size, initial concentration, functionalization, location of spacer or fiducial, and intra-tumor biodistribution, the dose enhancement can be customized to maximize dose to tumor cells while minimizing toxicity to healthy cells. The hypothesis is that the CuRE approach will be a more efficacious method for concomitant cisplatin/carboplatin/oxaliplatin and radiotherapy treatment of localized prostate cancer due to significant dose boost to the PCa cells with minimal toxicity to healthy tissue. To investigate this hypothesis, microdosimetry calculations employing the energy loss formula of Cole were used to calculate the dose enhancement to the PCa cells from the CNPs/CaNPs/OPNs. The dose enhancement ratio (DEF) representing the ratio of the overall dose in the presence of CNPs/CaNPs/ONPs to the dose without CNPs/CaNPs/ONPs was determined for a range of CNP/CaNP/OPN concentrations up to their FDA approved limits. The dose enhancement to endothelial cells with (EDEF) with single concentration of cisplatin (42.8 mg/g) was found 2.6 with Pd-103. When EBRT source was used with single concentration of cisplatin, with 10cm x 10

Chemiluminescence involving acidic and ambient ion light emitters. The chemiluminescence of the 9-acridinepercarboxylate anion

DOE Office of Scientific and Technical Information (OSTI.GOV)

White, E.H.; Roswell, D.F.; Dupont, A.C.

The reaction of phenyl 9-acridinecarboxylate with an excess of peroxide ion in THF/water (67/33 mol %) leads to the emission of either bright yellow-green light or bright blue light, depending on the reaction conditions. The blue emission is favored by high concentrations of hydrogen peroxide and water, for example. 9-Acridinepercarboxylic acid is a common intermediate in the reactions. The light emitter responsible for the blue chemiluminescence is acridone, whereas that responsible for the yellow-green chemiluminescence is the anion of acridone. The effects of base concentration and solvent composition on the relative proportions of these two emitters have produced evidence that,more » contrary to the expectation of simple theory, a dioxetanone is not an intermediate in the reaction. Other cases where chemiluminescence may involve percarboxylate and peroxide ions are discussed.« less

Ultrathin diamond-like carbon film coated silver nanoparticles-based substrates for surface-enhanced Raman spectroscopy.

PubMed

Liu, Fanxin; Cao, Zhishen; Tang, Chaojun; Chen, Ling; Wang, Zhenlin

2010-05-25

We have demonstrated that by coating with a thin dielectric layer of tetrahedral amorphous carbon (ta-C), a biocompatible and optical transparent material in the visible range, the Ag nanoparticle-based substrate becomes extremely suitable for surface-enhanced Raman spectroscopy (SERS). Our measurements show that a 10 A or thicker ta-C layer becomes efficient to protect the oxygen-free Ag in air and prevent Ag ionizing in aqueous solutions. Furthermore, the Ag nanoparticles substrate coated with a 10 A ta-C film shows a higher enhancement of Raman signals than the uncoated substrate. These observations are further supported by our numerical simulations. We suggest that biomolecule detections in analytic assays could be easily realized using ta-C-coated Ag-based substrate for SERS especially in the visible range. The coated substrate also has higher mechanical stability, chemical inertness, and technological compliance, and may be useful, for example, to enhance TiO(2) photocatalysis and solar-cell efficiency by the surface plasmons.

Comparative study of β-glucan induced respiratory burst measured by nitroblue tetrazolium assay and real-time luminol-enhanced chemiluminescence assay in common carp (Cyprinus carpio L.).

PubMed

Vera-Jimenez, N I; Pietretti, D; Wiegertjes, G F; Nielsen, M E

2013-05-01

The respiratory burst is an important feature of the immune system. The increase in cellular oxygen uptake that marks the initiation of the respiratory burst is followed by the production of reactive oxygen species (ROS) such as superoxide anion and hydrogen peroxide which plays a role in the clearance of pathogens and tissue regeneration processes. Therefore, the respiratory burst and associated ROS constitute important indicators of fish health status. This paper compares two methods for quantitation of ROS produced during the respiratory burst in common carp: the widely used, single-point measurement based on the intracellular reduction of nitroblue tetrazolium (NBT) and a real-time luminol-enhanced assay based on the detection of native chemiluminescence. Both assays allowed for detection of dose-dependent changes in magnitude of the respiratory burst response induced by β-glucans in head kidney cells of carp. However, whereas the NBT assay was shown to detect the production of only superoxide anions, the real-time luminol-enhanced assay could detect the production of both superoxide anions and hydrogen peroxide. Only the chemiluminescence assay could reliably record the production of ROS on a real-time scale at frequent and continual time intervals for time course experiments, providing more detailed information on the respiratory burst response. The real-time chemiluminescence assay was used to measure respiratory burst activity in macrophage and neutrophilic granulocyte-enriched head kidney cell fractions and total head kidney cell suspensions and proved to be a fast, reliable, automated multiwell microplate assay to quantitate fish health status modulated by β-glucans. Copyright © 2013 Elsevier Ltd. All rights reserved.

Method of generating chemiluminescent light

DOEpatents

Spurlin, Stanford R.; Yeung, Edward S.

1986-01-01

A method of chemiluminescently determining a sulfide which is either hydrogen sulfide or methyl mercaptan by reacting the sulfide with chlorine dioxide at low pressure and under conditions which allow a longer reaction time in emission of a single photon for every two sulfide containing species, and thereafter, chemiluminescently detecting and determining the sulfide. The invention also relates not only to the detection method, but the novel chemical reaction that generates chemiluminescent light and a specifically designed chemiluminescence detection cell for the reaction.

An enhanced chemiluminescence resonance energy transfer system based on target recycling G-guadruplexes/hemin DNAzyme catalysis and its application in ultrasensitive detection of DNA.

PubMed

Chen, Jia; Huang, Yong; Vdovenko, Marina; Sakharov, Ivan Yu; Su, Guifa; Zhao, Shulin

2015-06-01

An enhanced chemiluminescence resonance energy transfer (CRET) system based on target recycling G-guadruplexes/hemin DNAzyme catalysis was developed for ultrasensitive detection of DNA. CRET system consists of luminol as chemiluminescent donor, and fluorescein isothiocyanate (FITC) as acceptor. The sensitive detection was achieved by using the system consisted of G-riched DNA, blocker DNA, and the Nb.BbvCI biocatalyst. Upon addition of target DNA to the system, target DNA hybridizes with the quasi-circular DNA structure, and forms a DNA duplex. The formation of DNA duplex triggers selective enzymatic cleavage of quasi-circular DNA by Nb.BbvCI, resulting in the release of target DNA and two G-riched DNAzyme segments. Released target DNA then hybridizes with another quasi-circular DNA structure to initiate the cleavage of the quasi-circular DNA structure. Eventually, each target DNA can go through many cycles, resulting in the digestion of many quasi-circular DNA structures, generating many G-riched DNAzyme segments. G-riched DNAzyme segment products assemble with hemin to form stable hemin/G-quadruplexes that exhibit peroxidase-like activity which can catalyze the oxidation of luminol by H2O2 to produce CL signals. In the presence of FITC, CL of luminol can excite FITC molecules, and thus produced CRET between the luminol and FITC. This unique analysis strategy gives a detection limit down to 80 fM, which is at least four orders of magnitude lower than that of unamplified DNA detection methods. Copyright © 2015 Elsevier B.V. All rights reserved.

[Development of selective determination methods for quinones with fluorescence and chemiluminescence detection and their application to environmental and biological samples].

PubMed

Kishikawa, Naoya

2010-10-01

Quinones are compounds that have various characteristics such as a biological electron transporter, an industrial product and a harmful environmental pollutant. Therefore, an effective determination method for quinones is required in many fields. This review describes the development of sensitive and selective determination methods for quinones based on some detection principles and their application to analyses in environmental, pharmaceutical and biological samples. Firstly, a fluorescence method was developed based on fluorogenic derivatization of quinones and applied to environmental analysis. Secondly, a luminol chemiluminescence method was developed based on generation of reactive oxygen species through the redox cycle of quinone and applied to pharmaceutical analysis. Thirdly, a photo-induced chemiluminescence method was developed based on formation of reactive oxygen species and fluorophore or chemiluminescence enhancer by the photoreaction of quinones and applied to biological and environmental analyses.

Enhancing endosomal escape for nanoparticle mediated siRNA delivery

NASA Astrophysics Data System (ADS)

Ma, Da

2014-05-01

Gene therapy with siRNA is a promising biotechnology to treat cancer and other diseases. To realize siRNA-based gene therapy, a safe and efficient delivery method is essential. Nanoparticle mediated siRNA delivery is of great importance to overcome biological barriers for systemic delivery in vivo. Based on recent discoveries, endosomal escape is a critical biological barrier to be overcome for siRNA delivery. This feature article focuses on endosomal escape strategies used for nanoparticle mediated siRNA delivery, including cationic polymers, pH sensitive polymers, calcium phosphate, and cell penetrating peptides. Work has been done to develop different endosomal escape strategies based on nanoparticle types, administration routes, and target organ/cell types. Also, enhancement of endosomal escape has been considered along with other aspects of siRNA delivery to ensure target specific accumulation, high cell uptake, and low toxicity. By enhancing endosomal escape and overcoming other biological barriers, great progress has been achieved in nanoparticle mediated siRNA delivery.

Plant tissue-based chemiluminescence biosensor for ethanol.

PubMed

Huang, Yuming; Wu, Fangqiong

2006-07-01

A plant tissue-based chemiluminescence biosensor for ethanol based on using mushroom (Agaricus bisporus) tissue as the recognition element is proposed in this paper. The principle for ethanol sensing relies on the luminol-potassium hexacyanoferrate(III)-hydrogen peroxide transducer reaction, in which hydrogen peroxide is produced from the ethanol enzymatic catalytic oxidation by oxygen under the catalysis of alcohol oxidase in the tissue column. Under optimum conditions, the method allowed the measurement of ethanol in the range of 0.001 - 2 mmol/l with a detection limit (3 sigma) of 0.2 micromol/l. The relative standard deviation (RSD) was 4.14% (n = 11) for 0.05 mmol/l ethanol. The proposed method has been applied to the determination of ethanol in biological fluids and beverages with satisfactory results.

Method of generating chemiluminescent light

DOEpatents

Spurlin, S.R.; Yeung, E.S.

1986-03-11

A method of chemiluminescently determining a sulfide which is either hydrogen sulfide or methyl mercaptan by reacting the sulfide with chlorine dioxide at low pressure and under conditions which allow a longer reaction time in emission of a single photon for every two sulfide containing species, and thereafter, chemiluminescently detecting and determining the sulfide. The invention also relates not only to the detection method, but the novel chemical reaction that generates chemiluminescent light and a specifically designed chemiluminescence detection cell for the reaction. 4 figs.

Surface plasmon coupled chemiluminescence during adsorption of oxygen on magnesium surfaces

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hagemann, Ulrich; Nienhaus, Hermann, E-mail: hermann.nienhaus@uni-due.de

The dissociative adsorption of oxygen molecules on magnesium surfaces represents a non-adiabatic reaction exhibiting exoelectron emission, chemicurrent generation, and weak chemiluminescence. Using thin film Mg/Ag/p-Si(111) Schottky diodes with 1 nm Mg on a 10-60 nm thick Ag layer as 2π-photodetectors, the chemiluminescence is internally detected with a much larger efficiency than external methods. The chemically induced photoyield shows a maximum for a Ag film thickness of 45 nm. The enhancement is explained by surface plasmon coupled chemiluminescence, i.e., surface plasmon polaritons are effectively excited in the Ag layer by the oxidation reaction and decay radiatively leading to the observed photocurrent.more » Model calculations of the maximum absorption in attenuated total reflection geometry support the interpretation. The study demonstrates the extreme sensitivity and the practical usage of internal detection schemes for investigating surface chemiluminescence.« less

Demonstration of surface-enhanced Raman scattering by tunable, plasmonic gallium nanoparticles.

PubMed

Wu, Pae C; Khoury, Christopher G; Kim, Tong-Ho; Yang, Yang; Losurdo, Maria; Bianco, Giuseppe V; Vo-Dinh, Tuan; Brown, April S; Everitt, Henry O

2009-09-02

Size-controlled gallium nanoparticles deposited on sapphire were explored as alternative substrates to enhance Raman spectral signatures. Gallium's resilience following oxidation is inherently advantageous in comparison with silver for practical ex vacuo nonsolution applications. Ga nanoparticles were grown using a simple molecular beam epitaxy-based fabrication protocol, and monitoring their corresponding surface plasmon resonance energy through in situ spectroscopic ellipsometry allowed the nanoparticles to be easily controlled for size. The Raman spectra obtained from cresyl fast violet (CFV) deposited on substrates with differing mean nanoparticle sizes represent the first demonstration of enhanced Raman signals from reproducibly tunable self-assembled Ga nanoparticles. Nonoptimized aggregate enhancement factors of approximately 80 were observed from the substrate with the smallest Ga nanoparticles for CFV dye solutions down to a dilution of 10 ppm.

Demonstration of surface-enhanced Raman scattering by tunable, plasmonic gallium nanoparticles

PubMed Central

Wu, Pae C; Khoury, Christopher G.; Kim, Tong-Ho; Yang, Yang; Losurdo, Maria; Bianco, Giuseppe V.; Vo-Dinh, Tuan; Brown, April S.; Everitt, Henry O.

2009-01-01

Size-controlled gallium nanoparticles deposited on sapphire are explored as alternative substrates to enhance Raman spectral signatures. Gallium’s resilience following oxidation is inherently advantageous compared to silver for practical ex vacuo, non-solution applications. Ga nanoparticles are grown using a simple, molecular beam epitaxy-based fabrication protocol, and by monitoring their corresponding surface plasmon resonance energy through in situ spectroscopic ellipsometry, the nanoparticles are easily controlled for size. Raman spectroscopy performed on cresyl fast violet (CFV) deposited on substrates of differing mean nanoparticle size represents the first demonstration of enhanced Raman signals from reproducibly tunable self-assembled Ga nanoparticles. Non-optimized aggregate enhancement factors of ~80 were observed from the substrate with the smallest Ga nanoparticles for CFV dye solutions down to a dilution of 10 ppm. PMID:19655747

Lipid-based nanoparticles for contrast-enhanced MRI and molecular imaging.

PubMed

Mulder, Willem J M; Strijkers, Gustav J; van Tilborg, Geralda A F; Griffioen, Arjan W; Nicolay, Klaas

2006-02-01

In the field of MR imaging and especially in the emerging field of cellular and molecular MR imaging, flexible strategies to synthesize contrast agents that can be manipulated in terms of size and composition and that can be easily conjugated with targeting ligands are required. Furthermore, the relaxivity of the contrast agents, especially for molecular imaging applications, should be very high to deal with the low sensitivity of MRI. Lipid-based nanoparticles, such as liposomes or micelles, have been used extensively in recent decades as drug carrier vehicles. A relatively new and promising application of lipidic nanoparticles is their use as multimodal MR contrast agents. Lipids are amphiphilic molecules with both a hydrophobic and a hydrophilic part, which spontaneously assemble into aggregates in an aqueous environment. In these aggregates, the amphiphiles are arranged such that the hydrophobic parts cluster together and the hydrophilic parts face the water. In the low concentration regime, a wide variety of structures can be formed, ranging from spherical micelles to disks or liposomes. Furthermore, a monolayer of lipids can serve as a shell to enclose a hydrophobic core. Hydrophobic iron oxide particles, quantum dots or perfluorocarbon emulsions can be solubilized using this approach. MR-detectable and fluorescent amphiphilic molecules can easily be incorporated in lipidic nanoparticles. Furthermore, targeting ligands can be conjugated to lipidic particles by incorporating lipids with a functional moiety to allow a specific interaction with molecular markers and to achieve accumulation of the particles at disease sites. In this review, an overview of different lipidic nanoparticles for use in MRI is given, with the main emphasis on Gd-based contrast agents. The mechanisms of particle formation, conjugation strategies and applications in the field of contrast-enhanced, cellular and molecular MRI are discussed. 2006 John Wiley & Sons, Ltd.

Apparently enhanced magnetization of Cu(I)-modified γ-Fe2O3 based nanoparticles

NASA Astrophysics Data System (ADS)

Qiu, Xiaoyan; He, Zhenghong; Mao, Hong; Zhang, Ting; Lin, Yueqiang; Liu, Xiaodong; Li, Decai; Meng, Xiangshen; Li, Jian

2017-11-01

Using a chemically induced transition method in FeCl2 solution, γ-Fe2O3 based magnetic nanoparticles, in which γ-Fe2O3 crystallites were coated with FeCl3ṡ6H2O, were prepared. During the synthesis of the γ-Fe2O3 nanoparticles Cu(I) modification of the particles was attempted. According to the results from both magnetization measurements and structural characterization, it was judged that a magnetic silent "dead layer", which can be attributed to spin disorder in the surface of the γ-Fe2O3 crystallites due to breaking of the crystal symmetry, existed in the unmodified particles. For the Cu(I)-modified sample, the CuCl thin layer on the γ-Fe2O3 crystallites incurred the crystal symmetry to reduce the spin disorder, which "awakened" the "dead layer" on the surface of the γ-Fe2O3 crystallites, enhancing the apparent magnetization of the Cu(I)-modified nanoparticles. It was determined that the surface spin disorder of the magnetic crystallite could be related to the coating layer on the crystallite, and can be modified by altering the coating layer to enhance the effective magnetization of the magnetic nanoparticles.

Surface enhanced Raman spectroscopy based nanoparticle assays for rapid, point-of-care diagnostics

NASA Astrophysics Data System (ADS)

Driscoll, Ashley J.

Nucleotide and immunoassays are important tools for disease diagnostics. Many of the current laboratory-based analytical diagnostic techniques require multiple assay steps and long incubation times before results are acquired. In the development of bioassays designed for detecting the emergence and spread of diseases in point-of-care (POC) and remote settings, more rapid and portable analytical methods are necessary. Nanoparticles provide simple and reproducible synthetic methods for the preparation of substrates that can be applied in colloidal assays, providing gains in kinetics due to miniaturization and plasmonic substrates for surface enhanced spectroscopies. Specifically, surface enhanced Raman spectroscopy (SERS) is finding broad application as a signal transduction method in immunological and nucleotide assays due to the production of narrow spectral peaks from the scattering molecules and the potential for simultaneous multiple analyte detection. The application of SERS to a no-wash, magnetic capture assay for the detection of West Nile Virus Envelope and Rift Valley Fever Virus N antigens is described. The platform utilizes colloid based capture of the target antigen in solution, magnetic collection of the immunocomplexes and acquisition of SERS spectra by a handheld Raman spectrometer. The reagents for a core-shell nanoparticle, SERS based assay designed for the capture of target microRNA implicated in acute myocardial infarction are also characterized. Several new, small molecule Raman scatterers are introduced and used to analyze the enhancing properties of the synthesized gold coated-magnetic nanoparticles. Nucleotide and immunoassay platforms have shown improvements in speed and analyte capture through the miniaturization of the capture surface and particle-based capture systems can provide a route to further surface miniaturization. A reaction-diffusion model of the colloidal assay platform is presented to understand the interplay of system

Enhanced detection of myeloperoxidase activity in deep tissues through luminescent excitation of near-infrared nanoparticles.

PubMed

Zhang, Ning; Francis, Kevin P; Prakash, Arun; Ansaldi, Daniel

2013-04-01

A previous study reported the use of luminol for the detection of myeloperoxidase (MPO) activity using optical imaging in infiltrating neutrophils under inflammatory disease conditions. The detection is based on a photon-emitting reaction between luminol and an MPO metabolite. Because of tissue absorption and scattering, however, luminol-emitted blue light can be efficiently detected from superficial inflammatory foci only. In this study we report a chemiluminescence resonance energy transfer (CRET) methodology in which luminol-generated blue light excites nanoparticles to emit light in the near-infrared spectral range, resulting in remarkable improvement of MPO detectability in vivo. CRET caused a 37-fold increase in luminescence emission over luminol alone in detecting MPO activity in lung tissues after lipopolysaccharide challenge. We demonstrated a dependence of the chemiluminescent signal on MPO activity using MPO-deficient mice. In addition, co-administration of 4-aminobenzoic acid hydrazide (4-ABAH), an irreversible inhibitor of MPO, significantly attenuated luminescent emission from inflamed lungs. Inhibition of nitric oxide synthase with a nonspecific inhibitor, L-NAME, had no effect on luminol-mediated chemiluminescence production. Pretreatment of mice with MLN120B, a selective inhibitor of IKK-2, resulted in suppression of neutrophil infiltration to the lung tissues and reduction of MPO activity. We also demonstrated that CRET can effectively detect MPO activity at deep tissue tumor foci due to tumor development-associated neutrophil infiltration. We developed a sensitive MPO detection methodology that provides a means for visualizing and quantifying oxidative stress in deep tissue. This method is amenable to rapid evaluation of anti-inflammatory agents in animal models.

Surface-enhanced Raman spectroscopy of double-shell hollow nanoparticles: electromagnetic and chemical enhancements.

PubMed

Mahmoud, Mahmoud A

2013-05-28

Enhancements of the Raman signal by the newly prepared gold-palladium and gold-platinum double-shell hollow nanoparticles were examined and compared with those using gold nanocages (AuNCs). The surface-enhanced Raman spectra (SERS) of thiophenol adsorbed on the surface of AuNCs assembled into a Langmuir-Blodgett monolayer were 10-fold stronger than AuNCs with an inner Pt or Pd shell. The chemical and electromagnetic enhancement mechanisms for these hollow nanoparticles were further proved by comparing the Raman enhancement of nitrothiophenol and nitrotoulene. Nitrothiophenol binds to the surface of the nanoparticles by covalent interaction, and Raman enhancement by both the two mechanisms is possible, while nitrotoulene does not form any chemical bond with the surface of the nanoparticles and hence no chemical enhancement is expected. Based on discrete dipole approximation (DDA) calculations and the experimental SERS results, AuNCs introduced a high electromagnetic enhancement, while the nanocages with inner Pt or Pd shell have a strong chemical enhancement. The optical measurements of the localized surface plasmon resonance (LSPR) of the nanocages with an outer Au shell and an inner Pt or Pd shell were found, experimentally and theoretically, to be broad compared with AuNCs. The possible reason could be due to the decrease of the coherence time of Au oscillated free electrons and fast damping of the plasmon energy. This agreed well with the fact that a Pt or Pd inner nanoshell decreases the electromagnetic field of the outer Au nanoshell while increasing the SERS chemical enhancement.

N-Hydroxysuccinimide as an effective chemiluminescence coreactant for highly selective and sensitive detection.

PubMed

Saqib, Muhammad; Li, Suping; Gao, Wenyue; Majeed, Saadat; Qi, Liming; Liu, Zhongyuan; Xu, Guobao

2016-12-01

The development of novel coreactants for chemiluminescence is very important to improve performance and widen its applications without using any other catalyst. N-Hydroxysuccinimide (NHS), a highly popular amine-reactive, activating, or protecting reagent in biochemical applications and organic synthesis, has been explored as an efficient and stable chemiluminescence coreactant for the first time. The chemiluminescence intensity of the newly developed luminol-NHS system is about 22 times higher than that of the traditional luminol-H 2 O 2 system. Chemiluminescence of this system is dramatically enhanced by Co 2+ . This new chemiluminescence system is then applied for the highly selective and ultrasensitive detection of Co 2+ with limit of detection (0.01 nM) better than those of several conventional analytical methods. This system also enables the efficient detection of luminol (LOD = 7 pM) and NHS (LOD = 3.0 μM) with excellent sensitivity. This chemiluminescence method was then also utilized to detect Co 2+ in tap water and blue silica gel with excellent recoveries in the range 99.20-103.07 %. This novel chemiluminescence system has several advantages, including simple, cost-effective, highly sensitive, selective, and wide linear range. We expect that this chemiluminescence system will be a promising candidate for chemical and biological sensing. Graphical Abstract Comparison of CL peak intensities of classical luminol-H 2 O 2 CL system and newly developed luminol-NHS CL system.

Using induced electroosmotic micromixer to enhance the reproducibility of chemiluminescence intensity.

PubMed

Chen, Hsiao-Ping; Yeh, Chun-Yi; Hung, Pei-Chin; Wang, Shau-Chun

2014-02-01

In this study, induced electroosmotic vortex flows were generated using an AC electric field by one pair of external electrodes to rapidly mix luminescence reagents in a 30 μL micromixer and enhance the reproducibility of chemiluminescence (CL) assays. A solution containing the catalyst reagent ferricyanide ions (4 μL) was pipetted into a reservoir containing luminol to produce CL in the presence of hydrogen peroxide. When the added ferricyanide aliquot contacted the reservoir solution, the CL began flashing, but rapidly diminished as the ferricyanide was consumed. In such a short illumination period, the solutes could not mix homogeneously. Therefore, the reproducibility of CL intensities collected using a CCD and multiple aliquot additions was determined to be inadequate. By contrast, when the solutes were efficiently mixed after adding a ferricyanide aliquot to a micromixer, the intensity reproducibility was significantly improved. When the CL temporal profile was analyzed using a PMT, a consistent improvement in reproducibility was observed between the CL intensity and estimated CL reaction rate. Replicating the proposed device would create a multiple well plate that contains a micromixer in each reservoir; this system is compatible with conventional CL instrumentation and requires no CL enhancer to slow a reaction. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A Greener Chemiluminescence Demonstration

ERIC Educational Resources Information Center

Jilani, Osman; Donahue, Trisha M.; Mitchell, Miguel O.

2011-01-01

Because they are dramatic and intriguing, chemiluminescence demonstrations have been used for decades to stimulate interest in chemistry. One of the most intense chemiluminescent reactions is the oxidation of diaryl oxalate diesters with hydrogen peroxide in the presence of a fluorescer. In typical lecture demonstrations, the commercially…

A microflow chemiluminescence sensor for indirect determination of dibutyl phthalate by hydrolyzing based on biological recognition materials.

PubMed

Qiu, Huamin; Fan, Lulu; Li, Xiangjun; Li, Leilei; Sun, Min; Luo, Chuannan

2013-03-05

A microflow chemiluminescence (CL) sensor for determination of dibutyl phthalate (DBP) based on magnetic molecularly imprinted polymer (MMIP) as recognition element was fabricated. Briefly, a hydrophilic molecularly imprinted polymer layer was produced at the surface of Fe₃O₄@SiO₂ magnetic nanoparticles (MNPs) via combination of molecular imprinting and reversible stimuli responsive hydrogel. In this protocol, the initial step involved co-precipitation of Fe²⁺ and Fe³⁺ in an ammonia solution. Silica was then coated on the Fe₃O₄ nanoparticles using a sol-gel method to obtain silica shell magnetic nanoparticles. The MMIP was synthesized using methacrylic acid (MAA) as functional monomer and ethylene glycol dimethacrylate (EGDMA) as cross-linker and 2,2-azobisisobutyronitrile (AIBN) as initiator in chloroform. Then the synthesized MMIP and magnetic non-molecular imprinted polymers (MNIP) were employed as recognition by packing into lab-made straight shape tubes, connected in CL analyzer for establishing the novel sensor with a single channel syringe pump. And a mixer for hydrolyzing of DBP was followed. Based on this experiment principle, DBP was determined indirectly. And the MMIP showed satisfactory recognition capacity to DBP, resulting to the wide linear range of 3.84 × 10⁻⁸ to 2.08 × 10⁻⁵ M and the low detection limit of 2.09 × 10⁻⁹ M (3σ) for DBP. The relative standard deviation (RSD) for DBP (3.20 × 10⁻⁶ M) was 1.40% (n=11). Besides improving sensitivity and selectivity, the sensor was reusable. The proposed DBP-MMIP-CL sensor has been successfully applied to determine DBP in drink samples. Copyright © 2012 Elsevier B.V. All rights reserved.

Molecularly imprinted polymer based on chemiluminescence imaging for the chiral recognition of dansyl-phenylalanine.

PubMed

Wang, Li; Zhang, Zhujun; Huang, Lianggao

2008-03-01

A new molecularly imprinted polymer (MIP)-chemiluminescence (CL) imaging detection approach towards chiral recognition of dansyl-phenylalanine (Phe) is presented. The polymer microspheres were synthesized using precipitation polymerization with dansyl-L-Phe as template. Polymer microspheres were immobilized in microtiter plates (96 wells) using poly(vinyl alcohol) (PVA) as glue. The analyte was selectively adsorbed on the MIP microspheres. After washing, the bound fraction was quantified based on peroxyoxalate chemiluminescence (PO-CL) analysis. In the presence of dansyl-Phe, bis(2,4,6-trichlorophenyl)oxalate (TCPO) reacted with hydrogen peroxide (H2O2) to emit chemiluminescence. The signal was detected and quantified with a highly sensitive cooled charge-coupled device (CCD). Influencing factors were investigated and optimized in detail. Control experiments using capillary electrophoresis showed that there was no significant difference between the proposed method and the control method at a confidence level of 95%. The method can perform 96 independent measurements simultaneously in 30 min and the limits of detection (LODs) for dansyl-L-Phe and dansyl-D-Phe were 0.025 micromol L(-1) and 0.075 micromol L(-1) (3sigma), respectively. The relative standard deviation (RSD) for 11 parallel measurements of dansyl-L-Phe (0.78 micromol L(-1)) was 8%. The results show that MIP-based CL imaging can become a useful analytical technology for quick chiral recognition.

N-bromosuccinimide-fluorescein based sensitive flow-injection chemiluminescence determination of phenformin.

PubMed

Wang, Zhouping; Zhang, Zhujun; Fu, Zhifeng; Fang, Luqiu; Zhang, Xiao

2004-02-01

A novel and highly sensitive method for the determination of phenformin over the range of 6 x 10(-9) - 1 x 10(-5) g ml(-1) in pharmaceutical formulations with flow-injection chemiluminescence (CL) detection is proposed. The method is based on the CL produced during the oxidation of N-bromosuccinimide (NBS) in an alkaline medium in the presence of fluorescein as an effective energy transfer agent. The use of cetyltrimethylammonium bromide (CTAB) as a sensitizer enhances the signal magnitude by about 100 times. The detection limit is 2 x 10(-9) g ml(-1) (3sigma) with a relative standard deviation of 2.3% (n = 11) at 1 x 10(-7) g ml(-1) phenformin. Ninety samples can be determined per hour. The method was evaluated by carrying out a recovery study and by the analysis of commercial formulations. The obtained results compared well with those by an official method, and demonstrated good accuracy and precision. The possible CL mechanism of the proposed system was also briefly analyzed.

Flow-injection chemiluminescence determination of melamine in urine and plasma.

PubMed

Tang, Xiaoshuang; Shi, Xiyan; Tang, Yuhai; Yue, Zhongjin; He, Qiqi

2012-01-01

A novel flow-injection chemiluminescence method for the determination of melamine in urine and plasma was developed. It was found that melamine can remarkably enhance chemiluminescence emission from the luminol-K(3) Fe(CN)(6) system in an alkaline medium. Under the optimum conditions, chemiluminescence intensity had a good linear relationship with the concentration of melamine in the range 9.0 × 10(-9) -7.0 × 10(-6) g/mL, with a correlation coefficient of 0.9992. The detection limit (3σ) was 3.5 ng/mL. The method has been applied to determine the concentration of melamine in samples using liquid-liquid extraction. Average recoveries of melamine were 102.6% in urine samples and 95.1% in plasma samples. The method provided a reproducible and stable approach for the sensitive detection of melamine in urine and plasma samples. Copyright © 2011 John Wiley & Sons, Ltd.

Biodegradable magnesium nanoparticle-enhanced laser hyperthermia therapy

PubMed Central

Wang, Qian; Xie, Liping; He, Zhizhu; Di, Derui; Liu, Jing

2012-01-01

Background Recently, nanoparticles have been demonstrated to have tremendous merit in terms of improving the treatment specificity and thermal ablation effect on tumors. However, the potential toxicity and long-term side effects caused by the introduced nanoparticles and by expelling them out of the body following surgery remain a significant challenge. Here, we propose for the first time to directly adopt magnesium nanoparticles as the heating enhancer in laser thermal ablation to avoid these problems by making full use of the perfect biodegradable properties of this specific material. Methods To better understand the new nano “green” hyperthermia modality, we evaluated the effects of magnesium nanoparticles on the temperature transients inside the human body subject to laser interstitial heating. Further, we experimentally investigated the heating enhancement effects of magnesium nanoparticles on a group of biological samples: oil, egg white, egg yolk, in vitro pig tissues, and the in vivo hind leg of rabbit when subjected to laser irradiation. Results Both the theoretical simulations and experimental measurements demonstrated that the target tissues injected with magnesium nanoparticles reached much higher temperatures than tissues without magnesium nanoparticles. This revealed the enhancing behavior of the new nanohyperthermia method. Conclusion Given the unique features of magnesium nanoparticles – their complete biological safety and ability to enhance heating – which most other advanced metal nanoparticles do not possess, the use of magnesium nanoparticles in hyperthermia therapy offers an important “green” nanomedicine modality for treating tumors. This method has the potential to be used in clinics in the near future. PMID:22956872

Review of Federal Reference Method for Ozone: Nitric Oxide-Chemiluminescence

EPA Science Inventory

•The proposed new FRM measurement principle for ozone is based on quantitative measurement of the chemiluminescence emission from the gas-phase reaction of ozone in an air sample with nitric oxide (NO).•The chemiluminescence from the NO-O3 reaction (with excess NO) is p...

Silica nanoparticle based techniques for extraction, detection, and degradation of pesticides.

PubMed

Bapat, Gandhali; Labade, Chaitali; Chaudhari, Amol; Zinjarde, Smita

2016-11-01

Silica nanoparticles (SiNPs) find applications in the fields of drug delivery, catalysis, immobilization and sensing. Their synthesis can be mediated in a facile manner and they display broad range compatibility and stability. Their existence in the form of spheres, wires and sheets renders them suitable for varied purposes. This review summarizes the use of silica nanostructures in developing techniques for extraction, detection and degradation of pesticides. Silica nanostructures on account of their sorbent properties, porous nature and increased surface area allow effective extraction of pesticides. They can be modified (with ionic liquids, silanes or amines), coated with molecularly imprinted polymers or magnetized to improve the extraction of pesticides. Moreover, they can be altered to increase their sensitivity and stability. In addition to the analysis of pesticides by sophisticated techniques such as High Performance Liquid Chromatography or Gas chromatography, silica nanoparticles related simple detection methods are also proving to be effective. Electrochemical and optical detection based on enzymes (acetylcholinesterase and organophosphate hydrolase) or antibodies have been developed. Pesticide sensors dependent on fluorescence, chemiluminescence or Surface Enhanced Raman Spectroscopic responses are also SiNP based. Moreover, degradative enzymes (organophosphate hydrolases, carboxyesterases and laccases) and bacterial cells that produce recombinant enzymes have been immobilized on SiNPs for mediating pesticide degradation. After immobilization, these systems show increased stability and improved degradation. SiNP are significant in developing systems for effective extraction, detection and degradation of pesticides. SiNPs on account of their chemically inert nature and amenability to surface modifications makes them popular tools for fabricating devices for 'on-site' applications. Copyright © 2016 Elsevier B.V. All rights reserved.

Chemiluminescence Resonance Energy Transfer-based Detection for Microchip Electrophoresis

PubMed Central

Huang, Yong; Shi, Ming; Liu, Rongjun

2010-01-01

Since the channels in micro- and nanofluidic devices are extremely small, a sensitive detection is required following microchip electrophoresis (MCE). This work describes a highly sensitive and yet universal detection scheme based on chemiluminescence resonance energy transfer (CRET) for MCE. It was found that an efficient CRET occurred between a luminol donor and a CdTe quantum dot (QD) acceptor in the luminol-NaBrO-QD system, and that it was sensitively suppressed by the presence of certain organic compounds of biological interest including biogenic amines and thiols, amino acids, organic acids, and steroids. These findings allowed developing sensitive MCE-CL assays for the tested compounds. The proposed MCE-CL methods showed desired analytical figures of merit such as a wide concentration range of linear response. Detection limits obtained were ~10−9 M for biogenic amines including dopamine and epinephrine, and ~ 10−8 M for biogenic thiols (e.g. glutathione and acetylcysteine), organic acids (i.e. ascorbic acid and uric acid), estrogens, and native amino acids. These were 10 to 1000 times more sensitive than those of previously reported MCE-based methods with chemiluminescence, electrochemical, or laser induced fluorescence detection for quantifying corresponding compounds. To evaluate the applicability of the present MCE-CL method for analyzing real biological samples, it was used to determine amino acids in individual human red blood cells. Nine amino acids including Lys, Ser, Ala, Glu, Trp, etc. were detected. The contents ranged from 3 to 31 amol /cell. The assay proved to be simple, quick, reproducible, and very sensitive. PMID:20121202

Oxygen transport enhancement by functionalized magnetic nanoparticles (FMP) in bioprocesses

NASA Astrophysics Data System (ADS)

Ataide, Filipe Andre Prata

nanoparticles on interfacial area and mass transfer coefficient. The parameters ranges used were: 250-750 rpm for stirring speed, 0-2 vvm for aeration and 0-0.00120 g g?1 magnetic nanoparticles mass fraction. It was found that 36 nm-sized nanoparticles produced during the course of this dissertation enhanced the volumetric mass transfer coefficient up to 3.3-fold and the interfacial area up to 3.3-fold in relation to gas-liquid dispersions without nanoparticles. These results are concordant with previously published enhancement data (kLa enhancement by 7.1-fold and a enhancement by 4.1-fold) (Olle et al. 2006). The magnetic nanoparticles synthesized in this thesis were stable (constant diameter) over a 1wide pH range (2-9). Statistical regression models showed that both kLa and a have high sensitivity to the nanoparticles loading. Empirical correlation models were derived for kLa and for interfacial area, a, as function of physical properties and nanoparticles loading. These correlations lay out a methodology that can help the scientific community to design and scale-up oxygen transfer systems that are based on nanoparticle suspensions. None None None None None None None None None None None None None None None None None None None None None None None None None None None None None None None None None None None None None None None None None None

Chemiluminescents Light Up the Night.

ERIC Educational Resources Information Center

Dashiell, Judy

1997-01-01

Provides a general description of chemiluminescence and distinguishes between the two types of chemistry that contribute to our understanding of chemiluminescence: fluorescence and the excitation process. Presents an activity that explores the phenomenon. (DDR)

Fluorosurfactant-capped gold nanoparticles-enhanced chemiluminescence from hydrogen peroxide-hydroxide and hydrogen peroxide-bicarbonate in presence of cobalt(II)

NASA Astrophysics Data System (ADS)

Li, Jinge; Li, Qianqian; Lu, Chao; Zhao, Lixia; Lin, Jin-Ming

2011-02-01

Nonionic fluorosurfactant (FSN)-capped gold nanoparticles (GNPs) remain excellently stable at a wider pH range and high ionic strength, which is useful to investigate some CL systems involved in high salt and a strict pH range. In this study, we utilized FSN-capped GNPs of different sizes to distinguish the emitting species from H 2O 2-Co 2+-NaOH and H 2O 2-Co 2+-NaHCO 3 systems. When the pH of FSN-capped gold colloidal solution was adjusted to 10.2 by dropwise addition of 0.05 M NaOH, the CL intensity of H 2O 2-Co 2+-NaHCO 3 system was enhanced 6-fold or 60-fold respectively in the presence of FSN-capped 14 nm or 69 nm GNPs with comparison to H 2O 2-Co 2+-NaOH. The variation of CL spectra and UV-vis spectra, as well as the quenching effect of reactive oxygen species scavengers were studied in detail to understand the CL enhancement mechanisms of FSN-capped GNPs on the two systems. For H 2O 2-Co 2+-NaOH system, the gold(I) complexes intermediate and singlet oxygen dimol species were proposed as the emitting species. The excited states of the carbon dioxide dimers and singlet oxygen dimol species were considered responsible for the light emission of H 2O 2-Co 2+-NaHCO 3 system. To our knowledge, this work is the first time to study the two CL systems simultaneously using nanoparticles.

Reagentless chemiluminescence-based fiber optic sensors for regenerative life support in space

NASA Astrophysics Data System (ADS)

Atwater, James E.; Akse, James R.; DeHart, Jeffrey; Wheeler, Richard R., Jr.

1995-04-01

The initial feasibility demonstration of a reagentless chemiluminescence based fiber optic sensor technology for use in advanced regenerative life support applications in space and planetary outposts is described. The primary constraints for extraterrestrial deployment of any technology are compatibility with microgravity and hypogravity environments; minimal size, weight, and power consumption; and minimal use of expendables due to the great expense and difficulty inherent to resupply logistics. In the current research, we report the integration of solid state flow through modules for the production of aqueous phase reagents into an integrated system for the detection of important analytes by chemiluminescence, with fiber optic light transmission. By minimizing the need for resupply expendables, the use of solid phase modules makes complex chemical detection schemes practical. For the proof of concept, hydrogen peroxide and glucose were chosen as analytes. The reaction is catalyzed by glucose oxidase, an immobilized enzyme. The aqueous phase chemistry required for sensor operation is implemented using solid phase modules which adjust the pH of the influent stream, catalyze the oxidation of analyte, and provide the controlled addition of the luminophore to the flowing aqueous stream. Precise control of the pH has proven essential for the long-term sustained release of the luminophore. Electrocatalysis is achieved using a controlled potential across gold mesh and gold foil electrodes which undergo periodic polarity reversals. The development and initial characterization of performance of the reagentless fiber optic chemiluminescence sensors are presented in this paper.

Lucigenin-dependent chemiluminescence in articular chondrocytes.

PubMed

Rathakrishnan, C; Tiku, M L

1993-08-01

We were recently able to measure intracellular levels of hydrogen peroxide within normal articular chondrocytes using the trapped indicator 2',7'-dichlorofluorescein diacetate. Further studies have shown that stimulated chondrocytes produce luminol-dependent chemiluminescence, suggesting that these cells produce hydrogen peroxide and singlet oxygen. In the present study, we have investigated the lucigenin-dependent chemiluminescence response in normal articular chondrocytes. Chondrocytes either in suspension or adhered to cover slips showed lucigenin-dependent chemiluminescence. There was a dose-dependent increase in chemiluminescence response when chondrocytes were incubated with soluble stimuli like phorbol-myristate-acetate, concanavalin A, and f-met-leu-phe. Catalase and the metabolic inhibitor, sodium azide, which inhibits the enzyme myeloperoxidase, had no inhibitory effect on lucigenin-dependent chemiluminescence production. Only the antioxidant, superoxide dismutase, prevented lucigenin-dependent chemiluminescence, indicating that this assay measures the production of superoxide anions by chondrocytes. We confirmed that chondrocytes release superoxide radicals using the biochemical assay of ferricytochrome c reduction. Since cartilage tissue is semi-transparent, we were able to measure chemiluminescence response in live cartilage tissue, showing that chondrocytes which are embedded within the matrix can also generate superoxide anion radicals. Reactive oxygen intermediates have been shown to play a significant role in the degradation of matrix in arthritis. Our previous and present studies suggest that oxygen radicals produced by chondrocytes may be an important mechanism by which chondrocytes induce cartilage matrix degradation.

Surface modification of protein enhances encapsulation in chitosan nanoparticles

NASA Astrophysics Data System (ADS)

Koyani, Rina D.; Andrade, Mariana; Quester, Katrin; Gaytán, Paul; Huerta-Saquero, Alejandro; Vazquez-Duhalt, Rafael

2018-04-01

Chitosan nanoparticles have a huge potential as nanocarriers for environmental and biomedical purposes. Protein encapsulation in nano-sized chitosan provides protection against inactivation, proteolysis, and other alterations due to environmental conditions, as well as the possibility to be targeted to specific tissues by ligand functionalization. In this work, we demonstrate that the chemical modification of the protein surface enhances the protein loading in chitosan nanocarriers. Encapsulation of green fluorescent protein and the cytochrome P450 was studied. The increase of electrostatic interactions between the free amino groups of chitosan and the increased number of free carboxylic groups in the protein surface enhance the protein loading, protein retention, and, thus, the enzymatic activity of chitosan nanoparticles. The chemical modification of protein surface with malonic acid moieties reduced drastically the protein isoelectric point increasing the protein interaction with the polycationic biomaterial and chitosan. The chemical modification of protein does not alter the morphology of chitosan nanoparticles that showed an average diameter of 18 nm, spheroidal in shape, and smooth surfaced. The strategy of chemical modification of protein surface, shown here, is a simple and efficient technique to enhance the protein loading in chitosan nanoparticles. This technique could be used for other nanoparticles based on polycationic or polyanionic materials. The increase of protein loading improves, doubtless, the performance of protein-loaded chitosan nanoparticles for biotechnological and biomedical applications.

Thermophysical Properties of Nanoparticle-Enhanced Ionic Liquids (NEILs) Heat-Transfer Fluids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fox, Elise B.; Visser, Ann E.; Bridges, Nicholas J.

2013-06-20

An experimental investigation was completed on nanoparticle enhanced ionic liquid heat transfer fluids as an alternative to conventional organic based heat transfer fluids (HTFs). These nanoparticle-based HTFs have the potential to deliver higher thermal conductivity than the base fluid without a significant increase in viscosity at elevated temperatures. The effect of nanoparticle morphology and chemistry on thermophysical properties was examined. Whisker shaped nanomaterials were found to have the largest thermal conductivity temperature dependence and were also less likely to agglomerate in the base fluid than spherical shaped nanomaterials.

Enhancing nanoparticle electrodynamics with gold nanoplate mirrors.

PubMed

Yan, Zijie; Bao, Ying; Manna, Uttam; Shah, Raman A; Scherer, Norbert F

2014-05-14

Mirrors and optical cavities can modify and enhance matter-radiation interactions. Here we report that chemically synthesized Au nanoplates can serve as micrometer-size mirrors that enhance electrodynamic interactions. Because of their plasmonic properties, the Au nanoplates enhance the brightness of scattered light from Ag nanoparticles near the nanoplate surface in dark-field microscopy. More importantly, enhanced optical trapping and optical binding of Ag nanoparticles are demonstrated in interferometric optical traps created from a single laser beam and its reflection from individual Au nanoplates. The enhancement of the interparticle force constant is ≈20-fold more than expected from the increased intensity due to standing wave interference. We show that the additional stability for optical binding arises from the restricted axial thermal motion of the nanoparticles that couples to and reduces the fluctuations in the lateral plane. This new mechanism greatly advances the photonic synthesis of ultrastable nanoparticle arrays and investigation of their properties.

New Dendrimer-Based Nanoparticles Enhance Curcumin Solubility.

PubMed

Falconieri, Maria Cristina; Adamo, Mauro; Monasterolo, Claudio; Bergonzi, Maria Camilla; Coronnello, Marcella; Bilia, Anna Rita

2017-03-01

Curcumin, the main curcuminoid of the popular Indian spice turmeric, is a potent chemopreventive agent and useful in many different diseases. A major limitation of applicability of curcumin as a health promoting and medicinal agent is its extremely low bioavailability due to efficient first pass metabolism, poor gastrointestinal absorption, rapid elimination, and poor aqueous solubility. In the present study, nanotechnology was selected as a choice approach to enhance the bioavailability of the curcuminis. A new polyamidoamine dendrimer (G0.5) was synthesized, characterized, and tested for cytotoxicity in human breast cancer cells (MCF-7). No cytotoxicity of G0.5 was found in the range between 10 -3 and 3 × 10 -8  M. Consequently, G0.5 was used to prepare spherical nanoparticles of ca. 150 nm, which were loaded with curcumin [molar ratio G0.5/curcumin 1 : 1 (formulation 1) and 1 : 0.5 (formulation 2)]. Remarkably, the occurrence of a single population of nanoparticles having an excellent polydispersity index (< 0.20) was found in both formulations. Formulation 1 was selected to test in vitro drug release because it was superior in terms of encapsulation efficiency (62 %) and loading capacity (32 %). The solubility of curcumin was increased ca. 415 and 150 times with respect to the unformulated drug, respectively, for formulation 1 and formulation 2. The release of curcumin from the nanoparticles showed an interesting prolonged and sustained release profile. Georg Thieme Verlag KG Stuttgart · New York.

Vitamin A determination in milk samples based on the luminol-periodate chemiluminescence system.

PubMed

Rishi, Lubna; Yaqoob, Mohammad; Waseem, Amir; Nabi, Abdul

2014-01-01

A simple and rapid flow injection (FI) method for the determination of retinyl acetate is reported based on its enhancing effect on the luminol-periodate chemiluminescence (CL) system in an alkaline medium. The detection limit (3s×blank) was 8.0×10⁻⁸ mol L⁻¹, with an injection throughput of 90 h⁻¹. The method allows linear increase of CL intensity over the retinyl acetate concentration range of 1.0-100×10⁻⁷ mol L⁻¹ (R²=0.9996) with relative standard deviations of 2.4% (n=10) for 5.0×10⁻⁷ mol L⁻¹. The key chemical and physical variables (reagent concentrations, flow rates, sample volume, and photomultiplier tube (PMT) voltage) were optimized and potential interferences were investigated. The method was successfully applied to human milk, fresh cow's milk and infant milk-based formulas and the results were in good agreement with the previously reported HPLC method. A brief discussion on the possible CL reaction mechanism is also presented.

Superparamagnetic nanoparticles for enhanced magnetic resonance and multimodal imaging

NASA Astrophysics Data System (ADS)

Sikma, Elise Ann Schultz

Magnetic resonance imaging (MRI) is a powerful tool for noninvasive tomographic imaging of biological systems with high spatial and temporal resolution. Superparamagnetic (SPM) nanoparticles have emerged as highly effective MR contrast agents due to their biocompatibility, ease of surface modification and magnetic properties. Conventional nanoparticle contrast agents suffer from difficult synthetic reproducibility, polydisperse sizes and weak magnetism. Numerous synthetic techniques and nanoparticle formulations have been developed to overcome these barriers. However, there are still major limitations in the development of new nanoparticle-based probes for MR and multimodal imaging including low signal amplification and absence of biochemical reporters. To address these issues, a set of multimodal (T2/optical) and dual contrast (T1/T2) nanoparticle probes has been developed. Their unique magnetic properties and imaging capabilities were thoroughly explored. An enzyme-activatable contrast agent is currently being developed as an innovative means for early in vivo detection of cancer at the cellular level. Multimodal probes function by combining the strengths of multiple imaging techniques into a single agent. Co-registration of data obtained by multiple imaging modalities validates the data, enhancing its quality and reliability. A series of T2/optical probes were successfully synthesized by attachment of a fluorescent dye to the surface of different types of nanoparticles. The multimodal nanoparticles generated sufficient MR and fluorescence signal to image transplanted islets in vivo. Dual contrast T1/T2 imaging probes were designed to overcome disadvantages inherent in the individual T1 and T2 components. A class of T1/T2 agents was developed consisting of a gadolinium (III) complex (DTPA chelate or DO3A macrocycle) conjugated to a biocompatible silica-coated metal oxide nanoparticle through a disulfide linker. The disulfide linker has the ability to be reduced

Chemiluminescence immunoassay for the rapid and sensitive detection of antibody against porcine parvovirus by using horseradish peroxidase/detection antibody-coated gold nanoparticles as nanoprobes.

PubMed

Zhou, Yuan; Zhou, Tao; Zhou, Rui; Hu, Yonggang

2014-06-01

A rapid, simple, facile, sensitive and enzyme-amplified chemiluminescence immunoassay (CLIA) method to detect antibodies against porcine parvovirus has been developed. Horseradish peroxidase (HRP) and the detection antibody were simultaneously co-immobilized on the surface of gold nanoparticles using the electrostatic method to form gold nanoparticle-based nanoprobes. This nanoprobe was employed in a sandwich-type CLIA, which enables CL signal readout from enzymatic catalysis and results in signal amplification. The presence of porcine parvovirus infection was determined in porcine parvovirus antibodies by measuring the CL intensity caused by the reaction of HRP-luminol with H2 O2 . Under optimal conditions, the obtained calibration plot for the standard positive serum was approximately linear within the dilution range of 1:80 to 1:5120. The limit of detection for the assay was 1:10,240 (S/N = 3), which is much lower than that typically achieved with an enzyme-linked immunosorbent assay (1:160; S/N = 3). A series of repeatability measurements using 1:320-fold diluted standard positive serum gave reproducible results with a relative standard deviation of 4.9% (n = 11). The ability of the immunosensor to analyze clinical samples was tested on porcine sera. The immunosensor had an efficiency of 90%, a sensitivity of 93.3%, and a specificity of 87.5% relative to the enzyme-linked immunosorbent assay results. Copyright © 2013 John Wiley & Sons, Ltd.

Chemiluminescence-based pesticide biosensor utilizing the intelligent evolved properties of the enzyme alkaline phosphatase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ayyagari, M.; Kamtekar, S.; Pande, R.

A methodology is described for immobilizing the enzyme alkaline phosphatase onto a glass surface using a novel biotinylated copolymer, poly(3-undecylthiophene-co-3- methanoithiophene). A streptavidin conjugate of alkaline phosphatase is used in this study. The biotinylated polymer is attached to the silanized glass surface via hydrophobic interactions and the enzyme is interfaced with the polymer through the classical biotin- streptavidin interaction. Alkaline phosphatase catalyzes the dephosphorylation of a macrocyclic compound, chloro-3-(4-methoxy spiro) (1,2 dioxetane-3-2`-tricyclo-) (3.3.1.1 )-(decani-4-yl) phenyl phosphate, to a species which emits energy by chemiluminescence. This chemiluminescence signal can be detected with a photomultiplier tube for enzymatic catalysis with the biocatalystmore » both in solution and immobilized on a glass surface. The signal generation is inhibited by the organophosphorus based insecticides such as paraoxon as well as nerve agents. We demonstrate in this study that a number of organophosphorus based insecticides inhibit the enzyme-mediated generation of chemiluminescence signal. This is true for the enzyme conjugate both free in solution and immobilized on a glass surface. In solution, the inhibition resembles the case of a partially uncompetitive system. By this type of inhibition we are able to detect pesticides down to about 50 ppb for the enzyme in solution. The pesticide detection limit of immobilized enzyme is currently being investigated. The enzyme is capable of a number of measurement cycles without significant loss of signal level.« less

Rapid Nanoprobe Signal Enhancement by In Situ Gold Nanoparticle Synthesis.

PubMed

Dias, Jorge T; Svedberg, Gustav; Nystrand, Mats; Andersson-Svahn, Helene; Gantelius, Jesper

2018-03-07

The use of nanoprobes such as gold, silver, silica or iron-oxide nanoparticles as detection reagents in bioanalytical assays can enable high sensitivity and convenient colorimetric readout. However, high densities of nanoparticles are typically needed for detection. The available synthesis-based enhancement protocols are either limited to gold and silver nanoparticles or rely on precise enzymatic control and optimization. Here, we present a protocol to enhance the colorimetric readout of gold, silver, silica, and iron oxide nanoprobes. It was observed that the colorimetric signal can be improved by up to a 10000-fold factor. The basis for such signal enhancement strategies is the chemical reduction of Au 3+ to Au 0 . There are several chemical reactions that enable the reduction of Au 3+ to Au 0 . In the protocol, Good's buffers and H2O2 are used and it is possible to favor the deposition of Au 0 onto the surface of existing nanoprobes, in detriment of the formation of new gold nanoparticles. The protocol consists of the incubation of the microarray with a solution consisting of chloroauric acid and H2O2 in 2-(N-morpholino)ethanesulfonic acid pH 6 buffer following the nanoprobe-based detection assay. The enhancement solution can be applied to paper and glass-based sensors. Moreover, it can be used in commercially available immunoassays as demonstrated by the application of the method to a commercial allergen microarray. The signal development requires less than 5 min of incubation with the enhancement solution and the readout can be assessed by naked eye or low-end image acquisition devices such as a table-top scanner or a digital camera.

Fluorosurfactant-capped gold nanoparticles-enhanced chemiluminescence from hydrogen peroxide-hydroxide and hydrogen peroxide-bicarbonate in presence of cobalt(II).

PubMed

Li, Jinge; Li, Qianqian; Lu, Chao; Zhao, Lixia; Lin, Jin-Ming

2011-02-01

Nonionic fluorosurfactant (FSN)-capped gold nanoparticles (GNPs) remain excellently stable at a wider pH range and high ionic strength, which is useful to investigate some CL systems involved in high salt and a strict pH range. In this study, we utilized FSN-capped GNPs of different sizes to distinguish the emitting species from H2O2-Co2+-NaOH and H2O2-Co2+-NaHCO3 systems. When the pH of FSN-capped gold colloidal solution was adjusted to 10.2 by dropwise addition of 0.05 M NaOH, the CL intensity of H2O2-Co2+-NaHCO3 system was enhanced 6-fold or 60-fold respectively in the presence of FSN-capped 14 nm or 69 nm GNPs with comparison to H2O2-Co2+-NaOH. The variation of CL spectra and UV-vis spectra, as well as the quenching effect of reactive oxygen species scavengers were studied in detail to understand the CL enhancement mechanisms of FSN-capped GNPs on the two systems. For H2O2-Co2+-NaOH system, the gold(I) complexes intermediate and singlet oxygen dimol species were proposed as the emitting species. The excited states of the carbon dioxide dimers and singlet oxygen dimol species were considered responsible for the light emission of H2O2-Co2+-NaHCO3 system. To our knowledge, this work is the first time to study the two CL systems simultaneously using nanoparticles. Copyright © 2010 Elsevier B.V. All rights reserved.

Rapid method for the quantification of hydroquinone concentration: chemiluminescent analysis.

PubMed

Chen, Tung-Sheng; Liou, Show-Yih; Kuo, Wei-Wen; Wu, Hsi-Chin; Jong, Gwo-Ping; Wang, Hsueh-Fang; Shen, Chia-Yao; Padma, V Vijaya; Huang, Chih-Yang; Chang, Yen-Lin

2015-11-01

Topical hydroquinone serves as a skin whitener and is usually available in cosmetics or on prescription based on the hydroquinone concentration. Quantification of hydroquinone content therefore becomes an important issue in topical agents. High-performance liquid chromatography (HPLC) is the commonest method for determining hydroquinone content in topical agents, but this method is time-consuming and uses many solvents that can become an environmental issue. We report a rapid method for quantifying hydroquinone content by chemiluminescent analysis. Hydroquinone induces the production of hydrogen peroxide in the presence of basic compounds. Hydrogen peroxide induced by hydroquinone oxidized light-emitting materials such as lucigenin, resulted in the production of ultra-weak chemiluminescence that was detected by a chemiluminescence analyzer. The intensity of the chemiluminescence was found to be proportional to the hydroquinone concentration. We suggest that the rapid (measurement time, 60 s) and virtually solvent-free (solvent volume, <2 mL) chemiluminescent method described here for quantifying hydroquinone content may be an alternative to HPLC analysis. Copyright © 2015 John Wiley & Sons, Ltd.

[A study on europium sensitized chemiluminescence of pipemidic acid].

PubMed

Li, Xia; Qiang, Hong; Wang, Xiao-li; Chen, Shi-lü; Zhao, Hui-chun

2004-12-01

A flow injection chemiluminescence method for the determination of Pipemidic acid (PPA) was developed. It is based on luminescence produced with KMnO4-Na2S2O4 CL system sensitized by Eu3+-PPA. The familar excipients such as starch and dextrine do not cause interference. The several kinds of affect on chemiluminescence were studied. The linear range and detection limit for PPA are 7.00 x 10(-9)-9.00 x 10(-7) mol x L(-1) and 4.09 x 10(-9) mol x L(-1), respectively. This method have successfully been applied to the determination of PPA in tablet and urine. And the mechanism of chemiluminescence is proposed.

Thermal conductivity enhancements and viscosity properties of water based Nanofluid containing carbon nanotubes decorated with ag nanoparticles

NASA Astrophysics Data System (ADS)

Gu, Yanni; Xu, Sheng; Wu, Xiaoshan

2018-01-01

The water based nanofluid containing carbon nanotube (CNT) decorated with Ag nanoparticles (Ag/CNT) is prepared. Its thermal conductivity (k) enhancement increases with the thermal filler loading and the decoration quantity of Ag nanoparticles. The low absolute CNT content will decrease the tangles or aggregations among the CNTs, and it will be good at the Brownian motion of CNTs in the water. It has positive effects on the thermal conductivity of nanofluid. With the increase of Ag loading, the average size of Ag nanoparticles increased, and further results in the decrease of dispersing amount of Ag/CNT as the weight of Ag/CNT is fixed. Little dispersing quantity of Ag/CNT makes it possible that the Ag/CNT particles disperse well in the fluid. So it is not easy for CNTs to form aggregation. The high intrinsic k of CNT and the effective thermal conductive networks forming by CNTs and Ag nanoparticles are good at the k enhancement. With temperature increase the k of Ag/CNT nanofluid appears improvement. The study results make it possible to develop high-efficiency nanofluid for advanced thermal management regions.

Thermal conductivity enhancements and viscosity properties of water based Nanofluid containing carbon nanotubes decorated with ag nanoparticles

NASA Astrophysics Data System (ADS)

Gu, Yanni; Xu, Sheng; Wu, Xiaoshan

2018-06-01

The water based nanofluid containing carbon nanotube (CNT) decorated with Ag nanoparticles (Ag/CNT) is prepared. Its thermal conductivity ( k) enhancement increases with the thermal filler loading and the decoration quantity of Ag nanoparticles. The low absolute CNT content will decrease the tangles or aggregations among the CNTs, and it will be good at the Brownian motion of CNTs in the water. It has positive effects on the thermal conductivity of nanofluid. With the increase of Ag loading, the average size of Ag nanoparticles increased, and further results in the decrease of dispersing amount of Ag/CNT as the weight of Ag/CNT is fixed. Little dispersing quantity of Ag/CNT makes it possible that the Ag/CNT particles disperse well in the fluid. So it is not easy for CNTs to form aggregation. The high intrinsic k of CNT and the effective thermal conductive networks forming by CNTs and Ag nanoparticles are good at the k enhancement. With temperature increase the k of Ag/CNT nanofluid appears improvement. The study results make it possible to develop high-efficiency nanofluid for advanced thermal management regions.

Homogeneous assay of target molecules based on chemiluminescence resonance energy transfer (CRET) using DNAzyme-linked aptamers.

PubMed

Mun, Hyoyoung; Jo, Eun-Jung; Li, Taihua; Joung, Hyou-Arm; Hong, Dong-Gu; Shim, Won-Bo; Jung, Cheulhee; Kim, Min-Gon

2014-08-15

We have designed a single-stranded DNAzyme-aptamer sensor for homogeneous target molecular detection based on chemiluminescence resonance energy transfer (CRET). The structure of the engineered single-stranded DNA (ssDNA) includes the horseradish peroxidase (HRP)-like DNAzyme, optimum-length linker (10-mer-length DNA), and target-specific aptamer sequences. A quencher dye was modified at the 3' end of the aptamer sequence. The incorporation of hemin into the G-quadruplex structure of DNAzyme yields an active HRP-like activity that catalyzes luminol to generate a chemiluminescence (CL) signal. In the presence of target molecules, such as ochratoxin A (OTA), adenosine triphosphate (ATP), or thrombin, the aptamer sequence was folded due to the formation of the aptamer/analyte complex, which induced the quencher dye close to the DNAzyme structure. Consequently, the CRET occurred between a DNAzyme-catalyzed chemiluminescence reaction and the quencher dye. Our results showed that CRET-based DNAzyme-aptamer biosensing enabled specific OTA analysis with a limit of detection of 0.27ng/mL. The CRET platform needs no external light source and avoids autofluorescence and photobleaching, and target molecules can be detected specifically and sensitively in a homogeneous manner. Copyright © 2014 Elsevier B.V. All rights reserved.

A highly sensitive and temporal visualization system for gaseous ethanol with chemiluminescence enhancer.

PubMed

Arakawa, Takahiro; Ando, Eri; Wang, Xin; Kumiko, Miyajima; Kudo, Hiroyuki; Saito, Hirokazu; Mitani, Tomoyo; Takahashi, Mitsuo; Mitsubayashi, Kohji

2012-01-01

A two-dimensional gaseous ethanol visualization system has been developed and demonstrated using a horseradish peroxidase-luminol-hydrogen peroxide system with high-purity luminol solution and a chemiluminescence (CL) enhancer. This system measures ethanol concentrations as intensities of CL via the luminol reaction. CL was emitted when the gaseous ethanol was injected onto an enzyme-immobilized membrane, which was employed as a screen for two-dimensional gas visualization. The average intensity of CL on the substrate was linearly related to the concentration of standard ethanol gas. These results were compared with the CL intensity of the CCD camera recording image in the visualization system. This system is available for gas components not only for spatial but also for temporal analysis in real time. A high-purity sodium salt HG solution (L-HG) instead of standard luminol solution and an enhancer, eosin Y (EY) solution, were adapted for improvement of CL intensity of the system. The visualization of gaseous ethanol was achieved at a detection limit of 3 ppm at optimized concentrations of L-HG solution and EY. Copyright © 2011 John Wiley & Sons, Ltd.

Nanoparticles based on quantum dots and a luminol derivative: implications for in vivo imaging of hydrogen peroxide by chemiluminescence resonance energy transfer.

PubMed

Lee, Eun Sook; Deepagan, V G; You, Dong Gil; Jeon, Jueun; Yi, Gi-Ra; Lee, Jung Young; Lee, Doo Sung; Suh, Yung Doug; Park, Jae Hyung

2016-03-18

Overproduction of hydrogen peroxide is involved in the pathogenesis of inflammatory diseases such as cancer and arthritis. To image hydrogen peroxide via chemiluminescence resonance energy transfer in the near-infrared wavelength range, we prepared quantum dots functionalized with a luminol derivative.

Concentration Dependence of Gold Nanoparticles for Fluorescence Enhancement

NASA Astrophysics Data System (ADS)

Solomon, Joel; Wittmershaus, Bruce

Noble metal nanoparticles possess a unique property known as surface plasmon resonance in which the conduction electrons oscillate due to incoming light, dramatically increasing their absorption and scattering of light. The oscillating electrons create a varying electric field that can affect nearby molecules. The fluorescence and photostability of fluorophores can be enhanced significantly when they are near plasmonic nanoparticles. This effect is called metal enhanced fluorescence (MEF). MEF from two fluorescence organic dyes, Lucifer Yellow CH and Riboflavin, was measured with different concentrations of 50-nm colloidal gold nanoparticles (Au-NP). The concentration range of Au-NP was varied from 2.5 to 250 pM. To maximize the interaction, the dyes were chosen so their emission spectra had considerable overlap with the absorption spectra of the Au-NP, which is common in MEF studies. If the dye molecules are too close to the surface of Au-NP, fluorescence quenching can occur instead of MEF. To try to observe this difference, silica-coated Au-NP were compared to citrate-based Au-NP; however, fluorescence quenching was observed with both Au-NP. This material is based upon work supported by the National Science Foundation under Grant Number NSF-ECCS-1306157.

A highly selective chemiluminescent probe for the detection of chromium(VI)

NASA Astrophysics Data System (ADS)

Jin, Yan; Sun, Yonghua; Li, Chongying; Yang, Chao

2018-03-01

In present work, rhodamine B hydrazide and rhodamine 6G hydrazide were synthesized and the chemiluminescence performance has been investigated. Based on the chemiluminescence of rhodamine 6G hydrazide-chromium(VI), a selective and sensitive method for the direct detection of chromium(VI) was developed. The chemiluminescence intensity was linearly related to the concentration of chromium(VI) in the range of 2.60 × 10- 8-8.00 × 10- 6 mol/L with a correlation coefficient of r = 0.998 and a detection limit of 1.4 × 10- 8 mol/L (S/N = 3). The results indicated rhodamine 6G hydrazide was an excellent chemiluminescent probe for chromium(VI) without reduction of chromium(VI) to chromium(III). A possible mechanism of CL emission was also suggested.

Cyclodextrin-PEG conjugate-wrapped magnetic ferrite nanoparticles for enhanced drug loading and release

NASA Astrophysics Data System (ADS)

Enoch, Israel V. M. V.; Ramasamy, Sivaraj; Mohiyuddin, Shanid; Gopinath, Packirisamy; Manoharan, R.

2018-05-01

Magnetic nanoparticles are envisaged to overcome the impediments in the methods of targeted drug delivery and hence cure cancer effectively. We report herein, manganese ferrite nanoparticles, coated with β-cyclodextrin-modified polyethylene glycol as a carrier for the drug, camptothecin. The particles are of the size of 100 nm and they show superparamagnetic behaviour. The saturation magnetization does not get diminished on polymer coverage of the nanoparticles. The β-cyclodextrin-polyethylene glycol conjugates are characterized using NMR and mass spectrometric techniques. By coating the magnetic nanoparticles with the cyclodextrin-tethered polymer, the drug-loading capacity is enhanced and the observed release of the drug is slow and sustained. The cell viability of HEK293 and HCT15 cells is evaluated and the cytotoxicity is enhanced when the drug is loaded in the polymer-coated magnetic nanoparticles. The noncovalent-binding based and enhanced drug loading on the nanoparticles and the sustained release make the nanocarrier a promising agent for carrying the payload to the target.

Indium nanoparticles for ultraviolet surface-enhanced Raman spectroscopy

NASA Astrophysics Data System (ADS)

Das, Rupali; Soni, R. K.

2018-05-01

Ultraviolet Surface-enhanced Raman spectroscopy (UVSERS) has emerged as an efficient molecular spectroscopy technique for ultra-sensitive and ultra-low detection of analyte concentration. The generic SERS substrates based on gold and silver nanostructures have been extensively explored for high local electric field enhancement only in visible-NIR region of the electromagnetic spectrum. The template synthesis of controlled nanoscale size metallic nanostructures supporting localized surface plasmon resonance (LSPR) in the UV region have been recently explored due to their ease of synthesis and potential applications in optoelectronic, catalysis and magnetism. Indium (In0) nanoparticles exhibit active surface plasmon resonance (SPR) in ultraviolet (UV) and deep-ultaviolet (DUV) region with optimal absorption losses. This extended accessibility makes indium a promising material for UV plasmonic, chemical sensing and more recently in UV-SERS. In this work, spherical indium nanoparticles (In NPs) were synthesized by modified polyol reduction method using NaBH4 having local surface plasmon resonance near 280 nm. The as-synthesized spherical In0 nanoparticles were then coated with thin silica shells of thickness ˜ 5nm by a modified Stober method protecting the nanoparticles from agglomeration, direct contact with the probed molecules as well as prevent oxidation of the nanoparticles. Morphological evolution of In0 nanoparticles and SiO2 coating were characterized by transmission electron microscope (TEM). An enhanced near resonant shell-isolated SERS activity from thin film of tryptophan (Tryp) molecules deposited on indium coated substrates under 325nm UV excitation was observed. Finite difference time domain (FDTD) method is employed to comprehend the experimental results and simulate the electric field contours which showed amplified electromagnetic field localized around the nanostructures. The comprehensive analysis indicates that indium is a promising alternate

Thermoelectric power factor enhancement by ionized nanoparticle scattering

NASA Astrophysics Data System (ADS)

Bahk, Je-Hyeong; Bian, Zhixi; Zebarjadi, Mona; Santhanam, Parthiban; Ram, Rajeev; Shakouri, Ali

2011-08-01

We show theoretically that the thermoelectric power factor can be enhanced in degenerate semiconductors when embedded nanoparticles donate carriers to the matrix and replace conventional impurity dopants as scattering centers. Nanoparticle scattering rates calculated by the partial wave method indicate a mobility enhancement over materials with equivalent doping by isolated ionized impurities while the Seebeck coefficient remains nearly intact. We find that the thermoelectric power factor of In0.53Ga0.47As from 300 K to 800 K is enhanced by 15% - 30% by nanoparticles 3-4 nm in diameter.

A turn-on chemiluminescence biosensor for selective and sensitive detection of adenosine based on HKUST-1 and QDs-luminol-aptamer conjugates.

PubMed

Lin, Yanna; Dai, Yuxue; Sun, Yuanling; Ding, Chaofan; Sun, Weiyan; Zhu, Xiaodong; Liu, Hao; Luo, Chuannan

2018-05-15

In this work, HKUST-1 and QDs-luminol-aptamer conjugates were prepared. The QDs-luminol-aptamer conjugates can be adsorbed by graphene oxide through π-π conjugation. When the adenosine was added, the QDs-luminol-aptamer conjugates were released from magnetic graphene oxide (MGO), the chemiluminescent switch was turned on. It was reported that HKUST-1 can catalyze the chemiluminescence reaction of luminol-H 2 O 2 system in an alkaline medium, and improve the chemiluminescence resonance energy transfer (CRET) between chemiluminescence and QDs indirectly. Thus, the adenosine can be detected sensitively. Based on this phenomenon, the excellent platform for detection of adenosine was established. Under the optimized conditions, the linear detection range for adenosine was 1.0 × 10 -12 -2.2 × 10 -10 mol/L with a detection limit of 2.1 × 10 -13 mol/L. The proposed method was successfully used for adenosine detection in biological samples. Copyright © 2018 Elsevier B.V. All rights reserved.

An amplified chemiluminescence system based on Si-doped carbon dots for detection of catecholamines.

PubMed

Amjadi, Mohammad; Hallaj, Tooba; Manzoori, Jamshid L; Shahbazsaghir, Tahmineh

2018-08-05

We report on a chemiluminescence (CL) system based on simultaneous enhancing effect of Si-doped carbon dots (Si-CDs) and cetyltrimethylammonium bromide (CTAB) on HCO 3 - -H 2 O 2 reaction . The possible CL mechanism is investigated and discussed. Excited-state Si-CDs was found to be the final emitting species, which are probably produced via electron and hole injection by oxy-radicals. The effect of several other heteroatom-doped CDs and undoped CDs was also investigated and compared with Si-CDs. Furthermore, it was found that catecholamines such as dopamine, adrenaline and noradrenaline remarkably diminish the CL intensity of Si-CD-HCO 3 - -H 2 O 2 -CTAB system. By taking advantage of this fact, a sensitive probe was designed for determination of dopamine, adrenaline and noradrenaline with a limit of detection of 0.07, 0.60 and 0.01 μM, respectively. The method was applied to the determination of catecholamines in human plasma samples. Copyright © 2018 Elsevier B.V. All rights reserved.

Experimental and theoretical investigation of intratumoral nanoparticle distribution to enhance magnetic nanoparticle hyperthermia

NASA Astrophysics Data System (ADS)

Attaluri, Anilchandra

Magnetic nanoparticles have gained prominence in recent years for use in clinical applications such as imaging, drug delivery, and hyperthermia. Magnetic nanoparticle hyperthermia is a minimally invasive and effective approach for confined heating in tumors with little collateral damage. One of the major problems in the field of magnetic nanoparticle hyperthermia is irregular heat distribution in tumors which caused repeatable heat distribution quite impossible. This causes under dosage in tumor area and overheating in normal tissue. In this study, we develop a unified approach to understand magnetic nanoparticle distribution and temperature elevations in gel and tumors. A microCT imaging system is first used to visualize and quantify nanoparticle distribution in both tumors and tissue equivalent phantom gels. The microCT based nanoparticle concentration is related to specific absorption rate (SAR) of the nanoparticles and is confirmed by heat distribution experiments in tissue equivalent phantom gels. An optimal infusion protocol is identified to generate controllable and repeatable nanoparticle distribution in tumors. In vivo animal experiments are performed to measure intratumoral temperature elevations in PC3 xenograft tumors implanted in mice during magnetic nanoparticle hyperthermia. The effect of nanofluid injection parameters on the resulted temperature distribution is studied. It shows that the tumor temperatures can be elevated above 50°C using very small amounts of ferrofluid with a relatively low magnetic field. Slower ferrofluid infusion rates result in smaller nanoparticle distribution volumes in the tumors, however, it gives the much required controllability and repeatability when compared to the higher infusion rates. More nanoparticles occupy a smaller volume in the vicinity of the injection site with slower infusion rates, causing higher temperature elevations in the tumors. Based on the microCT imaging analyses of nanoparticles in tumors, a mass

Enhanced photoelectric performance in self-powered UV detectors based on ZnO nanowires with plasmonic Au nanoparticles scattered electrolyte

NASA Astrophysics Data System (ADS)

Zeng, Yiyu; Ye, Zhizhen; Lu, Bin; Dai, Wei; Pan, Xinhua

2016-04-01

Vertically aligned ZnO nanowires (NWs) were grown on a fluorine-doped tin-oxide-coated glass substrate by a hydrothermal method. Au nanoparticles were well dispersed in the mixed solution of ethanol and deionized water. A simple self-powered ultraviolet detector based on solid-liquid heterojunction was fabricated, utilizing ZnO NWs as active photoanode and such prepared mixed solution as electrolyte. The introduction of Au nanoparticles results in considerable improvements in the responsivity and sensitivity of the device compared with the one using deionized water as electrolyte, which is attributed to the enhanced light harvesting by Au nanoparticles.

Microspot-based ELISA in microfluidics: chemiluminescence and colorimetry detection using integrated thin-film hydrogenated amorphous silicon photodiodes.

PubMed

Novo, Pedro; Prazeres, Duarte Miguel França; Chu, Virginia; Conde, João Pedro

2011-12-07

Microfluidic technology has the potential to decrease the time of analysis and the quantity of sample and reactants required in immunoassays, together with the potential of achieving high sensitivity, multiplexing, and portability. A lab-on-a-chip system was developed and optimized using optical and fluorescence microscopy. Primary antibodies are adsorbed onto the walls of a PDMS-based microchannel via microspotting. This probe antibody is then recognised using secondary FITC or HRP labelled antibodies responsible for providing fluorescence or chemiluminescent and colorimetric signals, respectively. The system incorporated a micron-sized thin-film hydrogenated amorphous silicon photodiode microfabricated on a glass substrate. The primary antibody spots in the PDMS-based microfluidic were precisely aligned with the photodiodes for the direct detection of the antibody-antigen molecular recognition reactions using chemiluminescence and colorimetry. The immunoassay takes ~30 min from assay to the integrated detection. The conditions for probe antibody microspotting and for the flow-through ELISA analysis in the microfluidic format with integrated detection were defined using antibody solutions with concentrations in the nM-μM range. Sequential colorimetric or chemiluminescence detection of specific antibody-antigen molecular recognition was quantitatively detected using the photodiode. Primary antibody surface densities down to 0.182 pmol cm(-2) were detected. Multiplex detection using different microspotted primary antibodies was demonstrated.

Label-free genotyping of cytochrome P450 2D6*10 using ligation-mediated strand displacement amplification with DNAzyme-based chemiluminescence detection.

PubMed

Wang, Hong-Qi; Wu, Zhan; Zhang, Yan; Tang, Li-Juan; Yu, Ru-Qin; Jiang, Jian-Hui

2012-01-13

Genotyping of cytochrome P450 monooxygenase 2D6*10 (CYP2D6*10) plays an important role in pharmacogenomics, especially in clinical drug therapy of Asian populations. This work reported a novel label-free technique for genotyping of CYP2D6*10 based on ligation-mediated strand displacement amplification (SDA) with DNAzyme-based chemiluminescence detection. Discrimination of single-base mismatch is firstly accomplished using DNA ligase to generate a ligation product. The ligated product then initiates a SDA reaction to produce aptamer sequences against hemin, which can be probed by chemiluminescence detection. The proposed strategy is used for the assay of CYP2D6*10 target and the genomic DNA. The results reveal that the proposed technique displays chemiluminescence responses in linear correlation to the concentrations of DNA target within the range from 1 pM to 1 nM. A detection limit of 0.1 pM and a signal-to-background ratio of 57 are achieved. Besides such high sensitivity, the proposed CYP2D6*10 genotyping strategy also offers superb selectivity, great robustness, low cost and simplified operations due to its label-free, homogeneous, and chemiluminescence-based detection format. These advantages suggest this technique may hold considerable potential for clinical CYP2D6*10 genotyping and association studies. Copyright © 2011 Elsevier B.V. All rights reserved.

Measurement of salivary cortisol by a chemiluminescent organic-based immunosensor.

PubMed

Pires, N M M; Dong, T

2014-01-01

A highly sensitive chemiluminescent immunoassay (CLIA) using a sensitive organic photodetector was developed to detect human cortisol, an important biomarker for stress-related diseases. The developed CLIA was performed onto gold-coated glass chips, on which anti-cortisol antibodies were immobilised and chemiluminescent horseradish peroxidase-luminol-peroxide reactions were generated. Using cortisol-spiked artificial saliva samples, the CLIA biosensor showed a linear range of detection between 0.1 ng/mL and 175 ng/mL and a detection limit of 80 pg/mL. The sensor response was highly specific to cortisol and did not vary significantly between assays. The results indicate the potential clinical application of the CLIA sensor. Furthermore, the simple layered structure of the organic photodetector may encourage the realisation of integrated optical biosensors for point-of-use measurement of salivary cortisol levels.

Chemiluminescence of Organic Compounds.

DTIC Science & Technology

1981-04-07

of organic reaction chemiluminescence (Rauiht, 197) ; Hastings and Wilson, 1976 ; Gundermann, 1974 ; White et al., 1974 ; McCapra, 1973 ; .oto, 1979...1977; Wilson, T., 1976; Turro et al., JI U4a; Mumtord, 1915), the chemiluminescence -4- of hydrazides (Roswell and White , 1978 ; White and Roswell...mechanical Iv exc, it cd . iii; q ie ed in a react inn, meaning energv is released in period ot t ime noi the *r?-!tcr of Ol I ess than thle t ime of a

A new approach for bisphenol A detection employing fluorosurfactant-capped gold nanoparticle-amplified chemiluminescence from cobalt(II) and peroxymonocarbonate.

PubMed

Pan, Feng; Liu, Lin; Dong, Shichao; Lu, Chao

2014-07-15

In this work, we utilized the nonionic fluorosurfactant-capped gold nanoparticles (GNPs) as a novel chemiluminescence (CL) probe for the determination of trace bisphenol A. Bisphenol A can induce a sharp decrease in CL intensity from the GNP-Co(2+)-peroxymonocarbonate (HCO4(-)) system. Under the selected experimental conditions, a linear relationship was obtained between the CL intensity and the logarithm of concentration of bisphenol A in the range of 0.05-50 μM (R(2) = 0.9936), and the detection limit at a signal-to-noise ratio of 3 for bisphenol A was 10 nM. The applicability of the proposed method has been validated by determining bisphenol A in real polycarbonate samples with satisfactory results. The recoveries for bisphenol A in spiked samples were found to be between 94.4% and 105.0%. The relative standard deviation (RSD) for 12 repeated measurements of 0.5 μM bisphenol A was 2.2%. The proposed method described herein was simple, selective and obviated the need of extensive sample pretreatment. Copyright © 2014 Elsevier B.V. All rights reserved.

Simultaneous determination of isoniazid and p-aminosalicylic acid by capillary electrophoresis using chemiluminescence detection.

PubMed

Zhang, Xinfeng; Xuan, Yuelan; Sun, Aimin; Lv, Yi; Hou, Xiandeng

2009-01-01

It was found that isoniazid (ISO) or p-aminosalicylic acid (PAS) could enhance the chemiluminescence (CL) emission from Cu (II)-luminol-hydrogen peroxide system, and the increased chemiluminescence signals were proportional to their concentrations, respectively. Based on this phenomenon, a chemiluminescence method coupled to capillary electrophoresis (CE) was established for simultaneous determination of ISO and PAS. The CE conditions including running buffer and running voltage were investigated in detail. The effects of the pH of H(2)O(2) solution and the concentrations of luminol, H(2)O(2) and Cu (II) on the CL signal were also investigated carefully. Under the optimized conditions, the analysis could be accomplished within 10 min, with the limits of detection of 0.3 microg mL(-1) for ISO and 1.1 microg mL(-1) for PAS, corresponding to 7.2 and 26.4 pg per injection (24 nL), respectively. Finally, the method was validated by determining the two analytes in pharmaceutical preparation and spiked human serum samples. The results of pharmaceutical tablet analysis were in good agreement with the labeled amounts. The recoveries for ISO and PAS in human serum were in the range of 92-104% and 90-113%, respectively. Copyright 2008 John Wiley & Sons, Ltd.

Gold nanoparticles enhance the anti-leukemia action of a 6-mercaptopurine chemotherapeutic agent.

PubMed

Podsiadlo, Paul; Sinani, Vladimir A; Bahng, Joong Hwan; Kam, Nadine Wong Shi; Lee, Jungwoo; Kotov, Nicholas A

2008-01-15

6-mercaptopurine and its riboside derivatives are some of the most widely utilized anti-leukemic and anti-inflammatory drugs. Their short biological half-life and severe side effects limit their use. A new delivery method for these drugs based on 4-5 nm gold nanoparticles can potentially resolve these issues. We have found substantial enhancement of the antiproliferative effect against K-562 leukemia cells of Au nanoparticles bearing 6-mercaptopurine-9-beta-d-ribofuranoside compared to the same drug in typically administered free form. The improvement was attributed to enhanced intracellular transport followed by the subsequent release in lysosomes. Enhanced activity and nanoparticle carriers will make possible the reduction of the overall concentration of the drug, renal clearance, and, thus, side effects. The nanoparticles with mercaptopurine also showed excellent stability over 1 year without loss of inhibitory activity.

Serum albumin 'camouflage' of plant virus based nanoparticles prevents their antibody recognition and enhances pharmacokinetics.

PubMed

Pitek, Andrzej S; Jameson, Slater A; Veliz, Frank A; Shukla, Sourabh; Steinmetz, Nicole F

2016-05-01

Plant virus-based nanoparticles (VNPs) are a novel class of nanocarriers with unique potential for biomedical applications. VNPs have many advantageous properties such as ease of manufacture and high degree of quality control. Their biocompatibility and biodegradability make them an attractive alternative to synthetic nanoparticles (NPs). Nevertheless, as with synthetic NPs, to be successful in drug delivery or imaging, the carriers need to overcome several biological barriers including innate immune recognition. Plasma opsonization can tag (V)NPs for clearance by the mononuclear phagocyte system (MPS), resulting in shortened circulation half lives and non-specific sequestration in non-targeted organs. PEG coatings have been traditionally used to 'shield' nanocarriers from immune surveillance. However, due to broad use of PEG in cosmetics and other industries, the prevalence of anti-PEG antibodies has been reported, which may limit the utility of PEGylation in nanomedicine. Alternative strategies are needed to tailor the in vivo properties of (plant virus-based) nanocarriers. We demonstrate the use of serum albumin (SA) as a viable alternative. SA conjugation to tobacco mosaic virus (TMV)-based nanocarriers results in a 'camouflage' effect more effective than PEG coatings. SA-'camouflaged' TMV particles exhibit decreased antibody recognition, as well as enhanced pharmacokinetics in a Balb/C mouse model. Therefore, SA-coatings may provide an alternative and improved coating technique to yield (plant virus-based) NPs with improved in vivo properties enhancing drug delivery and molecular imaging. Copyright © 2016 Elsevier Ltd. All rights reserved.

Apparatus for use in sulfide chemiluminescence detection

DOEpatents

Spurlin, Stanford R.; Yeung, Edward S.

1987-01-01

A method of chemiluminescently determining a sulfide which is either hydrogen sulfide or methyl mercaptan by reacting the sulfide with chlorine dioxide at low pressure and under conditions which allow a longer reaction time in emission of a single photon for every two sulfide containing species, and thereafter, chemiluminescently detecting and determining the sulfide. The invention also relates not only to the detection method, but the novel chemical reaction and a specifically designed chemiluminescence detection cell for the reaction.

Oleic acid-enhanced transdermal delivery pathways of fluorescent nanoparticles

NASA Astrophysics Data System (ADS)

Lo, Wen; Ghazaryan, Ara; Tso, Chien-Hsin; Hu, Po-Sheng; Chen, Wei-Liang; Kuo, Tsung-Rong; Lin, Sung-Jan; Chen, Shean-Jen; Chen, Chia-Chun; Dong, Chen-Yuan

2012-05-01

Transdermal delivery of nanocarriers provides an alternative pathway to transport therapeutic agents, alleviating pain, improving compliance of patients, and increasing overall effectiveness of delivery. In this work, enhancement of transdermal delivery of fluorescent nanoparticles and sulforhodamine B with assistance of oleic acid was visualized utilizing multiphoton microscopy (MPM) and analyzed quantitatively using multi-photon excitation-induced fluorescent signals. Results of MPM imaging and MPM intensity-based spatial depth-dependent analysis showed that oleic acid is effective in facilitating transdermal delivery of nanoparticles.

Large enhancement of oscillating chemiluminescence with [Ru(bpy)3 ](2+) -catalyzed Belousov-Zhabotinsky reaction in the presence of tri-n-propylamine.

PubMed

Lan, Xiaolan; Zheng, Baozhan; Zhao, Yan; Yuan, Hongyan; Du, Juan; Xiao, Dan

2013-01-01

Oscillating chemiluminescence enhanced by the addition of tri-n-propylamine (TPrA) to the typical Belousov-Zhabotinsky (BZ) reaction system catalyzed by ruthenium(II)tris(2.2'-bipyridine)(Ru(bpy)3 (2+) ) was investigated using a luminometry method. The [Ru(bpy)3 ](2+) /TPrA system was first used as the catalyst for a BZ oscillator in a closed system, which exhibited a shorter induction period, higher amplitude and much more stable chemiluminescence (CL) oscillation. The effects of various concentrations of TPrA, oxygen and nitrogen flow rate on the oscillating behavior of this system were examined. In addition, the CL intensity of the [Ru(bpy)3 ](2+) /TPrA-BZ system was found to be inhibited by phenol, thus providing a way for use of the BZ system in the determination of phenolic compounds. Moreover, the possible mechanism of the oscillating CL reaction catalyzed by [Ru(bpy)3 ](2+) /TPrA and the inhibition effects of oxygen and phenol on this oscillating CL system were considered. Copyright © 2012 John Wiley & Sons, Ltd.

Polycrystalline Si nanoparticles and their strong aging enhancement of blue photoluminescence

NASA Astrophysics Data System (ADS)

Yang, Shikuan; Cai, Weiping; Zeng, Haibo; Li, Zhigang

2008-07-01

Nearly spherical polycrystalline Si nanoparticles with 20 nm diameter were fabricated based on laser ablation of silicon wafer immersed in sodium dodecyl sulfate aqueous solution. Such Si nanoparticles consist of disordered areas and ultrafine grains of 3 nm in mean size and exhibit significant photoluminescence in blue region. Importantly, aging at ambient air leads to continuing enhancement of the emission (more than 130 times higher in 16 weeks) showing stable and strong blue emission. This aging enhancement is attributed to progressive passivation of nonradiative Pb centers corresponding to silicon dangling bonds on the particles' surface. This study could be helpful in pushing Si into optoelectronic field and Si-based full color display, biomedical tagging, and flash memories.

Resonant Raman scattering from silicon nanoparticles enhanced by magnetic response.

PubMed

Dmitriev, Pavel A; Baranov, Denis G; Milichko, Valentin A; Makarov, Sergey V; Mukhin, Ivan S; Samusev, Anton K; Krasnok, Alexander E; Belov, Pavel A; Kivshar, Yuri S

2016-05-05

Enhancement of optical response with high-index dielectric nanoparticles is attributed to the excitation of their Mie-type magnetic and electric resonances. Here we study Raman scattering from crystalline silicon nanoparticles and reveal that magnetic dipole modes have a much stronger effect on the scattering than electric modes of the same order. We demonstrate experimentally a 140-fold enhancement of the Raman signal from individual silicon spherical nanoparticles at the magnetic dipole resonance. Our results confirm the importance of the optically-induced magnetic response of subwavelength dielectric nanoparticles for enhancing light-matter interactions.

Adenosine Triphosphate-Encapsulated Liposomes with Plasmonic Nanoparticles for Surface Enhanced Raman Scattering-Based Immunoassays.

PubMed

Pham, Xuan-Hung; Hahm, Eunil; Kim, Tae Han; Kim, Hyung-Mo; Lee, Sang Hun; Lee, Yoon-Sik; Jeong, Dae Hong; Jun, Bong-Hyun

2017-06-23

In this study, we prepared adenosine triphosphate (ATP) encapsulated liposomes, and assessed their applicability for the surface enhanced Raman scattering (SERS)-based assays with gold-silver alloy (Au@Ag)-assembled silica nanoparticles (NPs; SiO₂@Au@Ag). The liposomes were prepared by the thin film hydration method from a mixture of l-α-phosphatidylcholine, cholesterol, and PE-PEG2000 in chloroform; evaporating the solvent, followed by hydration of the resulting thin film with ATP in phosphate-buffered saline (PBS). Upon lysis of the liposome, the SERS intensity of the SiO₂@Au@Ag NPs increased with the logarithm of number of ATP-encapsulated liposomes after lysis in the range of 8 × 10⁶ to 8 × 10 10 . The detection limit of liposome was calculated to be 1.3 × 10 -17 mol. The successful application of ATP-encapsulated liposomes to SiO₂@Au@Ag NPs based SERS analysis has opened a new avenue for Raman label chemical (RCL)-encapsulated liposome-enhanced SERS-based immunoassays.

Apparatus for use in sulfide chemiluminescence detection

DOEpatents

Spurlin, S.R.; Yeung, E.S.

1987-01-06

A method is described for chemiluminescently determining a sulfide which is either hydrogen sulfide or methyl mercaptan by reacting the sulfide with chlorine dioxide at low pressure and under conditions which allow a longer reaction time in emission of a single photon for every two sulfide containing species, and thereafter, chemiluminescently detecting and determining the sulfide. The invention also relates not only to the detection method, but the novel chemical reaction and a specifically designed chemiluminescence detection cell for the reaction. 4 figs.

Bare laser-synthesized Au-based nanoparticles as nondisturbing surface-enhanced Raman scattering probes for bacteria identification.

PubMed

Kögler, Martin; Ryabchikov, Yury V; Uusitalo, Sanna; Popov, Alexey; Popov, Anton; Tselikov, Gleb; Välimaa, Anna-Liisa; Al-Kattan, Ahmed; Hiltunen, Jussi; Laitinen, Riitta; Neubauer, Peter; Meglinski, Igor; Kabashin, Andrei V

2018-02-01

The ability of noble metal-based nanoparticles (NPs) (Au, Ag) to drastically enhance Raman scattering from molecules placed near metal surface, termed as surface-enhanced Raman scattering (SERS), is widely used for identification of trace amounts of biological materials in biomedical, food safety and security applications. However, conventional NPs synthesized by colloidal chemistry are typically contaminated by nonbiocompatible by-products (surfactants, anions), which can have negative impacts on many live objects under examination (cells, bacteria) and thus decrease the precision of bioidentification. In this article, we explore novel ultrapure laser-synthesized Au-based nanomaterials, including Au NPs and AuSi hybrid nanostructures, as mobile SERS probes in tasks of bacteria detection. We show that these Au-based nanomaterials can efficiently enhance Raman signals from model R6G molecules, while the enhancement factor depends on the content of Au in NP composition. Profiting from the observed enhancement and purity of laser-synthesized nanomaterials, we demonstrate successful identification of 2 types of bacteria (Listeria innocua and Escherichia coli). The obtained results promise less disturbing studies of biological systems based on good biocompatibility of contamination-free laser-synthesized nanomaterials. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Determination of total sulfur content via sulfur-specific chemiluminescence detection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kubala, S.W.; Campbell, D.N.; DiSanzo, F.P.

A specially designed system, based upon sulfur-specific chemiluminescence detection (SSCD), was developed to permit the determination of total sulfur content in a variety of samples. This type of detection system possesses several advantages such as excellent linearity and selectivity, low minimum detectable levels, and an equimolar response to various sulfur compounds. This paper will focus on the design and application of a sulfur-specific chemiluminescence detection system for use in determining total sulfur content in gasoline.

Enhancing the magnetic anisotropy of maghemite nanoparticles via the surface coordination of molecular complexes

NASA Astrophysics Data System (ADS)

Prado, Yoann; Daffé, Niéli; Michel, Aude; Georgelin, Thomas; Yaacoub, Nader; Grenèche, Jean-Marc; Choueikani, Fadi; Otero, Edwige; Ohresser, Philippe; Arrio, Marie-Anne; Cartier-Dit-Moulin, Christophe; Sainctavit, Philippe; Fleury, Benoit; Dupuis, Vincent; Lisnard, Laurent; Fresnais, Jérôme

2015-12-01

Superparamagnetic nanoparticles are promising objects for data storage or medical applications. In the smallest--and more attractive--systems, the properties are governed by the magnetic anisotropy. Here we report a molecule-based synthetic strategy to enhance this anisotropy in sub-10-nm nanoparticles. It consists of the fabrication of composite materials where anisotropic molecular complexes are coordinated to the surface of the nanoparticles. Reacting 5 nm γ-Fe2O3 nanoparticles with the [CoII(TPMA)Cl2] complex (TPMA: tris(2-pyridylmethyl)amine) leads to the desired composite materials and the characterization of the functionalized nanoparticles evidences the successful coordination--without nanoparticle aggregation and without complex dissociation--of the molecular complexes to the nanoparticles surface. Magnetic measurements indicate the significant enhancement of the anisotropy in the final objects. Indeed, the functionalized nanoparticles show a threefold increase of the blocking temperature and a coercive field increased by one order of magnitude.

Enhancing the magnetic anisotropy of maghemite nanoparticles via the surface coordination of molecular complexes

PubMed Central

Prado, Yoann; Daffé, Niéli; Michel, Aude; Georgelin, Thomas; Yaacoub, Nader; Grenèche, Jean-Marc; Choueikani, Fadi; Otero, Edwige; Ohresser, Philippe; Arrio, Marie-Anne; Cartier-dit-Moulin, Christophe; Sainctavit, Philippe; Fleury, Benoit; Dupuis, Vincent; Lisnard, Laurent; Fresnais, Jérôme

2015-01-01

Superparamagnetic nanoparticles are promising objects for data storage or medical applications. In the smallest—and more attractive—systems, the properties are governed by the magnetic anisotropy. Here we report a molecule-based synthetic strategy to enhance this anisotropy in sub-10-nm nanoparticles. It consists of the fabrication of composite materials where anisotropic molecular complexes are coordinated to the surface of the nanoparticles. Reacting 5 nm γ-Fe2O3 nanoparticles with the [CoII(TPMA)Cl2] complex (TPMA: tris(2-pyridylmethyl)amine) leads to the desired composite materials and the characterization of the functionalized nanoparticles evidences the successful coordination—without nanoparticle aggregation and without complex dissociation—of the molecular complexes to the nanoparticles surface. Magnetic measurements indicate the significant enhancement of the anisotropy in the final objects. Indeed, the functionalized nanoparticles show a threefold increase of the blocking temperature and a coercive field increased by one order of magnitude. PMID:26634987

Correction: Shell-isolated nanoparticle-enhanced Raman spectroscopy study of the adsorption behaviour of DNA bases on Au(111) electrode surfaces.

PubMed

Wen, Bao-Ying; Jin, Xi; Li, Yue; Wang, Ya-Hao; Li, Chao-Yu; Liang, Miao-Miao; Panneerselvam, Rajapandiyan; Xu, Qing-Chi; Wu, De-Yin; Yang, Zhi-Lin; Li, Jian-Feng; Tian, Zhong-Qun

2016-06-21

Correction for 'Shell-isolated nanoparticle-enhanced Raman spectroscopy study of the adsorption behaviour of DNA bases on Au(111) electrode surfaces' by Bao-Ying Wen et al., Analyst, 2016, DOI: 10.1039/c6an00180g.

Super-resolution of fluorescence-free plasmonic nanoparticles using enhanced dark-field illumination based on wavelength-modulation

DOE PAGES

Zhang, Peng; Lee, Seungah; Yu, Hyunung; ...

2015-06-15

Super-resolution imaging of fluorescence-free plasmonic nanoparticles (NPs) was achieved using enhanced dark-field (EDF) illumination based on wavelength-modulation. Indistinguishable adjacent EDF images of 103-nm gold nanoparticles (GNPs), 40-nm gold nanorods (GNRs), and 80-nm silver nanoparticles (SNPs) were modulated at their wavelengths of specific localized surface plasmon scattering. The coordinates (x, y) of each NP were resolved by fitting their point spread functions with a two-dimensional Gaussian. The measured localization precisions of GNPs, GNRs, and SNPs were 2.5 nm, 5.0 nm, and 2.9 nm, respectively. From the resolved coordinates of NPs and the corresponding localization precisions, super-resolution images were reconstructed. Depending onmore » the spontaneous polarization of GNR scattering, the orientation angle of GNRs in two-dimensions was resolved and provided more elaborate localization information. This novel fluorescence-free super-resolution method was applied to live HeLa cells to resolve NPs and provided remarkable subdiffraction limit images.« less

Novel resveratrol nanodelivery systems based on lipid nanoparticles to enhance its oral bioavailability

PubMed Central

Neves, Ana Rute; Lúcio, Marlene; Martins, Susana; Lima, José Luís Costa; Reis, Salette

2013-01-01

Introduction Resveratrol is a polyphenol found in grapes and red wines. Interest in this polyphenol has increased due to its pharmacological cardio- and neuroprotective, chemopreventive, and antiaging effects, among others. Nevertheless, its pharmacokinetic properties are less favorable, since the compound has poor bioavailability, low water solubility, and is chemically unstable. To overcome these problems, we developed two novel resveratrol nanodelivery systems based on lipid nanoparticles to enhance resveratrol’s oral bioavailability for further use in medicines, supplements, and nutraceuticals. Methods and materials Solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) loaded with resveratrol were successfully produced by a modified hot homogenization technique. These were completely characterized to evaluate the quality of the developed resveratrol-loaded nanoparticles. Results Cryo-scanning electron microscopy morphology studies showed spherical and uniform nanoparticles with a smooth surface. An average resveratrol entrapment efficiency of ~70% was obtained for both SLNs and NLCs. Dynamic light scattering measurements gave a Z-average of 150–250 nm, polydispersity index of ~0.2, and a highly negative zeta potential of around −30 mV with no statistically significant differences in the presence of resveratrol. These characteristics remained unchanged for at least 2 months, suggesting good stability. Differential scanning calorimetry studies confirmed the solid state of the SLNs and NLCs at both room and body temperatures. The NLCs had a less ordered crystalline structure conferred by the inclusion of the liquid lipid, since they had lower values for phase transition temperature, melting enthalpy, and the recrystallization index. The presence of resveratrol induced a disorder in the crystal structure of the nanoparticles, suggesting a favoring of its entrapment. The in vitro release studies on conditions of storage showed a negligible

Effect of the size of silver nanoparticles on SERS signal enhancement

NASA Astrophysics Data System (ADS)

He, Rui Xiu; Liang, Robert; Peng, Peng; Norman Zhou, Y.

2017-08-01

The localized surface plasmon resonance arising from plasmonic materials is beneficial in solution-based and thin-film sensing applications, which increase the sensitivity of the analyte being tested. Silver nanoparticles from 35 to 65 nm in diameter were synthesized using a low-temperature method and deposited in a monolayer on a (3-aminopropyl)triethoxysilane (APTES)-functionalized glass slide. The effect of particle size on monolayer structure, optical behavior, and surface-enhanced Raman scattering (SERS) is studied. While increasing particle size decreases particle coverage, it also changes the localized surface plasmon resonance and thus the SERS activity of individual nanoparticles. Using a laser excitation wavelength of 633 nm, the stronger localized surface plasmon resonance coupling to this excitation wavelength at larger particle sizes trumps the loss in surface coverage, and greater SERS signals are observed. The SERS signal enhancement accounts for the higher SERS signal, which was verified using a finite element model of a silver nanoparticle dimer with various nanoparticle sizes and separation distances.

Antioxidant properties of biohybrids based on liposomes and sage silver nanoparticles.

PubMed

Barbinta-Patrascu, Marcela Elisabeta; Bunghez, Ioana-Raluca; Iordache, Stefan Marian; Badea, Nicoleta; Fierascu, Radu-Claudiu; Ion, Rodica Mariana

2013-03-01

This paper is aimed to describe a simple and rapid eco-friendly bottom-up approach for the preparation of antioxidant silver bionanostructures using a leaf extract from sage (Salvia officinalis L.). The bioreduction property of sage in the synthesis of silver nanoparticles was investigated by UV-VIS and Attenuated Total Reflectance Fourier Transform Infrared spectroscopy. During their preparation, the particle size analysis was performed by using Dynamic Light Scattering technique. Ultrasonic irradiation was used to obtain sage silver nanoparticles. The morphology (size and shape) of the herbal silver nanoparticles was evaluated by Scanning Electron Microscopy that revealed the formation of spherical phytonanoparticles with size less than 80 nm. In order to increase their stability and their biocompatibility, the sage silver nanoparticles were introduced in two types of liposomes: soybean lecithin- and Chla-DPPC-lipid vesicles which were prepared by thin film hydration method. X-Ray Fluorescence analysis confirmed the silver presence in liposomes/sage-AgNPs biohybrids. The stability of liposomes/herbal AgNPs bioconstructs was checked by zeta potential measurements. The most stable biohybrids: Chla-DPPC/sage-AgNPs with zeta potential value of -34.2 mV, were characterized by Atomic Force Microscopy revealing the spherical and quasi-spherical shaped profiles of these nanobiohybrids with size less than 96 nm. The antioxidant activity of the silver bionanostructures was evaluated using chemiluminescence assay. The developed eco-friendly silver phytonanostructures based on lipid membranes, nanosilver and sage extract, manifest strong antioxidant properties (between 86.5% and 98.6%).

Enhanced optical output power of blue light-emitting diodes with quasi-aligned gold nanoparticles.

PubMed

Jin, Yuanhao; Li, Qunqing; Li, Guanhong; Chen, Mo; Liu, Junku; Zou, Yuan; Jiang, Kaili; Fan, Shoushan

2014-01-06

The output power of the light from GaN-based light-emitting diodes (LEDs) was enhanced by fabricating gold (Au) nanoparticles on the surface of p-GaN. Quasi-aligned Au nanoparticle arrays were prepared by depositing Au thin film on an aligned suspended carbon nanotube thin film surface and then putting the Au-CNT system on the surface of p-GaN and thermally annealing the sample. The size and position of the Au nanoparticles were confined by the carbon nanotube framework, and no other additional residual Au was distributed on the surface of the p-GaN substrate. The output power of the light from the LEDs with Au nanoparticles was enhanced by 55.3% for an injected current of 100 mA with the electrical property unchanged compared with the conventional planar LEDs. The enhancement may originate from the surface plasmon effect and scattering effect of the Au nanoparticles.

Enhanced optical output power of blue light-emitting diodes with quasi-aligned gold nanoparticles

PubMed Central

2014-01-01

The output power of the light from GaN-based light-emitting diodes (LEDs) was enhanced by fabricating gold (Au) nanoparticles on the surface of p-GaN. Quasi-aligned Au nanoparticle arrays were prepared by depositing Au thin film on an aligned suspended carbon nanotube thin film surface and then putting the Au-CNT system on the surface of p-GaN and thermally annealing the sample. The size and position of the Au nanoparticles were confined by the carbon nanotube framework, and no other additional residual Au was distributed on the surface of the p-GaN substrate. The output power of the light from the LEDs with Au nanoparticles was enhanced by 55.3% for an injected current of 100 mA with the electrical property unchanged compared with the conventional planar LEDs. The enhancement may originate from the surface plasmon effect and scattering effect of the Au nanoparticles. PMID:24393473

A Chemiluminescence Detector for Ozone Measurement.

ERIC Educational Resources Information Center

Carroll, H.; And Others

An ozone detector was built and evaluated for its applicability in smog chamber studies. The detection method is based on reaction of ozone with ethylene and measurement of resultant chemiluminescence. In the first phase of evaluation, the detector's response to ozone was studied as a function of several instrument parameters, and optimum…

Flow injection chemiluminescence determination of lercanidipine based on N-chlorosuccinimide-eosin Y post-chemiluminescence reaction.

PubMed

Wang, Guowei; Zhao, Fang; Gao, Ying

2014-12-01

A novel post-chemiluminescence (PCL) reaction was discovered when lercanidipine was injected into the CL reaction mixture of N-chlorosuccinimide with alkaline eosin Y in the presence of cetyltrimethylammonium bromide (CTAB), where eosin Y was used as the CL reagent and CTAB as the surfactant. Based on this observation, a simple and highly sensitive PCL method combined with a flow injection (FI) technique was developed for the assay of lercanidipine. Under optimum conditions, the CL signal was linearly related to the concentration of lercanidipine in the range 7.0 × 10(-10) to 3.0 × 10(-6)  g/mL with a detection limit of 2.3 × 10(-10) g/mL (3σ). The relative standard deviation (RSD) was 2.1% for 1.0 × 10(-8) g/mL lercanidipine (n = 13). The proposed method had been applied to the estimation of lercanidipine in tablets and human serum samples with satisfactory results. The possible CL mechanism is also discussed briefly. Copyright © 2014 John Wiley & Sons, Ltd.

Use of magnetic nanoparticles to enhance bioethanol production in syngas fermentation.

PubMed

Kim, Young-Kee; Lee, Haryeong

2016-03-01

The effect of two types of nanoparticles on the enhancement of bioethanol production in syngas fermentation by Clostridium ljungdahlii was examined. Methyl-functionalized silica and methyl-functionalized cobalt ferrite-silica (CoFe2O4@SiO2-CH3) nanoparticles were used to improve syngas-water mass transfer. Of these, CoFe2O4@SiO2-CH3 nanoparticles showed better enhancement of syngas mass transfer. The nanoparticles were recovered using a magnet and reused five times to evaluate reusability, and it was confirmed that their capability for mass transfer enhancement was maintained. Both types of nanoparticles were applied to syngas fermentation, and production of biomass, ethanol, and acetic acid was enhanced. CoFe2O4@SiO2-CH3 nanoparticles were more efficient for the productivity of syngas fermentation due to improved syngas mass transfer. The biomass, ethanol, and acetic acid production compared to a control were increased by 227.6%, 213.5%, and 59.6%, respectively by addition of CoFe2O4@SiO2-CH3 nanoparticles. The reusability of the nanoparticles was confirmed by reuse of recovered nanoparticles for fermentation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Enhanced chemiluminescent detection scheme for trace vapor sensing in pneumatically-tuned hollow core photonic bandgap fibers.

PubMed

Stolyarov, Alexander M; Gumennik, Alexander; McDaniel, William; Shapira, Ofer; Schell, Brent; Sorin, Fabien; Kuriki, Ken; Benoit, Gilles; Rose, Aimee; Joannopoulos, John D; Fink, Yoel

2012-05-21

We demonstrate an in-fiber gas phase chemical detection architecture in which a chemiluminescent (CL) reaction is spatially and spectrally matched to the core modes of hollow photonic bandgap (PBG) fibers in order to enhance detection efficiency. A peroxide-sensitive CL material is annularly shaped and centered within the fiber's hollow core, thereby increasing the overlap between the emission intensity and the intensity distribution of the low-loss fiber modes. This configuration improves the sensitivity by 0.9 dB/cm compared to coating the material directly on the inner fiber surface, where coupling to both higher loss core modes and cladding modes is enhanced. By integrating the former configuration with a custom-built optofluidic system designed for concomitant controlled vapor delivery and emission measurement, we achieve a limit-of-detection of 100 parts per billion (ppb) for hydrogen peroxide vapor. The PBG fibers are produced by a new fabrication method whereby external gas pressure is used as a control knob to actively tune the transmission bandgaps through the entire visible range during the thermal drawing process.

Targeted nanoparticles for enhanced X-ray radiation killing of multidrug-resistant bacteria.

PubMed

Luo, Yang; Hossain, Mainul; Wang, Chaoming; Qiao, Yong; An, Jincui; Ma, Liyuan; Su, Ming

2013-01-21

This paper describes a nanoparticle enhanced X-ray irradiation based strategy that can be used to kill multidrug resistant (MDR) bacteria. In the proof-of-concept experiment using MDR Pseudomonas aeruginosa (P. aeruginosa) as an example, polyclonal antibody modified bismuth nanoparticles are introduced into bacterial culture to specifically target P. aeruginosa. After washing off uncombined bismuth nanoparticles, the bacteria are irradiated with X-rays, using a setup that mimics a deeply buried wound in humans. Results show that up to 90% of MDR P. aeruginosa are killed in the presence of 200 μg ml(-1) bismuth nanoparticles, whereas only ∼6% are killed in the absence of bismuth nanoparticles when exposed to 40 kVp X-rays for 10 min. The 200 μg ml(-1) bismuth nanoparticles enhance localized X-ray dose by 35 times higher than the control with no nanoparticles. In addition, no significant harmful effects on human cells (HeLa and MG-63 cells) have been observed with 200 μg ml(-1) bismuth nanoparticles and 10 min 40 kVp X-ray irradiation exposures, rendering the potential for future clinical use. Since X-rays can easily penetrate human tissues, this bactericidal strategy has the potential to be used in effectively killing deeply buried MDR bacteria in vivo.

Following glucose oxidase activity by chemiluminescence and chemiluminescence resonance energy transfer (CRET) processes involving enzyme-DNAzyme conjugates.

PubMed

Niazov, Angelica; Freeman, Ronit; Girsh, Julia; Willner, Itamar

2011-01-01

A hybrid consisting of glucose oxidase-functionalized with hemin/G-quadruplex units is used for the chemiluminescence detection of glucose. The glucose oxidase-mediated oxidation of glucose yields gluconic acid and H(2)O(2). The latter in the presence of luminol acts as substrate for the hemin/G-quadruplex-catalyzed generation of chemiluminescence. The glucose oxidase/hemin G-quadruplex hybrid was immobilized on CdSe/ZnS quantum dots (QDs). The light generated by the hybrid, in the presence of glucose, activated a chemiluminescence resonance energy transfer process to the QDs, resulting in the luminescence of the QDs. The intensities of the luminescence of the QDs at different concentrations of glucose provided an optical means to detect glucose.

Curcumin-loaded polymeric nanoparticles for enhanced anti-colorectal cancer applications.

PubMed

Udompornmongkol, Panisa; Chiang, Been-Huang

2015-11-01

The purpose of the present study was to fabricate polymeric nanoparticles as drug carriers for encapsulated curcumin with enhanced anti-colorectal cancer applications. Nanoparticles were formulated from chitosan and gum arabic, natural polysaccharides, via an emulsification solvent diffusion method. The formation of curcumin nanoparticles was confirmed by Fourier transform infrared spectroscopy and differential scanning calorimeter. The results show that curcumin was entrapped in carriers with +48 mV, 136 nm size, and high encapsulation efficiency (95%). Based on an in vitro release study, we inferred that curcumin nanoparticles could tolerate hydrolysis due to gastric juice or small intestinal enzymes, and therefore, it should reach the colon largely intact. In addition, curcumin nanoparticles had higher anti-colorectal cancer properties than free curcumin due to greater cellular uptake. Therefore, we concluded that curcumin was successfully encapsulated in chitosan-gum arabic nanoparticles with superior anti-colorectal cancer activity. © The Author(s) 2015.

Tested Demonstrations. A Chemiluminescence Demonstration - Oxalyl Chloride Oxidation.

ERIC Educational Resources Information Center

Gilber, George L., Ed.

1979-01-01

This inexpensive, effective chemiluminescence demonstration requires minimal preparation. It is based on the oxidation of oxalyl chloride by hydrogen peroxide in the presence of an appropriate fluorescent sensitizer. The reaction mechanism is not completely understood. (BB)

Pediatric and young adult exposure to chemiluminescent glow sticks.

PubMed

Hoffman, Robert J; Nelson, Lewis S; Hoffman, Robert S

2002-09-01

Although chemiluminescent plastic rods, commonly called "glow sticks" or "light sticks," are typically considered to be minimally toxic or nontoxic, published data about exposure to these products are scarce. To test our hypothesis that exposure to chemiluminescent products is unlikely to result in significant morbidity or mortality and to describe factors associated with exposure by reviewing reports to our urban poison control center of human exposure to chemiluminescent products. Pediatric and young adult exposure to chemiluminescent products reported between January 1, 2000, and April 1, 2001, to our poison control center were evaluated with regard to demographic group, type of product involved, circumstances of exposure, symptoms, and management. Reported routes of exposure (n = 118) included ingestion (n = 108), ocular (n = 9), and dermal exposure (n = 1). Only patients exposed to chemiluminescent fluid from a leaking container reported symptoms (n = 27). Symptoms were limited to transient irritation of the exposure site, and no systemic toxicity occurred. All adults (n = 4) inadvertently ruptured or swallowed intact light sticks while at a dance club or dance party. Most exposure and all adult exposure occurred on holidays or weekends. Most incidences of exposure to chemiluminescent products involve asymptomatic ingestion of fluid that leaks from glow sticks or ingestion of an intact glow stick. Symptoms occur after exposure to chemiluminescent fluid and consist of transient irritation at the site of exposure. The clustering of reported exposure on weekends and in dance clubs and parties coupled with a lack of occupational or workplace exposure suggest that recreational use is a major contributory factor. Exposure to chemiluminescent products infrequently resulted in symptoms and the symptoms reported were minor. Exposure to chemiluminescent products as described is unlikely to cause significant morbidity or mortality.

Resonant silicon nanoparticles for enhancement of light absorption and photoluminescence from hybrid perovskite films and metasurfaces.

PubMed

Tiguntseva, E; Chebykin, A; Ishteev, A; Haroldson, R; Balachandran, B; Ushakova, E; Komissarenko, F; Wang, H; Milichko, V; Tsypkin, A; Zuev, D; Hu, W; Makarov, S; Zakhidov, A

2017-08-31

Recently, hybrid halide perovskites have emerged as one of the most promising types of materials for thin-film photovoltaic and light-emitting devices because of their low-cost and potential for high efficiency. Further boosting their performance without detrimentally increasing the complexity of the architecture is critically important for commercialization. Despite a number of plasmonic nanoparticle based designs having been proposed for solar cell improvement, inherent optical losses of the nanoparticles reduce photoluminescence from perovskites. Here we use low-loss high-refractive-index dielectric (silicon) nanoparticles for improving the optical properties of organo-metallic perovskite (MAPbI 3 ) films and metasurfaces to achieve strong enhancement of photoluminescence as well as useful light absorption. As a result, we observed experimentally a 50% enhancement of photoluminescence intensity from a perovskite layer with silicon nanoparticles and 200% enhancement for a nanoimprinted metasurface with silicon nanoparticles on top. Strong increase in light absorption is also demonstrated and described by theoretical calculations. Since both silicon nanoparticle fabrication/deposition and metasurface nanoimprinting techniques are low-cost, we believe that the developed all-dielectric approach paves the way to novel scalable and highly effective designs of perovskite based metadevices.

Determination of hyperin in seed of Cuscuta chinensis Lam. by enhanced chemiluminescence of CdTe quantum dots on calcein/K3Fe(CN)6 system.

PubMed

Kang, Jing; Li, Xuwen; Geng, Jiayang; Han, Lu; Tang, Jieli; Jin, Yongri; Zhang, Yihua

2012-10-15

In this paper, 3-mercaptocarboxylic acid (MPA) modified CdTe quantum dots (QDs) were used as sensitizers, to enhance the chemiluminescence (CL) of the calcein/K(3)Fe(CN)(6) system. A new CL system of CdTe/calcein/K(3)Fe(CN)(6) was developed. The effects of reactant concentrations and the particle sizes of CdTe QDs on the CL emission were investigated in detail. The possible enhancement mechanism of the CL was also further investigated based on the photoluminescence (PL) and CL spectra. Polyphenols such as chlorogenic acid, quercetin, hyperin, catechin and kaempferol, were observed to inhibit the CL signal of the CdTe/calcein/K(3)Fe(CN)(6) system and determined by the proposed method. The proposed method was applied to the determination of hyperin in seed of Cuscuta chinensis Lam. and the results obtained were satisfactory. Copyright © 2012 Elsevier Ltd. All rights reserved.

The Chemiluminescence of Organometallic Compounds

NASA Astrophysics Data System (ADS)

Tolstikov, Genrikh A.; Bulgakov, Ramil G.; Kazakov, Valeri P.

1985-11-01

Studies on the liquid-phase and gas-phase reactions of organometallic compounds accompanied by the emission of light are described systematically and discussed. The influence of the magnetic field on the chemiluminescence of Grignard reagents and the study of the electrochemiluminescence of solutions of organometallic compounds are examined. The ways leading to further development of the field of the chemiluminescence of organometallic compounds and certain possible applications of the phenomenon in the monitoring of industrial processes are discussed. The bibliography includes 80 references.

Following Glucose Oxidase Activity by Chemiluminescence and Chemiluminescence Resonance Energy Transfer (CRET) Processes Involving Enzyme-DNAzyme Conjugates

PubMed Central

Niazov, Angelica; Freeman, Ronit; Girsh, Julia; Willner, Itamar

2011-01-01

A hybrid consisting of glucose oxidase-functionalized with hemin/G-quadruplex units is used for the chemiluminescence detection of glucose. The glucose oxidase-mediated oxidation of glucose yields gluconic acid and H2O2. The latter in the presence of luminol acts as substrate for the hemin/G-quadruplex-catalyzed generation of chemiluminescence. The glucose oxidase/hemin G-quadruplex hybrid was immobilized on CdSe/ZnS quantum dots (QDs). The light generated by the hybrid, in the presence of glucose, activated a chemiluminescence resonance energy transfer process to the QDs, resulting in the luminescence of the QDs. The intensities of the luminescence of the QDs at different concentrations of glucose provided an optical means to detect glucose. PMID:22346648

Flow injection chemiluminescence determination of vitamin B12 using on-line UV-persulfate photooxidation and charge coupled device detection.

PubMed

Murillo Pulgarín, José A; García Bermejo, Luisa F; Sánchez García, M Nieves

2011-01-01

A sensitive chemiluminescence method for vitamin B(12) using a charge-coupled device (CCD) photodetector combined with on-line UV-persulfate oxidation in a simple continuous flow system has been developed. The principle for the determination of vitamin B(12) is based on the enhancive effect of cobalt (II) on the chemiluminescence reaction between luminol and percarbonate in alkaline medium. In addition, percarbonate has been investigated and proposed as a powerful source of hydrogen peroxide as oxidant agent in this chemiluminescence reaction. The digestion of vitamin B(12) to release the cobalt (II) is reached by UV irradiation treatment in a persulfate medium. The CCD detector, directly connected to the flow cell, is used with the continuous flow manifold to obtain the full spectral characteristics of cobalt (II) catalyzed luminol-percarbonate reaction. The vitamin B(12) oxidation process and chemical conditions for the chemiluminescence reaction were investigated and optimized. The increment of the emission intensity was proportional to the concentration of vitamin B(12) , giving a second-order calibration graph over the cobalt (II) concentration range from 10 to 5000 μg L(-1)(r(2) = 0.9985) with a detection limit of 9.3 μg L(-1). The proposed method was applied to the determination of vitamin B(12) in different kinds of pharmaceuticals. Copyright © 2011 John Wiley & Sons, Ltd.

On the relationship between the specific heat enhancement of salt-based nanofluids and the ionic exchange capacity of nanoparticles.

PubMed

Mondragón, Rosa; Juliá, J Enrique; Cabedo, Luis; Navarrete, Nuria

2018-05-14

Nanoparticles have been used in thermal applications to increase the specific heat of the molten salts used in Concentrated Solar Power plants for thermal energy storage. Although several mechanisms for abnormal enhancement have been proposed, they are still being investigated and more research is necessary. However, this nanoparticle-salt interaction can also be found in chemical applications in which nanoparticles have proved suitable to be used as an adsorbent for nitrate removal given their high specific surface, reactivity and ionic exchange capacity. In this work, the ionic exchange capacity mechanism for the nanoparticles functionalization phenomenon was evaluated. The ionic exchange capacity of silica and alumina nanoparticles dispersed in lithium, sodium and potassium nitrates was measured. Fourier-transform infrared spectroscopy tests confirmed the adsorption of nitrate ions on the nanoparticle surface. A relationship between the ionic exchange capacity of nanoparticles and the specific heat enhancement of doped molten salts was proposed for the first time.

Enhanced response of a proteinase K-based conductometric biosensor using nanoparticles.

PubMed

Nouira, Wided; Maaref, Abderrazak; Elaissari, Hamid; Vocanson, Francis; Siadat, Maryam; Jaffrezic-Renault, Nicole

2014-07-23

Proteinases are involved in a multitude of important physiological processes, such as protein metabolism. For this reason, a conductometric enzyme biosensor based on proteinase K was developed using two types of nanoparticles (gold and magnetic). The enzyme was directly adsorbed on negatively charged nanoparticles and then deposited and cross-linked on a planar interdigitated electrode (IDE). The biosensor was characterized with bovine serum albumin (BSA) as a standard protein. Higher sensitivity was obtained using gold nanoparticles. The linear range for BSA determination was then from 0.5 to 10 mg/L with a maximum response of 154 µs. These results are greater than that found without any nanoparticles (maximum response of 10 µs). The limit of detection (LOD) was 0.3 mg/L. An inter-sensor reproducibility of 3.5% was obtained.

A novel alcohol dehydrogenase biosensor based on solid-state electrogenerated chemiluminescence by assembling dehydrogenase to Ru(bpy)(3)2+-Au nanoparticles aggregates.

PubMed

Zhang, Lihua; Xu, Zhiai; Sun, Xuping; Dong, Shaojun

2007-01-15

Based on electrogenerated chemiluminescence (ECL), a novel method for fabrication of alcohol dehydrogenase (ADH) biosensor by self-assembling ADH to Ru(bpy)(3)(2+)-AuNPs aggregates (Ru-AuNPs) on indium tin oxide (ITO) electrode surface has been developed. Positively charged Ru(bpy)(3)(2+) could be immobilized stably on the electrode surface with negatively charged AuNPs in the form of aggregate via electrostatic interaction. On the other hand, AuNPs are favourable candidates for the immobilization of enzymes because amine groups and cysteine residues in the enzymes are known to bind strongly with AuNPs. Moreover, AuNPs can act as tiny conduction centers to facilitate the transfer of electrons. Such biosensor combined enzymatic selectivity with the sensitivity of ECL detection for quantification of enzyme substrate, and it displayed wide linear range, high sensitivity and good stability.

Flow injection chemiluminescence determination of 6-mercaptopurine based on a new system of potassium permanganate-thioacetamide-sodium hexametaphosphate.

PubMed

Wang, Lun; Ling, Bo; Chen, Hongqi; Liang, Ani; Qian, Binbin; Fu, Jie

2010-01-01

A novel chemiluminescence method for the determination of 6-mercaptopurine was established based on 6-mercaptopurine inhibition of the chemiluminescence emission of potassium permanganate-thioacetamide-sodium hexametaphosphate system. The peak height was proportional to log 6-mercaptopurine concentration in the range 7.0 × 10(-10) to 1.0 × 10(-7)  g/mL and the detection limit was 1.9 × 10(-11)  g/mL (S/N = 3). The relative standard deviation was 1.5% for the determination of 8.0 × 10(-8)  g/mL 6-mercaptopurine (n = 11). The proposed sensor was successfully applied to the analysis of 6-mercaptopurine in human serum samples. Copyright © 2009 John Wiley & Sons, Ltd.

Multivalent Porous Silicon Nanoparticles Enhance the Immune Activation Potency of Agonistic CD40 Antibody

PubMed Central

Gu, Luo; Ruff, Laura E.; Qin, Zhengtao; Corr, Maripat P.; Hedrick, Stephen M.; Sailor, Michael J.

2012-01-01

One of the fundamental paradigms in the use of nanoparticles to treat disease is to evade or suppress the immune system in order to minimize systemic side effects and deliver sufficient nanoparticle quantities to the intended tissues. However, the immune system is the body's most important and effective defense against diseases. It protects the host by identifying and eliminating foreign pathogens as well as selfmalignancies. Here we report a nanoparticle engineered to work with the immune system, enhancing the intended activation of antigen presenting cells (APCs). We show that luminescent porous silicon nanoparticles (LPSiNPs), each containing multiple copies of an agonistic antibody (FGK45) to the APC receptor CD40, greatly enhance activation of B cells. The cellular response to the nanoparticle-based stimulators is equivalent to a 30–40 fold larger concentration of free FGK45. The intrinsic near-infrared photoluminescence of LPSiNPs is used to monitor degradation and track the nanoparticles inside APCs. PMID:22689074

Recent Advances on Inorganic Nanoparticle-Based Cancer Therapeutic Agents

PubMed Central

Wang, Fenglin; Li, Chengyao; Cheng, Jing; Yuan, Zhiqin

2016-01-01

Inorganic nanoparticles have been widely investigated as therapeutic agents for cancer treatments in biomedical fields due to their unique physical/chemical properties, versatile synthetic strategies, easy surface functionalization and excellent biocompatibility. This review focuses on the discussion of several types of inorganic nanoparticle-based cancer therapeutic agents, including gold nanoparticles, magnetic nanoparticles, upconversion nanoparticles and mesoporous silica nanoparticles. Several cancer therapy techniques are briefly introduced at the beginning. Emphasis is placed on how these inorganic nanoparticles can provide enhanced therapeutic efficacy in cancer treatment through site-specific accumulation, targeted drug delivery and stimulated drug release, with elaborations on several examples to highlight the respective strategies adopted. Finally, a brief summary and future challenges are included. PMID:27898016

Recent Advances on Inorganic Nanoparticle-Based Cancer Therapeutic Agents.

PubMed

Wang, Fenglin; Li, Chengyao; Cheng, Jing; Yuan, Zhiqin

2016-11-25

Inorganic nanoparticles have been widely investigated as therapeutic agents for cancer treatments in biomedical fields due to their unique physical/chemical properties, versatile synthetic strategies, easy surface functionalization and excellent biocompatibility. This review focuses on the discussion of several types of inorganic nanoparticle-based cancer therapeutic agents, including gold nanoparticles, magnetic nanoparticles, upconversion nanoparticles and mesoporous silica nanoparticles. Several cancer therapy techniques are briefly introduced at the beginning. Emphasis is placed on how these inorganic nanoparticles can provide enhanced therapeutic efficacy in cancer treatment through site-specific accumulation, targeted drug delivery and stimulated drug release, with elaborations on several examples to highlight the respective strategies adopted. Finally, a brief summary and future challenges are included.

Development of a chemiluminescence competitive PCR for the detection and quantification of parvovirus B19 DNA using a microplate luminometer.

PubMed

Fini, F; Gallinella, G; Girotti, S; Zerbini, M; Musiani, M

1999-09-01

Quantitative PCR of viral nucleic acids can be useful clinically in diagnosis, risk assessment, and monitoring of antiviral therapy. We wished to develop a chemiluminescence competitive PCR (cPCR) for parvovirus B19. Parvovirus DNA target sequences and competitor sequences were coamplified and directly labeled. Amplified products were then separately hybridized by specific biotin-labeled probes, captured onto streptavidin-coated ELISA microplates, and detected immunoenzymatically using chemiluminescent substrates of peroxidase. Chemiluminescent signals were quantitatively analyzed by a microplate luminometer and were correlated to the amounts of amplified products. Luminol-based systems displayed constant emission but had a higher detection limit (100-1000 genome copies) than the acridan-based system (20 genome copies). The detection limit of chemiluminescent substrates was lower (20 genome copies) than colorimetric substrates (50 genome copies). In chemiluminescence cPCR, the titration curves showed linear correlation above 100 target genome copies. Chemiluminescence cPCR was positive in six serum samples from patients with parvovirus infections and negative in six control sera. The chemiluminescence cPCR appears to be a sensitive and specific method for the quantitative detection of viral DNAs.

Chemiluminescence: An Illuminating Experiment

ERIC Educational Resources Information Center

Gafney, Harry D.; Adamson, Arthur W.

1975-01-01

Describes an experiment in which luminescence is observed during a reaction between sodium borohydride and trisbipyridalruthenium (III). Includes a discussion of the theory of chemiluminescence. (MLH)

Silver nanoparticle based surface enhanced Raman scattering spectroscopy of diabetic and normal rat pancreatic tissue under near-infrared laser excitation

NASA Astrophysics Data System (ADS)

Huang, H.; Shi, H.; Feng, S.; Lin, J.; Chen, W.; Huang, Z.; Li, Y.; Yu, Y.; Lin, D.; Xu, Q.; Chen, R.

2013-04-01

This paper presents the use of high spatial resolution silver nanoparticle based near-infrared surface enhanced Raman scattering (SERS) from rat pancreatic tissue to obtain biochrmical information about the tissue. A high quality SERS signal from a mixture of pancreatic tissues and silver nanoparticles can be obtained within 10 s using a Renishaw micro-Raman system. Prominent SERS bands of pancreatic tissue were assigned to known molecular vibrations, such as the vibrations of DNA bases, RNA bases, proteins and lipids. Different tissue structures of diabetic and normal rat pancreatic tissues have characteristic features in SERS spectra. This exploratory study demonstrated great potential for using SERS imaging to distinguish diabetic and normal pancreatic tissues on frozen sections without using dye labeling of functionalized binding sites.

Release of oxygen radicals by articular chondrocytes: a study of luminol-dependent chemiluminescence and hydrogen peroxide secretion.

PubMed

Rathakrishnan, C; Tiku, K; Raghavan, A; Tiku, M L

1992-10-01

We previously established that normal articular chondrocytes, like macrophages, express class II major histocompatibility antigens, present antigen, and induce mixed and autologous lymphocyte stimulation. In a recent study using the trapped indicator 2',7'-dichlorofluorescein diacetate, we were able to measure levels of intracellular hydrogen peroxide within normal articular chondrocytes (J Immunol 245:690-696, 1990). In the present study, we utilized the technique of chemiluminescence and the biochemical method of quantitating hydrogen peroxide release to measure the production of reactive oxygen intermediates by articular chondrocytes. Chondrocytes, in suspension or adherent to coverslips, showed luminol-dependent chemiluminescence that was dependent on the number and viability of cells. There was a dose-dependent increase in chemiluminescence in response to soluble stimuli, such as phorbol myristate acetate (PMA), concanavalin A (ConA), and f-Met-Leu-Phe (FMLP). Azide inhibited chemiluminescence, suggesting that the light emission in chondrocytes is myeloperoxidase dependent. The antioxidant, catalase, inhibited chemiluminescence but superoxide dismutase had no effect, suggesting that luminol-dependent chemiluminescence in chondrocytes mostly measured hydrogen peroxide. Chemiluminescence was also observed in fragments of live cartilage tissue, indicating that chondrocytes that are cartilage matrix bound can generate the respiratory burst response. Using the scopoletin oxidation assay, we confirmed the release of increasing amounts of hydrogen peroxide by chondrocytes exposed to interleukin-1, rabbit interferon, and tumor necrosis factor alpha. Tumor necrosis factor alpha had both priming and enhancing effects on reactive oxygen intermediate production by chondrocytes. Reactive oxygen intermediates have been shown to play a significant role in matrix degradation. We suggest that reactive oxygen intermediates produced by chondrocytes play an important role in the

TU-H-CAMPUS-TeP3-05: Evaluation of the Microscopic Dose Enhancement in the Nanoparticle-Enhanced Auger Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sung, W; Jung, S; Ye, S

Purpose: The aim of this study is to apply Monte Carlo simulations to investigate the nanoparticle dose enhancement for Auger therapy. Methods: Two nanoparticle fabrications were considered: nanoshell and nanosphere. In the first step, a single nanoparticle was irradiated with Auger emitters. The electrons were scored in a phase space at the outer surface of the nanoparticle with Geant4-Penelope. In the second step, the previously recorded phase space was used as a source and placed at the center of a cell-size water phantom. The nanoscale dose was evaluated in water around the nanoparticle with Geant4-DNA. The dose enhancement factor (DEF)more » is defined as the ratio of doses with and without nanoparticles. The nanoparticles were replaced by corresponding water nanoparticle with the same size and volume source which represents typical situation of Auger emitters without nanoparticle. Various sizes/materials of nanoparticles and isotopes were considered. Results: Nanoshell - Microscopic dose was increased up to 130% at 20 – 100 nm distances from the surface of Au-{sup 125}I nanoshell. However, dose at less than 20 nm distance was reduced due to absorbed low energy electrons in gold nanoshell. The amounts and regions of the dose enhancement were dependent on nanoshell size, materials, and isotopes. Nanosphere - The increased amounts of electrons up to 300% and reduced average energy with nanosphere were observed compared with water nanoparticle. We observed localized dose enhancement (up to a factor 3.6) in the immediate vicinity (< 50 nm) of Au-{sup 125} I nanosphere. The dose enhancement patterns vary according to nanosphere sizes and isotopes. Conclusion: We conclude that Auger therapy with nanoparticles can lead to change of electron energy spectrum and dose enhancements at certain range. The dose enhancement patterns vary according to nanoparticle sizes, materials, and isotopes. This work was supported by the National Research Foundation of Korea (NRF

Electroluminescence Efficiency Enhancement using Metal Nanoparticles

DTIC Science & Technology

2008-06-22

ABSTRACT We apply the “effective mode volume” theory to evaluate enhancement of the electroluminescence efficiency of semiconductor emitters placed in... Electroluminescence efficiency enhancement using metal nanoparticles J. B. Khurgin,1 G. Sun,2,a and R. A. Soref3 1Department of Electrical and Computer...published online 17 July 2008 We apply the “effective mode volume” theory to evaluate enhancement of the electroluminescence efficiency of semiconductor

Chemiluminescence-based multivariate sensing of local equivalence ratios in premixed atmospheric methane-air flames

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tripathi, Markandey M.; Krishnan, Sundar R.; Srinivasan, Kalyan K.

Chemiluminescence emissions from OH*, CH*, C2, and CO2 formed within the reaction zone of premixed flames depend upon the fuel-air equivalence ratio in the burning mixture. In the present paper, a new partial least square regression (PLS-R) based multivariate sensing methodology is investigated and compared with an OH*/CH* intensity ratio-based calibration model for sensing equivalence ratio in atmospheric methane-air premixed flames. Five replications of spectral data at nine different equivalence ratios ranging from 0.73 to 1.48 were used in the calibration of both models. During model development, the PLS-R model was initially validated with the calibration data set using themore » leave-one-out cross validation technique. Since the PLS-R model used the entire raw spectral intensities, it did not need the nonlinear background subtraction of CO2 emission that is required for typical OH*/CH* intensity ratio calibrations. An unbiased spectral data set (not used in the PLS-R model development), for 28 different equivalence ratio conditions ranging from 0.71 to 1.67, was used to predict equivalence ratios using the PLS-R and the intensity ratio calibration models. It was found that the equivalence ratios predicted with the PLS-R based multivariate calibration model matched the experimentally measured equivalence ratios within 7%; whereas, the OH*/CH* intensity ratio calibration grossly underpredicted equivalence ratios in comparison to measured equivalence ratios, especially under rich conditions ( > 1.2). The practical implications of the chemiluminescence-based multivariate equivalence ratio sensing methodology are also discussed.« less

Temperature-dependent ozone chemiluminescence: A new approach for hydrocarbon monitoring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marley, N.; Gaffney, J.

1996-12-31

Ozone chemiluminescent reactions have been used for some time to detect oxides of nitrogen, ozone, and olefins in air quality studies. Current procedures use non-methane hydrocarbon analyzers based on the flame ionization detector (FID), which quantitate total non-methane hydrocarbons but do not differentiate between the wide variety of volatile organic classes and oxygenates. The other methodology that has been used, gas chromatography/mass spectroscopy (GC/MS), can measure a variety of individual hydrocarbon species and classes, but it is costly, time-consuming, and labor intensive and is not amenable to real-time measurements. Presented here is preliminary research aimed at the development of anmore » alternative to FID and GC/MS: the ozone chemiluminescent detector (OCD) for measurement of a variety of hydrocarbon species and classes by use of the temperature dependence of ozone chemiluminescent reactions. Responses for various hydrocarbon classes obtained with an OCD operated at 170 C or the FID were compared. The results indicate that the OCD detector responds like a total carbon detector at this temperature, with sensitivities 10-100 times higher than those of a FID. Use of the temperature dependence of the chemiluminescent reaction and prereactors will apparently make a real-time hydrocarbon analyzer based on this approach feasible for determination of high-, moderate-, and low-reactivity hydrocarbon levels in ambient air. The OCD approach may be very useful in determining oxygenate emissions from motor vehicles, particularly alternative fuels. The OCD may also be useful in monitoring of ambient air for natural hydrocarbon emissions.« less

Convection-enhanced delivery and in vivo imaging of polymeric nanoparticles for the treatment of malignant glioma.

PubMed

Bernal, Giovanna M; LaRiviere, Michael J; Mansour, Nassir; Pytel, Peter; Cahill, Kirk E; Voce, David J; Kang, Shijun; Spretz, Ruben; Welp, Ulrich; Noriega, Sandra E; Nunez, Luis; Larsen, Gustavo F; Weichselbaum, Ralph R; Yamini, Bakhtiar

2014-01-01

A major obstacle to the management of malignant glioma is the inability to effectively deliver therapeutic agent to the tumor. In this study, we describe a polymeric nanoparticle vector that not only delivers viable therapeutic, but can also be tracked in vivo using MRI. Nanoparticles, produced by a non-emulsion technique, were fabricated to carry iron oxide within the shell and the chemotherapeutic agent, temozolomide (TMZ), as the payload. Nanoparticle properties were characterized and subsequently their endocytosis-mediated uptake by glioma cells was demonstrated. Convection-enhanced delivery (CED) can disperse nanoparticles through the rodent brain and their distribution is accurately visualized by MRI. Infusion of nanoparticles does not result in observable animal toxicity relative to control. CED of TMZ-bearing nanoparticles prolongs the survival of animals with intracranial xenografts compared to control. In conclusion, the described nanoparticle vector represents a unique multifunctional platform that can be used for image-guided treatment of malignant glioma. GBM remains one of the most notoriously treatment-unresponsive cancer types. In this study, a multifunctional nanoparticle-based temozolomide delivery system was demonstrated to possess enhanced treatment efficacy in a rodent xenograft GBM model, with the added benefit of MRI-based tracking via the incorporation of iron oxide as a T2* contrast material in the nanoparticles. © 2014.

Long-term chemiluminescence signal is produced in the course of luminol oxidation catalyzed by enhancer-independent peroxidase purified from Jatropha curcas leaves.

PubMed

Duan, Peipei; Cai, Feng; Luo, Yongting; Chen, Yangxi; Zou, Shujuan

2015-09-01

Isoenzyme c of horseradish peroxidase (HRP-C) is widely used in enzyme immunoassay combined with chemiluminescence (CL) detection. For this application, HRP-C activity measurement is usually based on luminol oxidation in the presence of hydrogen peroxide (H2O2). However, this catalysis reaction was enhancer dependent. In this study, we demonstrated that Jatropha curcas peroxidase (JcGP1) showed high efficiency in catalyzing luminol oxidation in the presence of H2O2. Compared with HRP-C, the JcGP1-induced reaction was enhancer independent, which made the enzyme-linked immunosorbent assay (ELISA) simpler. In addition, the JcGP1 catalyzed reaction showed a long-term stable CL signal. We optimized the conditions for JcGP1 catalysis and determined the favorable conditions as follows: 50 mM Tris buffer (pH 8.2) containing 10 mM H2 O2, 14 mM luminol and 0.75 M NaCl. The optimum catalysis temperature was 30°C. The detection limit of JcGP1 under optimum condition was 0.2 pM. Long-term stable CL signal combined with enhancer-independent property indicated that JcGP1 might be a valuable candidate peroxidase for clinical diagnosis and enzyme immunoassay with CL detection. Copyright © 2014 John Wiley & Sons, Ltd.

TH-E-BRD-01: Innovation in (gold) Nanoparticle-Enhanced Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krishnan, S; Chithrani, B; Berbeco, R

2014-06-15

Radiation therapy relies on the concept of delivering high dose to tumor volumes whilst simultaneously aiming to minimize irradiation of healthy tissue. Gold and other metallic nanoparticles (GNPs) have the potential to greatly enhance dose depositions in their close proximity. While it was originally thought that this effect would only be significant for kV photon beams, it has been shown that GNPs also enhance dose and increase cell killing and survival fraction for MV photons as well as protons. GNPs have been shown to be preferentially taken up in tumors, depending on the GNP properties either internalized in the tumormore » cells or clustering in the tumor vasculature. Therefore GNPs offer an intriguing additional option to target the tumor while sparing healthy tissue. While a growing amount of research shows GNP induced enhancement factors in the order of 1.5 and higher, GNPs have not yet entered into clinical routine. In this symposium we will have three presentations discussing the current status of GNP based research, the potential to include GNPs in radiation therapy and the limitations and problems to use GNPs in the clinic. Physical and biological underpinnings of radiosensitization with gold nano particles An evolving body of recent literature alludes to the potential to sensitize tumors to radiation therapy using metallic nanoparticles. In preclinical studies, the techniques that hold promise for eventual clinical deployment are nanoparticle-assisted radiation dose enhancement and hyperthermic radiosensitization. To understand the underlying nanoparticle-radiation interactions, computational techniques offer an explanation for and predict the biophysical consequences at a nano-/meso-scopic scale. Nonetheless, there are persisting gaps in knowledge relating to the molecular mechanism of action of these radiosensitization approaches — some of these issues will be addressed. Since the literature relating to the diverse disciplines involved in these

Enhanced Formation of Oxidants from Bimetallic Nickel-Iron Nanoparticles in the Presence of Oxygen

PubMed Central

Lee, Changha; Sedlak, David L.

2009-01-01

Nanoparticulate zero-valent iron (nZVI) rapidly reacts with oxygen to produce strong oxidants, capable of transforming organic contaminants in water. However, the low yield of oxidants with respect to the iron added normally limits the application of this system. Bimetallic nickel-iron nanoparticles (nNi-Fe; i.e., Ni-Fe alloy and Ni-coated Fe nanoparticles) exhibited enhanced yields of oxidants compared to nZVI. nNi-Fe (Ni-Fe alloy nanoparticles with [Ni]/[Fe] = 0.28 and Ni-coated Fe nanoparticles with [Ni]/[Fe] = 0.035) produced approximately 40% and 85% higher yields of formaldehyde from the oxidation of methanol relative to nZVI at pH 4 and 7, respectively. Ni-coated Fe nanoparticles showed a higher efficiency for oxidant production relative to Ni-Fe alloy nanoparticles based on Ni content. Addition of Ni did not enhance the oxidation of 2-propanol or benzoic acid, indicating that Ni addition did not enhance hydroxyl radical formation. The enhancement in oxidant yield was observed over a pH range of 4 – 9. The enhanced production of oxidant by nNi-Fe appears to be attributable to two factors. First, the nNi-Fe surface is less reactive toward hydrogen peroxide (H2O2) than the nZVI surface, which favors the reaction of H2O2 with dissolved Fe(II) (the Fenton reaction). Second, the nNi-Fe surface promotes oxidant production from the oxidation of ferrous ion by oxygen at neutral pH values. PMID:19068843

Plasma - enhanced dispersion of metal and ceramic nanoparticles in polymer nanocomposite films

NASA Astrophysics Data System (ADS)

Maguire, Paul; Liu, Yazi; Askari, Sadegh; Patel, Jenish; Macia-Montero, Manuel; Mitra, Somak; Zhang, Richao; Sun, Dan; Mariotti, Davide

2015-09-01

In this work we demonstrate a facile method to synthesize a nanoparticle/PEDOT:PSS hybrid nanocomposite material in aqueous solution through atmospheric pressure direct current (DC) plasma processing at room temperature. Both metal (Au) and ceramic (TiO2) nanoparticle composite films have been fabricated. Nanoparticle dispersion is enhanced considerable and remains stable. TiO2/polymer hybrid nanoparticles with a distinct core shell structure have been obtained. Increased nanoparticle/PEDOT:PSS nanocomposite electrical conductivity has been observed. The improvement in nanocomposite properties is due to the enhanced dispersion and stability in liquid polymer of microplasma processed Au or TiO2 nanoparticles. Both plasma induced surface charge and nanoparticle surface termination with specific plasma chemical species are thought to provide an enhanced barrier to nanoparticle agglomeration and promote nanoparticle-polymer bonding. This is expected to have a significant benefit in materials processing with inorganic nanoparticles for applications in energy storage, photocatalysis and biomedical sensors. Engineering and Physical Sciences Research Council (EPSRC: EP/K006088/1, EP/K006142, Nos. EP/K022237/1).

Near-infrared surface-enhanced fluorescence using silver nanoparticles in solution

NASA Astrophysics Data System (ADS)

Furtaw, Michael D.

Fluorescence spectroscopy is a widely used detection technology in many research and clinical assays. Further improvement to assay sensitivity may enable earlier diagnosis of disease, novel biomarker discovery, and ultimately, improved outcomes of clinical care along with reduction in costs. Near-infrared, surface-enhanced fluorescence (NIR-SEF) is a promising approach to improve assay sensitivity via simultaneous increase in signal with a reduction in background. This dissertation describes research conducted with the overall goal to determine the extent to which fluorescence in solution may be enhanced by altering specific variables involved in the formation of plasmon-active nanostructures of dye-labeled protein and silver nanoparticles in solution, with the intent of providing a simple solution that may be readily adopted by current fluorescence users in the life science research community. First, it is shown that inner-filtering, re-absorption of the emitted photons, can red-shift the optimal fluorophore spectrum away from the resonant frequency of the plasmon-active nanostructure. It is also shown that, under certain conditions, the quality factor may be a better indicator of SEF than the commonly accepted overlap of the fluorophore spectrum with the plasmon resonance of the nanostructure. Next, it is determined that streptavidin is the best choice for carrier protein, among the most commonly used dye-labeled detection antibodies, to enable the largest fluorescence enhancement when labeled with IRDye 800CW and used in combination with silver nanoparticles in solution. It is shown that the relatively small and symmetric geometry of streptavidin enables substantial electromagnetic-field confinement when bound to silver nanoparticles, leading to strong and reproducible enhancement. The role of silver nanoparticle aggregation is demonstrated in a droplet-based microfluidic chip and further optimized in a standard microtiter-plate format. A NIR-SEF technology

Detection of hydrogen peroxide with chemiluminescent micelles

PubMed Central

Lee, Dongwon; Erigala, Venkata R; Dasari, Madhuri; Yu, Junhua; Dickson, Robert M; Murthy, Niren

2008-01-01

The overproduction of hydrogen peroxide is implicated in the progress of numerous life-threatening diseases and there is a great need for the development of contrast agents that can detect hydrogen peroxide in vivo. In this communication, we present a new contrast agent for hydrogen peroxide, termed peroxalate micelles, which detect hydrogen peroxide through chemiluminescence, and have the physical/chemical properties needed for in vivo imaging applications. The peroxalate micelles are composed of amphiphilic peroxalate based copolymers and the fluorescent dye rubrene, they have a ‘stealth’ polyethylene glycol (PEG) corona to evade macrophage phagocytosis, and a diameter of 33 nm to enhance extravasation into permeable tissues. The peroxalate micelles can detect nanomolar concentrations of hydrogen peroxide (>50 nM) and thus have the sensitivity needed to detect physiological concentrations of hydrogen peroxide. We anticipate numerous applications of the peroxalate micelles for in vivo imaging of hydrogen peroxide, given their high sensitivity, small size, and biocompatible PEG corona. PMID:19337415

Direct Real-Time Monitoring of Prodrug Activation by Chemiluminescence.

PubMed

Gnaim, Samer; Scomparin, Anna; Das, Sayantan; Blau, Rachel; Satchi-Fainaro, Ronit; Shabat, Doron

2018-05-22

The majority of theranostic prodrugs reported so far relay information through a fluorogenic response generated upon release of the active chemotherapeutic agent. A chemiluminescence detection mode offers significant advantages over fluorescence, mainly due to the superior signal-to-noise ratio of chemiluminescence. Here we report the design and synthesis of the first theranostic prodrug monitored by a chemiluminescence diagnostic mode. As a representative model, we prepared a prodrug from the chemotherapeutic monomethyl auristatin E, which was modified for activation by β-galactosidase. The activation of the prodrug in the presence of β-galactosidase is accompanied by emission of a green photon. Light emission intensities, which increase with increasing concentration of the prodrug, were linearly correlated with a decrease in the viability of a human cell line that stably expresses β-galactosidase. We obtained sharp intravital chemiluminescent images of endogenous enzymatic activity in β-galactosidase-overexpressing tumor-bearing mice. The exceptional sensitivity achieved with the chemiluminescence diagnostic mode should allow the exploitation of theranostic prodrugs for personalized cancer treatment. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Enhanced drug transport through alginate biofilms using magnetic nanoparticles

NASA Astrophysics Data System (ADS)

McGill, Shayna L.; Cuylear, Carla; Adolphi, Natalie L.; Osinski, Marek; Smyth, Hugh

2009-02-01

The development of microbiological biofilms greatly reduces the efficacy of antibiotic therapies and is a serious problem in chronic infection and for implantable medical devices. We investigated the potential of superparamagnetic nanoparticles to increase transport through in vitro models of alginate biofilms. An in vitro alginate biofilm model was developed to mimic the composition of in vivo samples of P. aeruginosa infections. Transport through this model biofilm was performed using both bulk diffusion methods and single particle tracking techniques in the presence and absence of an external magnetic field. Bulk diffusion of nanoparticles through the biofilm was significantly enhanced in the presence of a magnetic field, both visually and quantitatively. Nanoparticle trajectories also showed transport increases were significantly higher when magnetic fields were applied. We also showed that surface chemistry (cationic, anioni, or neutral) of the nanoparticles significantly influenced transport rates. Finally, nanoparticle size also influenced the transport rates and variability of transport rates through the biofilm. In these first studies using magnetic nanoparticles in bacterial biofilms, we demonstrate that transport enhancement can be achieved and further studies are warranted.

Evaluation of lophine derivatives as L-012 (luminol analog)-dependent chemiluminescence enhancers for measuring horseradish peroxidase and H2O2.

PubMed

Ichibangase, T; Ohba, Y; Kishikawa, N; Nakashima, K; Kuroda, N

2014-03-01

8-Amino-5-chloro-7-phenylpyrido[3,4-d]pyridazine-1,4(2H,3H)dione (L-012) was recently synthesized as a new chemiluminescence (CL) probe; the light intensity and the sensitivity of L-012 are higher than those of other CL probes such as luminol. Previously, our group developed four lophine-based CL enhancers of the horseradish peroxidase (HRP)-catalyzed CL oxidation of luminol, namely 2-(4-hydroxyphenyl)-4,5-diphenylimidazole (HDI), 2-(4-hydroxyphenyl)-4,5-di(2-pyridyl)imidazole (HPI), 4-(4,5-diphenyl-1H-imidazol-2-yl)phenylboronic acid (DPA), and 4-[4,5-di(2-pyridyl)-1H-imidazol-2-yl]phenylboronic acid (DPPA), and showed that DPPA was suitable for the photographic detection of HRP. In this study, we replaced luminol with L-012 and evaluated these as L-012-dependent CL enhancers. In addition, to detect HRP and/or H2O2 with higher sensitivity, each detection condition for the L-012-HRP-H2O2 enhanced CL was optimized. All the derivatives enhanced the L-012-dependent CL as well as luminol CL; HPI generated the highest enhanced luminescence. Under optimized conditions for HRP detection, the detection limit of HRP was 0.08 fmol. By contrast, the detection limit of HRP with the enhanced L-012-dependent CL using 4-iodophenol, which is a common enhancer of luminol CL, was 1.1 fmol. With regard to H2O2 detection, the detection limits for enhanced CL with HPI and 4-iodophenol were 0.29 and 1.5 pmol, respectively. Therefore, it is demonstrated that HPI is the most superior L-012-dependent CL enhancer. Copyright © 2013 John Wiley & Sons, Ltd.

Enhancing regenerative approaches with nanoparticles

PubMed Central

Habibovic, Pamela

2017-01-01

In this review, we discuss recent developments in the field of nanoparticles and their use in tissue regeneration approaches. Owing to their unique chemical properties and flexibility in design, nanoparticles can be used as drug delivery systems, to create novel features within materials or as bioimaging agents, or indeed these properties can be combined to create smart multifunctional structures. This review aims to provide an overview of this research field where the focus will be on nanoparticle-based strategies to stimulate bone regeneration; however, the same principles can be applied for other tissue and organ regeneration strategies. In the first section, nanoparticle-based methods for the delivery of drugs, growth factors and genetic material to promote tissue regeneration are discussed. The second section deals with the addition of nanoparticles to materials to create nanocomposites. Such materials can improve several material properties, including mechanical stability, biocompatibility and biological activity. The third section will deal with the emergence of a relatively new field of research using nanoparticles in advanced cell imaging and stem cell tracking approaches. As the development of nanoparticles continues, incorporation of this technology in the field of regenerative medicine will ultimately lead to new tools that can diagnose, track and stimulate the growth of new tissues and organs. PMID:28404870

Enhancing regenerative approaches with nanoparticles.

PubMed

van Rijt, Sabine; Habibovic, Pamela

2017-04-01

In this review, we discuss recent developments in the field of nanoparticles and their use in tissue regeneration approaches. Owing to their unique chemical properties and flexibility in design, nanoparticles can be used as drug delivery systems, to create novel features within materials or as bioimaging agents, or indeed these properties can be combined to create smart multifunctional structures. This review aims to provide an overview of this research field where the focus will be on nanoparticle-based strategies to stimulate bone regeneration; however, the same principles can be applied for other tissue and organ regeneration strategies. In the first section, nanoparticle-based methods for the delivery of drugs, growth factors and genetic material to promote tissue regeneration are discussed. The second section deals with the addition of nanoparticles to materials to create nanocomposites. Such materials can improve several material properties, including mechanical stability, biocompatibility and biological activity. The third section will deal with the emergence of a relatively new field of research using nanoparticles in advanced cell imaging and stem cell tracking approaches. As the development of nanoparticles continues, incorporation of this technology in the field of regenerative medicine will ultimately lead to new tools that can diagnose, track and stimulate the growth of new tissues and organs. © 2017 The Author(s).

Dual UV irradiation-based metal oxide nanoparticles for enhanced antimicrobial activity in Escherichia coli and M13 bacteriophage

PubMed Central

Jin, Su-Eon; Hwang, Woochul; Lee, Hyo Jung; Jin, Hyo-Eon

2017-01-01

Metal oxide (MO) nanoparticles have been studied as nano-antibiotics due to their antimicrobial activities even in antibiotic-resistant microorganisms. We hypothesized that a hybrid system of dual UV irradiation and MO nanoparticles would have enhanced antimicrobial activities compared with UV or MO nanoparticles alone. In this study, nanoparticles of ZnO, ZnTiO3, MgO, and CuO were selected as model nanoparticles. A dual UV collimated beam device of UV-A and UV-C was developed depending upon the lamp divided by coating. Physicochemical properties of MO nanoparticles were determined using powder X-ray diffractometry (PXRD), Brunauer-Emmett-Teller analysis, and field emission-scanning electron microscopy with energy-dispersive X-ray spectroscopy. Atomic force microscopy with an electrostatic force microscopy mode was used to confirm the surface topology and electrostatic characteristics after dual UV irradiation. For antimicrobial activity test, MO nanoparticles under dual UV irradiation were applied to Escherichia coli and M13 bacteriophage (phage). The UV-A and UV-C showed differential intensities in the coated and uncoated areas (UV-A, coated = uncoated; UV-C, coated ≪ uncoated). MO nanoparticles showed sharp peaks in PXRD patterns, matched to pure materials. Their primary particle sizes were less than 100 nm with irregular shapes, which had an 8.6~25.6 m2/g of specific surface area with mesopores of 22~262 nm. The electrostatic properties of MO nanoparticles were modulated after UV irradiation. ZnO, MgO, and CuO nanoparticles, except ZnTiO3 nanoparticles, showed antibacterial effects on E. coli. Antimicrobial effects on E. coli and phages were also enhanced after cyclic exposure of dual UV and MO nanoparticle treatment using the uncoated area, except ZnO nanoparticles. Our results demonstrate that dual UV-MO nanoparticle hybrid system has a potential for disinfection. We anticipate that it can be developed as a next-generation disinfection system in

Dual UV irradiation-based metal oxide nanoparticles for enhanced antimicrobial activity in Escherichia coli and M13 bacteriophage.

PubMed

Jin, Su-Eon; Hwang, Woochul; Lee, Hyo Jung; Jin, Hyo-Eon

2017-01-01

Metal oxide (MO) nanoparticles have been studied as nano-antibiotics due to their antimicrobial activities even in antibiotic-resistant microorganisms. We hypothesized that a hybrid system of dual UV irradiation and MO nanoparticles would have enhanced antimicrobial activities compared with UV or MO nanoparticles alone. In this study, nanoparticles of ZnO, ZnTiO 3 , MgO, and CuO were selected as model nanoparticles. A dual UV collimated beam device of UV-A and UV-C was developed depending upon the lamp divided by coating. Physicochemical properties of MO nanoparticles were determined using powder X-ray diffractometry (PXRD), Brunauer-Emmett-Teller analysis, and field emission-scanning electron microscopy with energy-dispersive X-ray spectroscopy. Atomic force microscopy with an electrostatic force microscopy mode was used to confirm the surface topology and electrostatic characteristics after dual UV irradiation. For antimicrobial activity test, MO nanoparticles under dual UV irradiation were applied to Escherichia coli and M13 bacteriophage (phage). The UV-A and UV-C showed differential intensities in the coated and uncoated areas (UV-A, coated = uncoated; UV-C, coated ≪ uncoated). MO nanoparticles showed sharp peaks in PXRD patterns, matched to pure materials. Their primary particle sizes were less than 100 nm with irregular shapes, which had an 8.6~25.6 m 2 /g of specific surface area with mesopores of 22~262 nm. The electrostatic properties of MO nanoparticles were modulated after UV irradiation. ZnO, MgO, and CuO nanoparticles, except ZnTiO 3 nanoparticles, showed antibacterial effects on E. coli . Antimicrobial effects on E. coli and phages were also enhanced after cyclic exposure of dual UV and MO nanoparticle treatment using the uncoated area, except ZnO nanoparticles. Our results demonstrate that dual UV-MO nanoparticle hybrid system has a potential for disinfection. We anticipate that it can be developed as a next-generation disinfection system in

Determination of dihydralazine based on chemiluminescence resonance energy transfer of hollow carbon nanodots

NASA Astrophysics Data System (ADS)

Han, Suqin; Fan, Zheyan; Chen, Xiaoxia; Wu, Yunfang; Wang, Jianbo

2017-08-01

The famous weak chemiluminescence (CL) system of potassium permanganate and sodium bisulfite (KMnO4-HSO3-) was enhanced by the hollow fluorescent carbon nanodots (HCNs). The investigation of mechanism revealed that the enhanced CL was induced by the excited-state HCNs (HCNs*), which could be produced from the electron-transfer annihilation of positively charged HCNs (HCNsrad +) and negatively charged HCNs (HCNsrad -) as well as by CL resonance energy transfer (CRET) from excited SO2 (SO2*)/1O2 to HCNs. The dihydralazine sulfate (DHZS) had a diminishing effect on the CL of HCNs-KMnO4-HSO3- system due to the competitive consumption of rad O2-. Under the optimal conditions, the reduced CL signal with the concentration of DHZS was linear in the range of 1.0 × 10- 7-7.0 × 10- 5 mol/L with a detection limit of 3.0 × 10- 8 mol/L. The relative standard deviation for seven repeated determination of 5.0 × 10- 6 mol/L DHZS was 2.1%. The established method was applied to the determination of DHZS in pharmaceutical preparations, human urine and plasma samples with good precision and accuracy.

Kinetics and selectivity of permanganate chemiluminescence: a study of hydroxyl and amino disubstituted benzene positional isomers.

PubMed

Slezak, Teo; Smith, Zoe M; Adcock, Jacqui L; Hindson, Christopher M; Barnett, Neil W; Nesterenko, Pavel N; Francis, Paul S

2011-11-30

Examination of the chemiluminescence reactions of dihydroxybenzenes, aminophenols and phenylenediamines with acidic potassium permanganate has provided a new understanding of the relationships between analyte structure, reaction conditions, kinetics of the light-producing pathway and emission intensity, with broad implications for this widely utilised chemiluminescence detection system. Using a permanganate reagent prepared in a polyphosphate solution and adjusted to pH 2.5, large differences in the rate of reaction with different positional isomers were observed, with the meta-substituted forms reacting far slower and therefore exhibiting much lower chemiluminescence intensities in flow analysis systems. The preliminary partial reduction of permanganate to form significant concentrations of Mn(III) increased the rate of reaction with all analytes tested, resulting in comparable or (in the case of aminophenol and phenylenediamine) even greater emission intensities for the meta-isomers, demonstrating the opportunity to tune the selectivity of the reagent towards certain classes of compound or even specific positional isomers of the same compound. Using more acidic permanganate reagents, in which polyphosphates are not required, the discrepancy between the chemiluminescence intensities was still observed, but was less prominent due to the generally faster rates of reaction. The enhancement of these chemiluminescence reactions by on-line addition of formic acid or formaldehyde can in part also be attributed to the generation of significant pools of the key Mn(III) precursor to the emitting species. Copyright © 2011 Elsevier B.V. All rights reserved.

Anticancer and enhanced antimicrobial activity of biosynthesizd silver nanoparticles against clinical pathogens

NASA Astrophysics Data System (ADS)

Rajeshkumar, Shanmugam; Malarkodi, Chelladurai; Vanaja, Mahendran; Annadurai, Gurusamy

2016-07-01

The present investigation shows the biosynthesis of eco-friendly silver nanoparticles using culture supernatant of Enterococcus sp. and study the effect of enhanced antimicrobial activity, anticancer activity against pathogenic bacteria, fungi and cancer cell lines. Silver nanoparticles was synthesized by adding 1 mM silver nitrate into the 100 ml of 24 h freshly prepared culture supernatant of Enterococcus sp. and were characterized by UV-vis spectroscopy, X-ray diffraction (XRD), Transmission Electron Microscope (TEM), Selected Area Diffraction X-Ray (SAED), Energy Dispersive X Ray (EDX) and Fourier Transform Infra red Spectroscopy (FT-IR). The synthesized silver nanoparticles were impregnated with commercial antibiotics for evaluation of enhanced antimicrobial activity. Further these synthesized silver nanoparticles were assessed for its anticancer activity against cancer cell lines. In this study crystalline structured nanoparticles with spherical in the size ranges from 10 to 80 nm and it shows excellent enhanced antimicrobial activity than the commercial antibiotics. The in vitro assay of silver nanoparticles on anticancer have great potential to inhibit the cell viability. Amide linkages and carboxylate groups of proteins from Enterococcus sp. may bind with silver ions and convert into nanoparticles. The activities of commercial antibiotics were enhanced by coating silver nanoparticles shows significant improved antimicrobial activity. Silver nanoparticles have the great potential to inhibit the cell viability of liver cancer cells lines (HepG2) and lung cancer cell lines (A549).

Direct competitive chemiluminescence immunoassays based on gold-coated magnetic particles for detection of chloramphenicol.

PubMed

Liang, Xiaohui; Fang, Xiangyi; Yao, Manwen; Yang, Yucong; Li, Junfeng; Liu, Hongjun; Wang, Linyu

2016-02-01

Direct competitive chemiluminescence immunoassays (CLIA) based on gold-coated magnetic nanospheres (Au-MNPs) were developed for rapid analysis of chloramphenicol (CAP). The Au-MNPs were modified with carboxyl groups and amino groups by 11-mercaptoundecanoic acid (MUA) and cysteamine respectively, and then were respectively conjugated with CAP base and CAP succinate via an activating reaction using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS). NSP-DMAE-NHS, a new and effective luminescence reagent, was employed to label anti-CAP antibody (mAb) as a tracer in direct CLIA for CAP detection using a 'homemade' luminescent measurement system that was set up with a photomultiplier tube (PMT) and a photon counting unit linked to a computer. The sensitivities and limits of detection (LODs) of the two methods were obtained and compared according to the inhibition curves. The 50% inhibition concentration (IC50 ) values of the two methods were about 0.044 ng/mL and 0.072 ng/mL respectively and LODs were approximately 0.001 ng/mL and 0.006 ng/mL respectively. To our knowledge, they were much more sensitive than any traditional enzyme-linked immunosorbent assay (ELISA) ever reported. Moreover, the new luminescence reagent NSP-DMAE-NHS is much more sensitive and stable than luminol and its derivatives, contributing to the sensitivity enhancement. Copyright © 2015 John Wiley & Sons, Ltd.

Enhanced reactive oxygen species through direct copper sulfide nanoparticle-doxorubicin complexation

NASA Astrophysics Data System (ADS)

Li, Yajuan; Cupo, Michela; Guo, Liangran; Scott, Julie; Chen, Yi-Tzai; Yan, Bingfang; Lu, Wei

2017-12-01

CuS-based nanostructures loading the chemotherapeutic agent doxorubicin (DOX) exerted excellent cancer photothermal chemotherapy under multi-external stimuli. The DOX loading was generally designed through electrostatic interaction or chemical linkers. However, the interaction between DOX molecules and CuS nanoparticles has not been investigated. In this work, we use PEGylated hollow copper sulfide nanoparticles (HCuSNPs) to directly load DOX through the DOX/Cu2+ chelation process. Distinctively, the synthesized PEG-HCuSNPs-DOX release the DOX/Cu2+ complexes into surrounding environment, which generate significant reactive oxygen species (ROS) in a controlled manner by near-infrared laser. The CuS nanoparticle-mediated photothermal ablation facilitates the ROS-induced cancer cell killing effect. Our current work reveals a DOX/Cu2+-mediated ROS-enhanced cell-killing effect in addition to conventional photothermal chemotherapy through the direct CuS nanoparticle-DOX complexation.

Selective recognition of dysprosium(III) ions by enhanced chemiluminescence CdSe quantum dots

NASA Astrophysics Data System (ADS)

Hosseini, Morteza; Ganjali, Mohammad R.; Vaezi, Zahra; Faridbod, Farnoush; Arabsorkhi, Batool; Sheikhha, Mohammad H.

2014-03-01

The intensity of emitted light from CdSe quantum dots (QDs)-H2O2 is described as a novel chemiluminescence (CL) reaction for determination of dysprosium. This reaction is based on the catalytic effect of Dy3+ ions, causing a significant increase in the light emission, as a result of the reaction of quantum dots (QDs) with hydrogen peroxide. In the optimum conditions, this method was satisfactorily described by linear calibration curve in the range of 8.3 × 10-7-5.0 × 10-6 M, the detection limit of 6.0 × 10-8 M, and the relative standard deviation for five determinations of 2.5 × 10-6 M Dy3+ 3.2%. The main experimental advantage of the proposed method is its selective to Dy3+ ions compared with common coexisting cations, therefore, it was successfully applied for the determination of dysprosium ions in water samples.

Green-synthetized silver nanoparticles for Nanoparticle-Enhanced Laser Induced Breakdown Spectroscopy (NELIBS) using a mobile instrument

NASA Astrophysics Data System (ADS)

Poggialini, F.; Campanella, B.; Giannarelli, S.; Grifoni, E.; Legnaioli, S.; Lorenzetti, G.; Pagnotta, S.; Safi, A.; Palleschi, V.

2018-03-01

When compared to other analytical techniques, LIBS shows relatively low precision and, generally, high Limits of Detection (LODs). Until recently, the attempts in improving the LIBS performances have been based on the use of more stable/powerful lasers, high sensitivity detectors or controlled environmental parameters. This can hinder the competitiveness of LIBS by increasing the instrumental setup cost and the difficulty of operation. Sample treatment has proved to be a viable and simple way to increase the LIBS signal; in particular, the Nanoparticle-Enhanced Laser Induced Breakdown Spectroscopy (NELIBS) methodology uses a deposition of metal nanoparticles on the sample to greatly increase the emission of the LIBS plasma. In this work, we used a simple, fast, "green" and low-cost method to synthetize silver nanoparticles by using coffee extract as reducing agents for a silver nitrate solution. This allowed us to obtain nanoparticles of about 25 nm in diameter. We then explored the application of such nanoparticles to the NELIBS analysis of metallic samples with a mobile LIBS instrument. By adjusting the laser parameters and optimizing the sample preparation procedure, we obtained a NELIBS signal that is 4 times the LIBS one. This showed the potential of green-synthetized nanoparticle for NELIBS applications and suggests the possibility of an in-situ application of the technique.

Computational evaluation of amplitude modulation for enhanced magnetic nanoparticle hyperthermia.

PubMed

Soetaert, Frederik; Dupré, Luc; Ivkov, Robert; Crevecoeur, Guillaume

2015-10-01

Magnetic nanoparticles (MNPs) can interact with alternating magnetic fields (AMFs) to deposit localized energy for hyperthermia treatment of cancer. Hyperthermia is useful in the context of multimodality treatments with radiation or chemotherapy to enhance disease control without increased toxicity. The unique attributes of heat deposition and transfer with MNPs have generated considerable attention and have been the focus of extensive investigations to elucidate mechanisms and optimize performance. Three-dimensional (3D) simulations are often conducted with the finite element method (FEM) using the Pennes' bioheat equation. In the current study, the Pennes' equation was modified to include a thermal damage-dependent perfusion profile to improve model predictions with respect to known physiological responses to tissue heating. A normal distribution of MNPs in a model liver tumor was combined with empirical nanoparticle heating data to calculate tumor temperature distributions and resulting survival fraction of cancer cells. In addition, calculated spatiotemporal temperature changes were compared among magnetic field amplitude modulations of a base 150-kHz sinusoidal waveform, specifically, no modulation, sinusoidal, rectangular, and triangular modulation. Complex relationships were observed between nanoparticle heating and cancer tissue damage when amplitude modulation and damage-related perfusion profiles were varied. These results are tantalizing and motivate further exploration of amplitude modulation as a means to enhance efficiency of and overcome technical challenges associated with magnetic nanoparticle hyperthermia (MNH).

Microfluidic biosensing systems. Part I. Development and optimisation of enzymatic chemiluminescent micro-biosensors based on silicon microchips.

PubMed

Davidsson, Richard; Genin, Frédéric; Bengtsson, Martin; Laurell, Thomas; Emnéus, Jenny

2004-10-01

Chemiluminescent (CL) enzyme-based flow-through microchip biosensors (micro-biosensors) for detection of glucose and ethanol were developed for the purpose of monitoring real-time production and release of glucose and ethanol from microchip immobilised yeast cells. Part I of this study focuses on the development and optimisation of the micro-biosensors in a microfluidic sequential injection analysis (microSIA) system. Glucose oxidase (GOX) or alcohol oxidase (AOX) was co-immobilised with horseradish peroxidase (HRP) on porous silicon flow through microchips. The hydrogen peroxide produced from oxidation of the corresponding analyte (glucose or ethanol) took part in the chemiluminescent (CL) oxidation of luminol catalysed by HRP enhanced by addition of p-iodophenol (PIP). All steps in the microSIA system, including control of syringe pump, multiposition valve (MPV) and data readout, were computer controlled. The influence of flow rate and luminol- and PIP concentration were investigated using a 2(3)-factor experiment using the GOX-HRP sensor. It was found that all estimated single factors and the highest order of interaction were significant. The optimum was found at 250 microM luminol and 150 microM PIP at a flow rate of 18 microl min(-1), the latter as a compromise between signal intensity and analysis time. Using the optimised system settings one sample was processed within 5 min. Two different immobilisation chemistries were investigated for both micro-biosensors based on 3-aminopropyltriethoxsilane (APTS)- or polyethylenimine (PEI) functionalisation followed by glutaraldehyde (GA) activation. GOX-HRP micro-biosensors responded linear in a log-log format within the range 10-1000 microM glucose. Both had an operational stability of at least 8 days, but the PEI-GOX-HRP sensor was more sensitive. The AOX-HRP micro-biosensors responded linear (log-log) in the range between 1 and 10 mM ethanol, but the PEI-AOX-HRP sensor was in general more sensitive. Both sensors

Albumin-based nanoparticle trehalose lyophilisation stress-down to preserve structure/function and enhanced binding.

PubMed

Siri, Macarena; Grasselli, Mariano; Alonso, Silvia Del V

2016-07-15

The aim of this study was to preserve albumin nanoparticle structure/function during the lyophilisation process. Bovine serum albumin nanoparticles were obtained by γ-irradiation. Nanoparticles were lyophilised in buffer, miliQ water or in trehalose/miliQ solution. The size and charge of the nanoparticles were tested after lyophilisation by light scattering and Z potential. The most relevant results in size of BSA nanoparticle were those lyophilised in PBS between 20 and 350nm, assembled in different aggregates, and negative Z potential obtained was 37±8mV in all, and those nanoparticles lyophilised with trehalose had a size range of 70±2nm and a negative Z potential of 20±5mV. Structure determination of surface aminoacids SH groups in the BSA NP lyophilised in PBS showed an increase in the free SH groups. Different aggregates had different amount of SH groups exposure from 55 to 938 (from smaller to bigger aggregates), whereas BSA NP lyophilised with trehalose showed no significant difference if compared with BSA NP. The binding properties of the BSA nanoparticle with a theragnostic probe (merocyanine 540) were studied after lyophilisation. Results showed more affinity between the BSA NP lyophilised with trehalose than that observed with non lyophilised BSA NP. As a result, the lyophilisation condition in trehalose 100μM solution is the best one to preserve the BSA NP structure/function and the one with the enhance binding affinity of the BSA NP. Copyright © 2016 Elsevier B.V. All rights reserved.

Recent advancements in nanoparticle based drug delivery for gastrointestinal disorders.

PubMed

Mittal, Rahul; Patel, Amit P; Jhaveri, Vasanti M; Kay, Sae-In S; Debs, Luca H; Parrish, James M; Pan, Debbie R; Nguyen, Desiree; Mittal, Jeenu; Jayant, Rahul Dev

2018-03-01

The emergent field of nanoparticles has presented a wealth of opportunities for improving the treatment of human diseases. Recent advances have allowed for promising developments in drug delivery, diagnostics, and therapeutics. Modified delivery systems allow improved drug delivery over traditional pH, microbe, or receptor dependent models, while antibody association allows for more advanced imaging modalities. Nanoparticles have potential clinical application in the field of gastroenterology as they offer several advantages compared to the conventional treatment systems including target drug delivery, enhanced treatment efficacy, and reduced side effects. Areas covered: The aim of this review article is to summarize the recent advancements in developing nanoparticle technologies to treat gastrointestinal diseases. We have covered the application of nanoparticles in various gastrointestinal disorders including inflammatory bowel disease and colorectal cancer. We also have discussed how the gut microbiota affects the nanoparticle based drug delivery in the gastrointestinal tract. Expert opinion: Nanoparticles based drug delivery offers a great platform for targeted drug delivery for gastrointestinal disorders. However, it is influenced by the presence of microbiota, drug interaction with nanoparticles, and cytotoxicity of nanoparticles. With the advancements in nanoparticle technology, it may be possible to overcome these barriers leading to efficient drug delivery for gastrointestinal disorders based on nanoparticle platform.

Enhanced Raman scattering of graphene by silver nanoparticles with different densities and locations

NASA Astrophysics Data System (ADS)

Sun, Hai-Bin; Fu, Can; Xia, Yan-Jie; Zhang, Chong-Wu; Du, Jiang-Hui; Yang, Wen-Chao; Guo, Peng-Fei; Xu, Jun-Qi; Wang, Chun-Lei; Jia, Yong-Lei; Liu, Jiang-Feng

2017-02-01

Graphene-metal nanoparticle heterojunctions greatly improve the surface-enhanced Raman scattering (SERS) by strong light-graphene interactions. In this work, to enhance the Raman scattering, Ag nanoparticles (NPs) underneath and on top of the graphene were used. Then, Raman scattering of graphene is significantly enhanced approximately 67-fold, and the enhancement factor of the graphene G peak increases with the Ag NP density at the same location. In addition, an obvious red-shift and broadening of the resonance peak of Ag NPs is presented, which may be correlated to the strength of Raman enhancement, the coupling of the deposited Ag NPs and the graphene. Further, graphene-Ag NP heterojunctions can be used as SERS substrates to obtain the strongest Raman signals of the rhodamine (R6G) molecules and the weakest photoluminescence (PL) background from the Ag NPs. Based on the tunable Raman enhancement, graphene-Ag NPs offer a promising platform for engineering SERS substrates to obtain highly sensitive detection of trace levels of analyte molecules.

Influence of dichloromethylene bisphosphonate on the in vitro phagocytosis of hydroxyapatite particles by rat peritoneal exudate cells: an electron microscopic and chemiluminescence study.

PubMed Central

Hyvönen, P M; Kowolik, M J

1992-01-01

Transmission electron microscopy and standard chemiluminescence assays were used to investigate the in vivo effect of dichloromethylene bisphosphonate (clodronate) on the phagocytosis of pure hydroxyapatite particles by rat peritoneal macrophages and the production of chemiluminescence by the peritoneal exudate cells. Hydroxyapatite (control) and a hydroxyapatite/clodronate suspension (28 mumol clodronate per gram of hydroxyapatite, experimental) were injected into the peritoneum of rats, the clodronate dose being 10 micrograms/kg. Macrophages were harvested at 12, 24, 48, and 96 hours after injection and the particle phagocytosis was assessed by transmission electron microscopy. Hydroxyapatite alone was completely phagocytosed by 24 hours and hydroxyapatite reacted with clodronate was completely phagocytosed by 48 hours. From 48 hours onwards hydroxyapatite particle dissolution was observed in the phagosomes of cells in the two groups. At 48 hours the chemiluminescence produced by the peritoneal exudate cells was also measured. Clodronate and clodronate/hydroxyapatite enhanced cell activity on subsequent challenge with phorbol myristate acetate or zymosan. Clodronate seemed to exhibit an inhibitory effect on the phagocytic activity and an enhancement of the chemiluminescence production by the cells in this model, indicating that it was modifying the inflammatory cell response. Images PMID:1532298

T cells enhance gold nanoparticle delivery to tumors in vivo.

PubMed

Kennedy, Laura C; Bear, Adham S; Young, Joseph K; Lewinski, Nastassja A; Kim, Jean; Foster, Aaron E; Drezek, Rebekah A

2011-04-04

Gold nanoparticle-mediated photothermal therapy (PTT) has shown great potential for the treatment of cancer in mouse studies and is now being evaluated in clinical trials. For this therapy, gold nanoparticles (AuNPs) are injected intravenously and are allowed to accumulate within the tumor via the enhanced permeability and retention (EPR) effect. The tumor is then irradiated with a near infrared laser, whose energy is absorbed by the AuNPs and translated into heat. While reliance on the EPR effect for tumor targeting has proven adequate for vascularized tumors in small animal models, the efficiency and specificity of tumor delivery in vivo, particularly in tumors with poor blood supply, has proven challenging. In this study, we examine whether human T cells can be used as cellular delivery vehicles for AuNP transport into tumors. We first demonstrate that T cells can be efficiently loaded with 45 nm gold colloid nanoparticles without affecting viability or function (e.g. migration and cytokine production). Using a human tumor xenograft mouse model, we next demonstrate that AuNP-loaded T cells retain their capacity to migrate to tumor sites in vivo. In addition, the efficiency of AuNP delivery to tumors in vivo is increased by more than four-fold compared to injection of free PEGylated AuNPs and the use of the T cell delivery system also dramatically alters the overall nanoparticle biodistribution. Thus, the use of T cell chaperones for AuNP delivery could enhance the efficacy of nanoparticle-based therapies and imaging applications by increasing AuNP tumor accumulation.

T cells enhance gold nanoparticle delivery to tumors in vivo

NASA Astrophysics Data System (ADS)

Kennedy, Laura C.; Bear, Adham S.; Young, Joseph K.; Lewinski, Nastassja A.; Kim, Jean; Foster, Aaron E.; Drezek, Rebekah A.

2011-12-01

Gold nanoparticle-mediated photothermal therapy (PTT) has shown great potential for the treatment of cancer in mouse studies and is now being evaluated in clinical trials. For this therapy, gold nanoparticles (AuNPs) are injected intravenously and are allowed to accumulate within the tumor via the enhanced permeability and retention (EPR) effect. The tumor is then irradiated with a near infrared laser, whose energy is absorbed by the AuNPs and translated into heat. While reliance on the EPR effect for tumor targeting has proven adequate for vascularized tumors in small animal models, the efficiency and specificity of tumor delivery in vivo, particularly in tumors with poor blood supply, has proven challenging. In this study, we examine whether human T cells can be used as cellular delivery vehicles for AuNP transport into tumors. We first demonstrate that T cells can be efficiently loaded with 45 nm gold colloid nanoparticles without affecting viability or function (e.g. migration and cytokine production). Using a human tumor xenograft mouse model, we next demonstrate that AuNP-loaded T cells retain their capacity to migrate to tumor sites in vivo. In addition, the efficiency of AuNP delivery to tumors in vivo is increased by more than four-fold compared to injection of free PEGylated AuNPs and the use of the T cell delivery system also dramatically alters the overall nanoparticle biodistribution. Thus, the use of T cell chaperones for AuNP delivery could enhance the efficacy of nanoparticle-based therapies and imaging applications by increasing AuNP tumor accumulation.

Enhanced antibacterial activity of silver nanoparticles/halloysite nanotubes/graphene nanocomposites with sandwich-like structure.

PubMed

Yu, Liang; Zhang, Yatao; Zhang, Bing; Liu, Jindun

2014-04-11

A sandwich-like antibacterial reagent (Ag/HNTs/rGO) was constructed through the direct growth of silver nanoparticles on the surface graphene-based HNTs nanosheets. Herein, various nanomaterials were combined by adhesion effect of DOPA after self-polymerization. Ag/HNTs/rGO possess enhanced antibacterial ability against E. coli and S. aureus compared with individual silver nanoparticles, rGO nanosheets or their nanocomposites.

Improving the sensitivity of immunoassay based on MBA-embedded Au@SiO2 nanoparticles and surface enhanced Raman spectroscopy

NASA Astrophysics Data System (ADS)

Wei, Chao; Xu, Min-Min; Fang, Cong-Wei; Jin, Qi; Yuan, Ya-Xian; Yao, Jian-Lin

2017-03-01

Traditional "sandwich" structure immunoassay is mainly based on the self-assembly of "antibody on solid substrate-antigen-antibody with nanotags" architectures, and the sensitivity of this strategy is critically depended on the surface enhanced Raman scattering (SERS) activities and stability of nanotags. Therefore, the rational design and fabrication on the SERS nanotags attracts the common interests to the bio-related detecting and imaging. Herein, silica encapsulated Au with mercaptobenzoic acid (MBA) core-shell nanoparticles (Au-MBA@SiO2) are fabricated instead of the traditional naked Au or Ag nanoparticles for the SERS-based immunoassay on human and mouse IgG antigens. The MBA molecules facilitate the formation of continuous pinhole-free silica shell and are also used as SERS labels. The silica shell is employed to protect MBA labels and to isolate Au core from the ambient solution for blocking the aggregation. This shell also played the similar role to BSA in inhibiting the nonspecific bindings, which allowed the procedures for constructing "sandwich" structures to be simplified. All of these merits of the Au-MBA@SiO2 brought the high performance in the related immunoassay. Benefiting from the introduction of silica shell to encapsulate MBA labels, the detection sensitivity was improved by about 1- 2 orders of magnitude by comparing with the traditional approach based on naked Au-MBA nanoparticles. This kind of label-embedded core-shell nanoparticles could be developed as the versatile nanotags for the bioanalysis and bioimaging.

Low-temperature thermoelectric power factor enhancement by controlling nanoparticle size distribution.

PubMed

Zebarjadi, Mona; Esfarjani, Keivan; Bian, Zhixi; Shakouri, Ali

2011-01-12

Coherent potential approximation is used to study the effect of adding doped spherical nanoparticles inside a host matrix on the thermoelectric properties. This takes into account electron multiple scatterings that are important in samples with relatively high volume fraction of nanoparticles (>1%). We show that with large fraction of uniform small size nanoparticles (∼1 nm), the power factor can be enhanced significantly. The improvement could be large (up to 450% for GaAs) especially at low temperatures when the mobility is limited by impurity or nanoparticle scattering. The advantage of doping via embedded nanoparticles compared to the conventional shallow impurities is quantified. At the optimum thermoelectric power factor, the electrical conductivity of the nanoparticle-doped material is larger than that of impurity-doped one at the studied temperature range (50-500 K) whereas the Seebeck coefficient of the nanoparticle doped material is enhanced only at low temperatures (∼50 K).

Plasmonic properties and enhanced fluorescence of gold and dye-doped silica nanoparticle aggregates

NASA Astrophysics Data System (ADS)

Green, Nathaniel Scott

scattering. Our aim is to promote heteroaggregation with functionalized silica nanoparticles while minimizing homoaggregation of silica-silica or gold-gold species. Reproducible production of multiple gold nanospheres about a dye-doped silica nanoparticle should lead to dramatic fluorescence brightness enhancements in solution. Gold nanorods can potentially be used to establish radiationless energy transfer between hetero dye-doped silica nanoparticles via gold nanorod plasmon mediated FRET by aggregating two different dye-doped silica nanoparticles preferentially at opposite ends of the nanorod. End-cap binding is accomplished by tuning the strength of gold binding ligands that functionalize the surface of the silica nanoparticles. The gold nanorod can then theoretically serve as a waveguide by employing the longitudinal plasmon as a non-radiative energy transfer agent between the two different fluorophores, giving rise to a new ultrafast signaling paradigm. Heteroaggregation of dye-doped silica nanoparticles and gold nanorods can be potentially employed to as nano waveguides. Construction and aggregation of functionalized silica and gold nano-materials provides an opportunity to advance the field of fluorescence. The synthesis of gold nano-particles allows control over their size and shape, which give rise to useful optical and electronic properties. Silica nanoparticles provide a framework allowing control over a requisite distance for increasing beneficial and deceasing non-radiative dye-metal interactions as well fluorophore protection. Our aim is to take advantage of fine-tuned synthetic control of functionalized nanomaterials to realize the great potential of solution based metal-enhanced fluorescence for future applications.

Enhanced antibacterial nanocomposite mats by coaxial electrospinning of polycaprolactone fibers loaded with Zn-based nanoparticles.

PubMed

Prado-Prone, Gina; Silva-Bermudez, Phaedra; Almaguer-Flores, Argelia; García-Macedo, Jorge A; García, Victor I; Rodil, Sandra E; Ibarra, Clemente; Velasquillo, Cristina

2018-04-16

ZnO and Zn acetate nanoparticles were embedded in polycaprolactone coaxial-fibers and uniaxial-fibers matrices to develop potential antibacterial nanocomposite wound dressings (mats). Morphology, composition, wettability, crystallinity and fiber structure of mats were characterized. Antibacterial properties of mats were tested against E. coli and S. aureus by turbidity and MTT assays. The effect of UVA illumination (prior to bacteria inoculation) on mats' antibacterial activity was also studied. Results showed that a coaxial-fibers design maintained nanoparticles distributed in the outer-shell of fibers and, in general, enhanced the antibacterial effect of the mats, in comparison to conventional uniaxial-fibers mats. Results indicated that mats simultaneously inhibited planktonic and biofilm bacterial growth by, probably, two main antibacterial mechanisms; 1) release of Zn 2+ ions (mainly from Zn acetate nanoparticles) and 2) photocatalytic oxidative processes exerted by ZnO nanoparticles. Antibacterial properties of mats were significantly improved by coaxial-fibers design and exposure to UVA-light prior to bacteria inoculation. Copyright © 2018 Elsevier Inc. All rights reserved.

Carbon Nanoparticle Enhance Photoacoustic Imaging and Therapy for Bone Tissue Engineering

NASA Astrophysics Data System (ADS)

Talukdar, Yahfi

Healing critical sized bone defects has been a challenge that led to innovations in tissue engineering scaffolds and biomechanical stimulations that enhance tissue regeneration. Carbon nanocomposite scaffolds have gained interest due to their enhanced mechanical properties. However, these scaffolds are only osteoconductive and not osteoinductive. Stimulating regeneration of bone tissue, osteoinductivity, has therefore been a subject of intense research. We propose the use of carbon nanoparticle enhanced photoacoustic (PA) stimulation to promote and enhance tissue regeneration in bone tissue-engineering scaffolds. In this study we test the feasibility of using carbon nanoparticles and PA for in vivo tissue engineering applications. To this end, we investigate 1) the effect of carbon nanoparticles, such as graphene oxide nanoplatelets (GONP), graphene oxide nano ribbons (GONR) and graphene nano onions (GNO), in vitro on mesenchymal stem cells (MSC), which are crucial for bone regeneration; 2) the use of PA imaging to detect and monitor tissue engineering scaffolds in vivo; and 3) we demonstrate the potential of carbon nanoparticle enhanced PA stimulation to promote tissue regeneration and healing in an in vivo rat fracture model. The results from these studies demonstrate that carbon nanoparticles such as GNOP, GONR and GNO do not affect viability or differentiation of MSCs and could potentially be used in vivo for tissue engineering applications. Furthermore, PA imaging can be used to detect and longitudinally monitor subcutaneously implanted carbon nanotubes incorporated polymeric nanocomposites in vivo. Oxygen saturation data from PA imaging could also be used as an indicator for tissue regeneration within the scaffolds. Lastly, we demonstrate that daily stimulation with carbon nanoparticle enhanced PA increases bone fracture healing. Rats stimulated for 10 minutes daily for two weeks showed 3 times higher new cortical bone BV/TV and 1.8 times bone mineral density

Impedimetric detection of bacteria by using a microfluidic chip and silver nanoparticle based signal enhancement.

PubMed

Wang, Renjie; Xu, Yi; Sors, Thomas; Irudayaraj, Joseph; Ren, Wen; Wang, Rong

2018-02-19

The authors describe a method that can significantly improve the performance of impedimetric detection of bacteria. A multifunctional microfluidic chip was designed consisting of interdigitated microelectrodes and a micro-mixing zone with a Tesla structure. This maximizes the coating of bacterial surfaces with nanoparticles and results in improved impedimetric detection. The method was applied to the detection of Escherichia coli O157:H7 (E. coli). Silver enhancement was accomplished by coating E.coli with the cationic polymer diallyldimethylammonium chloride (PDDA) to form positively charged E. coli/PDDA complexes. Then, gold nanoparticles (AuNPs) were added, and the resulting E. coli/PDDA/AuNPs complexes were collected at interdigitated electrodes via positive dielectrophoresis (pDEP). A silver adduct was then formed on the E. coli/PDDA/AuNP complexes by using silver enhancement solutions and by using the AuNPs as catalysts. The combination of pDEP based capture and of using silver adducts reduces impedance by increasing the conductivity of the solution and the double layer capacitance around the microelectrodes. Impedance decreases linearly in the 2 × 10 3 -2 × 10 5  cfu·mL -1 E. coli concentration range, with a 500 cfu·mL -1 detection limit. Egg shell wash samples and tap water spiked with E. coli were successfully used for validation, and this demonstrates the practical application of this method. Graphical abstract Schematic representation of the AuNP@Ag enhancement method integrated with multifunctional microfluidic chip platform for impedimetric quantitation of bacteria. The method significantly improves the performance of impedimetric detection of bacteria.

Optical analysis of nanoparticles via enhanced backscattering facilitated by 3-D photonic nanojets

NASA Astrophysics Data System (ADS)

Li, Xu; Chen, Zhigang; Taflove, Allen; Backman, Vadim

2005-01-01

We report the phenomenon of ultra-enhanced backscattering of visible light by nanoparticles facilitated by the 3-D photonic nanojet a sub-diffraction light beam appearing at the shadow side of a plane-waveilluminated dielectric microsphere. Our rigorous numerical simulations show that backscattering intensity of nanoparticles can be enhanced up to eight orders of magnitude when locating in the nanojet. As a result, the enhanced backscattering from a nanoparticle with diameter on the order of 10 nm is well above the background signal generated by the dielectric microsphere itself. We also report that nanojet-enhanced backscattering is extremely sensitive to the size of the nanoparticle, permitting in principle resolving sub-nanometer size differences using visible light. Finally, we show how the position of a nanoparticle could be determined with subdiffractional accuracy by recording the angular distribution of the backscattered light. These properties of photonic nanojets promise to make this phenomenon a useful tool for optically detecting, differentiating, and sorting nanoparticles.

[Peripheral blood cells luminol-dependent chemiluminescence at the different stages of atopic dermatitis].

PubMed

Elistratova, I V; Morozov, S G; Zakharova, I A; Tarasova, M V

2015-01-01

Aim of this work was to record the luminol-dependent spontaneous and induced chemiluminescence at the different stages of atopic dermatitis. Peripheral blood cells were obtained from adult patient with atopic dermatitis followed by the registration of luminol-dependent chemiluminescence on luminograph. Opsonized zymosan as well as yeasts Candida tropicalis have been used to induce the chemiluminescence. Spontaneous and induced chemiluminescence were slightly elevated at the mild atopic dermatitis but were decreased at the severe stage of disease. Statistically significant difference has been found between group with mild and severe atopic dermatitis, Skin contamination by yeasts Candida tropicalis causes the increased level of blood cells chemiluminescence at the first week of atopic relapse when the disease was mild. Severe stage of atopic dermatitis was coupled with statistically significant inhibition of both, spontaneous and induced chemiluminescence. Luminol-dependent chemiluminescence of peripheral blood cells from adult atopic dermatitis patients may be stimulated at the mild stage and suppressed at severe stage of atopic dermatitis.

Nanofluids Containing γ-Fe2O3 Nanoparticles and Their Heat Transfer Enhancements

NASA Astrophysics Data System (ADS)

Guo, Shou-Zhu; Li, Yang; Jiang, Ji-Sen; Xie, Hua-Qing

2010-07-01

Homogeneous and stable magnetic nanofluids containing γ-Fe2O3 nanoparticles were prepared using a two-step method, and their thermal transport properties were investigated. Thermal conductivities of the nanofluids were measured to be higher than that of base fluid, and the enhanced values increase with the volume fraction of the nanoparticles. Viscosity measurements showed that the nanofluids demonstrated Newtonian behavior and the viscosity of the nanofluids depended strongly on the tested temperatures and the nanoparticles loadings. Convective heat transfer coefficients tested in a laminar flow showed that the coefficients increased with the augment of Reynolds number and the volume fraction.

Composite Materials with Magnetically Aligned Carbon Nanoparticles Having Enhanced Electrical Properties and Methods of Preparation

NASA Technical Reports Server (NTRS)

Peterson, G.P. (Bud) (Inventor); Hong, Haiping (Inventor); Salem, David R. (Inventor)

2016-01-01

Magnetically aligned carbon nanoparticle composites have enhanced electrical properties. The composites comprise carbon nanoparticles, a host material, magnetically sensitive nanoparticles and a surfactant. In addition to enhanced electrical properties, the composites can have enhanced mechanical and thermal properties.

Cancer imaging using Surface-Enhanced Resonance Raman Scattering (SERRS) nanoparticles

PubMed Central

Harmsen, Stefan; Wall, Matthew A.; Huang, Ruimin

2017-01-01

The unique spectral signatures and biologically inert compositions of surface-enhanced (resonance) Raman scattering (SE(R)RS) nanoparticles make them promising contrast agents for in vivo cancer imaging. Subtle aspects of their preparation can shift their limit of detection by orders of magnitude. In this protocol, we present the optimized, step-by-step procedure for generating reproducible SERRS nanoparticles with femtomolar (10−15 M) limits of detection. We introduce several applications of these nanoprobes for biomedical research, with a focus on intraoperative cancer imaging via Raman imaging. A detailed account is provided for successful intravenous administration of SERRS nanoparticles such that delineation of cancerous lesions may be achieved without the need for specific biomarker targeting. The time estimate for this straightforward, yet comprehensive protocol from initial de novo gold nanoparticle synthesis to SE(R)RS nanoparticle contrast-enhanced preclinical Raman imaging in animal models is ~96 h. PMID:28686581

Highly luminescent S,N co-doped carbon quantum dots-sensitized chemiluminescence on luminol-H2 O2 system for the determination of ranitidine.

PubMed

Chen, Jianqiu; Shu, Juan; Chen, Jiao; Cao, Zhiran; Xiao, An; Yan, Zhengyu

2017-05-01

S,N co-doped carbon quantum dots (N,S-CQDs) with super high quantum yield (79%) were prepared by the hydrothermal method and characterized by transmission electron microscopy, photoluminescence, UV-Vis spectroscopy and Fourier transformed infrared spectroscopy. N,S-CQDs can enhance the chemiluminescence intensity of a luminol-H 2 O 2 system. The possible mechanism of the luminol-H 2 O 2 -(N,S-CQDs) was illustrated by using chemiluminescence, photoluminescence and ultraviolet analysis. Ranitidine can quench the chemiluminescence intensity of a luminol-H 2 O 2 -N,S-CQDs system. So, a novel flow-injection chemiluminescence method was designed to determine ranitidine within a linear range of 0.5-50 μg ml -1 and a detection limit of 0.12 μg ml -1 . The method shows promising application prospects. Copyright © 2016 John Wiley & Sons, Ltd.

Multifunctional platinum-based nanoparticles for biomedical applications.

PubMed

Cheng, Qinqin; Liu, Yangzhong

2017-03-01

Platinum-based anticancer drugs play a central role in current cancer therapy. However, their applicability and efficacy are limited by drug resistance and adverse effects. Nanocarrier-based platinum drug delivery systems are promising alternatives to circumvent the disadvantages of bare platinum drugs. The various properties of nanoparticle chemistry allow for the trend toward multiple functionality. Nanoparticles preferentially accumulate at the tumor site through passive targeting, and the attachment of tumor targeting moieties further enhances their tumor-specific localization as well as tumor cell uptake. The introduction of stimuli-responsive groups into drug delivery systems can further achieve spatially and temporally controlled drug release in response to specific stimuli. Combination therapy strategies have been used to promote synergetic efficacy and overcome the resistance of platinum drugs. The tumor-localized drug delivery strategies exhibit benefits for preventing local tumor recurrence. In addition, the combination of platinum drugs and imaging agents in one unity allows the cancer diagnostics for real-time monitoring the distribution of drug-loaded nanoparticles inside the body and tumor. This review discusses recent scientific advances in multifunctional nanoparticle formulations of platinum drugs, and these designs exhibit new potential of multifunctional nanoparticles for delivering platinum-based anticancer drugs. WIREs Nanomed Nanobiotechnol 2017, 9:e1410. doi: 10.1002/wnan.1410 For further resources related to this article, please visit the WIREs website. © 2016 Wiley Periodicals, Inc.

Enhanced photoelectrocatalytic performance of heterostructured TiO2-based nanoparticles decorated nanotubes

NASA Astrophysics Data System (ADS)

Wu, Liangpeng; Yang, Xu; Huang, Yanqin; Li, Xinjun

2017-06-01

Titanium oxide nanotubes were prepared by hydrothermal treatment of TiO2 powder in NaOH aqueous solution and subsequently calcined. Titanium oxide nanotubes were further decorated by TiO2 nanoparticles through in situ hydrolysis of titanium isopropoxide containing alcohol and ammonia in an aqueous medium to form the composite catalyst (TNP/TiO2NTs). The morphology and structure of TNP/TiO2NTs were characterized by scanning and transmission electron microscopy, X-ray diffraction, UV-Vis, and Raman spectra. The separation efficiency of photo-excited carriers was investigated by photoluminescence technique and photoelectrochemical behavior. The photocatalytic activity was evaluated by the photocatalytic degradation of methyl orange. Due to the synergy effect caused by the interaction of titanium oxide nanotubes and TiO2 nanoparticles, the TNP/TiO2NTs composite shows efficient photogenerated carriers' separation and the increased light absorption. The photocatalytic activity was enhanced.

Electrogenerated Chemiluminescence Behavior of Au nanoparticles-hybridized Pb (II) metal-organic framework and its application in selective sensing hexavalent chromium.

PubMed

Ma, Hongmin; Li, Xiaojian; Yan, Tao; Li, Yan; Liu, Haiyang; Zhang, Yong; Wu, Dan; Du, Bin; Wei, Qin

2016-02-23

In this work, a novel electrochemiluminescence (ECL) sensor based on Au nanoparticles-hybridized Pb (II)-β-cyclodextrin (Pb-β-CD) metal-organic framework for detecting hexavalent chromium (Cr(VI)) was developed. Pb-β-CD shows excellent ECL behavior and unexpected reducing ability towards Au ions. Au nanoparticles could massively form on the surface of Pb-β-CD (Au@Pb-β-CD) without use of any additional reducing agent. In the presence of coreactant K2S2O8, the ECL emission of Pb-β-CD was enhanced by the formation of Au nanoparticles. Cr(VI) can collisionally quench the ECL behavior of Au@Pb-β-CD/S2O8(2-) system and the detection mechanism was investigated. This ECL sensor is found to have a linear response in the range of 0.01-100 μM and a low detection limit of 3.43 nM (S/N = 3) under the optimal conditions. These results suggest that metal-organic framework Au@Pb-β-CD has great potential in extending the application in the ECL field as an efficient luminophore.

Enhanced Antibacterial Activity of Silver Nanoparticles/Halloysite Nanotubes/Graphene Nanocomposites with Sandwich-Like Structure

PubMed Central

Yu, Liang; Zhang, Yatao; Zhang, Bing; Liu, Jindun

2014-01-01

A sandwich-like antibacterial reagent (Ag/HNTs/rGO) was constructed through the direct growth of silver nanoparticles on the surface graphene-based HNTs nanosheets. Herein, various nanomaterials were combined by adhesion effect of DOPA after self-polymerization. Ag/HNTs/rGO posses enhanced antibacterial ability against E. coli and S. aureus compared with individual silver nanoparticles, rGO nanosheets or their nanocomposites. PMID:24722502

[Three-dimensional vertically aligned CNTs coated by Ag nanoparticles for surface-enhanced Raman scattering].

PubMed

Zhang, Xiao-Lei; Zhang, Jie; Fan, Tuo; Ren, Wen-Jie; Lai, Chun-Hong

2014-09-01

In order to make surface-enhanced Raman scattering (SERS) substrates contained more "hot spots" in a three-dimensional (3D) focal volume, and can be adsorbed more probe molecules and metal nanoparticles, to obtain stronger Raman spectral signal, a new structure based on vertically aligned carbon nanotubes (CNTs) coated by Ag nanoparticles for surface Raman enhancement is presented. The vertically aligned CNTs are synthesized by chemical vapor deposition (CVD). A silver film is first deposited on the vertically aligned CNTs by magnetron sputtering. The samples are then annealed at different temperature to cause the different size silver nanoparticles to coat on the surface and sidewalls of vertically aligned CNTs. The result of scanning electron microscopy(SEM) shows that Ag nanoparticles are attached onto the sidewalls and tips of the vertically aligned CNTs, as the annealing temperature is different , pitch size, morphology and space between the silver nanoparticles is vary. Rhodamine 6G is served as the probe analyte. Raman spectrum measurement indicates that: the higher the concentration of R6G, the stronger the Raman intensity, but R6G concentration increase with the enhanced Raman intensity varies nonlinearly; when annealing temperature is 450 °C, the average size of silver nanoparticles is about 100 to 120 nm, while annealing temperature is 400 °C, the average size is about 70 nm, and the Raman intensity of 450 °C is superior to the annealing temperature that of 400 °C and 350 °C.

Fluorescence and chemiluminescence behavior of distyrylbenzene bearing two arms of dipicolylaminomethyl groups: Interactions with zinc ion and ATP

NASA Astrophysics Data System (ADS)

Motoyoshiya, Jiro; Wada, Jun-ya; Itoh, Keiko; Wakabayashi, Kazuaki; Maruyama, Takayuki; Ono, Kazuki; Fukasawa, Kota; Fujimoto, Tetsuya; Akaiwa, Yuji; Nonaka, Eiji

2018-04-01

The absorption and fluorescence spectral study of the distyrylbenzene bearing two arms of the dipicolylaminomethyl groups, the effective ligands for Zn2+, was studied in the presence of Zn2+ and ATP. Upon complexation of the distyrylbenzene with zinc ions in acetonitrile, enhancement of the fluorescence intensity was observed due to inhibition of intramolecular PET (photo-induced electron transfer) quenching, but no effect was found in aqueous media because the equilibrium laid to the free form of the ligands. In contrast, the addition of ATP disodium salt was effective to enhance the fluorescence intensity of the combination of the distyrylbenzne and Zn2+ in aqueous media. This assembly was applied to the peroxyoxalate chemiluminescence system and a significant increase in the intensity was observed, which provides a potential detection for ATP by chemiluminescence.

Cu2+-imprinted cross-linked chitosan resin as micro-column packing materials for online chemiluminescence determination of trace copper.

PubMed

Nie, Feng; Hao, Liang; Gao, Mei; Wu, Yingchun; Li, Xinsheng; Yu, Sha

2011-01-01

The Cu(2+)-imprinted cross-linked chitosan resin was synthesized and the binding characteristic of the resin to Cu(2+) was evaluated. The prepared resin was packed into a micro-glass column and used as micro-separating column. The micro-separating column was connected into the chemiluminescence flow system and placed in front of the window of the photomultiplier tube. Based on the luminol-hydrogen peroxide chemiluminescence system, a flow injection online chemiluminescence method for determination of trace copper was developed and trace Cu(2+) in complex samples was successfully determined. The proposed method improved the shortcomings of chemiluminescence method's poor selectivity. Copyright © 2010 John Wiley & Sons, Ltd.

Au-Ag-Au double shell nanoparticles-based localized surface plasmon resonance and surface-enhanced Raman scattering biosensor for sensitive detection of 2-mercapto-1-methylimidazole.

PubMed

Liao, Xue; Chen, Yanhua; Qin, Meihong; Chen, Yang; Yang, Lei; Zhang, Hanqi; Tian, Yuan

2013-12-15

In this paper, Au-Ag-Au double shell nanoparticles were prepared based on the reduction of the metal salts HAuCl4 and AgNO3 at the surface of seed particles. Due to the synergistic effect between Au and Ag, the hybrid nanoparticles are particularly stable and show excellent performances on the detection of 2-mercapto-1-methylimidazole (methimazole). The binding of target molecule at the surface of Au-Ag-Au double shell nanoparticles was demonstrated based on both localized surface plasmon resonance (LSPR) and surface-enhanced Raman scattering (SERS) spectra. The LSPR intensity is directly proportional to the methimazole concentration in the range of 0.10-3.00×10(-7) mol L(-1). The SERS spectrum can be applied in identification of methimazole molecule. The LSPR coupled with SERS based on the Au-Ag-Au double shell nanoparticles would be very attractive for the quantitative determination and qualitative analysis of the analytes in medicines. © 2013 Elsevier B.V. All rights reserved.

Enhanced Performance Consistency in Nanoparticle/TIPS Pentacene-Based Organic Thin Film Transistors

DOE Office of Scientific and Technical Information (OSTI.GOV)

He, Zhengran; Xiao, Kai; Durant, William Mark

2011-01-01

In this study, inorganic silica nanoparticles are used to manipulate the morphology of 6,13-bis(triisopropylsilylethynyl)-pentacene (TIPS pentacene) thin films and the performance of solution-processed organic thin-film transistors (OTFTs). This approach is taken to control crystal anisotropy, which is the origin of poor consistency in TIPS pentacene based OTFT devices. Thin film active layers are produced by drop-casting mixtures of SiO{sub 2} nanoparticles and TIPS pentacene. The resultant drop-cast films yield improved morphological uniformity at {approx}10% SiO{sub 2} loading, which also leads to a 3-fold increase in average mobility and nearly 4 times reduction in the ratio of measured mobility standard deviationmore » ({mu}{sub Stdev}) to average mobility ({mu}{sub Avg}). Grazing-incidence X-ray diffraction, scanning and transmission electron microscopy as well as polarized optical microscopy are used to investigate the nanoparticle-mediated TIPS pentacene crystallization. The experimental results suggest that the SiO{sub 2} nanoparticles mostly aggregate at TIPS pentacene grain boundaries, and 10% nanoparticle concentration effectively reduces the undesirable crystal misorientation without considerably compromising TIPS pentacene crystallinity.« less

Line scanning system for direct digital chemiluminescence imaging of DNA sequencing blots

DOE Office of Scientific and Technical Information (OSTI.GOV)

Karger, A.E.; Weiss, R.; Gesteland, R.F.

A cryogenically cooled charge-coupled device (CCD) camera equipped with an area CCD array is used in a line scanning system for low-light-level imaging of chemiluminescent DNA sequencing blots. Operating the CCD camera in time-delayed integration (TDI) mode results in continuous data acquisition independent of the length of the CCD array. Scanning is possible with a resolution of 1.4 line pairs/mm at the 50% level of the modulation transfer function. High-sensitivity, low-light-level scanning of chemiluminescent direct-transfer electrophoresis (DTE) DNA sequencing blots is shown. The detection of DNA fragments on the blot involves DNA-DNA hybridization with oligonucleotide-alkaline phosphatase conjugate and 1,2-dioxetane-based chemiluminescence.more » The width of the scan allows the recording of up to four sequencing reactions (16 lanes) on one scan. The scan speed of 52 cm/h used for the sequencing blots corresponds to a data acquisition rate of 384 pixels/s. The chemiluminescence detection limit on the scanned images is 3.9 [times] 10[sup [minus]18] mol of plasmid DNA. A conditional median filter is described to remove spikes caused by cosmic ray events from the CCD images. 39 refs., 9 refs.« less

Highly sensitive determination of diclofenac based on resin beads and a novel polyclonal antibody by using flow injection chemiluminescence competitive immunoassay

NASA Astrophysics Data System (ADS)

Shi, Jing; Xu, Mingxia; Tang, Qinghui; Zhao, Kang; Deng, Anping; Li, Jianguo

2018-02-01

A novel flow injection chemiluminescence immunoassay for simple, sensitive and low-cost detection of diclofenac was established based on specific binding of antigen and antibody. Carboxylic resin beads used as solid phase carrier materials provided good biocompatibility and large surface-to-volume ratio for modifying more coating antigen. There was a competitive process between the diclofenac in solution and the immobilized coating antigen to react with the limited binding sites of the polyclonal antibody to form the immunocomplex. The second antibody labelled with horseradish peroxidase was introduced into the immunosensor and trapped by captured polyclonal antibody against diclofenac, which could effectively amplify chemiluminescence signals of luminol-PIP-H2O2. Under optimal conditions, the diclofenac could be detected quantitatively. The chemiluminescence intensity decreased linearly with the logarithm of the diclofenac concentration in the range of 0.1-100 ng mL- 1 with a detection limit of 0.05 ng mL- 1 at a signal-to-noise ratio of 3. The immunosensor exhibited high sensitivity, specificity and acceptable stability. This easy-operated and cost-effective analytical method could be valuable for the diclofenac determination in real water samples.

Experimental analysis to improving thermosyphon (TPCT) thermal efficiency using nanoparticles/based fluids (water)

NASA Astrophysics Data System (ADS)

Hoseinzadeh, S.; Sahebi, S. A. R.; Ghasemiasl, R.; Majidian, A. R.

2017-05-01

In the present study an experimental set-up is used to investigate the effect of a nanofluid as a working fluid to increase thermosyphon efficiency. Nanofluids are a new form of heat transfer media prepared by suspending metallic and nonmetallic nanoparticles in a base fluid. The nanoparticles added to the fluid enhance the thermal characteristics of the base fluid. The nanofluid used in this experiment was a mixture of water and nanoparticles prepared with 0.5%, 1%, 1.5%, or 2% (v) concentration of silicon carbide (SiC) nanoparticles and 1%, 2% and 3% (v) concentration of aluminum oxide (Al2O3) in an ultrasonic homogenizer. The results indicate that the SiC/water and Al2O3/water nanofluids increase the thermosyphon performance. The efficiency of the thermosyphon using the 2% (v) (SiC) nanoparticles nanofluid was 1.11 times that of pure water and the highest efficiency occurs for the 3% (Al2O3) nanoparticle concentration with input power of 300 W. The decrease in the temperature difference between the condenser and evaporator confirms these enhancements.

Micromachined microfluidic chemiluminescent system for explosives detection

NASA Astrophysics Data System (ADS)

Park, Yoon; Neikirk, Dean P.; Anslyn, Eric V.

2007-04-01

Results will be reported from efforts to develop a self-contained micromachined microfluidic detection system for the presence of specific target analytes under the US Office of Naval Research Counter IED Basic Research Program. Our efforts include improving/optimizing a dedicated micromachined sensor array with integrated photodetectors and the synthesis of chemiluminescent receptors for nitramine residues. Our strategy for developing chemiluminescent synthetic receptors is to use quenched peroxyoxalate chemiluminescence; the presence of the target analyte would then trigger chemiluminescence. Preliminary results are encouraging as we have been able to measure large photo-currents from the reaction. We have also fabricated and demonstrated the feasibility of integrating photodiodes within an array of micromachined silicon pyramidal cavities. One particular advantage of such approach over a conventional planar photodiode would be its collection efficiency without the use of external optical components. Unlike the case of a normal photodetector coupled to a focused or collimated light source, the photodetector for such a purpose must couple to an emitting source that is approximately hemispherical; hence, using the full sidewalls of the bead's confining cavity as the detector allows the entire structure to act as its own integrating sphere. At the present time, our efforts are concentrating on improving the signal-to-noise ratio by reducing the leakage current by optimizing the fabrication sequence and the design.

Nanoparticle-based Therapies for Wound Biofilm Infection: Opportunities and Challenges

PubMed Central

Kim, Min-Ho

2016-01-01

Clinical data from human chronic wounds implicates biofilm formation with the onset of wound chronicity. Despite the development of novel antimicrobial agents, the cost and complexity of treating chronic wound infections associated with biofilms remain a serious challenge, which necessitates the development of new and alternative approaches for effective anti-biofilm treatment. Recent advancement in nanotechnology for developing a new class of nanoparticles that exhibit unique chemical and physical properties holds promise for the treatment of biofilm infections. Over the last decade, nanoparticle-based approaches against wound biofilm infection have been directed toward developing nanoparticles with intrinsic antimicrobial properties, utilizing nanoparticles for controlled antimicrobials delivery, and applying nanoparticles for antibacterial hyperthermia therapy. In addition, a strategy to functionalize nanoparticles towards enhanced penetration through the biofilm matrix has been receiving considerable interest recently by means of achieving an efficient targeting to the bacterial cells within biofilm matrix. This review summarizes and highlights the recent development of these nanoparticle-based approaches as potential therapeutics for controlling wound biofilm infection, along with current challenges that need to be overcome for their successful clinical translation. PMID:26955044

NO2 measurement by chemiluminescence

NASA Technical Reports Server (NTRS)

Conway, E. J.; Rogowski, R. S.; Richards, R. R.

1979-01-01

Compact device monitors specific chemiluminescent reaction of heated solid material such as 3,5 diaminobezoic or polyvinyl alcohol after contact with gas sample to detect and quantify nitrogen dioxide concentration.

Chemiluminescent imaging of transpired ethanol from the palm for evaluation of alcohol metabolism.

PubMed

Arakawa, Takahiro; Kita, Kazutaka; Wang, Xin; Miyajima, Kumiko; Toma, Koji; Mitsubayashi, Kohji

2015-05-15

A 2-dimensional imaging system was constructed and applied in measurements of gaseous ethanol emissions from the human palm. This imaging system measures gaseous ethanol concentrations as intensities of chemiluminescence by luminol reaction induced by alcohol oxidase and luminol-hydrogen peroxide-horseradish peroxidase system. Conversions of ethanol distributions and concentrations to 2-dimensional chemiluminescence were conducted on an enzyme-immobilized mesh substrate in a dark box, which contained a luminol solution. In order to visualize ethanol emissions from human palm skin, we developed highly sensitive and selective imaging system for transpired gaseous ethanol at sub ppm-levels. Thus, a mixture of a high-purity luminol solution of luminol sodium salt HG solution instead of standard luminol solution and an enhancer of eosin Y solution was adapted to refine the chemiluminescent intensity of the imaging system, and improved the detection limit to 3 ppm gaseous ethanol. The highly sensitive imaging allows us to successfully visualize the emissions dynamics of transdermal gaseous ethanol. The intensity of each site on the palm shows the reflection of ethanol concentrations distributions corresponding to the amount of alcohol metabolized upon consumption. This imaging system is significant and useful for the assessment of ethanol measurement of the palmar skin. Copyright © 2014 Elsevier B.V. All rights reserved.

Preparation and Investigation of Foaming Amphiphilic Fluorinated Nanoparticles for Enhanced Oil Recovery.

PubMed

Wang, Keliang; Wang, Gang; Lu, Chunjing; Pei, Cuiying; Wang, Ying

2017-12-08

Amphiphilic nanoparticles have attracted increasing interest as Pickering emulsifiers owing to the combined advantages of both traditional surfactants and homogeneous particles. Here, foaming amphiphilic fluorinated nanoparticles were prepared for enhanced oil recovery by the toposelective surface modification method. The structure and properties of amphiphilic nanoparticles were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, a laser diffraction method, fluorescence microscopy, a pendant drop tensiometer, and foamscan. It was found that the amphiphilic fluorinated nanoparticles exhibited significant interfacial activity at the air-water interface and generated stabilized aqueous foams against coalescence and drainage even in the absence of surfactants. When the particle concentration reached 0.6 wt %, the adsorption of the amphiphilic nanoparticles at the interface was saturated and the equilibrium surface tension dropped to around 32.7 mN/m. When the particle concentration reached 0.4 wt %, the Gibbs stability criterion was fulfilled. The amphiphilic nanoparticles foam system has a better plugging capacity and enhanced oil recovery capacity. The results obtained provide fundamental insights into the understanding of the self-assembly behavior and foam properties of amphiphilic fluorinated nanoparticles and further demonstrate the future potential of the amphiphilic nanoparticles used as colloid surfactants for enhanced oil recovery applications.

Preparation and Investigation of Foaming Amphiphilic Fluorinated Nanoparticles for Enhanced Oil Recovery

PubMed Central

Wang, Keliang; Lu, Chunjing; Pei, Cuiying; Wang, Ying

2017-01-01

Amphiphilic nanoparticles have attracted increasing interest as Pickering emulsifiers owing to the combined advantages of both traditional surfactants and homogeneous particles. Here, foaming amphiphilic fluorinated nanoparticles were prepared for enhanced oil recovery by the toposelective surface modification method. The structure and properties of amphiphilic nanoparticles were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, a laser diffraction method, fluorescence microscopy, a pendant drop tensiometer, and foamscan. It was found that the amphiphilic fluorinated nanoparticles exhibited significant interfacial activity at the air–water interface and generated stabilized aqueous foams against coalescence and drainage even in the absence of surfactants. When the particle concentration reached 0.6 wt %, the adsorption of the amphiphilic nanoparticles at the interface was saturated and the equilibrium surface tension dropped to around 32.7 mN/m. When the particle concentration reached 0.4 wt %, the Gibbs stability criterion was fulfilled. The amphiphilic nanoparticles foam system has a better plugging capacity and enhanced oil recovery capacity. The results obtained provide fundamental insights into the understanding of the self-assembly behavior and foam properties of amphiphilic fluorinated nanoparticles and further demonstrate the future potential of the amphiphilic nanoparticles used as colloid surfactants for enhanced oil recovery applications. PMID:29292747

Enhancement of Chiroptical Signals by Circular Differential Mie Scattering of Nanoparticles.

PubMed

Yoo, SeokJae; Park, Q-Han

2015-09-25

We enhance the weak optical signals of small chiral molecules via circular differential Mie scattering (CDMS) of nanoparticles immersed in them. CDMS is the preferential Mie scattering of left- and right-handed circularly polarized light by nanoparticles whose sizes are about the same as the wavelength of light. Solving the Mie scattering theory for chiral media, we find that the CDMS signal of the particle is linearly proportional to the chirality parameter κ of the molecules. This linear amplitude enhancement by CDMS of the particle holds, even for large particles, which have a retardation effect. We also demonstrate that the CDMS of a nanoparticle is sensitive to changes of molecular concentration, and that the nanoparticle can be utilized as a chiroptical biosensor detecting the concentration of analyte. We expect that the enhancement of molecular chiroptical signals by CDMS will pave the way for novel chiroptical spectroscopy using nanostructures.

Screening test for rapid food safety evaluation by menadione-catalysed chemiluminescent assay.

PubMed

Yamashoji, Shiro; Yoshikawa, Naoko; Kirihara, Masayuki; Tsuneyoshi, Toshihiro

2013-06-15

The chemiluminescent assay of menadione-catalysed H2O2 production by living mammalian cells was proposed to be useful for rapid food safety evaluation. The tested foods were extracted with water, ethanol and dimethylsulfoxide, and each extract was incubated with NIH3T3, Neuro-2a and HepG2 cells for 4h. Menadione-catalysed H2O2 production by living mammalian cells exposed to each extract was determined by the chemiluminescent assay requiring only 10 min, and the viability of the cells was estimated as percentage based on H2O2 production by intact cells. In this study the cytotoxicity of food was rated in order of inhibitory effect on H2O2 production by intact cells. The well known natural toxins such as Fusarium mycotoxin, tomato toxin tomatine, potato toxin solanine and marine toxins terodotoxin and brevetoxin could be detected by the above chemiluminescent assay. Copyright © 2012 Elsevier Ltd. All rights reserved.

Size-dependent abnormal thermo-enhanced luminescence of ytterbium-doped nanoparticles.

PubMed

Cui, Xiangshui; Cheng, Yao; Lin, Hang; Huang, Feng; Wu, Qingping; Wang, Yuansheng

2017-09-21

Thermal quenching above 300 K is widely expected in photoluminescence. Luminescence quenching is usually ascribed to the non-radiative relaxation of excited electrons to the ground state of the activators, during which a high temperature always plays a role in pushing the excited electrons towards the quenching channels, leading to thermal quenching. For the lanthanide-doped nanoparticles, however, there is a special luminescence quenching channel that does not exist in their bulk counterparts, i.e., energy migration-induced surface quenching. Herein, a size-dependent abnormal thermal enhancement of luminescence in the temperature range of 300 K to 423 K in the ytterbium-doped fluoride nanoparticles is presented for the first time. Importantly, in this work, we originally demonstrate that the energy migration-induced surface quenching can be suppressed by increasing temperature, which results in the abnormal thermal enhancement of luminescence. According to the temperature-dependent X-ray diffraction and lifetime analyses, an underlying mechanism based on the effect of thermal lattice expansion on ytterbium-mediated energy migration is proposed. This new finding adds new insights to the size effect on the luminescent characteristics of nanoparticles, which could be utilized to construct some unique nanostructures, especially for many important temperature-related purposes, such as thermal sensing technology.

A novel self-enhanced electrochemiluminescence immunosensor based on hollow Ru-SiO2@PEI nanoparticles for NSE analysis

NASA Astrophysics Data System (ADS)

Zhou, Limin; Huang, Jianshe; Yu, Bin; You, Tianyan

2016-02-01

Poly(ethylenimine) (PEI) and Ru(bpy)32+-doped silica (Ru-SiO2) nanoparticles were simply mixed together to prepare a novel self-enhanced electrochemiluminescence (ECL) composite of Ru-SiO2@PEI. The hollow Ru-SiO2@PEI nanoparticles were used to build an ECL immunosensor for the analysis of neuron specific enolase (NSE). PEI not only assembled on the surface of Ru-SiO2 nanoparticles through the electrostatic interaction to act as co-reactant for Ru(bpy)32+ ECL, but also provided alkaline condition to etch the Ru-SiO2 nanoparticles to form the hollow Ru-SiO2@PEI nanoparticles with porous shell. The unique structure of the Ru-SiO2@PEI nanoparticles loaded both a large amount of Ru(bpy)32+ and its co-reactant PEI at the same time, which shortened the electron-transfer distance, thereby greatly enhanced the luminous efficiency and amplified the ECL signal. The developed immunosensor showed a wide linear range from 1.0 × 10-11 to 1.0 × 10-5 mg mL-1 with a low detection limit of 1.0 × 10-11 mg mL-1 for NSE. When the immunosensor was used for the determination of NSE in clinical human serum, the results were comparable with those obtained by using enzyme-linked immunosorbent assay (ELISA) method. The proposed method provides a promising alternative for NSE analysis in clinical samples.

E-beam deposited Ag-nanoparticles plasmonic organic solar cell and its absorption enhancement analysis using FDTD-based cylindrical nano-particle optical model.

PubMed

Kim, Richard S; Zhu, Jinfeng; Park, Jeung Hun; Li, Lu; Yu, Zhibin; Shen, Huajun; Xue, Mei; Wang, Kang L; Park, Gyechoon; Anderson, Timothy J; Pei, Qibing

2012-06-04

We report the plasmon-assisted photocurrent enhancement in Ag-nanoparticles (Ag-NPs) embedded PEDOT:PSS/P3HT:PCBM organic solar cells, and systematically investigate the causes of the improved optical absorption based on a cylindrical Ag-NPs optical model which is simulated with a 3-Dimensional finite difference time domain (FDTD) method. The proposed cylindrical Ag-NPs optical model is able to explain the optical absorption enhancement by the localized surface plasmon resonance (LSPR) modes, and to provide a further understanding of Ag-NPs shape parameters which play an important role to determine the broadband absorption phenomena in plasmonic organic solar cells. A significant increase in the power conversion efficiency (PCE) of the plasmonic solar cell was experimentally observed and compared with that of the solar cells without Ag-NPs. Finally, our conclusion was made after briefly discussing the electrical effects of the fabricated plasmonic organic solar cells.

Can More Nanoparticles Induce Larger Viscosities of Nanoparticle-Enhanced Wormlike Micellar System (NEWMS)?

PubMed

Zhao, Mingwei; Zhang, Yue; Zou, Chenwei; Dai, Caili; Gao, Mingwei; Li, Yuyang; Lv, Wenjiao; Jiang, Jianfeng; Wu, Yining

2017-09-18

There have been many reports about the thickening ability of nanoparticles on the wormlike micelles in the recent years. Through the addition of nanoparticles, the viscosity of wormlike micelles can be increased. There still exists a doubt: can viscosity be increased further by adding more nanoparticles? To answer this issue, in this work, the effects of silica nanoparticles and temperature on the nanoparticles-enhanced wormlike micellar system (NEWMS) were studied. The typical wormlike micelles (wormlike micelles) are prepared by 50 mM cetyltrimethyl ammonium bromide (CTAB) and 60 mM sodium salicylate (NaSal). The rheological results show the increase of viscoelasticity in NEWMS by adding nanoparticles, with the increase of zero-shear viscosity and relaxation time. However, with the further increase of nanoparticles, an interesting phenomenon appears. The zero-shear viscosity and relaxation time reach the maximum and begin to decrease. The results show a slight increasing trend for the contour length of wormlike micelles by adding nanoparticles, while no obvious effect on the entanglement and mesh size. In addition, with the increase of temperature, remarkable reduction of contour length and relaxation time can be observed from the calculation. NEWMS constantly retain better viscoelasticity compared with conventional wormlike micelles without silica nanoparticles. According to the Arrhenius equation, the activation energy E a shows the same increase trend of NEWMS. Finally, a mechanism is proposed to explain this interesting phenomenon.

Flow Injection Technique for Biochemical Analysis with Chemiluminescence Detection in Acidic Media

PubMed Central

Chen, Jing; Fang, Yanjun

2007-01-01

A review with 90 references is presented to show the development of acidic chemiluminescence methods for biochemical analysis by use of flow injection technique in the last 10 years. A brief discussion of both the chemiluminescence and flow injection technique is given. The proposed methods for biochemical analysis are described and compared according to the used chemiluminescence system.

Chemiluminescent prediction of service life

NASA Technical Reports Server (NTRS)

Hassell, J. A.; Mendenhall, G. D.; Nathan, R. A.

1976-01-01

Technique can be used to predict polymer degradation under actual expected-use conditions, without imposing artificial conditions. Smooth or linear correlations are obtained between chemiluminescence and physical properties of purified polymer gums.

Quercetin-Based Modified Porous Silicon Nanoparticles for Enhanced Inhibition of Doxorubicin-Resistant Cancer Cells.

PubMed

Liu, Zehua; Balasubramanian, Vimalkumar; Bhat, Chinmay; Vahermo, Mikko; Mäkilä, Ermei; Kemell, Marianna; Fontana, Flavia; Janoniene, Agne; Petrikaite, Vilma; Salonen, Jarno; Yli-Kauhaluoma, Jari; Hirvonen, Jouni; Zhang, Hongbo; Santos, Hélder A

2017-02-01

One of the most challenging obstacles in nanoparticle's surface modification is to achieve the concept that one ligand can accomplish multiple purposes. Upon such consideration, 3-aminopropoxy-linked quercetin (AmQu), a derivative of a natural flavonoid inspired by the structure of dopamine, is designed and subsequently used to modify the surface of thermally hydrocarbonized porous silicon (PSi) nanoparticles. This nanosystem inherits several advanced properties in a single carrier, including promoted anticancer efficiency, multiple drug resistance (MDR) reversing, stimuli-responsive drug release, drug release monitoring, and enhanced particle-cell interactions. The anticancer drug doxorubicin (DOX) is efficiently loaded into this nanosystem and released in a pH-dependent manner. AmQu also effectively quenches the fluorescence of the loaded DOX, thereby allowing the use of the nanosystem for monitoring the intracellular drug release. Furthermore, a synergistic effect with the presence of AmQu is observed in both normal MCF-7 and DOX-resistant MCF-7 breast cancer cells. Due to the similar structure as dopamine, AmQu may facilitate both the interaction and internalization of PSi into the cells. Overall, this PSi-based platform exhibits remarkable superiority in both multifunctionality and anticancer efficiency, making this nanovector a promising system for anti-MDR cancer treatment. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Computer enhancement of ESR spectra of magnetite nanoparticles

NASA Astrophysics Data System (ADS)

Dobosz, B.; Krzyminiewski, R.; Koralewski, M.; Hałupka-Bryl, M.

2016-06-01

We present ESR measurements of non-interacting magnetic nanoparticle systems. Temperature and orientational dependence of ESR spectra were measured for Fe3O4 nanoparticle coated by dextran or oleic acid, frozen in different magnetic field. Several parameters describing magnetic properties such as g-factor, line width, the anisotropy constant were calculated and discussed. The ESR spectra of investigated nanoparticles were also subjected to Computer Resolution Enhancement Method (CREM). This procedure allows to separate a narrow line on the background of the broad line, which presence in this type of materials was recognized in the recent literature and have been further discussed in the paper. CREM is a valuable tool for monitoring of changes on the surface of magnetic core of nanoparticles.

Rapid and simultaneous detection of ricin, staphylococcal enterotoxin B and saxitoxin by chemiluminescence-based microarray immunoassay.

PubMed

Szkola, A; Linares, E M; Worbs, S; Dorner, B G; Dietrich, R; Märtlbauer, E; Niessner, R; Seidel, M

2014-11-21

Simultaneous detection of small and large molecules on microarray immunoassays is a challenge that limits some applications in multiplex analysis. This is the case for biosecurity, where fast, cheap and reliable simultaneous detection of proteotoxins and small toxins is needed. Two highly relevant proteotoxins, ricin (60 kDa) and bacterial toxin staphylococcal enterotoxin B (SEB, 30 kDa) and the small phycotoxin saxitoxin (STX, 0.3 kDa) are potential biological warfare agents and require an analytical tool for simultaneous detection. Proteotoxins are successfully detected by sandwich immunoassays, whereas competitive immunoassays are more suitable for small toxins (<1 kDa). Based on this need, this work provides a novel and efficient solution based on anti-idiotypic antibodies for small molecules to combine both assay principles on one microarray. The biotoxin measurements are performed on a flow-through chemiluminescence microarray platform MCR3 in 18 minutes. The chemiluminescence signal was amplified by using a poly-horseradish peroxidase complex (polyHRP), resulting in low detection limits: 2.9 ± 3.1 μg L(-1) for ricin, 0.1 ± 0.1 μg L(-1) for SEB and 2.3 ± 1.7 μg L(-1) for STX. The developed multiplex system for the three biotoxins is completely novel, relevant in the context of biosecurity and establishes the basis for research on anti-idiotypic antibodies for microarray immunoassays.

Numerical investigation of field enhancement by metal nano-particles using a hybrid FDTD-PSTD algorithm.

PubMed

Pernice, W H; Payne, F P; Gallagher, D F

2007-09-03

We present a novel numerical scheme for the simulation of the field enhancement by metal nano-particles in the time domain. The algorithm is based on a combination of the finite-difference time-domain method and the pseudo-spectral time-domain method for dispersive materials. The hybrid solver leads to an efficient subgridding algorithm that does not suffer from spurious field spikes as do FDTD schemes. Simulation of the field enhancement by gold particles shows the expected exponential field profile. The enhancement factors are computed for single particles and particle arrays. Due to the geometry conforming mesh the algorithm is stable for long integration times and thus suitable for the simulation of resonance phenomena in coupled nano-particle structures.

Capillary electrophoresis with gold nanoparticles enhanced electrochemiluminescence for the detection of roxithromycin.

PubMed

Wang, Jingwu; Yang, Zhiming; Wang, Xiaoxia; Yang, Nianjun

2008-06-30

Tris(2,2'-bipyridyl) ruthenium(II) (Ru(bpy)(3)(2+))-roxithromycin based electrochemiluminescence (ECL) was enhanced greatly by gold nanoparticles 10 nm in diameter. Capillary electrophoresis (CE) was coupled with the resultant ECL system as a detector for roxithromycin. This ECL emission is explained by the coreactant mechanism where roxithromycin behaves as a coreactant to generate strong reducing species and gold nanoparticles act as "floating nanoelectrodes". The reaction of Ru(bpy)(3)(3+) with the generated strong reducing species on the Pt working electrode as well as on "floating nanoelectrodes" releases Ru(bpy)(3)(2+*), resulting in enhancement of ECL emission. The selectivity of this detection system towards roxithromycin was examined by CE. Under the optimized conditions, the intensity of ECL emission varies linearly with the concentration of roxithromycin from 24 nM to 0.24 mM. The detection limit is 8.4 nM, while without adding gold nanoparticles it is only 84 nM. The detection of roxithromycin in pharmaceutical and urine samples was also performed by the proposed CE-ECL method.

Coupling of Ag Nanoparticle with Inverse Opal Photonic Crystals as a Novel Strategy for Upconversion Emission Enhancement of NaYF4: Yb(3+), Er(3+) Nanoparticles.

PubMed

Shao, Bo; Yang, Zhengwen; Wang, Yida; Li, Jun; Yang, Jianzhi; Qiu, Jianbei; Song, Zhiguo

2015-11-18

Rare-earth-ion-doped upconversion (UC) nanoparticles have generated considerable interest because of their potential application in solar cells, biological labeling, therapeutics, and imaging. However, the applications of UC nanoparticles were still limited because of their low emission efficiency. Photonic crystals and noble metal nanoparticles are applied extensively to enhance the UC emission of rare earth ions. In the present work, a novel substrate consisting of inverse opal photonic crystals and Ag nanoparticles was prepared by the template-assisted method, which was used to enhance the UC emission of NaYF4: Yb(3+), Er(3+) nanoparticles. The red or green UC emissions of NaYF4: Yb(3+), Er(3+) nanoparticles were selectively enhanced on the inverse opal substrates because of the Bragg reflection of the photonic band gap. Additionally, the UC emission enhancement of NaYF4: Yb(3+), Er(3+) nanoparticles induced by the coupling of metal nanoparticle plasmons and photonic crystal effects was realized on the Ag nanoparticles included in the inverse opal substrate. The present results demonstrated that coupling of Ag nanoparticle with inverse opal photonic crystals provides a useful strategy to enhance UC emission of rare-earth-ion-doped nanoparticles.

Chemiluminescence Study on Thermal Degradation of Aircraft Tire Elastomers

NASA Technical Reports Server (NTRS)

Mendenhall, G. D.; Stanford, T. B.; Nathan, R. A.

1976-01-01

Since the autoxidative process accounts in part for the degradation of rubber, including aircraft tires, it was felt that a study of the chemiluminescence from unsaturated elastomers could contribute significantly to an understanding of the degradation mechanism. The study revealed similarities in chemiluminescence behavior between four elastomers which were investigated, and it shows that similar oxidation mechanisms occur. Oxidative chemiluminescence was observed from purified samples of cis-1,4-polybutadiene, cis-1,4-polyisoprene, trans-polypentenamer, and 1,2-polybutadiene in an oxygen atmosphere at 25-150 C. The elastomer samples were placed in a 600 watt oven which is equipped with gas inlets for introducing any desired atmosphere. Chemiluminescence emission from the samples was focused with a two inch quartz lens onto the detector of a 12" photomultiplier which is connected to a photon counter. A strip-chart recorder, connected to the counter, permitted automatic data collection. Diagrams of the apparatus are included. The chemical reactions which occurred from the thermal decomposition of the polymer samples are described, and results (and tabulated data) are discussed.

PEGylation of zinc nanoparticles amplifies their ability to enhance olfactory responses to odorant

PubMed Central

Singletary, Melissa; Hagerty, Samantha; Muramoto, Shin; Daniels, Yasmine; MacCrehan, William A.; Stan, Gheorghe; Lau, June W.; Pustovyy, Oleg; Globa, Ludmila; Morrison, Edward E.; Sorokulova, Iryna

2017-01-01

Olfactory responses are intensely enhanced with the addition of endogenous and engineered primarily-elemental small zinc nanoparticles (NPs). With aging, oxidation of these Zn nanoparticles eliminated the observed enhancement. The design of a polyethylene glycol coating to meet storage requirements of engineered zinc nanoparticles is evaluated to achieve maximal olfactory benefit. The zinc nanoparticles were covered with 1000 g/mol or 400 g/mol molecular weight polyethylene glycol (PEG). Non-PEGylated and PEGylated zinc nanoparticles were tested by electroolfactogram with isolated rat olfactory epithelium and odorant responses evoked by the mixture of eugenol, ethyl butyrate and (±) carvone after storage at 278 K (5 oC), 303 K (30 oC) and 323 K (50 oC). The particles were analyzed by atomic force microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and laser Doppler velocimetry. Our data indicate that stored ZnPEG400 nanoparticles maintain physiologically-consistent olfactory enhancement for over 300 days. These engineered Nanoparticles support future applications in olfactory research, sensitive detection, and medicine. PMID:29261701

Gold Nanoparticle Conjugation Enhances the Antiacanthamoebic Effects of Chlorhexidine

PubMed Central

Aqeel, Yousuf; Siddiqui, Ruqaiyyah; Anwar, Ayaz; Shah, Muhammad Raza

2015-01-01

Acanthamoeba keratitis is a serious infection with blinding consequences and often associated with contact lens wear. Early diagnosis, followed by aggressive topical application of drugs, is a prerequisite in successful treatment, but even then prognosis remains poor. Several drugs have shown promise, including chlorhexidine gluconate; however, host cell toxicity at physiologically relevant concentrations remains a challenge. Nanoparticles, subcolloidal structures ranging in size from 10 to 100 nm, are effective drug carriers for enhancing drug potency. The overall aim of the present study was to determine whether conjugation with gold nanoparticles enhances the antiacanthamoebic potential of chlorhexidine. Gold-conjugated chlorhexidine nanoparticles were synthesized. Briefly, gold solution was mixed with chlorhexidine and reduced by adding sodium borohydride, resulting in an intense deep red color, indicative of colloidal gold-conjugated chlorhexidine nanoparticles. The synthesis was confirmed using UV-visible spectrophotometry that shows a plasmon resonance peak of 500 to 550 nm, indicative of gold nanoparticles. Further characterization using matrix-assisted laser desorption ionization-mass spectrometry showed a gold-conjugated chlorhexidine complex at m/z 699 ranging in size from 20 to 100 nm, as determined using atomic force microscopy. To determine the amoebicidal and amoebistatic effects, amoebae were incubated with gold-conjugated chlorhexidine nanoparticles. For controls, amoebae also were incubated with gold and silver nanoparticles alone, chlorhexidine alone, neomycin-conjugated nanoparticles, and neomycin alone. The findings showed that gold-conjugated chlorhexidine nanoparticles exhibited significant amoebicidal and amoebistatic effects at 5 μM. Amoebicidal effects were observed by parasite viability testing using a Trypan blue exclusion assay and flow-cytometric analysis using propidium iodide, while amoebistatic effects were observed using growth

Removal of Protein Capping Enhances the Antibacterial Efficiency of Biosynthesized Silver Nanoparticles

PubMed Central

Jain, Navin; Bhargava, Arpit; Rathi, Mohit; Dilip, R. Venkataramana; Panwar, Jitendra

2015-01-01

The present study demonstrates an economical and environmental affable approach for the synthesis of “protein-capped” silver nanoparticles in aqueous solvent system. A variety of standard techniques viz. UV-visible spectroscopy, transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) measurements were employed to characterize the shape, size and composition of nanoparticles. The synthesized nanoparticles were found to be homogenous, spherical, mono-dispersed and covered with multi-layered protein shell. In order to prepare bare silver nanoparticles, the protein shell was removed from biogenic nanoparticles as confirmed by UV-visible spectroscopy, FTIR and photoluminescence analysis. Subsequently, the antibacterial efficacy of protein-capped and bare silver nanoparticles was compared by bacterial growth rate and minimum inhibitory concentration assay. The results revealed that bare nanoparticles were more effective as compared to the protein-capped silver nanoparticles with varying antibacterial potential against the tested Gram positive and negative bacterial species. Mechanistic studies based on ROS generation and membrane damage suggested that protein-capped and bare silver nanoparticles demonstrate distinct mode of action. These findings were strengthened by the TEM imaging along with silver ion release measurements using inductively coupled plasma atomic emission spectroscopy (ICP-AES). In conclusion, our results illustrate that presence of protein shell on silver nanoparticles can decrease their bactericidal effects. These findings open new avenues for surface modifications of nanoparticles to modulate and enhance their functional properties. PMID:26226385

Development of enhancing agglutination reaction using gold nanoparticle for pre-transfusion testing.

PubMed

Choktaweesak, N; Krasathong, P; Ammaranond, P

2016-10-01

To explore an alternative way for antibody detection testing, the examination of gold nanoparticle solution for enhancing unexpected antibodies for pre-transfusion testing was investigated. Exposure of foreign antigens on red blood cells from transfusion can trigger the immune system to produce unexpected antibodies. This immunological response may cause the complication to future transfusion. For detection of unexpected antibodies, the antibody screening test is performed approximately 30-60 min. To reduce turnaround time, enhancing reagent, low-ionic strength solution (LISS), is widely used. However, cost of enhancing reagent is an issue which has concerned in resource limited countries. Gold nanoparticle solution can increase red blood cells agglutination reaction. To solve this issue, study of gold nanoparticle solution was investigated. Samples were performed comparing between LISS and gold nanoparticle solution at antiglobulin phase. After reading the agglutination reaction, supernatants were collected and measured at the optical density at 760 nm by spectrophotometer. The optical density in the tube of gold nanoparticle solution was higher than in the tube of 2-5% cell suspension and monoclonal antibody. It has been observed that gold nanoparticle solution enhanced the reaction of agglutination 98% while LISS enhanced the agglutination only 60·8%. Employing a commercially available enhancing reagent, parallel samples confirmed results providing validation of the assay. It approximately costs $1 US dollars compared to $30 for a commercially available reagent. The low cost and yet effective time-consuming test for antibody screening is a practical and viable solution alternative way for performing in antibody screening test in resource limited countries. © 2016 British Blood Transfusion Society.

Video approach to chemiluminescence detection using a low-cost complementary metal oxide semiconductor (CMOS)-based camera: determination of paracetamol in pharmaceutical formulations.

PubMed

Lahuerta-Zamora, Luis; Mellado-Romero, Ana M

2017-06-01

A new system for continuous flow chemiluminescence detection, based on the use of a simple and low-priced lens-free digital camera (with complementary metal oxide semiconductor technology) as a detector, is proposed for the quantitative determination of paracetamol in commercial pharmaceutical formulations. Through the camera software, AVI video files of the chemiluminescence emission are captured and then, using friendly ImageJ public domain software (from National Institutes for Health), properly processed in order to extract the analytical information. The calibration graph was found to be linear over the range 0.01-0.10 mg L -1 and over the range 1.0-100.0 mg L -1 of paracetamol, the limit of detection being 10 μg L -1 . No significative interferences were found. Paracetamol was determined in three different pharmaceutical formulations: Termalgin®, Efferalgan® and Gelocatil®. The obtained results compared well with those declared on the formulation label and with those obtained through the official analytical method of British Pharmacopoeia. Graphical abstract Abbreviated scheme of the new chemiluminescence detection system proposed in this paper.

Silver-nanoparticle-based surface-enhanced Raman scattering wiper for the detection of dye adulteration of medicinal herbs.

PubMed

Li, Dan; Zhu, Qingxia; Lv, Diya; Zheng, Binxing; Liu, Yanhua; Chai, Yifeng; Lu, Feng

2015-08-01

By using a silver nanoparticle wiper as a surface-enhanced Raman scattering substrate, a highly sensitive, convenient, and rapid platform for detecting dye adulteration of medicinal herbs was obtained. Commercially available filter paper was functionalized with silver nanoparticles to transform it into the flexible wiper. This device was found to collect dye molecules with unprecedented ease. Experiments were performed to optimize various factors such as the type of wiper used, the wetting reagent, and the wetting/wiping mode and time. Excellent wiper performance was observed in the detection of the simulated adulteration of samples with dyes at various concentrations. The limits of detection for nine dyes, including 10(-6) g/mL for malachite green, 10(-7) g/mL for Rhodamine 6G, and 5 × 10(-8) g/mL for methylene blue, were discerned. The results of this investigation show that this proposed method is potentially highly advantageous for field-based applications. Graphical Abstract Schematic diagram illustrating the fabrication of the paper-based SERS substrate, sample collection process on a herb and SERS examination with the portable Raman spectrometer.

Enhancement of antibiotic effect via gold:silver-alloy nanoparticles

NASA Astrophysics Data System (ADS)

dos Santos, Margarida Moreira; Queiroz, Margarida João; Baptista, Pedro V.

2012-05-01

A strategy for the development of novel antimicrobials is to combine the stability and pleiotropic effects of inorganic compounds with the specificity and efficiency of organic compounds, such as antibiotics. Here we report on the use of gold:silver-alloy (Au:Ag-alloy) nanoparticles, obtained via a single-step citrate co-reduction method, combined to conventional antibiotics to enhance their antimicrobial effect on bacteria. Addition of the alloy nanoparticles considerably decreased the dose of antibiotic necessary to show antimicrobial effect, both for bacterial cells growing in rich medium in suspension and for bacterial cells resting in a physiological buffer on a humid cellulose surface. The observed effect was more pronounced than the sum of the individual effects of the nanoparticles and antibiotic. We demonstrate the enhancement effect of Au:Ag-alloy nanoparticles with a size distribution of 32.5 ± 7.5 nm mean diameter on the antimicrobial effect of (i) kanamycin on Escherichia coli (Gram-negative bacterium), and (ii) a β-lactam antibiotic on both a sensitive and resistant strain of Staphylococcus aureus (Gram-positive bacterium). Together, these results may pave the way for the combined use of nanoparticle-antibiotic conjugates towards decreasing antibiotic resistance currently observed for certain bacteria and conventional antibiotics.

A novel self-enhanced electrochemiluminescence immunosensor based on hollow Ru-SiO2@PEI nanoparticles for NSE analysis.

PubMed

Zhou, Limin; Huang, Jianshe; Yu, Bin; You, Tianyan

2016-02-26

Poly(ethylenimine) (PEI) and Ru(bpy)3(2+)-doped silica (Ru-SiO2) nanoparticles were simply mixed together to prepare a novel self-enhanced electrochemiluminescence (ECL) composite of Ru-SiO2@PEI. The hollow Ru-SiO2@PEI nanoparticles were used to build an ECL immunosensor for the analysis of neuron specific enolase (NSE). PEI not only assembled on the surface of Ru-SiO2 nanoparticles through the electrostatic interaction to act as co-reactant for Ru(bpy)3(2+) ECL, but also provided alkaline condition to etch the Ru-SiO2 nanoparticles to form the hollow Ru-SiO2@PEI nanoparticles with porous shell. The unique structure of the Ru-SiO2@PEI nanoparticles loaded both a large amount of Ru(bpy)3(2+) and its co-reactant PEI at the same time, which shortened the electron-transfer distance, thereby greatly enhanced the luminous efficiency and amplified the ECL signal. The developed immunosensor showed a wide linear range from 1.0 × 10(-11) to 1.0 × 10(-5) mg mL(-1) with a low detection limit of 1.0 × 10(-11) mg mL(-1) for NSE. When the immunosensor was used for the determination of NSE in clinical human serum, the results were comparable with those obtained by using enzyme-linked immunosorbent assay (ELISA) method. The proposed method provides a promising alternative for NSE analysis in clinical samples.

Magnetic bead-sensing-platform-based chemiluminescence resonance energy transfer and its immunoassay application.

PubMed

Qin, Guoxin; Zhao, Shulin; Huang, Yong; Jiang, Jing; Ye, Fanggui

2012-03-20

A competitive immunoassay based on chemiluminescence resonance energy transfer (CRET) on the magnetic beads (MBs) is developed for the detection of human immunoglobulin G (IgG). In this protocol, carboxyl-modified MBs were conjugated with horseradish peroxidase (HRP)-labeled goat antihuman IgG (HRP-anti-IgG) and incubated with a limited amount of fluorescein isothiocyanate (FITC)-labeled human IgG to immobilize the antibody-antigen immune complex on the surface of the MBs, which was further incubated with the target analyte (human IgG) for competitive immunoreaction and separated magnetically to remove the supernatant. The chemiluminescence (CL) buffer (containing luminol and H(2)O(2)) was then added, and the CRET from donor luminol to acceptor FITC in the immunocomplex on the surface of MBs occured immediately. The present protocol was evaluated for the competitive immunoassay of human IgG, and a linear relationship between CL intensity ratio (R = I(425)/I(525)) and human IgG concentration in the range of 0.2-4.0 nM was obtained with a correlation coefficient of 0.9965. The regression equation was expressed as R = 1.9871C + 2.4616, and a detection limit of 2.9 × 10(-11) M was obtained. The present method was successfully applied for the detection of IgG in human serum. The results indicate that the present protocol is quite promising for the application of CRET in immunoassays. It could also be developed for detection of other antigen-antibody immune complexes by using the corresponding antigens and respective antibodies.

Chemiluminescence and bioluminescence microbe detection

NASA Technical Reports Server (NTRS)

Taylor, R. E.; Chappelle, E.; Picciolo, G. L.; Jeffers, E. L.; Thomas, R. R.

1978-01-01

Automated biosensors for online use with NASA Water Monitoring System employs bioluminescence and chemiluminescence techniques to rapidly measure microbe contamination of water samples. System eliminates standard laboratory procedures requiring time duration of 24 hours or longer.

Determination of estradiol valerate in pharmaceutical preparations and human serum by flow injection chemiluminescence.

PubMed

Liu, Wenwen; Xie, Liangxiao; Liu, Hongshuang; Xu, Shichao; Hu, Bingcheng; Cao, Wei

2013-01-01

A novel method for the detection of trace estradiol valerate (EV) in pharmaceutical preparations and human serum was developed by inhibition of luminol chemiluminescence (CL) by estradiol valerate on the zinc deuteroporphyrin (ZnDP)-enhanced luminol-K3 Fe(CN)6 chemiluminescence system. Under optimized experimental conditions, CL intensity and concentration of estradiol valerate had a good linear relationship in the ranges of 8.0 × 10(-8) to 1.0 × 10(-5) g/mL. Detection limit (3σ) was estimated to be 3.5 × 10(-8) g/mL. The proposed method was applied successfully for the determination of estradiol valerate in pharmaceutical preparations and human serum and recoveries were 97.0-105.0% and 95.5-106.0%, respectively. The possible mechanism of the CL system is discussed. Copyright © 2012 John Wiley & Sons, Ltd.

Molecular imaging with targeted perfluorocarbon nanoparticles: Quantification of the concentration dependence of contrast enhancement for binding to sparse cellular epitopes

PubMed Central

Marsh, Jon N.; Partlow, Kathryn C.; Abendschein, Dana R.; Scott, Michael J.; Lanza, Gregory M.; Wickline, Samuel A.

2007-01-01

Targeted, liquid perfluorocarbon nanoparticles are effective agents for acoustic contrast enhancement of abundant cellular epitopes (e.g. fibrin in thrombi) and for lower prevalence binding sites, such as integrins associated with tumor neovasculature. In this study we sought to delineate the quantitative relationship between the extent of contrast enhancement of targeted surfaces and the density (and concentration) of bound perfluorocarbon (PFC) nanoparticles. Two dramatically different substrates were utilized for targeting. In one set of experiments, the surfaces of smooth, flat, avidin-coated agar disks were exposed to biotinylated nanoparticles to yield a thin layer of targeted contrast. For the second set of measurements, we targeted PFC nanoparticles applied in thicker layers to cultured smooth muscle cells expressing the transmembrane glycoprotein “tissue factor” at the cell surface. An acoustic microscope was used to characterize reflectivity for all samples as a function of bound PFC (determined via gas chromatography). We utilized a formulation of low-scattering nanoparticles having oil-based cores to compete against high-scattering PFC nanoparticles for binding, to elucidate the dependence of contrast enhancement on PFC concentration. The relationship between reflectivity enhancement and bound PFC content varied in a curvilinear fashion, and exhibited an apparent asymptote (approximately 16 dB and 9 dB enhancement for agar and cell samples, respectively) at the maximum concentrations (~150 μg and ~1000 μg PFOB for agar and cell samples, respectively). Samples targeted with only oil-based nanoparticles exhibited mean backscatter values that were nearly identical to untreated samples (<1 dB difference), confirming the oil particles’ low-scattering behavior. The results of this study indicate that substantial contrast enhancement with liquid perfluorocarbon nanoparticles can be realized even in cases of partial surface coverage (as might be

Determination of manganese- and manganese-containing fungicides with lucigenin-Tween-20-enhanced chemiluminescence detection.

PubMed

Yaqoob, Mohammad; Asghar, Mohammad; Nabi, Abdul

2015-11-01

A flow-injection (FI) method is reported for the determination of Mn(II), maneb and mancozeb fungicides based on the catalytic effect of Mn(II) on the oxidation of lucigenin and dissolved oxygen in a basic solution. The Tween-20 surfactant has been reported for first time to enhance lucigenin chemiluminescence (CL) intensity in the presence of Mn(II) (53%) and maneb and mancozeb (89%). The calibration graphs were linear in the concentration range of 0.001-1.5 mg L(-1) (R(2) = 0.9982 (n = 11) with a limit of detection (S/N = 3) of 0.1 µg L(-1) for Mn(II) and 0.01-3.0 mg L(-1) [R(2) = 0.9989 and R(2) = 0.9992 (n = 6)] with a limit of detection (S/N =3) of 1.0 µg L(-1) for maneb and mancozeb respectively. Injection throughputs of 90 and 120 h(-1) for Mn(II) and maneb and mancozeb respectively, and relative standard deviations of 1.0-3.4% were obtained in the concentration range studied. The experimental variables, e.g., reagents concentrations, flow rates, sample volume, and photomultiplier tube voltage, were optimized and potential interferences were investigated. The analysis of Mn(II) in river water reference materials (SLRS-4 and SLRS-5) showed good agreement with the certified values incorporating an on-line 8-hydroxyquinoline chelating column in the manifold for removing interfering metal ions. Recoveries for maneb and mancozeb were in the range of 92 ± 5 to 104 ± 3% and 91 ± 2 to 100 ± 4% (n = 3) respectively. The effect of 30 other pesticides (fungicides, herbicides and insecticides) was also examined in the lucigenin-Tween-20 CL system. Copyright © 2015 John Wiley & Sons, Ltd.

Dose of radiation enhancement, using silver nanoparticles in a human tissue equivalent gel dosimeter.

PubMed

Hassan, Muhammad; Waheed, Muhammad Mohsin; Anjum, Muhammad Naeem

2016-01-01

To quantify the radiation dose enhancement in a human tissue-equivalent polymer gel impregnated with silver nanoparticles. The case-control study was conducted at the Bahawalpur Institute of Nuclear Medicine and Oncology, Bahawalpur, Pakistan, in January 2014. Silver nanoparticles used in this study were prepared by wet chemical method. Polymer gel was prepared by known quantity of gelatine, methacrylic acid, ascorbic acid, copper sulphate pentahydrate, hydroquinone and water. Different concentrations of silver nanoparticles were added to the gel during its cooling process. The gel was cooled in six plastic vials of 50ml each. Two vials were used as a control sample while four vials were impregnated with silver nanoparticles. After 22 hours, the vials were irradiated with gamma rays by aCobalt-60 unit. Radiation enhancement was assessed by taking magnetic resonance images of the vials. The images were analysed using Image J software. The dose enhancement factor was 24.17% and 40.49% for 5Gy and 10Gy dose respectively. The dose enhancement factor for the gel impregnated with 0.10mM silver nanoparticles was 32.88% and 51.98% for 5Gy and 10Gy dose respectively. The impregnation of a tissue-equivalent gel with silver nanoparticles resulted in dose enhancement and this effect was magnified up to a certain level with the increase in concentration of silver nanoparticles.

Capillary electrophoresis-chemiluminescence detection for carcino-embryonic antigen based on aptamer/graphene oxide structure.

PubMed

Zhou, Zi-Ming; Feng, Zhe; Zhou, Jun; Fang, Bi-Yun; Qi, Xiao-Xiao; Ma, Zhi-Ya; Liu, Bo; Zhao, Yuan-Di; Hu, Xue-Bin

2015-02-15

A new strategy is proposed for determination of carcino-embryonic antigen (CEA) based on aptamer/graphene oxide (Apt/GO) by capillary electrophoresis-chemiluminescence (CE-CL) detection system. CEA aptamer conjugated with horseradish peroxidase (HRP) firstly mixes with GO, and the CL will be quenched because the stack of HRP-Apt on GO leads to chemiluminescence resonance energy transfer (CRET). When CEA exists, the specific combination of HRP-Apt and CEA can form HRP-Apt-CEA complex, which dissociates from GO. Then, the CL catalyzed by HRP-Apt-CEA complex can be detected without any CRET, and the content of CEA can be estimated by the CL intensity. It has been proved that the interference issue resulted from free HRP-Apt is solved well by mixing GO firstly with HRP-Apt, which blocks the free HRP-Apt's CL signal due to CL quenching effect of GO; and the interference resulted from GO to CL is also solved by CE, then the sensitivity and accuracy can be greatly improved. Results also showed that the CL intensity had a linear relationship with the concentration of CEA in the range from 0.0654 to 6.54 ng/mL, and the limit of detection was approximately 4.8 pg/mL (S/N = 3). This proposed method with high specificity offers a new way for separation and determination of biomolecule, and has good potential in application of biochemistry and bioanalysis. Copyright © 2014 Elsevier B.V. All rights reserved.

Evaluation of endotoxin (LPS) activity in bovine blood using neutrophil dependent chemiluminescence

USDA-ARS?s Scientific Manuscript database

The purpose of this study was to evaluate the applicability of a neutrophil chemiluminescence-based assay for the measurement of LPS stimulatory activity in bovine whole blood. The assay is based on the capacity for LPS to trigger the respiratory oxidative burst activity (RBA) of autologous neutroph...

Acidic Potassium Permanganate Chemiluminescence for the Determination of Antioxidant Potential in Three Cultivars of Ocimum basilicum.

PubMed

Srivastava, Shivani; Adholeya, Alok; Conlan, Xavier A; Cahill, David M

2016-03-01

Ocimum basilicum, a member of the family Lamiaceae, is a rich source of polyphenolics that have antioxidant properties. The present study describes the development and application of an online HPLC-coupled acidic potassium permanganate chemiluminescence assay for the qualitative and quantitative assessment of antioxidants in three cultivars of O. basilicum grown under greenhouse conditions. The chemiluminescence based assay was found to be a sensitive and efficient method for assessment of total and individual compound antioxidant potential. Leaves, flowers and roots were found to be rich reserves of the antioxidant compounds which showed intense chemiluminescence signals. The polyphenolics such as rosmarinic, chicoric, caffeic, p-coumaric, m-coumaric and ferulic acids showed antioxidant activity. Further, rosmarinic acid was found to be the major antioxidant component in water-ethanol extracts. The highest levels of rosmarinic acid was found in the leaves and roots of cultivars "holy green" (14.37; 11.52 mM/100 g DW respectively) followed by "red rubin" (10.02; 10.75 mM/100 g DW respectively) and "subja" (6.59; 4.97 mM/100 g DW respectively). The sensitivity, efficiency and ease of use of the chemiluminescence based assay should now be considered for its use as a primary method for the identification and quantification of antioxidants in plant extracts.

Prospective validation of an automated chemiluminescence-based assay of renin and aldosterone for the work-up of arterial hypertension.

PubMed

Rossi, Gian Paolo; Ceolotto, Giulio; Rossitto, Giacomo; Seccia, Teresa Maria; Maiolino, Giuseppe; Berton, Chiara; Basso, Daniela; Plebani, Mario

2016-09-01

The availability of simple and accurate assays of plasma active renin (DRC) and aldosterone concentration (PAC) can improve the detection of secondary forms of arterial hypertension. Thus, we investigated the performance of an automated chemiluminescent assay for DRC and PAC in referred hypertensive patients. We prospectively recruited 260 consecutive hypertensive patients referred to an ESH Center for Hypertension. After exclusion of six protocol violations, 254 patients were analyzed: 67.3% had primary hypertension, 17.3% an aldosterone producing adenoma (APA), 11.4% idiopathic hyperaldosteronism (IHA), 2.4% renovascular hypertension (RVH), 0.8% familial hyperaldosteronism type 1 (FH-1), 0.4% apparent mineralocorticoid excess (AME), 0.4% a renin-producing tumor, and 3.9% were adrenalectomized APA patients. Bland-Altman plots and Deming regression were used to analyze results. The diagnostic accuracy (area under the curve, AUC of the ROC) of the DRC-based aldosterone-renin ratio (ARRCL) was compared with that of the PRA-based ARR (ARRRIA) using as reference the conclusive diagnosis of APA. At Bland-Altman plot, the DRC and PAC assay showed no bias as compared to the PRA and PAC assay. A tight relation was found between the DRC and the PRA values (concordance correlation coefficient=0.92, p<0.0001) and the PAC values measured with radioimmunoassay and chemiluminescence (concordance correlation coefficient=0.93, p<0.001). For APA identification the AUC of the ARRCL was higher than that of the ARRRIA [0.974 (95% CI 0.940-0.991) vs. 0.894 (95% CI 0.841-0.933), p=0.02]. This rapid automated chemiluminescent DRC/PAC assay performed better than validated PRA/PAC radioimmunoassays for the identification of APA in referred hypertensive patients.

Active control of silver nanoparticles spacing using dielectrophoresis for surface-enhanced Raman scattering.

PubMed

Chrimes, Adam F; Khoshmanesh, Khashayar; Stoddart, Paul R; Kayani, Aminuddin A; Mitchell, Arnan; Daima, Hemant; Bansal, Vipul; Kalantar-zadeh, Kourosh

2012-05-01

We demonstrate an active microfluidic platform that integrates dielectrophoresis for the control of silver nanoparticles spacing, as they flow in a liquid channel. By careful control of the nanoparticles spacing, we can effectively increase the surface-enhanced Raman scattering (SERS) signal intensity based on augmenting the number of SERS-active hot-spots, while avoiding irreversible aggregation of the particles. The system is benchmarked using dipicolinate (2,6-pyridinedicarboxylic acid) (DPA), which is a biomarker of Bacillus anthracis. The validity of the results is discussed using several complementing characterization scenarios.

Quantification of 2,4-dichlorophenoxyacetic acid in oranges and mandarins by chemiluminescent ELISA.

PubMed

Vdovenko, Marina M; Stepanova, Alexandra S; Eremin, Sergei A; Van Cuong, Nguyen; Uskova, Natalia A; Yu Sakharov, Ivan

2013-11-15

Direct competitive enzyme-linked immunosorbent assay (ELISA) for 2,4-dichlorophenoxyacetic acid (2,4-D) was developed. Varying the concentrations of monoclonal anti-2,4-D-antibody and the conjugate of soybean peroxidase and 2,4-D the conditions of ELISA performance were optimised. The chemiluminescent method based on peroxidase-catalysed oxidation of luminol was applied to measure the enzyme activity of the conjugate. A mixture of 3-(10'-phenothiazinyl)propane-1-sulfonate and 4-morpholinopyridine was used as potent enhancer of chemiluminescence signal. It was shown that the values of the lower detection limit, IC50 and the working range were 1.5, 64.0, and 6.5-545ng/mL, respectively. The recovery values of CL-ELISA from 10 spiked samples of oranges (n=5) and mandarins (n=5) cultivated in green house without use of 2,4-D and containing different 2,4-D concentrations (10-300ng/mL) were ranged from 92% to 104% that indicated on the absence of matrix effect for the fruit extracts of interest. Determination of 2,4-D in peel of five oranges and five mandarins purchased from stores in Vietnam showed that 2,4-D content in oranges fruits (79-104μg/kg) was significantly higher than that in mandarins (1.66-2.82μg/kg). Copyright © 2013 Elsevier Ltd. All rights reserved.

CdTe quantum dots@luminol as signal amplification system for chrysoidine with chemiluminescence-chitosan/graphene oxide-magnetite-molecularly imprinting sensor

NASA Astrophysics Data System (ADS)

Duan, Huimin; Li, Leilei; Wang, Xiaojiao; Wang, Yanhui; Li, Jianbo; Luo, Chuannan

2016-01-01

A sensitive chemiluminescence (CL) sensor based on chemiluminescence resonance energy transfer (CRET) in CdTe quantum dots@luminol (CdTe QDs@luminol) nanomaterials combined with chitosan/graphene oxide-magnetite-molecularly imprinted polymer (Cs/GM-MIP) for sensing chrysoidine was developed. CdTe QDs@luminol was designed to not only amplify the signal of CL but also reduce luminol consumption in the detection of chrysoidine. On the basis of the abundant hydroxy and amino, Cs and graphene oxide were introduced into the GM-MIP to improve the adsorption ability. The adsorption capacities of chrysoidine by both Cs/GM-MIP and non-imprinted polymer (Cs/GM-NIP) were investigated, and the CdTe QDs@luminol and Cs/GM-MIP were characterized by UV-vis, FTIR, SEM and TEM. The proposed sensor can detect chrysoidine within a linear range of 1.0 × 10- 7 - 1.0 × 10- 5 mol/L with a detection limit of 3.2 × 10- 8 mol/L (3δ) due to considerable chemiluminescence signal enhancement of the CdTe quantum dots@luminol detector and the high selectivity of the Cs/GM-MIP system. Under the optimal conditions of CL, the CdTe QDs@luminol-Cs/GM-MIP-CL sensor was used for chrysoidine determination in samples with satisfactory recoveries in the range of 90-107%.

Probing nanoparticles and nanoparticle-conjugated biomolecules using time-of-flight secondary ion mass spectrometry.

PubMed

Kim, Young-Pil; Shon, Hyun Kyong; Shin, Seung Koo; Lee, Tae Geol

2015-01-01

Bio-conjugated nanoparticles have emerged as novel molecular probes in nano-biotechnology and nanomedicine and chemical analyses of their surfaces have become challenges. The time-of-flight (TOF) secondary ion mass spectrometry (SIMS) has been one of the most powerful surface characterization techniques for both nanoparticles and biomolecules. When combined with various nanoparticle-based signal enhancing strategies, TOF-SIMS can probe the functionalization of nanoparticles as well as their locations and interactions in biological systems. Especially, nanoparticle-based SIMS is an attractive approach for label-free drug screening because signal-enhancing nanoparticles can be designed to directly measure the enzyme activity. The chemical-specific imaging analysis using SIMS is also well suited to screen nanoparticles and nanoparticle-biomolecule conjugates in complex environments. This review presents some recent applications of nanoparticle-based TOF-SIMS to the chemical analysis of complex biological systems. © 2014 Wiley Periodicals, Inc.

Brain-Eating Amoebae: Silver Nanoparticle Conjugation Enhanced Efficacy of Anti-Amoebic Drugs against Naegleria fowleri.

PubMed

Rajendran, Kavitha; Anwar, Ayaz; Khan, Naveed Ahmed; Siddiqui, Ruqaiyyah

2017-12-20

The overall aim of this study was to determine whether conjugation with silver nanoparticles enhances effects of available drugs against primary amoebic meningoencephalitis due to Naegleria fowleri. Amphotericin B, Nystatin, and Fluconazole were conjugated with silver nanoparticles, and synthesis was confirmed using UV-visible spectrophotometry. Atomic force microscopy determined their size in range of 20-100 nm. To determine amoebicidal effects, N. fowleri were incubated with drugs-conjugated silver nanoparticles, silver nanoparticles alone, and drugs alone. The findings revealed that silver nanoparticles conjugation significantly enhanced antiamoebic effects of Nystatin and Amphotericin B but not Fluconazole at micromolar concentrations, compared with the drugs alone. For the first time, our findings showed that silver nanoparticle conjugation enhances efficacy of antiamoebic drugs against N. fowleri. Given the rarity of the disease and challenges in developing new drugs, it is hoped that modifying existing drugs to enhance their antiamoebic effects is a useful avenue that holds promise in improving the treatment of brain-eating amoebae infection due to N. fowleri.

Enhanced cellular uptake of size-separated lipophilic silicon nanoparticles

NASA Astrophysics Data System (ADS)

Kusi-Appiah, Aubrey E.; Mastronardi, Melanie L.; Qian, Chenxi; Chen, Kenneth K.; Ghazanfari, Lida; Prommapan, Plengchart; Kübel, Christian; Ozin, Geoffrey A.; Lenhert, Steven

2017-03-01

Specific size, shape and surface chemistry influence the biological activity of nanoparticles. In the case of lipophilic nanoparticles, which are widely used in consumer products, there is evidence that particle size and formulation influences skin permeability and that lipophilic particles smaller than 6 nm can embed in lipid bilayers. Since most nanoparticle synthetic procedures result in mixtures of different particles, post-synthetic purification promises to provide insights into nanostructure-function relationships. Here we used size-selective precipitation to separate lipophilic allyl-benzyl-capped silicon nanoparticles into monodisperse fractions within the range of 1 nm to 5 nm. We measured liposomal encapsulation and cellular uptake of the monodisperse particles and found them to have generally low cytotoxicities in Hela cells. However, specific fractions showed reproducibly higher cytotoxicity than other fractions as well as the unseparated ensemble. Measurements indicate that the cytotoxicity mechanism involves oxidative stress and the differential cytotoxicity is due to enhanced cellular uptake by specific fractions. The results indicate that specific particles, with enhanced suitability for incorporation into lipophilic regions of liposomes and subsequent in vitro delivery to cells, are enriched in certain fractions.

Plasmon enhanced fluorescence with aggregated shell-isolated nanoparticles.

PubMed

Osorio-Román, Igor O; Guerrero, Ariel R; Albella, Pablo; Aroca, Ricardo F

2014-10-21

Shell-isolated nanoparticles (SHINs) nanostructures provide a versatile substrate where the localized surface plasmon resonances (LSPRs) are well-defined. For SHINEF, the silver (or gold) metal core is protected by the SiO2 coating, which is thicker than the critical distance for minimum quenching by the metal. In the present work, it is shown that an increase in the SHINEF enhancement factor may be achieved by inducing SHIN aggregation with electrolytes in solution. The proof of concept is demonstrated using NaCl as aggregating agent, although other inorganic salts will also aggregate SHIN nanoparticles. As much as a 10-fold enhancement in the SHINEF enhancement factor (EF) may be achieved by tuning the electrolyte concentrations in solution. The SHINEF experiments include the study of the aggregation effect controlling gold SHIN's surface concentration via spraying. Au-SHINs are sprayed onto layer-by-layer (LbL) and Langmuir-Blodgett (LB) films, and samples are fabricated using fluorophores with low and also high quantum yield.

Gold nanoclusters-based chemiluminescence resonance energy transfer method for sensitive and label-free detection of trypsin.

PubMed

You, Xiaoying; Li, Yinhuan; Li, Baoping; Ma, Jie

2016-01-15

A chemiluminescence resonance energy transfer (CRET) platform was developed for sensitive and label-free detection of protease by using trypsin as a model analyte. In this CRET platform, bis(2,4,6-trichlorophenyl)oxalate-hydrogen peroxide chemiluminescence (CL) reaction was utilized as an energy donor and bovine serum albumin (BSA)-stabilized gold nanoclusters (Au NCs) as an energy acceptor. The BSA-stabilized Au NCs triggered the CRET phenomenon by accepting the energy from TCPO-H2O2 CL reaction, thus producing intense CL. In the presence of trypsin, the protein template of BSA-stabilized Au NCs was digested, which frustrated the energy transfer efficiency between the CL donor and the BSA-stabilized Au NCs, leading to a significant decrease in the CL signal. The decreased CL signal was proportional to the logarithm of trypsin concentration in the range of 0.01-50.0µg mL(-1). The detection limit for trypsin was 9ng mL(-)(1) and the relative standard deviations were lesser than 3% (n=11). This Au NCs-based CRET platform was successfully applied to the determination of trypsin in human urine samples, demonstrating its potential application in clinical diagnosis. Copyright © 2015 Elsevier B.V. All rights reserved.

Enhanced Immunomodulatory Activity of Gelatin-Encapsulated Rubus coreanus Miquel Nanoparticles

PubMed Central

Seo, Yong Chang; Choi, Woon Yong; Lee, Choon Geun; Cha, Seon Woo; Kim, Young Ock; Kim, Jin-Chul; Drummen, Gregor P. C.; Lee, Hyeon Yong

2011-01-01

The aim of this work was to investigate the immunomodulatory activities of Rubus coreanus Miquel extract-loaded gelatin nanoparticles. The mean size of the produced nanoparticles was 143 ± 18 nm with a bandwidth of 76 nm in the size distribution and a maximum size of ~200 nm, which allows effective nanoparticle uptake by cells. Confocal imaging confirmed this, since the nanoparticles were internalized within 30 min and heterogeneously distributed throughout the cell. Zeta-potential measurements showed that from pH = 5 onwards, the nanoparticles were highly negatively charged, which prevents agglomeration to clusters by electrostatic repulsion. This was confirmed by TEM imaging, which showed a well dispersed colloidal solution. The encapsulation efficiency was nearly 60%, which is higher than for other components encapsulated in gelatin nanoparticles. Measurements of immune modulation in immune cells showed a significant effect by the crude extract, which was only topped by the nanoparticles containing the extract. Proliferation of B-, T- and NK cells was notably enhanced by Rubus coreanus-gelatin nanoparticles and in general ~2–3 times higher than control and on average ~2 times higher than ferulic acid. R. coreanus-gelatin nanoparticles induced cytokine secretion (IL-6 and TNF-α) from B- and T-cells on average at a ~2–3 times higher rate compared with the extract and ferulic acid. In vivo immunomodulatory activity in mice fed with R. coreanus-gelatin nanoparticles at 1 mL/g body weight showed a ~5 times higher antibody production compared to control, a ~1.3 times higher production compared to the extract only, and a ~1.6 times higher production compared to ferulic acid. Overall, our results suggest that gelatin nanoparticles represent an excellent transport vehicle for Rubus coreanus extract and extracts from other plants generally used in traditional Asian medicine. Such nanoparticles ensure a high local concentration that results in enhancement of immune

Synthesis, characterization, and 3D-FDTD simulation of Ag@SiO2 nanoparticles for shell-isolated nanoparticle-enhanced Raman spectroscopy.

PubMed

Uzayisenga, Viviane; Lin, Xiao-Dong; Li, Li-Mei; Anema, Jason R; Yang, Zhi-Lin; Huang, Yi-Fan; Lin, Hai-Xin; Li, Song-Bo; Li, Jian-Feng; Tian, Zhong-Qun

2012-06-19

Au-seed Ag-growth nanoparticles of controllable diameter (50-100 nm), and having an ultrathin SiO(2) shell of controllable thickness (2-3 nm), were prepared for shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS). Their morphological, optical, and material properties were characterized; and their potential for use as a versatile Raman signal amplifier was investigated experimentally using pyridine as a probe molecule and theoretically by the three-dimensional finite-difference time-domain (3D-FDTD) method. We show that a SiO(2) shell as thin as 2 nm can be synthesized pinhole-free on the Ag surface of a nanoparticle, which then becomes the core. The dielectric SiO(2) shell serves to isolate the Raman-signal enhancing core and prevent it from interfering with the system under study. The SiO(2) shell also hinders oxidation of the Ag surface and nanoparticle aggregation. It significantly improves the stability and reproducibility of surface-enhanced Raman scattering (SERS) signal intensity, which is essential for SERS applications. Our 3D-FDTD simulations show that Ag-core SHINERS nanoparticles yield at least 2 orders of magnitude greater enhancement than Au-core ones when excited with green light on a smooth Ag surface, and thus add to the versatility of our SHINERS method.

Nanoparticle-enhanced x-ray therapy for cancer

NASA Astrophysics Data System (ADS)

Letfullin, Renat R.; Rice, Colin E. W.; George, Thomas F.

2016-03-01

Photothermal therapies of nanophotohyperthermia and nanophotothermolysis utilize the light absorptive properties of nanoparticles to create heat and free radicals in a small localized region. Conjugating nanoparticles with various biomolecules allows for targeted delivery to specific tissues or even specific cells, cancerous cells being of particular interest. Previous studies have investigated nanoparticles at visible and infrared wavelengths where surface plasmon resonance leads to unique absorption characteristics. However, issues such as poor penetration depth of the visible light through biological tissues limits the effectiveness of delivery by noninvasive means. In other news, various nanoparticles have been investigated as contrast agents for traditional X-ray procedures, utilizing the strong absorption characteristics of the nanoparticles to enhance contrast of the detected X-ray image. Using X-rays to power photothermal therapies has three main advantages over visiblespectra wavelengths: the high penetration depth of X-rays through biological media makes noninvasive treatments very feasible; the high energy of individual photons means nanoparticles can be heated to desired temperatures with lower beam intensities, or activated to produce the free radicals; and X-ray sources are already common throughout the medical industry, making future implementation on existing equipment possible. This paper uses Lorenz-Mie theory to investigate the light absorption properties of various size gold nanoparticles over photon energies in the 1-100 keV range. These absorption values are then plugged into a thermal model to determine the temperatures reached by the nanoparticles for X-ray exposures of differing time and intensity. The results of these simulations are discussed in relation to the effective implementation of nanophotohyperthermia and nanophotothermolysis treatments.

Evaluation of the local dose enhancement in the combination of proton therapy and nanoparticles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martínez-Rovira, I., E-mail: immamartinez@gmail.com; Prezado, Y.

Purpose: The outcome of radiotherapy can be further improved by combining irradiation with dose enhancers such as high-Z nanoparticles. Since 2004, spectacular results have been obtained when low-energy x-ray irradiations have been combined with nanoparticles. Recently, the same combination has been explored in hadron therapy. In vitro studies have shown a significant amplification of the biological damage in tumor cells charged with nanoparticles and irradiated with fast ions. This has been attributed to the increase in the ionizations and electron emissions induced by the incident ions or the electrons in the secondary tracks on the high-Z atoms, resulting in amore » local energy deposition enhancement. However, this subject is still a matter of controversy. Within this context, the main goal of the authors’ work was to provide new insights into the dose enhancement effects of nanoparticles in proton therapy. Methods: For this purpose, Monte Carlo calculations (GATE/GEANT4 code) were performed. In particular, the GEANT4-DNA toolkit, which allows the modeling of early biological damages induced by ionizing radiation at the DNA scale, was used. The nanometric radial energy distributions around the nanoparticle were studied, and the processes (such as Auger deexcitation or dissociative electron attachment) participating in the dose deposition of proton therapy treatments in the presence of nanoparticles were evaluated. It has been reported that the architecture of Monte Carlo calculations plays a crucial role in the assessment of nanoparticle dose enhancement and that it may introduce a bias in the results or amplify the possible final dose enhancement. Thus, a dosimetric study of different cases was performed, considering Au and Gd nanoparticles, several nanoparticle sizes (from 4 to 50 nm), and several beam configurations (source-nanoparticle distances and source sizes). Results: This Monte Carlo study shows the influence of the simulations’ parameters on

Enhanced visible light-induced photocatalytic activity of surface-modified BiOBr with Pd nanoparticles

NASA Astrophysics Data System (ADS)

Meng, Xiangchao; Li, Zizhen; Chen, Jie; Xie, Hongwei; Zhang, Zisheng

2018-03-01

Palladium nanoparticles well-dispersed on BiOBr surfaces were successfully prepared via a two-step process, namely hydrothermal synthesis of BiOBr followed by photodeposition of palladium. Surface-exposed palladium nanoparticles may improve the harvesting capacity of visible light photons via the surface plasmonic resonance effect to produce extra electrons. Palladium is an excellent electron acceptor, and therefore favours the separation of photogenerated electron/hole pairs. As a result, palladium significantly improves the photocatalytic activity of BiOBr in the removal of organic pollutants (phenol) under visible light irradiation. In addition to as-prepared samples which were comprehensively characterized, the mechanism for the enhancement via the deposition of palladium nanoparticles was also proposed based on results. This work may serve as solid evidence to confirm that surface-deposited palladium nanoparticles are capable of improving photocatalytic activity, and that photodeposition may be an effective approach to load metal nanoparticles onto a surface.

Cooperative plasmonic effect of Ag and Au nanoparticles on enhancing performance of polymer solar cells.

PubMed

Lu, Luyao; Luo, Zhiqiang; Xu, Tao; Yu, Luping

2013-01-09

This article describes a cooperative plasmonic effect on improving the performance of polymer bulk heterojunction solar cells. When mixed Ag and Au nanoparticles are incorporated into the anode buffer layer, dual nanoparticles show superior behavior on enhancing light absorption in comparison with single nanoparticles, which led to the realization of a polymer solar cell with a power conversion efficiency of 8.67%, accounting for a 20% enhancement. The cooperative plasmonic effect aroused from dual resonance enhancement of two different nanoparticles. The idea was further unraveled by comparing Au nanorods with Au nanoparticles for solar cell application. Detailed studies shed light into the influence of plasmonic nanostructures on exciton generation, dissociation, and charge recombination and transport inside thin film devices.

An Enhanced Soft Vibrotactile Actuator Based on ePVC Gel with Silicon Dioxide Nanoparticles.

PubMed

Park, Won-Hyeong; Shin, Eun-Jae; Yun, Sungryul; Kim, Sang-Youn

2018-01-01

In this paper, we propose a soft vibrotactile actuator made by mixing silicon dioxide nanoparticles and plasticized PVC gel. The effect of the silicon dioxide nanoparticles in the plasticized PVC gel for the haptic performance is investigated in terms of electric, dielectric, and mechanical properties. Furthermore, eight soft vibrotactile actuators are prepared as a function of the content. Experiments are conducted to examine the haptic performance of the prepared eight soft vibrotactile actuators and to find the best weight ratio of the plasticized PVC gel to the nanoparticles. The experiments should show that the plasticized PVC gel with silicon dioxide nanoparticles improves the haptic performance of the plasticized PVC gel-based vibrotactile actuator, and the proposed vibrotactile actuator can create a variety of haptic sensations in a wide frequency range.

Chemiluminescence and chemiluminescence resonance energy transfer (CRET) aptamer sensors using catalytic hemin/G-quadruplexes.

PubMed

Liu, Xiaoqing; Freeman, Ronit; Golub, Eyal; Willner, Itamar

2011-09-27

The incorporation of hemin into the thrombin/G-quadruplex aptamer assembly or into the ATP/G-quadruplex nanostructure yields active DNAzymes that catalyze the generation of chemiluminescence. These catalytic processes enable the detection of thrombin and ATP with detection limits corresponding to 200 pM and 10 μM, respectively. The conjugation of the antithrombin or anti-ATP aptamers to CdSe/ZnS semiconductor quantum dots (QDs) allowed the detection of thrombin or ATP through the luminescence of the QDs that is powered by a chemiluminescence resonance energy-transfer (CRET) process stimulated by the hemin/G-quadruplex/thrombin complex or the hemin/G-quadruplex/ATP nanostructure, in the presence of luminol/H(2)O(2). The advantages of applying the CRET process for the detection of thrombin or ATP, by the resulting hemin/G-quadruplex DNAzyme structures, are reflected by low background signals and the possibility to develop multiplexed aptasensor assays using different sized QDs. © 2011 American Chemical Society

Ultrathin free-standing close-packed gold nanoparticle films: Conductivity and Raman scattering enhancement

NASA Astrophysics Data System (ADS)

Yu, Qing; Huang, Hongwen; Peng, Xinsheng; Ye, Zhizhen

2011-09-01

A simple filtration technique was developed to prepare large scale free-standing close-packed gold nanoparticle ultrathin films using metal hydroxide nanostrands as both barrier layer and sacrificial layer. As thin as 70 nm, centimeter scale robust free-standing gold nanoparticle thin film was obtained. The thickness of the films could be easily tuned by the filtration volumes. The electronic conductivities of these films varied with the size of the gold nanoparticles, post-treatment temperature, and thickness, respectively. The conductivity of the film prepared from 20 nm gold nanoparticles is higher than that of the film prepared from 40 nm gold nanoparticle by filtering the same filtration volume of their solution, respectively. Their conductivities are comparable to that of the 220 nm thick ITO film. Furthermore, these films demonstrated an average surface Raman scattering enhancement up to 6.59 × 105 for Rhodamine 6 G molecules on the film prepared from 40 nm gold nanoparticles. Due to a lot of nano interspaces generated from the close-packed structures, two abnormal enhancements and relative stronger intensities of the asymmetrical vibrations at 1534 and 1594 cm-1 of R6G were observed, respectively. These robust free-standing gold nanoparticle films could be easily transferred onto various solid substrates and hold the potential application for electrodes and surface enhanced Raman detectors. This method is applicable for preparation of other nanoparticle free-standing thin films.A simple filtration technique was developed to prepare large scale free-standing close-packed gold nanoparticle ultrathin films using metal hydroxide nanostrands as both barrier layer and sacrificial layer. As thin as 70 nm, centimeter scale robust free-standing gold nanoparticle thin film was obtained. The thickness of the films could be easily tuned by the filtration volumes. The electronic conductivities of these films varied with the size of the gold nanoparticles, post

Synergistic effect of PLGA nanoparticles and submicron triglyceride droplets in enhancing the intestinal solubilisation of a lipophilic weak base.

PubMed

Joyce, Paul; Prestidge, Clive A

2018-06-15

A novel hybrid microparticulate system composed of poly(lactic-co-glycolic) acid (PLGA) nanoparticles and submicron medium-chain triglyceride (MCT) droplets was fabricated to overcome the pH-dependent solubility and precipitation challenges associated with a model poorly water-soluble weak base, cinnarizine (CIN). Molecular CIN was confined within both the lipid and polymer phase of PLGA-lipid hybrid (PLH) and PLGA-lipid-mannitol hybrid (PLMH) particles, which offered significant biopharmaceutical advantages in comparison to the unformulated drug, submicron MCT droplets and PLGA nanoparticles. This was highlighted by a substantial reduction in the pH-induced precipitation during in vitro gastrointestinal two-step dissolution studies. A >2.5-fold solubilisation enhancement was observed for the composite particles during simulated intestinal conditions, compared to pure CIN. Furthermore, the drug solubilisation capacity during in vitro intestinal digesting conditions was ~2-2.5 times greater for PLMH particles compared to the precursor emulsion droplets and PLGA nanoparticles. The observations from this study indicate that a synergy exists between the degradation products of PLGA nanoparticles and lipid droplets, whereby the dual-phase release and dissolution mechanism of the hybrid particles aids in prolonging pH-provoked precipitation. Subsequently, the ability for PLGA polymers and oligomers to act as polymeric precipitation inhibitors has been highlighted for the first time. Copyright © 2018 Elsevier B.V. All rights reserved.

Bioinspired photonic structures by the reflector layer of firefly lantern for highly efficient chemiluminescence

PubMed Central

Chen, Linfeng; Shi, Xiaodi; Li, Mingzhu; Hu, Junping; Sun, Shufeng; Su, Bin; Wen, Yongqiang; Han, Dong; Jiang, Lei; Song, Yanlin

2015-01-01

Fireflies have drawn considerable attention for thousands of years due to their highly efficient bioluminescence, which is important for fundamental research and photonic applications. However, there are few reports on the reflector layer (RL) of firefly lantern, which contributes to the bright luminescence. Here we presented the detailed microstructure of the RL consisting of random hollow granules, which had high reflectance in the range from 450 nm to 800 nm. Inspired by the firefly lantern, artificial films with high reflectance in the visible region were fabricated using hollow silica microparticles mimicking the structure of the RL. Additionally, the bioinspired structures provided an efficient RL for the chemiluminescence system and could substantially enhance the initial chemiluminescence intensity. The work not only provides new insight into the bright bioluminescence of fireflies, but also is importance for the design of photonic materials for theranostics, detection, and imaging. PMID:26264643

Enhanced Intratumoral Delivery of SN38 as a Tocopherol Oxyacetate Prodrug Using Nanoparticles in a Neuroblastoma Xenograft Model.

PubMed

Nguyen, Ferro; Alferiev, Ivan; Guan, Peng; Guerrero, David T; Kolla, Venkatadri; Moorthy, Ganesh S; Chorny, Michael; Brodeur, Garrett M

2018-06-01

Purpose: Currently, <50% of high-risk pediatric solid tumors like neuroblastoma can be cured, and many survivors experience serious or life-threatening toxicities, so more effective, less toxic therapy is needed. One approach is to target drugs to tumors using nanoparticles, which take advantage of the enhanced permeability of tumor vasculature. Experimental Design: SN38, the active metabolite of irinotecan (CPT-11), is a potent therapeutic agent that is readily encapsulated in polymeric nanoparticles. Tocopherol oxyacetate (TOA) is a hydrophobic mitocan that was linked to SN38 to significantly increase hydrophobicity and enhance nanoparticle retention. We treated neuroblastomas with SN38-TOA nanoparticles and compared the efficacy with the parent prodrug CPT-11 using a mouse xenograft model. Results: Nanoparticle treatment induced prolonged event-free survival (EFS) in most mice, compared with CPT-11. This was shown for both SH-SY5Y and IMR-32 neuroblastoma xenografts. Enhanced efficacy was likely due to increased and sustained drug levels of SN38 in the tumor compared with conventional CPT-11 delivery. Interestingly, when recurrent CPT-11-treated tumors were re-treated with SN38-TOA nanoparticles, the tumors transformed from undifferentiated neuroblastomas to maturing ganglioneuroblastomas. Furthermore, these tumors were infiltrated with Schwann cells of mouse origin, which may have contributed to the differentiated histology. Conclusions: Nanoparticle delivery of SN38-TOA produced increased drug delivery and prolonged EFS compared to conventional delivery of CPT-11. Also, lower total dose and drug entrapment in nanoparticles during circulation should decrease toxicity. We propose that nanoparticle-based delivery of a rationally designed prodrug is an attractive approach to enhance chemotherapeutic efficacy in pediatric and adult tumors. Clin Cancer Res; 24(11); 2585-93. ©2018 AACR . ©2018 American Association for Cancer Research.

Enzyme-linked immunosorbent assay by enhanced chemiluminescence detection for the standardization of estrogenic miroestrol in Pueraria candollei Graham ex Benth.

PubMed

Yusakul, Gorawit; Udomsin, Orapin; Tanaka, Hiroyuki; Morimoto, Satoshi; Juengwatanatrakul, Thaweesak; Putalun, Waraporn

2015-08-01

Miroestrol (ME) is a potent phytoestrogen from the P. candollei tuberous root. It has been approved for use in clinical trials due to its beneficial effect on disorders associated with estrogen deficiency. To ensure medical efficacy and safety, high performance analytical methods for ME analysis are required to standardize products from the P. candollei root. An enhanced chemiluminescence enzyme-linked immunosorbent assay (ECL-ELISA) was developed and validated using a polyclonal antibody against ME and a chemiluminescent system of luminol-H2 O2 -horseradish peroxidase-4-(1-imidazolyl) phenol. The ECL-ELISA system exhibited linearity over a concentration range of 0.31-10.00 ng mL(-1) , for which the relative standard variation (%RSD) was less than 10% for both intra- and interplate determinations. The ECL-ELISA is reliable for the determination of ME as reflected by the high recovery percentage (101.22-103.06%). As a comparative analysis, the ME content in each sample determined by ECL-ELISA was correlated with high coefficients of determination with colorimetric ELISA (R(2)  = 0.998) and high performance liquid chromatography (HPLC) (R(2)  = 0.998) methods. The ECL-ELISA method could be applied to all of the commercial products containing P. candollei root, when the products contain between 0.706 ± 0.046 and 13.123 ± 0.794 µg g(-1) dry wt. of ME. This method is useful as a high performance analytical method for the quantity control of ME in raw materials and end products at both the research and industrial levels. Copyright © 2014 John Wiley & Sons, Ltd.

A gas-phase chemiluminescence-based analyzer for waterborne arsenic

USGS Publications Warehouse

Idowu, A.D.; Dasgupta, P.K.; Genfa, Z.; Toda, K.; Garbarino, J.R.

2006-01-01

We show a practical sequential injection/zone fluidics-based analyzer that measures waterborne arsenic. The approach is capable of differentiating between inorganic As(III) and As(V). The principle is based on generating AsH 3 from the sample in a confined chamber by borohydride reduction at controlled pH, sparging the chamber to drive the AsH3 to a small reflective cell located atop a photomultiplier tube, allowing it to react with ozone generated from ambient air, and measuring the intense chemiluminescence that results. Arsine generation and removal from solution results in isolation from the sample matrix, avoiding the pitfalls encountered in some solution-based analysis techniques. The differential determination of As(III) and As(V) is based on the different pH dependence of the reducibility of these species to AsH3. At pH ???1, both As(III) and As(V) are quantitatively converted to arsine in the presence of NaBH4. At a pH of 4-5, only As(III) is converted to arsine. In the present form, the limit of detection (S/N = 3) is 0.05 ??g/L As at pH ???1 and 0.09 ??g/L As(III) at pH ???4-5 for a 3-mL sample. The analyzer is intrinsically automated and requires 4 min per determination. It is also possible to determine As(III) first at pH 4.5 and then determine the remaining As in a sequential manner; this requires 6 min. There are no significant practical interferences. A new borohydride solution formulation permits month-long reagent stability. ?? 2006 American Chemical Society.

Enhanced chemiluminescence of carminic acid-permanganate by CdS quantum dots and its application for sensitive quenchometric flow injection assays of cloxacillin.

PubMed

Khataee, Alireza; Hasanzadeh, Aliyeh; Lotfi, Roya; Joo, Sang Woo

2016-05-15

A novel chemiluminescence (CL) system is introduced based on the oxidation of carminic acid by KMnO4 in acidic conditions. CdS quantum dots (QDs) were synthesized using a facile hydrothermal method which efficiently enhanced the intensity of the CL system. A possible mechanism for the proposed system is presented using the kinetic curves, CL spectra, photoluminescence (PL), and ultraviolet-visible (UV-Vis) analysis. The emission intensity of the KMnO4-carminic acid-CdS QDs system was quenched in the presence of a trace level of cloxacillin. Based on this quenching effect, a novel and sensitive flow injection CL method was developed for determining cloxacillin concentrations. At optimal experimental conditions, the decreased CL intensity had a good linear relation with the cloxacillin concentration in the range of 0.008 to 22.0 mg L(-1). The detection limit (3σ) was 5.8 µg L(-1). The precision of the method was calculated by analyzing samples containing 4.0 mg L(-1) of cloxacillin (n=11), and the relative standard deviations (RSD%) were 2.08%. The feasibility of the method is also demonstrated for determining cloxacillin concentrations in environmental water samples and a pharmaceutical formulation. Copyright © 2016 Elsevier B.V. All rights reserved.

Investigation of singlet oxygen generation in Vit C-Cu2+ -LDL system by chemiluminescence method

NASA Astrophysics Data System (ADS)

Wang, Juan; Xing, Da; Tan, Shici; Tang, Yonghong; He, Yonghong

2002-04-01

In this study, by chemiluminescence method using a Cypridina luciferin analog, 2-methyl-6-(p-methoxyphenyl)-3,7- dihydroimidazo[1,2-a]pyrazin-3-one (MCLA), as a selective and sensitive chemiluminescence probe, singlet oxygen (1O2) formation was observed in the vit C- LDL-Cu2+ reaction system. Another experimental evidence for the generation of 1O2 was the quenching effect of sodium azide (NaN3) on vit C-induced chemiluminescence in the reaction mixture of LDL- Cu2+-MCLA. Analysis based on the experimental results indicated the plausible reaction mechanism is that vit C converts Cu2+ to its reduced state and vit C becomes vit C radical itself, thereby stimulating the formation of peroxyl radicals, and bimolecular reaction of peroxyl radicals results in 1O2 production in the above systems.

Finite-size effects in surface-enhanced Raman scattering in noble-metal nanoparticles: a semiclassical approach.

PubMed

Pustovit, Vitaliy N; Shahbazyan, Tigran V

2006-06-01

We study finite-size effects in surface-enhanced Raman scattering (SERS) from molecules adsorbed on small metal particles. Within an electromagnetic description of SERS, the enhancement of the Raman signal originates from the local field of the surface plasmon resonance in a nanoparticle. With decreasing particle sizes, this enhancement is reduced due to the size-dependent Landau damping of the surface plasmon. We show that, in small noble-metal particles, the reduction of interband screening in the surface layer leads to an additional increase in the local field acting on a molecule close to the metal surface. The overall size dependence of Raman signal enhancement is determined by the interplay between Landau damping and underscreening effects. Our calculations, based on a two-region model, show that the role of the surface layer increases for smaller nanoparticle sizes due to a larger volume fraction of the underscreened region.

How can macromolecular crowding inhibit biological reactions? The enhanced formation of DNA nanoparticles

PubMed Central

Hou, Sen; Trochimczyk, Piotr; Sun, Lili; Wisniewska, Agnieszka; Kalwarczyk, Tomasz; Zhang, Xuzhu; Wielgus-Kutrowska, Beata; Bzowska, Agnieszka; Holyst, Robert

2016-01-01

In contrast to the already known effect that macromolecular crowding usually promotes biological reactions, solutions of PEG 6k at high concentrations stop the cleavage of DNA by HindIII enzyme, due to the formation of DNA nanoparticles. We characterized the DNA nanoparticles and probed the prerequisites for their formation using multiple techniques such as fluorescence correlation spectroscopy, dynamic light scattering, fluorescence analytical ultracentrifugation etc. In >25% PEG 6k solution, macromolecular crowding promotes the formation of DNA nanoparticles with dimensions of several hundreds of nanometers. The formation of DNA nanoparticles is a fast and reversible process. Both plasmid DNA (2686 bp) and double-stranded/single-stranded DNA fragment (66bp/nt) can form nanoparticles. We attribute the enhanced nanoparticle formation to the depletion effect of macromolecular crowding. This study presents our idea to enhance the formation of DNA nanoparticles by macromolecular crowding, providing the first step towards a final solution to efficient gene therapy. PMID:26903405

How can macromolecular crowding inhibit biological reactions? The enhanced formation of DNA nanoparticles.

PubMed

Hou, Sen; Trochimczyk, Piotr; Sun, Lili; Wisniewska, Agnieszka; Kalwarczyk, Tomasz; Zhang, Xuzhu; Wielgus-Kutrowska, Beata; Bzowska, Agnieszka; Holyst, Robert

2016-02-23

In contrast to the already known effect that macromolecular crowding usually promotes biological reactions, solutions of PEG 6k at high concentrations stop the cleavage of DNA by HindIII enzyme, due to the formation of DNA nanoparticles. We characterized the DNA nanoparticles and probed the prerequisites for their formation using multiple techniques such as fluorescence correlation spectroscopy, dynamic light scattering, fluorescence analytical ultracentrifugation etc. In >25% PEG 6k solution, macromolecular crowding promotes the formation of DNA nanoparticles with dimensions of several hundreds of nanometers. The formation of DNA nanoparticles is a fast and reversible process. Both plasmid DNA (2686 bp) and double-stranded/single-stranded DNA fragment (66 bp/nt) can form nanoparticles. We attribute the enhanced nanoparticle formation to the depletion effect of macromolecular crowding. This study presents our idea to enhance the formation of DNA nanoparticles by macromolecular crowding, providing the first step towards a final solution to efficient gene therapy.

Analytical Applications of Bioluminescence and Chemiluminescence

NASA Technical Reports Server (NTRS)

Chappelle, E. W. (Editor); Picciolo, G. L. (Editor)

1975-01-01

Bioluminescence and chemiluminescence studies were used to measure the amount of adenosine triphosphate and therefore the amount of energy available. Firefly luciferase - luciferin enzyme system was emphasized. Photometer designs are also considered.

Simplified ozone detection by chemiluminescence

NASA Technical Reports Server (NTRS)

Conway, E. J.; Rogowski, R. S.; Richards, R. R.

1977-01-01

Ozone is detected by film coated with solid, such as rubrene, that reacts with ozone to degree proportional to concentration in sample gas. Gas flow is stopped, and film is heated to produce light (chemiluminescence) in proportion to amount of reacted material on sensor.

Enhancing magnetic nanoparticle-based DNA transfection: Intracellular-active cassette features

NASA Astrophysics Data System (ADS)

Vernon, Matthew Martin

Efficient plasmid DNA transfection of embryonic stem cells, mesenchymal stem cells, neural cell lines and the majority of primary cell lines is a current challenge in gene therapy research. Magnetic nanoparticle-based DNA transfection is a gene vectoring technique that is promising because it is capable of outperforming most other non-viral transfection methods in terms of both transfection efficiency and cell viability. The nature of the DNA vector implemented depends on the target cell phenotype, where the particle surface chemistry and DNA binding/unbinding kinetics of the DNA carrier molecule play a critical role in the many steps required for successful gene transfection. Accordingly, Neuromag, an iron oxide/polymer nanoparticle optimized for transfection of neural phenotypes, outperforms many other nanoparticles and lipidbased DNA carriers. Up to now, improvements to nanomagnetic transfection techniques have focused mostly on particle functionalization and transfection parameter optimization (cell confluence, growth media, serum starvation, magnet oscillation parameters, etc.). None of these parameters are capable of assisting the nuclear translocation of delivered plasmid DNA once the particle-DNA complex is released from the endosome and dissociates in the cell's cytoplasm. In this study, incorporation of a DNA targeting sequence (DTS) feature in the transfecting plasmid DNA confers improved nuclear translocation, demonstrating significant improvement in nanomagnetic transfection efficiency in differentiated SH-SY5Y neuroblastoma cells. Other parameters, such as days in vitro, are also found to play a role and represent potential targets for further optimization.

Recent Advances of Activatable Molecular Probes Based on Semiconducting Polymer Nanoparticles in Sensing and Imaging

PubMed Central

Lyu, Yan

2017-01-01

Molecular probes that change their signals in response to the target of interest have a critical role in fundamental biology and medicine. Semiconducting polymer nanoparticles (SPNs) have recently emerged as a new generation of purely organic photonic nanoagents with desirable properties for biological applications. In particular, tunable optical properties of SPNs allow them to be developed into photoluminescence, chemiluminescence, and photoacoustic probes, wherein SPNs usually serve as the energy donor and internal reference for luminescence and photoacoustic probes, respectively. Moreover, facile surface modification and intraparticle engineering provide the versatility to make them responsive to various biologically and pathologically important substances and indexes including small‐molecule mediators, proteins, pH and temperature. This article focuses on recent advances in the development of SPN‐based activatable molecular probes for sensing and imaging. The designs and applications of these probes are discussed in details, and the present challenges to further advance them into life science are also analyzed. PMID:28638783

beta 2-glycoprotein I (apolipoprotein H) modulates uptake and endocytosis associated chemiluminescence in rat Kupffer cells.

PubMed

Gomes, L F; Gonçalves, L M; Fonseca, F L A; Celli, C M; Videla, L A; Chaimovich, H; Junqueira, V B C

2002-07-01

beta 2-Glycoprotein I (beta 2 GPI) is known to influence macrophage uptake of particles with phosphatidylserine containing surfaces, as apoptotic thymocytes and unilamellar vesicles in vitro. Nevertheless, effects upon macrophage activation induced by this interaction are still unknown. beta 2 GPI influence upon the reactive species production by Kupffer cells was evaluated in order to investigate whether beta 2 GPI modulates the macrophage response to negatively charged surfaces. Chemiluminescence of isolated non-parenchymal rat liver cells was measured after phagocytosis of opsonized zymosan or phorbolymristate acetate (PMA) stimulation, in the presence and absence of large unilamellar vesicles (LUVs) containing 25 mol% phosphatidylserine (PS) or 50 mol% cardiolipin (CL) and complementary molar ratio of phosphatidylcholine (PC). beta 2 GPI decreased by 50% the chemiluminescence response induced by opsonized zymosan, with a 66% reduction of the initial light emission rate. PMA stimulated Kupffer cell chemiluminescence was insensitive to human or rat beta 2 GPI. Albumin (500 micrograms/ml) showed no effect upon chemiluminescence. beta 2 GPI increased PS/PC LUV uptake and degradation by Kupffer cells in a concentration-dependent manner, without leakage of the internal contents of the LUVs, as shown by fluorescence intensity enhancement. LUVs opsonized with antiphospholipid antibodies (aPL) from syphilitic patients increased light emission by Kupffer cells. Addition of beta 2 GPI to the assay reduced chemiluminescence due to opsonization with purified IgG antibodies from systemic lupus erythematosus (SLE or syphilis (Sy) patient sera. A marked net increase in chemiluminescence is observed in the presence of Sy aPL antibodies, whereas a decrease was found when SLE aPL were added to the assay, in the presence or absence of beta 2 GPI. At a concentration of 125 micrograms/ml, beta 2 GPI significantly reduced Kupffer cell Candida albicans phagocytosis index and killing

A magnetic particles-based chemiluminescence enzyme immunoassay for rapid detection of ovalbumin.

PubMed

Feng, Xiao-Li; Ren, Hong-Lin; Li, Yan-Song; Hu, Pan; Zhou, Yu; Liu, Zeng-Shan; Yan, Dong-Ming; Hui, Qi; Liu, Dong; Lin, Chao; Liu, Nan-Nan; Liu, Yan-Yan; Lu, Shi-Ying

2014-08-15

Egg allergy is an important public health and safety concern, so quantification and administration of food or vaccines containing ovalbumin (OVA) are urgently needed. This study aimed to establish a rapid and sensitive magnetic particles-chemiluminescence enzyme immunoassay (MPs-CLEIA) for the determination of OVA. The proposed method was developed on the basis of a double antibodies sandwich immunoreaction and luminol-H2O2 chemiluminescence system. The MPs served as both the solid phase and separator, the anti-OVA MPs-coated polyclonal antibodies (pAbs) were used as capturing antibody, and the horseradish peroxidase (HRP)-labeled monoclonal antibody (mAb) was taken as detecting antibody. The parameters of the method were evaluated and optimized. The established MPs-CLEIA method had a linear range from 0.31 to 100ng/ml with a detection limit of 0.24ng/ml. The assays showed low reactivities and less than 5% of intraassay and interassay coefficients of variation (CVs), and the average recoveries were between 92 and 97%. Furthermore, the developed method was applied in real samples analysis successfully, and the correlation coefficient with the commercially available OVA kit was 0.9976. Moreover, it was more rapid and sensitive compared with the other methods for testing OVA. Copyright © 2014 Elsevier Inc. All rights reserved.

Enhanced peroxydisulfate electrochemiluminescence for dopamine biosensing based on Au nanoparticle decorated reduced graphene oxide.

PubMed

Yan, Yuting; Liu, Qian; Wang, Kun; Jiang, Ling; Yang, Xingwang; Qian, Jing; Dong, Xiaoya; Qiu, Baijing

2013-12-07

This work reports a novel strategy to amplify the electrochemiluminescence (ECL) signal of peroxydisulfate solution based on the Au nanoparticle decorated reduced graphene oxide (Au NP-RGO), and further an ECL biosensor for sensitive and selective detection of dopamine (DA) was constructed. Due to the synergistic amplification of Au NPs and RGO, the ECL signal of peroxydisulfate solution on the Au NP-RGO modified electrode was about 5-fold enhanced compared to that of the bare electrode with the ECL onset potential positively shifted from -1.2 V to -0.9 V. More interestingly, the ECL intensity of peroxydisulfate solution increased with the increase of DA concentration, based on which an ECL biosensor for DA determination was fabricated. The as-prepared solid-state ECL DA sensor showed a wide linear response of 0.02-40 μM with a detection limit of 6.7 nM (S/N = 3). Moreover, we expect this work would open up a new field in the application of peroxydisulfate solution ECL for highly sensitive bioassays.

Fabrication of large area plasmonic nanoparticle grating structure on silver halide based transmission electron microscope film and its application as a surface enhanced Raman spectroscopy substrate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sudheer,, E-mail: sudheer@rrcat.gov.in; Tiwari, P.; Singh, M. N.

The plasmonic responses of silver nanoparticle grating structures of different periods made on silver halide based electron microscope film are investigated. Raster scan of the conventional scanning electron microscope (SEM) is used to carry out electron beam lithography for fabricating the plasmonic nanoparticle grating (PNG) structures. Morphological characterization of the PNG structures, carried out by the SEM and the atomic force microscope, indicates that the depth of the groove decreases with a decrease in the grating period. Elemental characterization performed by the energy dispersive spectroscopy and the x-ray diffraction shows the presence of nanoparticles of silver in the PNG grating.more » The optical characterization of the gratings shows that the localized surface plasmon resonance peak shifts from 366 to 378 nm and broadens with a decrease in grating period from 10 to 2.5 μm. The surface enhanced Raman spectroscopy of the Rhodamine-6G dye coated PNG structure shows the maximum enhancement by two orders of magnitude in comparison to the randomly distributed silver nanoparticles having similar size and shape as the PNG structure.« less

Enhanced Bioactivity of α-Tocopheryl Succinate Based Block Copolymer Nanoparticles by Reduced Hydrophobicity.

PubMed

Palao-Suay, Raquel; Aguilar, María Rosa; Parra-Ruiz, Francisco J; Maji, Samarendra; Hoogenboom, Richard; Rohner, Nathan A; Thomas, Susan N; Román, Julio San

2016-12-01

Well-structured amphiphilic copolymers are necessary to obtain self-assembled nanoparticles (NPs) based on synthetic polymers. Highly homogeneous and monodispersed macromolecules obtained by controlled polymerization have successfully been used for this purpose. However, disaggregation of the organized macromolecules is desired when a bioactive element, such as α-tocopheryl succinate, is introduced in self-assembled NPs and this element must be exposed or released to exert its action. The aim of this work is to demonstrate that the bioactivity of synthetic NPs based on defined reversible addition-fragmentation chain transfer polymerization copolymers can be enhanced by the introduction of hydrophilic comonomers in the hydrophobic segment. The amphiphilic terpolymers are based on poly(ethylene glycol) (PEG) as hydrophilic block, and a hydrophobic block based on a methacrylic derivative of α-tocopheryl succinate (MTOS) and small amounts of 2-hydroxyethyl methacrylate (HEMA) (PEG-b-poly(MTOS-co-HEMA)). The introduction of HEMA reduces hydrophobicity and introduces "disorder" both in the homogeneous blocks and the compact core of the corresponding NPs. These NPs are able to encapsulate additional α-tocopheryl succinate (α-TOS) with high efficiency and their biological activity is much higher than that described for the unmodified copolymers, proposedly due to more efficient degradation and release of α-TOS, demonstrating the importance of the hydrophilic-hydrophobic balance. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Contrast-enhanced magneto-photo-acoustic imaging in vivo using dual-contrast nanoparticles.

PubMed

Qu, Min; Mehrmohammadi, Mohammad; Truby, Ryan; Graf, Iulia; Homan, Kimberly; Emelianov, Stanislav

2014-06-01

By mapping the distribution of targeted plasmonic nanoparticles (NPs), photoacoustic (PA) imaging offers the potential to detect the pathologies in the early stages. However, optical absorption of the endogenous chromophores in the background tissue significantly reduces the contrast resolution of photoacoustic imaging. Previously, we introduced MPA imaging - a synergistic combination of magneto-motive ultrasound (MMUS) and PA imaging, and demonstrated MPA contrast enhancement using cell culture studies. In the current study, contrast enhancement was investigated in vivo using the magneto-photo-acoustic (MPA) imaging augmented with dual-contrast nanoparticles. Liposomal nanoparticles (LNPs) possessing both optical absorption and magnetic properties were injected into a murine tumor model. First, photoacoustic signals were generated from both the endogenous absorbers in the tissue and the liposomal nanoparticles in the tumor. Then, given significant differences in magnetic properties of tissue and LNPs, the magnetic response of LNPs (i.e. MMUS signal) was utilized to suppress the unwanted PA signals from the background tissue and thus improves the PA imaging contrast. In this study, we demonstrated the 3D MPA image of LNP-labeled xenografted tumor in a live animal. Compared to conventional PA imaging, the MPA images show significantly enhanced contrast between the nanoparticle-labeled tumor and the background tissue. Our results suggest the feasibility of MPA for high contrast in vivo mapping of dual-contrast nanoparticles.

Multifunctional Surface-Enhanced Raman Spectroscopy-Detectable Silver Nanoparticles Combined Photodynamic Therapy and pH-Triggered Chemotherapy.

PubMed

Srinivasan, Supriya; Bhardwaj, Vinay; Nagasetti, Abhignyan; Fernandez-Fernandez, Alicia; McGoron, Anthony J

2016-12-01

This research paper reports the development of a multifunctional anti-cancer prodrug system based on silver nanoparticles. This prodrug system is composed of 70-nm sized nanoparticles and features photodynamic therapeutic properties and active, pH-triggered drug release. The silver nanoparticles are decorated with a folic acid (FA) targeting ligand via an amide bond, and also conjugated to the chemotherapeutic drug doxorubicin (DOX) via an acid-cleavable hydrazone bond. Both FA and DOX are attached to the silver nanoparticles through a polyethylene glycol (PEG) spacer. This prodrug system can preferentially enter cells that over-express folic acid receptors, with subsequent intracellular drug release triggered by reduced intracellular pH. Moreover, the silver nanoparticle carrier system exhibits photodynamic therapeutic (PDT) activity, so that the cell viability of cancer cells that overexpress folate receptors can be further reduced upon light irradiation. The dual effects of pH-triggered drug release and PDT increase the therapeutic efficacy of this system. The multifunctional nanoparticles can be probed intracellularly through Surface-Enhanced Raman Spectroscopy (SERS) and fluorescence spectroscopy. The current report explores the applicability of this multifunctional silver nanoparticle-based system for cancer theranostics.

Plasma treatment of paper for protein immobilization on paper-based chemiluminescence immunodevice.

PubMed

Zhao, Mei; Li, Huifang; Liu, Wei; Guo, Yumei; Chu, Weiru

2016-05-15

A novel protein immobilization method based on plasma treatment of paper on the low-cost paper-based immunodevice was established in this work. By using a benchtop plasma cleaner, the paper microzone was treated by oxygen plasma treatment for 4 min and then the antibody can be directly immobilized on the paper surface. Aldehyde group was produced after the plasma treatment, which can be verified from the fourier transform infrared spectroscopy (FT-IR) spectra and x-ray photoelectron spectroscopy (XPS) spectra. By linked to aldehyde group, the antibody can be immobilized on the paper surface without any other pretreatment. A paper-based immunodevice was introduced here through this antibody immobilization method. With sandwich chemiluminescence (CL) immunoassay method, the paper-based immunodevice was successfully performed for carcinoembryonic antigen (CEA) detection in human serum with a linear range of 0.1-80.0 ng/mL. The detection limit was 0.03 ng/mL, which was 30 times lower than the clinical CEA level. Comparing to the other protein immobilization methods on paper-based device, this strategy was faster and simpler and had potential applications in point-of-care testing, public health and environmental monitoring. Copyright © 2015 Elsevier B.V. All rights reserved.

Chemiluminescence of creatinine/H2O2/Co(2+) and its application for selective creatinine detection.

PubMed

Hanif, Saima; John, Peter; Gao, Wenyue; Saqib, Muhammad; Qi, Liming; Xu, Guobao

2016-01-15

Creatinine is an important biomarker in clinical diagnosis and biomonitoring programs as well as urinary metabolomic/metabonomics research. Current methods are either nonselective, time consuming or require heavy and expensive instruments. In this study, chemiluminescence of creatinine with hydrogen peroxide has been reported for the first time, and its chemiluminescence is remarkably enhanced in the presence of cobalt ions. By utilizing these phenomena, we have developed a sensitive and selective chemiluminescence method for creatinine determination by coupling with flow injection analysis. The calibration curve is linear in the range of 1×10(-7)-3×10(-5)mol/L with a limit of detection (S/N=3) of 7.2×10(-8)mol/L, which is adequate for detecting creatinine in the clinically accepted range. The relative standard deviation for seven measurements of 3×10(-5)mol/L creatinine is 1.2%. The chemiluminescence method was then utilized to detect creatinine in human urine samples after simple dilution with water. It takes less than 1min each measurement and the recoveries for spiked urine samples were 100-103%. The interference study demonstrates that some common species in urine, such as amino acids, ascorbic acid and creatine, have negligible effects on creatinine detection. The present method does not use expensive instruments, enzymes and separation technique. This method has the advantages of sensitivity, selectivity, simplicity, rapidity, and low cost. It holds great promise for basic or comprehensive metabolic panel, drug screening, anti-dopping, and urinary metabolomic/metabonomics research. Copyright © 2015 Elsevier B.V. All rights reserved.

Thiolated chitosan nanoparticles enhance anti-inflammatory effects of intranasally delivered theophylline

PubMed Central

Lee, Dong-Won; Shirley, Shawna A; Lockey, Richard F; Mohapatra, Shyam S

2006-01-01

Background Chitosan, a polymer derived from chitin, has been used for nasal drug delivery because of its biocompatibility, biodegradability and bioadhesiveness. Theophylline is a drug that reduces the inflammatory effects of allergic asthma but is difficult to administer at an appropriate dosage without causing adverse side effects. It was hypothesized that adsorption of theophylline to chitosan nanoparticles modified by the addition of thiol groups would improve theophylline absorption by the bronchial epithelium and enhance its anti-inflammatory effects. Objectives We sought to develop an improved drug-delivery matrix for theophylline based on thiolated chitosan, and to investigate whether thiolated chitosan nanoparticles (TCNs) can enhance theophylline's capacity to alleviate allergic asthma. Methods A mouse model of allergic asthma was used to test the effects of theophylline in vivo. BALB/c mice were sensitized to ovalbumin (OVA) and OVA-challenged to produce an inflammatory allergic condition. They were then treated intranasally with theophylline alone, chitosan nanoparticles alone or theophylline adsorbed to TCNs. The effects of theophylline on cellular infiltration in bronchoalveolar lavage (BAL) fluid, histopathology of lung sections, and apoptosis of lung cells were investigated to determine the effectiveness of TCNs as a drug-delivery vehicle for theophylline. Results Theophylline alone exerts a moderate anti-inflammatory effect, as evidenced by the decrease in eosinophils in BAL fluid, the reduction of bronchial damage, inhibition of mucus hypersecretion and increased apoptosis of lung cells. The effects of theophylline were significantly enhanced when the drug was delivered by TCNs. Conclusion Intranasal delivery of theophylline complexed with TCNs augmented the anti-inflammatory effects of the drug compared to theophylline administered alone in a mouse model of allergic asthma. The beneficial effects of theophylline in treating asthma may be enhanced

Thiolated chitosan nanoparticles enhance anti-inflammatory effects of intranasally delivered theophylline.

PubMed

Lee, Dong-Won; Shirley, Shawna A; Lockey, Richard F; Mohapatra, Shyam S

2006-08-24

Chitosan, a polymer derived from chitin, has been used for nasal drug delivery because of its biocompatibility, biodegradability and bioadhesiveness. Theophylline is a drug that reduces the inflammatory effects of allergic asthma but is difficult to administer at an appropriate dosage without causing adverse side effects. It was hypothesized that adsorption of theophylline to chitosan nanoparticles modified by the addition of thiol groups would improve theophylline absorption by the bronchial epithelium and enhance its anti-inflammatory effects. We sought to develop an improved drug-delivery matrix for theophylline based on thiolated chitosan, and to investigate whether thiolated chitosan nanoparticles (TCNs) can enhance theophylline's capacity to alleviate allergic asthma. A mouse model of allergic asthma was used to test the effects of theophylline in vivo. BALB/c mice were sensitized to ovalbumin (OVA) and OVA-challenged to produce an inflammatory allergic condition. They were then treated intranasally with theophylline alone, chitosan nanoparticles alone or theophylline adsorbed to TCNs. The effects of theophylline on cellular infiltration in bronchoalveolar lavage (BAL) fluid, histopathology of lung sections, and apoptosis of lung cells were investigated to determine the effectiveness of TCNs as a drug-delivery vehicle for theophylline. Theophylline alone exerts a moderate anti-inflammatory effect, as evidenced by the decrease in eosinophils in BAL fluid, the reduction of bronchial damage, inhibition of mucus hypersecretion and increased apoptosis of lung cells. The effects of theophylline were significantly enhanced when the drug was delivered by TCNs. Intranasal delivery of theophylline complexed with TCNs augmented the anti-inflammatory effects of the drug compared to theophylline administered alone in a mouse model of allergic asthma. The beneficial effects of theophylline in treating asthma may be enhanced through the use of this novel drug delivery

Templated assembly of albumin-based nanoparticles for simultaneous gene silencing and magnetic resonance imaging

NASA Astrophysics Data System (ADS)

Mertz, Damien; Affolter-Zbaraszczuk, Christine; Barthès, Julien; Cui, Jiwei; Caruso, Frank; Baumert, Thomas F.; Voegel, Jean-Claude; Ogier, Joelle; Meyer, Florent

2014-09-01

In this article, we address the design of innovative human serum albumin (HSA)-based nanoparticles loaded with silencing RNA and grafted with gadolinium complexes having average sizes ranging from ca. 50 to 150 nm according to the siRNA/HSA composition. The non-covalent siRNA/HSA assembly is formed on isobutyramide-modified mesoporous silica and the self-supported HSA-based nanoparticles are obtained following the silica template dissolution. These original protein particles provide simultaneous magnetic resonance imaging contrast enhancement and cellular in vitro gene silencing.In this article, we address the design of innovative human serum albumin (HSA)-based nanoparticles loaded with silencing RNA and grafted with gadolinium complexes having average sizes ranging from ca. 50 to 150 nm according to the siRNA/HSA composition. The non-covalent siRNA/HSA assembly is formed on isobutyramide-modified mesoporous silica and the self-supported HSA-based nanoparticles are obtained following the silica template dissolution. These original protein particles provide simultaneous magnetic resonance imaging contrast enhancement and cellular in vitro gene silencing. Electronic supplementary information (ESI) available: Experimental details and supporting Fig. S1-S4. See DOI: 10.1039/c4nr02623c

Ultrathin free-standing close-packed gold nanoparticle films: conductivity and Raman scattering enhancement.

PubMed

Yu, Qing; Huang, Hongwen; Peng, Xinsheng; Ye, Zhizhen

2011-09-01

A simple filtration technique was developed to prepare large scale free-standing close-packed gold nanoparticle ultrathin films using metal hydroxide nanostrands as both barrier layer and sacrificial layer. As thin as 70 nm, centimeter scale robust free-standing gold nanoparticle thin film was obtained. The thickness of the films could be easily tuned by the filtration volumes. The electronic conductivities of these films varied with the size of the gold nanoparticles, post-treatment temperature, and thickness, respectively. The conductivity of the film prepared from 20 nm gold nanoparticles is higher than that of the film prepared from 40 nm gold nanoparticle by filtering the same filtration volume of their solution, respectively. Their conductivities are comparable to that of the 220 nm thick ITO film. Furthermore, these films demonstrated an average surface Raman scattering enhancement up to 6.59 × 10(5) for Rhodamine 6 G molecules on the film prepared from 40 nm gold nanoparticles. Due to a lot of nano interspaces generated from the close-packed structures, two abnormal enhancements and relative stronger intensities of the asymmetrical vibrations at 1534 and 1594 cm(-1) of R6G were observed, respectively. These robust free-standing gold nanoparticle films could be easily transferred onto various solid substrates and hold the potential application for electrodes and surface enhanced Raman detectors. This method is applicable for preparation of other nanoparticle free-standing thin films.

A dual-targeting strategy for enhanced drug delivery and synergistic therapy based on thermosensitive nanoparticles.

PubMed

Wang, Mingxin; You, Chaoqun; Gao, Zhiguo; Wu, Hongshuai; Sun, Baiwang; Zhu, Xiaoli; Chen, Renjie

2018-08-01

The functionalized nanoparticles have been widely studied and reported as carriers of drug transport recently. Furthermore, many groups have focused more on developing novel and efficient treatment methods, such as photodynamic therapy and photothermal therapy, since both therapies have shown inspiring potential in the application of antitumor. The mentioned treatments exhibited the superiority of cooperative manner and showed the ability to compensate for the adverse effects caused by conventional monotherapy in proposed strategies. In view of the above descriptions, we formulated a thermosensitive drug delivery system, which achieved the enhanced delivery of cisplatin and two photosensitizers (ICG and Ce6) by dual-targeting traction. Drawing on the thin film hydration method, cisplatin and photosensitizers were encapsulated inside nanoparticles. Meanwhile, the targeting peptide cRGD and targeting molecule folate can be modified on the surface of nanoparticles to realize the active identification of tumor cells. The measurements of dynamic light scattering showed that the prepared nanoparticles had an ideal dispersibility and uniform particle size of 102.6 nm. On the basis of the results observed from confocal laser scanning microscope, the modified nanoparticles were more efficient endocytosed by MCF-7 cells as a contrast to SGC-7901 cells. Photothermal conversion-triggered drug release and photo-therapies produced a significant apoptosis rate of 85.9% on MCF-7 cells. The distinguished results made it believed that the formulated delivery system had conducted great efforts and innovations for the realization of concise collaboration and provided a promising strategy for the treatment of breast cancer.

Chitosan-based biocatalytic nanoparticles for pollutant removal from wastewater.

PubMed

Alarcón-Payán, Dulce A; Koyani, Rina D; Vazquez-Duhalt, Rafael

2017-05-01

Chitosan, a renewable biopolymer has the prospective applications in different fields due to its gelation capacity. Nanoconfiguration of chitosan through ionotropic gelation to encapsulate enzymatic activity offers numerous potential applications. In the present study, the preparation and characterization of chitosan nanoparticles loaded with versatile peroxidase are reported. Their performance in bioremediation process and the resistance enhancement against natural microbial biodegradation were studied. The average diameter of enzymatic nanoparticles was 120nm and showed a high enzyme loading capacity. The kinetic parameters of nanoparticles exhibited a slightly lower catalytic activity (k cat ), similar affinity constant (Km) for hydrogen peroxide and higher Km value for the phenolic compound when compared with the free enzyme. The enzymatic nanoparticles showed higher thermostability and the same pH activity profile than those from free enzyme. Ten phenolic compounds, including pesticides, halogenated compounds, endocrine disruptors and antibacterials were transformed by the enzymatic nanoparticles. The transformation rate was lower than those obtained with free enzyme suggesting mass transfer limitations. But very importantly, the enzymatic nanoparticles showed a significant increase of the operational stability in real conditions of wastewater treatment process. Moreover, chemical modification of nanoparticles with different aldehydes still enhanced the operational stability of nanoparticulated enzymes. This enhancement of stability in real conditions and the potential use of biocatalytic nanoparticles in bioremediation processes are discussed. Copyright © 2017 Elsevier Inc. All rights reserved.

Biocompatible and biodegradable nanoparticles for enhancement of anti-cancer activities of phytochemicals

PubMed Central

Chuan, Li; Jia, Zhang; Yu-Jiao, Zu; Shu-Fang, Nie; Jun, Cao; Qian, Wang; Shao-Ping, Nie; Ze-Yuan, Deng; Ming-Yong, Xie; Shu, Wang

2017-01-01

Many phytochemicals show promise in cancer prevention and treatment, but their low aqueous solubility, poor stability, unfavorable bioavailability, and low target specificity make administering them at therapeutic doses unrealistic. This is particularly true for (–)-epigallocatechin gallate, curcumin, quercetin, resveratrol, and genistein. There is an increasing interest in developing novel delivery strategies for these natural products. Liposomes, micelles, nanoemulsions, solid lipid nanoparticles, nanostructured lipid carriers and poly (lactide-co-glycolide) nanoparticles are biocompatible and biodegradable nanoparticles. Those nanoparticles can increase the stability and solubility of phytochemicals, exhibit a sustained release property, enhance their absorption and bioavailability, protect them from premature enzymatic degradation or metabolism, prolong their circulation time, improve their target specificity to cancer cells or tumors via passive or targeted delivery, lower toxicity or side-effects to normal cells or tissues through preventing them from prematurely interacting with the biological environment, and enhance anti-cancer activities. Nanotechnology opens a door for developing phytochemical-loaded nanoparticles for prevention and treatment of cancer. PMID:26412423

Diffusion of Sticky Nanoparticles in a Polymer Melt: Crossover from Suppressed to Enhanced Transport

DOE PAGES

Carroll, Bobby; Bocharova, Vera; Carrillo, Jan-Michael Y.; ...

2018-03-09

The self-diffusion of a single large particle in a fluid is usually described by the classic Stokes–Einstein (SE) hydrodynamic relation. However, there are many fluids where the SE prediction for nanoparticles diffusion fails. These systems include diffusion of nanoparticles in porous media, in entangled and unentangled polymer melts and solutions, and protein diffusion in biological environments. A fundamental understanding of the microscopic parameters that govern nanoparticle diffusion is relevant to a wide range of applications. Here in this work, we present experimental measurements of the tracer diffusion coefficient of small and large nanoparticles that experience strong attractions with unentangled andmore » entangled polymer melt matrices. For the small nanoparticle system, a crossover from suppressed to enhanced diffusion is observed with increasing polymer molecular weight. We interpret these observations based on our theoretical and simulation insights of the preceding article (paper 1) as a result of a crossover from an effective hydrodynamic core–shell to a nonhydrodynamic vehicle mechanism of transport, with the latter strongly dependent on polymer–nanoparticle desorption time. In conclusion, a general zeroth-order qualitative picture for small sticky nanoparticle diffusion in polymer melts is proposed.« less

Diffusion of Sticky Nanoparticles in a Polymer Melt: Crossover from Suppressed to Enhanced Transport

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carroll, Bobby; Bocharova, Vera; Carrillo, Jan-Michael Y.

The self-diffusion of a single large particle in a fluid is usually described by the classic Stokes–Einstein (SE) hydrodynamic relation. However, there are many fluids where the SE prediction for nanoparticles diffusion fails. These systems include diffusion of nanoparticles in porous media, in entangled and unentangled polymer melts and solutions, and protein diffusion in biological environments. A fundamental understanding of the microscopic parameters that govern nanoparticle diffusion is relevant to a wide range of applications. Here in this work, we present experimental measurements of the tracer diffusion coefficient of small and large nanoparticles that experience strong attractions with unentangled andmore » entangled polymer melt matrices. For the small nanoparticle system, a crossover from suppressed to enhanced diffusion is observed with increasing polymer molecular weight. We interpret these observations based on our theoretical and simulation insights of the preceding article (paper 1) as a result of a crossover from an effective hydrodynamic core–shell to a nonhydrodynamic vehicle mechanism of transport, with the latter strongly dependent on polymer–nanoparticle desorption time. In conclusion, a general zeroth-order qualitative picture for small sticky nanoparticle diffusion in polymer melts is proposed.« less

Degradable polyphosphoester-based silver-loaded nanoparticles as therapeutics for bacterial lung infections

NASA Astrophysics Data System (ADS)

Zhang, Fuwu; Smolen, Justin A.; Zhang, Shiyi; Li, Richen; Shah, Parth N.; Cho, Sangho; Wang, Hai; Raymond, Jeffery E.; Cannon, Carolyn L.; Wooley, Karen L.

2015-01-01

In this study, a new type of degradable polyphosphoester-based polymeric nanoparticle, capable of carrying silver cations via interactions with alkyne groups, has been developed as a potentially effective and safe treatment for lung infections. It was found that up to 15% (w/w) silver loading into the nanoparticles could be achieved, consuming most of the pendant alkyne groups along the backbone, as revealed by Raman spectroscopy. The well-defined Ag-loaded nanoparticles released silver in a controlled and sustained manner over 5 days, and displayed enhanced in vitro antibacterial activities against cystic fibrosis-associated pathogens and decreased cytotoxicity to human bronchial epithelial cells, in comparison to silver acetate.In this study, a new type of degradable polyphosphoester-based polymeric nanoparticle, capable of carrying silver cations via interactions with alkyne groups, has been developed as a potentially effective and safe treatment for lung infections. It was found that up to 15% (w/w) silver loading into the nanoparticles could be achieved, consuming most of the pendant alkyne groups along the backbone, as revealed by Raman spectroscopy. The well-defined Ag-loaded nanoparticles released silver in a controlled and sustained manner over 5 days, and displayed enhanced in vitro antibacterial activities against cystic fibrosis-associated pathogens and decreased cytotoxicity to human bronchial epithelial cells, in comparison to silver acetate. Electronic supplementary information (ESI) available: Materials, experimental details, and characterization. See DOI: 10.1039/c4nr07103d

Gadolinium-based nanoparticles to improve the hadrontherapy performances.

PubMed

Porcel, Erika; Tillement, Olivier; Lux, François; Mowat, Pierre; Usami, Noriko; Kobayashi, Katsumi; Furusawa, Yoshiya; Le Sech, Claude; Li, Sha; Lacombe, Sandrine

2014-11-01

Nanomedicine is proposed as a novel strategy to improve the performance of radiotherapy. High-Z nanoparticles are known to enhance the effects of ionizing radiation. Recently, multimodal nanoparticles such as gadolinium-based nanoagents were proposed to amplify the effects of x-rays and g-rays and to improve MRI diagnosis. For tumors sited in sensitive tissues, childhood cases and radioresistant cancers, hadrontherapy is considered superior to x-rays and g-rays. Hadrontherapy, based on fast ion radiation, has the advantage of avoiding damage to the tissues behind the tumor; however, the damage caused in front of the tumor is its major limitation. Here, we demonstrate that multimodal gadolinium-based nanoparticles amplify cell death with fast ions used as radiation. Molecular scale experiments give insights into the mechanisms underlying the amplification of radiation effects. This proof-of-concept opens up novel perspectives for multimodal nanomedicine in hadrontherapy, ultimately reducing negative radiation effects in healthy tissues in front of the tumor. Gadolinium-chelating polysiloxane nanoparticles were previously reported to amplify the anti-tumor effects of x-rays and g-rays and to serve as MRI contrast agents. Fast ion radiation-based hadrontherapy avoids damage to the tissues behind the tumor, with a major limitation of tissue damage in front of the tumor. This study demonstrates a potential role for the above nanoagents in optimizing hadrontherapy with preventive effects in healthy tissue and amplified cell death in the tumor. Copyright © 2014 Elsevier Inc. All rights reserved.

3D-printed and CNC milled flow-cells for chemiluminescence detection.

PubMed

Spilstead, Kara B; Learey, Jessica J; Doeven, Egan H; Barbante, Gregory J; Mohr, Stephan; Barnett, Neil W; Terry, Jessica M; Hall, Robynne M; Francis, Paul S

2014-08-01

Herein we explore modern fabrication techniques for the development of chemiluminescence detection flow-cells with features not attainable using the traditional coiled tubing approach. This includes the first 3D-printed chemiluminescence flow-cells, and a milled flow-cell designed to split the analyte stream into two separate detection zones within the same polymer chip. The flow-cells are compared to conventional detection systems using flow injection analysis (FIA) and high performance liquid chromatography (HPLC), with the fast chemiluminescence reactions of an acidic potassium permanganate reagent with morphine and a series of adrenergic phenolic amines. Copyright © 2014 Elsevier B.V. All rights reserved.

Design, Synthesis of Novel Lipids as Chemical Permeation Enhancers and Development of Nanoparticle System for Transdermal Drug Delivery

PubMed Central

Shah, Punit P.; Etukala, Jagan Reddy; Vemuri, Adithi; Singh, Mandip

2013-01-01

In the present study, we designed and developed novel lipids that include (Z)-1-(Octadec-9-en-1-yl)-pyrrolidine (Cy5T), 1, 1-Di-((Z)-octadec-9-en-1-yl)pyrrolidin-1-ium iodide (Cy5), (Z)-1-(Octadec-9-en-1-yl)-piperidine (Cy6T), and 1, 1-Di-((Z)-octadec-9-en-1-yl) piperidin-1-ium iodide (Cy6) to enhance the transdermal permeation of some selected drugs. Firstly, we evaluated the transdermal permeation efficacies of these lipids as chemical permeation enhancers in vehicle formulations for melatonin, ß-estradiol, caffeine, α-MSH, and spantide using franz diffusion cells. Among them Cy5 lipid was determined to be the most efficient by increasing the transdermal permeation of melatonin, ß-estradiol, caffeine, α-MSH, and spantide by 1.5 to 3.26-fold more at the epidermal layer and 1.3 to 2.5-fold more at the dermal layer, in comparison to either NMP or OA. Hence we developed a nanoparticle system (cy5 lipid ethanol drug nanoparticles) to evaluate any further improvement in the drug penetration. Cy5 lipid formed uniformly sized nanoparticles ranging from 150–200 nm depending on the type of drug. Further, Cy5 based nanoparticle system significantly (p<0.05) increased the permeation of all the drugs in comparison to the lipid solution and standard permeation enhancers. There were about 1.54 to 22-fold more of drug retained in the dermis for the Cy5 based nanoparticles compared to OA/NMP standard enhancers and 3.87 to 66.67-fold more than lipid solution. In addition, epifluorescent microscopic analysis in rhodamine-PE permeation studies confirmed the superior permeation enhancement of LEDs (detection of fluorescence up to skin depth of 340 μm) more than lipid solution, which revealed fluorescence up to skin depth of only 260 μm. In summary the present findings demonstrate that i) cationic lipid with 5 membered amine heterocyclic ring has higher permeating efficacy than the 6 membered amine hertocyclic ring. ii) The nanoparticle system prepared with Cy5 showed

Detection of neurotransmitters by a light scattering technique based on seed-mediated growth of gold nanoparticles

NASA Astrophysics Data System (ADS)

Shang, Li; Dong, Shaojun

2008-03-01

A simple light scattering detection method for neurotransmitters has been developed, based on the growth of gold nanoparticles. Neurotransmitters (dopamine, L-dopa, noradrenaline and adrenaline) can effectively function as active reducing agents for generating gold nanoparticles, which result in enhanced light scattering signals. The strong light scattering of gold nanoparticles then allows the quantitative detection of the neurotransmitters simply by using a common spectrofluorometer. In particular, Au-nanoparticle seeds were added to facilitate the growth of nanoparticles, which was found to enhance the sensing performance greatly. Using this light scattering technique based on the seed-mediated growth of gold nanoparticles, detection limits of 4.4 × 10-7 M, 3.5 × 10-7 M, 4.1 × 10-7 M, and 7.7 × 10-7 M were achieved for dopamine, L-dopa, noradrenaline and adrenaline, respectively. The present strategy can be extended to detect other biologically important molecules in a very fast, simple and sensitive way, and may have potential applications in a wide range of fields.

Sulfate-based anionic diblock copolymer nanoparticles for efficient occlusion within zinc oxide

NASA Astrophysics Data System (ADS)

Ning, Y.; Fielding, L. A.; Andrews, T. S.; Growney, D. J.; Armes, S. P.

2015-04-01

Occlusion of copolymer particles within inorganic crystalline hosts not only provides a model for understanding the crystallisation process, but also may offer a direct route for the preparation of novel nanocomposite materials with emergent properties. In the present paper, a series of new well-defined anionic diblock copolymer nanoparticles are synthesised by polymerisation-induced self-assembly (PISA) via reversible addition-fragmentation chain transfer (RAFT) aqueous emulsion polymerisation and then evaluated as crystal habit modifiers for the in situ formation of ZnO in aqueous solution. Systematic studies indicate that both the chemical nature (i.e. whether sulfate-based or carboxylate-based) and the mean degree of polymerisation (DP) of the anionic stabiliser block play vital roles in determining the crystal morphology. In particular, sulfate-functionalised nanoparticles are efficiently incorporated within the ZnO crystals whereas carboxylate-functionalised nanoparticles are excluded, thus anionic character is a necessary but not sufficient condition for successful occlusion. Moreover, the extent of nanoparticle occlusion within the ZnO phase can be as high as 23% by mass depending on the sulfate-based nanoparticle concentration. The optical properties, chemical composition and crystal structure of the resulting nanocomposite crystals are evaluated and an occlusion mechanism is proposed based on the observed evolution of the ZnO morphology in the presence of sulfate-based anionic nanoparticles. Finally, controlled deposition of a 5 nm gold sol onto porous ZnO particles (produced after calcination of the organic nanoparticles) significantly enhances the rate of photocatalytic decomposition of a model rhodamine B dye on exposure to a relatively weak UV source.Occlusion of copolymer particles within inorganic crystalline hosts not only provides a model for understanding the crystallisation process, but also may offer a direct route for the preparation of novel

Plasmon-Enhanced Photocleaving Dynamics in Colloidal MicroRNA-Functionalized Silver Nanoparticles Monitored with Second Harmonic Generation.

PubMed

Kumal, Raju R; Abu-Laban, Mohammad; Landry, Corey R; Kruger, Blake; Zhang, Zhenyu; Hayes, Daniel J; Haber, Louis H

2016-10-11

The photocleaving dynamics of colloidal microRNA-functionalized nanoparticles are studied using time-dependent second harmonic generation (SHG) measurements. Model drug-delivery systems composed of oligonucleotides attached to either silver nanoparticles or polystyrene nanoparticles using a nitrobenzyl photocleavable linker are prepared and characterized. The photoactivated controlled release is observed to be most efficient on resonance at 365 nm irradiation, with pseudo-first-order rate constants that are linearly proportional to irradiation powers. Additionally, silver nanoparticles show a 6-fold plasmon enhancement in photocleaving efficiency over corresponding polystyrene nanoparticle rates, while our previous measurements on gold nanoparticles show a 2-fold plasmon enhancement compared to polystyrene nanoparticles. Characterizations including extinction spectroscopy, electrophoretic mobility, and fluorimetry measurements confirm the analysis from the SHG results. The real-time SHG measurements are shown to be a highly sensitive method for investigating plasmon-enhanced photocleaving dynamics in model drug delivery systems.

Hydrazine-induced post-chemiluminescence phenomenon of permanganate-luminol reaction and its applications.

PubMed

Du, Jianxiu; Lu, Jiuru

2004-01-01

The post-chemiluminescence phenomenon arising from the permanganate-luminol reaction induced by hydrazine and isoniazid was investigated. When hydrazine or isoniazid was injected into the mixture after the end of the reaction of permanganate with alkaline luminol, a new chemiluminescence (CL) reaction was initiated and strong CL signal was detected. A possible CL mechanism is suggested, based upon the studies of the kinetic characteristics of the CL reaction, the UV-visible spectra, the CL spectra and some other experiments. The present reactions allow the determination of 0.1-10.0 mg/L hydrazine and 0.02-1.0 mg/L isoniazid, with detection limits of 0.03 mg/L and 0.006 mg/L, respectively. The method was applied to the determination of isoniazid in pharmaceutical preparations.

Chemiluminescence Study of the Autoxidation of cis-1,4-Polyisoprene

NASA Technical Reports Server (NTRS)

Mendenhall, G. David; Nathan, Richard A.; Golub, Morton A.

1978-01-01

The free-radical mechanism for the autoxidation of cis-1,4-polyisoprene (natural rubber or its synthetic counterpart) has been investigated extensively. An important feature of this mechanism, and indeed also of the autoxidation of hydrocarbons generally, is that it is a chain process propagated by alkyl and peroxy radicals and terminated through bimolecular reactions involving these same radicals. In the usual oxidation situation, that is, at all oxygen pressures greater than a few torr, the alkyl radicals are rapidly converted to peroxy radicals, and the termination step proceeds almost exclusively through the latter radicals. The bimolecular decay of the peroxy radicals is accompanied by a weak emission of light or chemiluminescence. Kinetic evidence is consistent with an electronically excited ketone produced in the termination reaction as the source of the emission. The first observation of chemiluminescence from the oxidative degradation of polymers was reported by Ashby, who dealt mainly with polypropylene but made passing mention of several other polymers. Subsequently, a number of papers have appeared dealing with oxidative chemiluminescence from a variety of polymers. In this paper we report the first detailed study of the chemiluminescence emitted in the autoxidation of cis-1,4-polyisoprene. The chemiluminescence technique is extremely sensitive and can follow rates of oxidation that are too slow to be measured conveniently by other means. This work thus offered the potential of throwing new light on the autoxidation of cis-1,4-polyisoprene, especially in the very early stages or under ambient conditions where conventional spectroscopic procedures are rather insensitive.

Atorvastatin calcium encapsulated eudragit nanoparticles with enhanced oral bioavailability, safety and efficacy profile.

PubMed

Kumar, Nagendra; Chaurasia, Sundeep; Patel, Ravi R; Khan, Gayasuddin; Kumar, Vikas; Mishra, Brahmeshwar

2017-03-01

Atorvastatin calcium (ATR), a second generation statin drug, was encapsulated in eudragit RSPO-based polymeric nanoparticles. The effect of independent variables (polymer content, stabilizer concentration, volume of chloroform and homogenization speed) on response variables (mean diameter particle size and entrapment efficiency) were investigated by employing central composite experimental design. All the independent variables were found to be significant for determining the response variables. Solid-state characterization study indicated the absence of physicochemical interaction between drug and polymer in formulation. Morphological study exhibited homogenous spherical shape of formulated nanoparticles. In vitro release study in phosphate buffer (pH 7.4) demonstrated sustained release profile over 24 h. Pharmacokinetic study in Charles Foster rats showed significant enhancement in oral bioavailability as compared to pure drug suspension. Efficacy study (lipid profile and blood glucose level) significantly justified the effectiveness of formulation having 50% less dose of ATR as compared to pure drug suspension. The effectiveness of formulation was further justified with an improved plasma safety profile of treated rats. Hence, ATR encapsulated eudragit RSPO nanoparticles can serve as potential drug delivery approach to enhance drug bioavailability, efficacy and safety profiles to alter existing marketed drug products.

Determination of sulpiride in pharmaceutical preparations and biological fluids using a Cr (III) enhanced chemiluminescence method.

PubMed

Khan, Muhammad Naeem; Jan, Muhammad Rasul; Shah, Jasmin; Lee, Sang Hak; Kim, Young Ho

2013-01-01

A highly sensitive and simple method for identifying sulpiride in pharmaceutical formulations and biological fluids is presented. The method is based on increased chemiluminescence (CL) intensity of a luminol-H2O2 system in response to the addition of Cr (III) under alkaline conditions. The CL intensity of the luminol-H2O2-Cr (III) system was greatly enhanced by the addition of sulpiride and the CL intensity was proportional to the concentration of sulpiride in a sample solution. Various parameters affecting the CL intensity were systematically investigated and optimized for determination of the sulpiride in a sample. Under the optimum conditions, the CL intensity was proportional to the concentration of sulpiride in the range of 0.068-4.0 µg/mL, with a good correlation coefficient of 0.997. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 8.50 × 10(-6) µg/mL and 2.83 × 10(-5) µg/mL, respectively. The method presented here produced good reproducibility with a relative standard deviation (RSD) of 2.70% (n = 7). The effects of common excipients and metal ions were studied for their interference effect. The method was validated statistically through recovery studies and successfully applied for the determination of sulpiride in pure form, pharmaceutical preparations and spiked human plasma samples. The percentage recoveries were found to range from 99.10 to 100.05% for pure form, 98.12 to 100.18% for pharmaceutical preparations and 97.9 to 101.4% for spiked human plasma. Copyright © 2012 John Wiley & Sons, Ltd.

The effect of nanoparticle surfactant polarization on trapping depth of vegetable insulating oil-based nanofluids

NASA Astrophysics Data System (ADS)

Li, Jian; Du, Bin; Wang, Feipeng; Yao, Wei; Yao, Shuhan

2016-02-01

Nanoparticles can generate charge carrier trapping and reduce the velocity of streamer development in insulating oils ultimately leading to an enhancement of the breakdown voltage of insulating oils. Vegetable insulating oil-based nanofluids with three sizes of monodispersed Fe3O4 nanoparticles were prepared and their trapping depths were measured by thermally stimulated method (TSC). It is found that the nanoparticle surfactant polarization can significantly influence the trapping depth of vegetable insulating oil-based nanofluids. A nanoparticle polarization model considering surfactant polarization was proposed to calculate the trapping depth of the nanofluids at different nanoparticle sizes and surfactant thicknesses. The results show the calculated values of the model are in a fairly good agreement with the experimental values.

Design of ligand-targeted nanoparticles for enhanced cancer targeting

NASA Astrophysics Data System (ADS)

Stefanick, Jared F.

Ligand-targeted nanoparticles are increasingly used as drug delivery vehicles for cancer therapy, yet have not consistently produced successful clinical outcomes. Although these inconsistencies may arise from differences in disease models and target receptors, nanoparticle design parameters can significantly influence therapeutic efficacy. By employing a multifaceted synthetic strategy to prepare peptide-targeted nanoparticles with high purity, reproducibility, and precisely controlled stoichiometry of functionalities, this work evaluates the roles of polyethylene glycol (PEG) coating, ethylene glycol (EG) peptide-linker length, peptide hydrophilicity, peptide density, and nanoparticle size on tumor targeting in a systematic manner. These parameters were analyzed in multiple disease models by targeting human epidermal growth factor receptor 2 (HER2) in breast cancer and very late antigen-4 (VLA-4) in multiple myeloma to demonstrate the widespread applicability of this approach. By increasing the hydrophilicity of the targeting peptide sequence and simultaneously optimizing the EG peptide-linker length, the in vitro cellular uptake of targeted liposomes was significantly enhanced. Specifically, including a short oligolysine chain adjacent to the targeting peptide sequence effectively increased cellular uptake ~80-fold using an EG6 peptide-linker compared to ~10-fold using an EG45 linker. In vivo, targeted liposomes prepared in a traditional manner lacking the oligolysine chain demonstrated similar biodistribution and tumor uptake to non-targeted liposomes. However, by including the oligolysine chain, targeted liposomes using an EG45 linker significantly improved tumor uptake ~8-fold over non-targeted liposomes, while the use of an EG6 linker decreased tumor accumulation and uptake, owing to differences in cellular uptake kinetics, clearance mechanisms, and binding site barrier effects. To further improve tumor targeting and enhance the selectivity of targeted

Gold nanoparticle dimer plasmonics: finite element method calculations of the electromagnetic enhancement to surface-enhanced Raman spectroscopy.

PubMed

McMahon, Jeffrey M; Henry, Anne-Isabelle; Wustholz, Kristin L; Natan, Michael J; Freeman, R Griffith; Van Duyne, Richard P; Schatz, George C

2009-08-01

Finite element method calculations were carried out to determine extinction spectra and the electromagnetic (EM) contributions to surface-enhanced Raman spectroscopy (SERS) for 90-nm Au nanoparticle dimers modeled after experimental nanotags. The calculations revealed that the EM properties depend significantly on the junction region, specifically the distance between the nanoparticles for spacings of less than 1 nm. For extinction spectra, spacings below 1 nm lead to maxima that are strongly red-shifted from the 600-nm plasmon maximum associated with an isolated nanoparticle. This result agrees qualitatively well with experimental transmission electron microscopy images and localized surface plasmon resonance spectra that are also presented. The calculations further revealed that spacings below 0.5 nm, and especially a slight fusing of the nanoparticles to give tiny crevices, leads to EM enhancements of 10(10) or greater. Assuming a uniform coating of SERS molecules around both nanoparticles, we determined that regardless of the separation, the highest EM fields always dominate the SERS signal. In addition, we determined that for small separations less than 3% of the molecules always contribute to greater than 90% of the signal.

Surface-enhanced Raman scattering on tunable plasmonic nanoparticle substrates

PubMed Central

Jackson, J. B.; Halas, N. J.

2004-01-01

Au and Ag nanoshells are investigated as substrates for surface-enhanced Raman scattering (SERS). We find that SERS enhancements on nanoshell films are dramatically different from those observed on colloidal aggregates, specifically that the Raman enhancement follows the plasmon resonance of the individual nanoparticles. Comparative finite difference time domain calculations of fields at the surface of smooth and roughened nanoshells reveal that surface roughness contributes only slightly to the total enhancement. SERS enhancements as large as 2.5 × 1010 on Ag nanoshell films for the nonresonant molecule p-mercaptoaniline are measured. PMID:15608058

Flow injection chemiluminescence determination of naphazoline hydrochloride in pharmaceuticals.

PubMed

Iranifam, Mortaza; Sorouraddin, Mohammad H

2014-02-01

A simple and sensitive flow injection chemiluminescence (FI-CL) method was developed for the determination of naphazoline hydrochloride (NPZ). The method is based on the enhancing effect of NPZ on the weak CL signal from the reaction of KIO4 with H2 O2 . Experimental parameters that affected the CL signal, including the pH of the KIO4 solution, concentrations of KIO4 , H2 O2 and disodium-EDTA and flow rate were optimized. Under the optimum conditions, the increment of CL intensity was linearly proportional to the concentration of NPZ in the range 5.0 × 10(-6) to 70 × 10(-6) mol/L. The detection limit was 1.0 × 10(-6) mol/L and the relative standard deviation for 50 × 10(-6) mol/L NPZ solution was 2.8% (n = 11). In addition, a high throughput of 120 samples/h was achieved. The utility of this method was demonstrated by determining NPZ in pharmaceuticals. Copyright © 2013 John Wiley & Sons, Ltd.

A novel polydopamine-based chemiluminescence resonance energy transfer method for microRNA detection coupling duplex-specific nuclease-aided target recycling strategy.

PubMed

Wang, Qian; Yin, Bin-Cheng; Ye, Bang-Ce

2016-06-15

MicroRNAs (miRNAs), functioning as oncogenes or tumor suppressors, play significant regulatory roles in regulating gene expression and become as biomarkers for disease diagnostics and therapeutics. In this work, we have coupled a polydopamine (PDA) nanosphere-assisted chemiluminescence resonance energy transfer (CRET) platform and a duplex-specific nuclease (DSN)-assisted signal amplification strategy to develop a novel method for specific miRNA detection. With the assistance of hemin, luminol, and H2O2, the horseradish peroxidase (HRP)-mimicking G-rich sequence in the sensing probe produces chemiluminescence, which is quickly quenched by the CRET effect between PDA as energy acceptor and excited luminol as energy donor. The target miRNA triggers DSN to partially degrade the sensing probe in the DNA-miRNA heteroduplex to repeatedly release G-quadruplex formed by G-rich sequence from PDA for the production of chemiluminescence. The method allows quantitative detection of target miRNA in the range of 80 pM-50 nM with a detection limit of 49.6 pM. The method also shows excellent specificity to discriminate single-base differences, and can accurately quantify miRNA in biological samples, with good agreement with the result from a commercial miRNA detection kit. The procedure requires no organic dyes or labels, and is a simple and cost-effective method for miRNA detection for early clinical diagnosis. Copyright © 2016 Elsevier B.V. All rights reserved.

Biological water quality monitoring using chemiluminescent and bioluminescent techniques

NASA Technical Reports Server (NTRS)

Thomas, R. R.

1978-01-01

Automated chemiluminescence and bioluminescence sensors were developed for the continuous monitoring of microbial levels in water supplies. The optimal chemical procedures were determined for the chemiluminescence system to achieve maximum sensitivity. By using hydrogen peroxide, reaction rate differentiation, ethylene diamine tetraacetic acid (EDTA), and carbon monoxide pretreatments, factors which cause interference were eliminated and specificity of the reaction for living and dead bacteria was greatly increased. By employing existing technology with some modifications, a sensitive and specific bioluminescent system was developed.

Efficient Surface Enhanced Raman Scattering substrates from femtosecond laser based fabrication

NASA Astrophysics Data System (ADS)

Parmar, Vinod; Kanaujia, Pawan K.; Bommali, Ravi Kumar; Vijaya Prakash, G.

2017-10-01

A fast and simple femtosecond laser based methodology for efficient Surface Enhanced Raman Scattering (SERS) substrate fabrication has been proposed. Both nano scaffold silicon (black silicon) and gold nanoparticles (Au-NP) are fabricated by femtosecond laser based technique for mass production. Nano rough silicon scaffold enables large electromagnetic fields for the localized surface plasmons from decorated metallic nanoparticles. Thus giant enhancement (approximately in the order of 104) of Raman signal arises from the mixed effects of electron-photon-phonon coupling, even at nanomolar concentrations of test organic species (Rhodamine 6G). Proposed process demonstrates the low-cost and label-less application ability from these large-area SERS substrates.

Multifunctional superparamagnetic nanoparticles for enhanced drug transport in cystic fibrosis

NASA Astrophysics Data System (ADS)

Armijo, Leisha M.; Brandt, Yekaterina I.; Rivera, Antonio C.; Cook, Nathaniel C.; Plumley, John B.; Withers, Nathan J.; Kopciuch, Michael; Smolyakov, Gennady A.; Huber, Dale L.; Smyth, Hugh D.; Osinski, Marek

2012-10-01

Iron oxide colloidal nanoparticles (ferrofluids) are investigated for application in the treatment of cystic fibrosis lung infections, the leading cause of mortality in cystic fibrosis patients. We investigate the use of iron oxide nanoparticles to increase the effectiveness of administering antibiotics through aerosol inhalation using two mechanisms: directed particle movement in the presence of an inhomogeneous static external magnetic field and magnetic hyperthermia. Magnetic hyperthermia is an effective method for decreasing the viscosity of the mucus and biofilm, thereby enhancing drug, immune cell, and antibody penetration to the affected area. Iron oxide nanoparticles of various sizes and morphologies were synthesized and tested for specific losses (heating power). Nanoparticles in the superparamagnetic to ferromagnetic size range exhibited excellent heating power. Additionally, iron oxide / zinc selenide core/shell nanoparticles were prepared, in order to enable imaging of the iron oxide nanoparticles. We also report on synthesis and characterization of MnSe/ZnSeS alloyed quantum dots.

Theoretical investigation on the magnetization enhancement of Fe3O4-reduced graphene oxide nanoparticle system

NASA Astrophysics Data System (ADS)

Majidi, M. A.; Wicaksono, Y.; Fauzi, A. D.; Taufik, A.; Saleh, R.; Rusydi, A.

2017-04-01

We present a theoretical study on the enhancement of magnetization of Fe3O4 nanoparticle system upon addition of reduced graphene oxide (rGO). Experimental data have shown that the magnetization of Fe3O4-rGO nanoparticle system increases with increasing rGO content up to about 5 wt%, but decreases back as the rGO content increases further. We propose that the enhancement is due to spin-flipping of Fe ions at the tetrahedral sites assisted by oxygen vacancies at the Fe3O4 particle boundaries. These oxygen vacancies are induced by the presence of rGO flakes that adsorb oxygen atoms from Fe3O4 particles around them. To understand the enhancement of the magnetization, we construct a tight-binding based model Hamiltonian for the Fe3O4 nanoparticle system with the concentration of oxygen vacancies being controlled by the rGO content. We calculate the magnetization as a function of the applied magnetic field for various values of rGO wt%. We use the method of dynamical mean-field theory and perform the calculations for a room temperature. Our result for rGO wt% dependence of the saturated magnetization shows a very good agreement with the existing experimental data of the Fe3O4-rGO nanoparticle system. This result may confirm that our model already carries the most essential idea needed to explain the above phenomenon of magnetization enhancement.

Diagnostic potential for gold nanoparticle-based surface-enhanced Raman spectroscopy to provide colorectal cancer screening using blood serum sample

NASA Astrophysics Data System (ADS)

Lin, Duo; Feng, Shangyuan; Pan, Jianji; Chen, Yanping; Lin, Juqiang; Sun, Liqing; Chen, Rong

2011-11-01

Surface-enhanced Raman spectroscopy (SERS) is a vibrational spectroscopic technique that is capable of probing the biomolecular changes associated with diseased transformation. The objective of our study was to explore gold nanoparticle based SERS to obtain blood serum biochemical information for non-invasive colorectal cancer detection. SERS measurements were performed on two groups of blood serum samples: one group from patients (n = 38) with pathologically confirmed colorectal cancer and the other group from healthy volunteers (control subjects, n = 45). Tentative assignments of the Raman bands in the measured SERS spectra suggested interesting cancer specific biomolecular changes, including an increase in the relative amounts of nucleic acid, a decrease in the percentage of saccharide and proteins contents in the blood serum of colorectal cancer patients as compared to that of healthy subjects. Principal component analysis (PCA) of the measured SERS spectra separated the spectral features of the two groups into two distinct clusters with little overlaps. Linear discriminate analysis (LDA) based on the PCA generated features differentiated the nasopharyngeal cancer SERS spectra from normal SERS spectra with high sensitivity (97.4%) and specificity (100%). The results from this exploratory study demonstrated that gold nanoparticle based SERS serum analysis combined with PCA-LDA has tremendous potential for the non-invasive detection of colorectal cancers.

Diagnostic potential for gold nanoparticle-based surface-enhanced Raman spectroscopy to provide colorectal cancer screening using blood serum sample

NASA Astrophysics Data System (ADS)

Lin, Duo; Feng, Shangyuan; Pan, Jianji; Chen, Yanping; Lin, Juqiang; Sun, Liqing; Chen, Rong

2012-03-01

Surface-enhanced Raman spectroscopy (SERS) is a vibrational spectroscopic technique that is capable of probing the biomolecular changes associated with diseased transformation. The objective of our study was to explore gold nanoparticle based SERS to obtain blood serum biochemical information for non-invasive colorectal cancer detection. SERS measurements were performed on two groups of blood serum samples: one group from patients (n = 38) with pathologically confirmed colorectal cancer and the other group from healthy volunteers (control subjects, n = 45). Tentative assignments of the Raman bands in the measured SERS spectra suggested interesting cancer specific biomolecular changes, including an increase in the relative amounts of nucleic acid, a decrease in the percentage of saccharide and proteins contents in the blood serum of colorectal cancer patients as compared to that of healthy subjects. Principal component analysis (PCA) of the measured SERS spectra separated the spectral features of the two groups into two distinct clusters with little overlaps. Linear discriminate analysis (LDA) based on the PCA generated features differentiated the nasopharyngeal cancer SERS spectra from normal SERS spectra with high sensitivity (97.4%) and specificity (100%). The results from this exploratory study demonstrated that gold nanoparticle based SERS serum analysis combined with PCA-LDA has tremendous potential for the non-invasive detection of colorectal cancers.

Enhanced and Extended Anti-Hypertensive Effect of VP5 Nanoparticles

PubMed Central

Yu, Ting; Zhao, Shengnan; Li, Ziqiang; Wang, Yi; Xu, Bei; Fang, Dailong; Wang, Fazhan; Zhang, Zhi; He, Lili; Song, Xiangrong; Yang, Jian

2016-01-01

Hypertension has become a significant global public health concern and is also one of the most common risk factors of cardiovascular disease. Recent studies have shown the promising result of peptides inhibiting angiotensin converting enzyme (ACE) in lowering the blood pressure in both animal models and humans. However, the oral bioavailability and continuous antihypertensive effectiveness require further optimization. Novel nanoparticle-based drug delivery systems are helpful to overcome these barriers. Therefore, a poly-(lactic-co-glycolic) acid nanoparticle (PLGANPs) oral delivery system, of the antihypertensive small peptides Val-Leu-Pro-Val-Pro (VLPVP, VP5) model, was developed in this study and its antihypertensive effect was investigated in spontaneously hypertensive rats (SHRs) for the first time. The obtained VP5 nanoparticles (VP5-NPs) showed a small particle size of 223.7 ± 2.3 nm and high entrapment efficiency (EE%) of 87.37% ± 0.92%. Transmission electronic microscopy (TEM) analysis showed that the nanoparticles were spherical and homogeneous. The optimal preparation of VP5-NPs exhibited sustained release of VP5 in vitro and a 96 h long-term antihypertensive effect with enhanced efficacy in vivo. This study illustrated that PLGANPs might be an optimal formulation for oral delivery of antihypertensive small peptides and VP5-NPs might be worthy of further development and use as a potential therapeutic strategy for hypertension in the future. PMID:27898022

Enhanced peroxidase activity and tumour tissue visualization by cobalt-doped magnetoferritin nanoparticles

NASA Astrophysics Data System (ADS)

Zhang, Tongwei; Cao, Changqian; Tang, Xu; Cai, Yao; Yang, Caiyun; Pan, Yongxin

2017-01-01

Magnetoferritin (M-HFn) is a biomimetic magnetic nanoparticle with a human heavy-chain ferritin (HFn) shell, trapping a magnetite (Fe3O4) core that has inherited peroxidase-like activity. In this study, cobalt-doped M-HFn nanoparticles (M-HFn-Co x Fe3-x O4) with different amounts of cobalt were successfully synthesized. Experimental results indicate that the controlled doping of a certain amount of cobalt into the magnetite cores of M-HFn nanoparticles enhances its peroxidase-like catalytic activity and efficacy for visualizing tumour tissues. For example, compared with sample Co0 (without cobalt doping), the peroxidase-like activity of the cobalt-doped nanoparticle sample Co60 (with a cobalt doping molar percentage of ˜34.2%) increases 1.7 times, and has the maximal reaction velocity (V max) values. Moreover, after a one-step incubation with Co60 nanoparticles, and using the peroxidase substrate 3,3‧-diaminobenzidine tetrahydrochloride (DAB) for colour development, the tumour tissues of breast, colorectal, stomach and pancreas tumours showed a deeper brown colour with clear boundaries between the healthy and tumourous cells. Therefore, this suggests that the cobalt-doped magnetoferritin nanoparticles enhance peroxidase activity and tumour tissue visualization.

Enhanced peroxidase activity and tumour tissue visualization by cobalt-doped magnetoferritin nanoparticles.

PubMed

Zhang, Tongwei; Cao, Changqian; Tang, Xu; Cai, Yao; Yang, Caiyun; Pan, Yongxin

2017-01-27

Magnetoferritin (M-HFn) is a biomimetic magnetic nanoparticle with a human heavy-chain ferritin (HFn) shell, trapping a magnetite (Fe 3 O 4 ) core that has inherited peroxidase-like activity. In this study, cobalt-doped M-HFn nanoparticles (M-HFn-Co x Fe 3-x O 4 ) with different amounts of cobalt were successfully synthesized. Experimental results indicate that the controlled doping of a certain amount of cobalt into the magnetite cores of M-HFn nanoparticles enhances its peroxidase-like catalytic activity and efficacy for visualizing tumour tissues. For example, compared with sample Co0 (without cobalt doping), the peroxidase-like activity of the cobalt-doped nanoparticle sample Co60 (with a cobalt doping molar percentage of ∼34.2%) increases 1.7 times, and has the maximal reaction velocity (V max ) values. Moreover, after a one-step incubation with Co60 nanoparticles, and using the peroxidase substrate 3,3'-diaminobenzidine tetrahydrochloride (DAB) for colour development, the tumour tissues of breast, colorectal, stomach and pancreas tumours showed a deeper brown colour with clear boundaries between the healthy and tumourous cells. Therefore, this suggests that the cobalt-doped magnetoferritin nanoparticles enhance peroxidase activity and tumour tissue visualization.

Novel Polysaccharide Based Polymers and Nanoparticles for Controlled Drug Delivery and Biomedical Imaging

NASA Astrophysics Data System (ADS)

Shalviri, Alireza

The use of polysaccharides as building blocks in the development of drugs and contrast agents delivery systems is rapidly growing. This can be attributed to the outstanding virtues of polysaccharides such as biocompatibility, biodegradability, upgradability, multiple reacting groups and low cost. The focus of this thesis was to develop and characterize novel starch based hydrogels and nanoparticles for delivery of drugs and imaging agents. To this end, two different systems were developed. The first system includes polymer and nanoparticles prepared by graft polymerization of polymethacrylic acid and polysorbate 80 onto starch. This starch based platform nanotechnology was developed using the design principles based on the pathophysiology of breast cancer, with applications in both medical imaging and breast cancer chemotherapy. The nanoparticles exhibited a high degree of doxorubicin loading as well as sustained pH dependent release of the drug. The drug loaded nanoparticles were significantly more effective against multidrug resistant human breast cancer cells compared to free doxorubicin. Systemic administration of the starch based nanoparticles co-loaded with doxorubicin and a near infrared fluorescent probe allowed for non-invasive real time monitoring of the nanoparticles biodistribution, tumor accumulation, and clearance. Systemic administration of the clinically relevant doses of the drug loaded particles to a mouse model of breast cancer significantly enhanced therapeutic efficacy while minimizing side effects compared to free doxorubicin. A novel, starch based magnetic resonance imaging (MRI) contrast agent with good in vitro and in vivo tolerability was formulated which exhibited superior signal enhancement in tumor and vasculature. The second system is a co-polymeric hydrogel of starch and xanthan gum with adjustable swelling and permeation properties. The hydrogels exhibited excellent film forming capability, and appeared to be particularly useful in

61Ni synchrotron radiation-based Mössbauer spectroscopy of nickel-based nanoparticles with hexagonal structure

PubMed Central

Masuda, Ryo; Kobayashi, Yasuhiro; Kitao, Shinji; Kurokuzu, Masayuki; Saito, Makina; Yoda, Yoshitaka; Mitsui, Takaya; Hosoi, Kohei; Kobayashi, Hirokazu; Kitagawa, Hiroshi; Seto, Makoto

2016-01-01

We measured the synchrotron-radiation (SR)-based Mössbauer spectra of Ni-based nanoparticles with a hexagonal structure that were synthesised by chemical reduction. To obtain Mössbauer spectra of the nanoparticles without 61Ni enrichment, we developed a measurement system for 61Ni SR-based Mössbauer absorption spectroscopy without X-ray windows between the 61Ni84V16 standard energy alloy and detector. The counting rate of the 61Ni nuclear resonant scattering in the system was enhanced by the detection of internal conversion electrons and the close proximity between the energy standard and the detector. The spectrum measured at 4 K revealed the internal magnetic field of the nanoparticles was 3.4 ± 0.9 T, corresponding to a Ni atomic magnetic moment of 0.3 Bohr magneton. This differs from the value of Ni3C and the theoretically predicted value of hexagonal-close-packed (hcp)-Ni and suggested the nanoparticle possessed intermediate carbon content between hcp-Ni and Ni3C of approximately 10 atomic % of Ni. The improved 61Ni Mössbauer absorption measurement system is also applicable to various Ni materials without 61Ni enrichment, such as Ni hydride nanoparticles. PMID:26883185

Enhanced Cellular Internalization: A Bactericidal Mechanism More Relative to Biogenic Nanoparticles than Chemical Counterparts.

PubMed

Kumari, Madhuree; Shukla, Shatrunajay; Pandey, Shipra; Giri, Ved P; Bhatia, Anil; Tripathi, Tusha; Kakkar, Poonam; Nautiyal, Chandra S; Mishra, Aradhana

2017-02-08

Biogenic synthesis of silver nanoparticles for enhanced antimicrobial activity has gained a lot of momentum making it an urgent need to search for a suitable biocandidate which could be utilized for efficient capping and shaping of silver nanoparticles with enhanced bactericidal activity utilizing its secondary metabolites. Current work illustrates the enhancement of antimicrobial efficacy of silver nanoparticles by reducing and modifying their surface with antimicrobial metabolites of cell free filtrate of Trichoderma viride (MTCC 5661) in comparison to citrate stabilized silver nanoparticles. Nanoparticles were characterized by visual observations, UV-visible spectroscopy, zetasizer, and transmission electron microscopy (TEM). Synthesized particles were monodispersed, spherical in shape and 10-20 nm in size. Presence of metabolites on surface of biosynthesized silver nanoparticles was observed by gas chromatography-mass spectroscopy (GC-MS), energy dispersive X-ray analysis (EDAX), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The antimicrobial activity of both silver nanoparticles was tested against Shigella sonnei, Pseudomonas aeruginosa (Gram-negative) and Staphylococcus aureus (Gram-positive) by growth inhibition curve analysis and colony formation unit assay. Further, it was noted that internalization of biosynthesized nanoparticles inside the bacterial cell was much higher as compared to citrate stabilized particles which in turn lead to higher production of reactive oxygen species. Increase in oxidative stress caused severe damage to bacterial membrane enhancing further uptake of particles and revoking other pathways for bacterial disintegration resulting in complete and rapid death of pathogens as evidenced by fluorescein diacetate/propidium iodide dual staining and TEM. Thus, study reveals that biologically synthesized silver nanoarchitecture coated with antimicrobial metabolites of T. viride was more potent than their

Enhanced tolerance and antitumor efficacy by docetaxel-loaded albumin nanoparticles.

PubMed

Tang, Xiaolei; Wang, Guijun; Shi, Runjie; Jiang, Ke; Meng, Lingtong; Ren, Hao; Wu, Jinhui; Hu, Yiqiao

2016-10-01

Docetaxel is one of the most active chemotherapeutic agents for cancer treatment. The traditional docetaxel injection (TAXOTERE®) is currently formulated in the surfactant polysorbate 80, which has been associated with severe adverse reactions. To avoid the use of polysorbate 80 as well as to reduce the systemic toxicity of docetaxel, in this study, docetaxel-loaded albumin nanoparticles were fabricated by a novel simple self-assembly method. The resulting nanoparticles showed a mean diameter size of 150 nm. After being encapsulated into nanoparticles, docetaxel displayed similar cytotoxicity to traditional injection. Since polysorbate 80 was not involved in nanoparticles, the hemolysis was completely eliminated. The maximal tolerance dose of nanoparticles was also increased, which allowed a higher dose to be safely intravenously injected and produced ideal antitumor effects. The 150 nm diameter also allowed the nanoparticles to accumulate in tumor tissue via the enhanced permeability and retention effect. The passive targeting ability further caused the higher antitumor effects of nanoparticles than that of traditional injection at the same dose (7.5 mg/kg). Therefore, docetaxel-loaded albumin nanoparticles fabricated by our strategy showed higher promise in their safety and effectiveness than the traditional docetaxel injection.

Enhanced lithium storage performances of hierarchical hollow MoS₂ nanoparticles assembled from nanosheets.

PubMed

Wang, Meng; Li, Guangda; Xu, Huayun; Qian, Yitai; Yang, Jian

2013-02-01

MoS(2), because of its layered structure and high theoretical capacity, has been regarded as a potential candidate for electrode materials in lithium secondary batteries. But it suffers from the poor cycling stability and low rate capability. Here, hierarchical hollow nanoparticles of MoS(2) nanosheets with an increased interlayer distance are synthesized by a simple solvothermal reaction at a low temperature. The formation of hierarchical hollow nanoparticles is based on the intermediate, K(2)NaMoO(3)F(3), as a self-sacrificed template. These hollow nanoparticles exhibit a reversible capacity of 902 mA h g(-1) at 100 mA g(-1) after 80 cycles, much higher than the solid counterpart. At a current density of 1000 mA g(-1), the reversible capacity of the hierarchical hollow nanoparticles could be still maintained at 780 mAh g(-1). The enhanced lithium storage performances of the hierarchical hollow nanoparticles in reversible capacities, cycling stability and rate performances can be attributed to their hierarchical surface, hollow structure feature and increased layer distance of S-Mo-S. Hierarchical hollow nanoparticles as an ensemble of these features, could be applied to other electrode materials for the superior electrochemical performance.

Novel silver nanoparticle-enhanced fluorometric determination of trace tetracyclines in aqueous solutions.

PubMed

Wang, Ping; Wu, Tun-Hua; Zhang, Yong

2016-01-01

Metal-enhanced fluorescence (MEF) has exhibited promise for applications in fluorometric assays. The effects of silver nanoparticles (AgNP) on the fluorescence behaviours of tetracycline hydrochloride (TCH) and chlortetracycline hydrochloride (CTC) in aqueous solutions were investigated. The experimental results demonstrated that the fluorescence intensities of each tetracycline in water solutions were greatly enhanced by AgNP through the MEF effect. In addition, a novel silver nanoparticle-enhanced fluorometric method was established for the direct determination of TCH and CTC in aqueous solutions. Under optimum experimental conditions, the linear dynamic ranges for the determination of TCH and CTC in aqueous solutions varied from 0.10 to 6.0 mg L(-1) and 0.050 to 3.0 mg L(-1) with detection limits of 0.63 µg L(-1) and 0.19 µg L(-1), respectively, and with the relative standard deviation of less than 1.9% (n=9). The experimental recovery results for the determination of TCH and CTC in aqueous solutions ranged from 93-106% and 95-104%, respectively. Compared with the established method without the addition of AgNP, the limits of quantitation of the silver nanoparticle-enhanced fluorometric method were approximately 5-fold lower for TCH and 3-fold lower for CTC. Moreover, the newly established silver nanoparticle-enhanced fluorometric method was successfully applied to the direct determination of TCH and CTC in pharmaceutical preparations. Copyright © 2015 Elsevier B.V. All rights reserved.

Potassium permanganate-acridine yellow chemiluminescence system for the determination of fluvoxamine, isoniazid and ceftriaxone.

PubMed

Abolhasani, Jafar; Hassanzadeh, Javad

2014-12-01

Based on the oxidation of acridine yellow by permanganate in basic medium, a new chemiluminescence system was developed for the sensitive determination of some important drugs. The remarkable inhibiting effect of fluvoxamine, ceftriaxone and isoniazid on this reaction was applied to their detection. A possible mechanism was proposed for this system based on chemiluminescence emission wavelengths and experimental observations. Under optimum conditions, calibration graphs were obtained for 1 × 10(-9) to 1 × 10(-6) mol/L of fluvoxamine; 2 × 10(-8) to 8 × 10(-6) mol/L of ceftriaxone and 5 × 10(-8) to 4 × 10(-5) mol/L of isoniazid. This proposed method was satisfactorily used in the determination of these drugs in pharmaceutical samples and human urine and serum. Copyright © 2014 John Wiley & Sons, Ltd.

Electrophoresis-chemiluminescence detection of phenols catalyzed by hemin.

PubMed

Shu, Lu; Zhu, Jinkun; Wang, Qingjiang; He, Pingang; Fang, Yuzhi

2014-09-01

Based on the catalytic activity of hemin, an efficient biocatalyst, an indirect capillary electrophoresis-chemiluminescence (CE-CL) detection method for phenols using a hemin-luminol-hydrogen peroxide system was developed. Through a series of static injection experiments, hemin was found to perform best in a neutral solution rather than an acidic or alkaline medium. Although halide ions such as Br(-) and F(-) could further enhance the CL signal catalyzed by hemin, it is difficult to apply these conditions to this CE-CL detection system because of the self-polymerization of hemin, as it hinders the CE process. The addition of concentrated ammonium hydroxide to an aqueous/dimethyl sulfoxide solution of hemin-luminol afforded a stable CE-CL baseline. The indirect CE-CL detection of five phenols using this method gave the following limits of detections: 4.8 × 10(-8) mol/L (o-sec-butylphenol), 4.9 × 10(-8) mol/L (o-cresol), 5.4 × 10(-8) mol/L (m-cresol), 5.3 × 10(-8) mol/L (2,4-dichlorophenol) and 7.1 × 10(-8) mol/L (phenol). Copyright © 2013 John Wiley & Sons, Ltd.

Biocompatible and biodegradable nanoparticles for enhancement of anti-cancer activities of phytochemicals.

PubMed

Li, Chuan; Zhang, Jia; Zu, Yu-Jiao; Nie, Shu-Fang; Cao, Jun; Wang, Qian; Nie, Shao-Ping; Deng, Ze-Yuan; Xie, Ming-Yong; Wang, Shu

2015-09-01

Many phytochemicals show promise in cancer prevention and treatment, but their low aqueous solubility, poor stability, unfavorable bioavailability, and low target specificity make administering them at therapeutic doses unrealistic. This is particularly true for (-)-epigallocatechin gallate, curcumin, quercetin, resveratrol, and genistein. There is an increasing interest in developing novel delivery strategies for these natural products. Liposomes, micelles, nanoemulsions, solid lipid nanoparticles, nanostructured lipid carriers and poly (lactide-co-glycolide) nanoparticles are biocompatible and biodegradable nanoparticles. Those nanoparticles can increase the stability and solubility of phytochemicals, exhibit a sustained release property, enhance their absorption and bioavailability, protect them from premature enzymatic degradation or metabolism, prolong their circulation time, improve their target specificity to cancer cells or tumors via passive or targeted delivery, lower toxicity or side-effects to normal cells or tissues through preventing them from prematurely interacting with the biological environment, and enhance anti-cancer activities. Nanotechnology opens a door for developing phytochemical-loaded nanoparticles for prevention and treatment of cancer. Copyright © 2015 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

Analysis of oral lesion biopsies identified and evaluated by visual examination, chemiluminescence and toluidine blue.

PubMed

Epstein, J B; Silverman, S; Epstein, J D; Lonky, S A; Bride, M A

2008-06-01

Conventional visual examination and palpation remains the gold-standard for the identification of oral mucosal lesions. The purpose of this study was to investigate the adjunctive value of a chemiluminescent light source (ViziLite, Zila Pharmaceuticals, Phoenix, Arizona) and application of pharmaceutical grade toluidine blue (TBlue(630), Zila Pharmaceuticals, Phoenix, Arizona) to further assess lesions identified during the conventional oral soft tissue examination. Lesions deemed clinically suspicious by visual examination under incandescent light were further assessed under chemiluminescence and then application of toluidine blue stain. Differences between the conventional visual examination and chemiluminescent examination were noted on four characteristics which may aid in lesion identification. Tissue retention of toluidine blue stain was documented. Each suspicious lesion was biopsied and diagnosed based upon routine histopathology. Both adjunctive exams were evaluated by comparing the histologic diagnosis. The additive value of toluidine blue stain retention was assessed in lesions diagnosed as "serious pathology" defined as severe dysplasia, carcinoma in situ and squamous cell carcinoma. Ninety-seven clinically suspicious lesions in 84 patients were identified. The chemiluminescent exam improved the brightness and/or sharpness of margin in 61.8% of identified lesions. Biopsied lesions with toluidine blue stain retention reduced the false positive rate by 55.26% while maintaining a 100% negative predictive value (NPV). Chemiluminescence was shown to increase the brightness and margins of mucosal lesions in a majority of cases and therefore may assist in identification of mucosal lesions not considered under traditional visual examination. Toluidine blue stain retention was associated with a large reduction in biopsies showing benign histology (false positive biopsy results), while maintaining a 100% NPV for the presence of severe dysplasia or cancer

A New Smart Surface-Enhanced Raman Scattering Sensor Based on pH-Responsive Polyacryloyl Hydrazine Capped Ag Nanoparticles.

PubMed

Yuan, Shuai; Ge, Fengyan; Zhou, Man; Cai, Zaisheng; Guang, Shanyi

2017-08-14

A novel pH-responsive Ag@polyacryloyl hydrazide (Ag@PAH) nanoparticle for the first time as a surface-enhanced Raman scattering (SERS) substrate was prepared without reducing agent and end-capping reagent. Ag@PAH nanoparticles exhibited an excellent tunable detecting performance in the range from pH = 4 to pH = 9. This is explained that the swelling-shrinking behavior of responsive PAH can control the distance between Ag NPs and the target molecules under external pH stimuli, resulting in the tunable LSPR and further controlled SERS. Furthermore, Ag@PAH nanoparticles possessed an ultra-sensitive detecting ability and the detection limit of Rhodamine 6G reduced to 10 -12  M. These advantages qualified Ag@PAH NP as a promising smart SERS substrate in the field of trace analysis and sensors.

A New Smart Surface-Enhanced Raman Scattering Sensor Based on pH-Responsive Polyacryloyl Hydrazine Capped Ag Nanoparticles

NASA Astrophysics Data System (ADS)

Yuan, Shuai; Ge, Fengyan; Zhou, Man; Cai, Zaisheng; Guang, Shanyi

2017-08-01

A novel pH-responsive Ag@polyacryloyl hydrazide (Ag@PAH) nanoparticle for the first time as a surface-enhanced Raman scattering (SERS) substrate was prepared without reducing agent and end-capping reagent. Ag@PAH nanoparticles exhibited an excellent tunable detecting performance in the range from pH = 4 to pH = 9. This is explained that the swelling-shrinking behavior of responsive PAH can control the distance between Ag NPs and the target molecules under external pH stimuli, resulting in the tunable LSPR and further controlled SERS. Furthermore, Ag@PAH nanoparticles possessed an ultra-sensitive detecting ability and the detection limit of Rhodamine 6G reduced to 10-12 M. These advantages qualified Ag@PAH NP as a promising smart SERS substrate in the field of trace analysis and sensors.

Nanoparticles based fiber optic SPR sensor

NASA Astrophysics Data System (ADS)

Shah, Kruti; Sharma, Navneet K.

2018-05-01

Localized surface plasmon resonance based fiber optic sensor using platinum nanoparticles is proposed and theoretically analyzed. Increase in thickness of nanoparticles layer increases the sensitivity of sensor. 50 nm thick platinum nanoparticles layer based sensor reveals highest sensitivity.

Recent Advances in Inorganic Nanoparticle-Based NIR Luminescence Imaging: Semiconductor Nanoparticles and Lanthanide Nanoparticles.

PubMed

Kim, Dokyoon; Lee, Nohyun; Park, Yong Il; Hyeon, Taeghwan

2017-01-18

Several types of nanoparticle-based imaging probes have been developed to replace conventional luminescent probes. For luminescence imaging, near-infrared (NIR) probes are useful in that they allow deep tissue penetration and high spatial resolution as a result of reduced light absorption/scattering and negligible autofluorescence in biological media. They rely on either an anti-Stokes or a Stokes shift process to generate luminescence. For example, transition metal-doped semiconductor nanoparticles and lanthanide-doped inorganic nanoparticles have been demonstrated as anti-Stokes shift-based agents that absorb NIR light through two- or three-photon absorption process and upconversion process, respectively. On the other hand, quantum dots (QDs) and lanthanide-doped nanoparticles that emit in NIR-II range (∼1000 to ∼1350 nm) were suggested as promising Stokes shift-based imaging agents. In this topical review, we summarize and discuss the recent progress in the development of inorganic nanoparticle-based luminescence imaging probes working in NIR range.

Photovoltaic devices having nanoparticle dipoles for enhanced performance and methods for making same

DOEpatents

Williams, George M [Portland, OR; Schut, David M [Philomath, OR; Stonas, Andreas [Albany, OR

2011-08-09

A photovoltaic device has nanoparticles sandwiched between a conductive substrate and a charge selective transport layer. Each of the nanoparticles has a ligand shell attached to the nanoparticle core. A first type of ligand is electron rich and attached to one hemisphere of the nanoparticle core, while a second type of ligand is electron poor and attached to an opposite hemisphere of the core. Consequently, the ligand shell induces an electric field within the nanoparticle, enhancing the photovoltaic effect. The arrangement of ligands types on different sides of the nanoparticle is obtained by a process involving ligand substitution after adhering the nanoparticles to the conductive substrate.

A comparison of flame ionization and ozone chemiluminescence for the determination of atmospheric hydrocarbons.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marley, N. A.; Gaffney, J. S.; Environmental Research

A reactive hydrocarbon analyzer has been constructed on the basis of chemiluminescence reaction with ozone. This detector is designed to operate at varying temperatures which take advantage of the different rates of reaction of the hydrocarbon classes with ozone to yield a measure of their atmospheric reactivity. When operated at high temperatures (170 C), all hydrocarbons will give a chemiluminescence signal. Reported here is a direct comparison of the ozone chemiluminescent detector (operated at a temperature of 170 C) with a flame ionization detector. This comparison was accomplished by connecting a capillary gas chromatograph to each of the two detectorsmore » by means of a switching valve. Twenty-seven compounds representing alkanes, alkenes, aromatics, and oxygenated hydrocarbons (aldehydes, ketones, alcohols, and ethers) were studied. For the compounds studied, analytical sensitivities were 10-1000 times better for the chemiluminescence detector. The results of this comparison indicate that the response of the chemiluminescent detector at 170 C correlates with a total carbon detector (flame ionization detection) and that total response is a measure of total carbon in the sample. The chemiluminescent system will be very useful for gas chromatographic detection of atmospheric hydrocarbons, particularly of oxygenates in complex mixtures.« less

Platinum nanoparticles decorated dendrite-like gold nanostructure on glassy carbon electrodes for enhancing electrocatalysis performance to glucose oxidation

NASA Astrophysics Data System (ADS)

Jia, Hongmei; Chang, Gang; Lei, Ming; He, Hanping; Liu, Xiong; Shu, Honghui; Xia, Tiantian; Su, Jie; He, Yunbin

2016-10-01

Platinum nanoparticles decorated dendrite-like gold nanostructure, bimetal composite materials on glassy carbon electrode (Pt/DGNs/GC) for enhancing electrocatalysis to glucose oxidation was designed and successfully fabricated by a facile two-step deposition method without any templates, surfactants, or stabilizers. Dendrite-like gold nanostructure was firstly deposited on the GC electrode via the potentiostatic method, and then platinum nanoparticles were decorated on the surface of gold substrate through chemical reduction deposition. X-ray diffraction (XRD), field-emission scanning electron microscope (FE-SEM), energy-dispersive X-ray spectroscopy (EDS) were applied to characterize the evolution of morphology and structure of the as-prepared Pt/DGNs/GC. Based on electrochemical measurements such as cyclic voltammetry, linear voltammetry and chronoamperometry, Pt/DGNs/GC exhibited significantly enhanced electrocatalytic performance to glucose oxidation compared those of pure dendrite-like Au nanoparticles in our previous report. Controlling chemical reduction deposition time, the amount of platinum nanoparticles on Au surface could be regulated, which further tuned electrocatalytic properties toward glucose oxidation. The dendrite-like gold surface partially covered by platinum nanoparticles dramatically enhanced the electrocatalytic performance for the oxidation of glucose because of excellent synergetic effects between gold and platinum species and the increased electrochemical active area from Pt nanoparticles loading. The non-enzymatic glucose biosensor based on Pt/DGNs/GC showed a rapid respond time (within 2 s), wide linear range (from 0.1 mM to 14 mM), low detection limit (0.01 mM), supernal sensitivity (275.44 μA cm-2 mM-1, R = 0.993), satisfactory reproducibility and good stability for glucose sensing. It was demonstrated that Pt/DGNs/GC could work as promising candidate for factual non-enzymatic glucose detection.

Chemiluminescent Nanomicelles for Imaging Hydrogen Peroxide and Self-Therapy in Photodynamic Therapy

PubMed Central

Chen, Rui; Zhang, Luzhong; Gao, Jian; Wu, Wei; Hu, Yong; Jiang, Xiqun

2011-01-01

Hydrogen peroxide is a signal molecule of the tumor, and its overproduction makes a higher concentration in tumor tissue compared to normal tissue. Based on the fact that peroxalates can make chemiluminescence with a high efficiency in the presence of hydrogen peroxide, we developed nanomicelles composed of peroxalate ester oligomers and fluorescent dyes, called peroxalate nanomicelles (POMs), which could image hydrogen peroxide with high sensitivity and stability. The potential application of the POMs in photodynamic therapy (PDT) for cancer was also investigated. It was found that the PDT-drug-loaded POMs were sensitive to hydrogen peroxide, and the PDT drug could be stimulated by the chemiluminescence from the reaction between POMs and hydrogen peroxide, which carried on a self-therapy of the tumor without the additional laser light resource. PMID:21765637

Nano-Advantage in Enhanced Drug Delivery with Biodegradable Nanoparticles: Contribution of Reduced Clearance

PubMed Central

Kadam, Rajendra S.; Bourne, David W. A.

2012-01-01

The aim of this study was to investigate the contribution of reduced apparent clearance to the enhanced exposure reported for biodegradable nanoparticles after extravascular and intravascular routes of administration. Plasma concentration profiles for drug and nanoparticle formulations after administration by intravenous, intraduodenal, and oral routes were extracted from the literature. Data were fit to pharmacokinetic models using BOOMER. The compartmental pharmacokinetic analysis of literature data for six drugs (camptothecin, 9-nitrocamptothecin, epirubicin, vinpocetine, clozapine, and cyclosporine) showed that the encapsulation of drug molecules in nanoparticles significantly reduced the apparent clearance and prolonged the apparent circulation half-life compared with those for the plain drug. Positively charged nanoparticles assessed in this study had lower apparent clearance, lower elimination rate constant values, and longer apparent circulation half-life than neutral and negatively charged nanoparticles. After oral administration, a reduction in apparent clearance contributed substantially to elevations in plasma drug exposure with nanoparticles. For the drugs and delivery systems examined, the nano-advantage in drug delivery enhancement can be explained, in part, by reduced clearance. PMID:22498894

Plasmonic nanoparticles enhanced dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Xu, Qi; Liu, Fang; Meng, Weisi; Huang, Yidong

2013-12-01

Here we present investigations on utilizing two kinds of plasmonic nanoparticles (NPs) to enhance the efficiency of dye sensitized solar cells (DSCs). The Au@PVP NPs is proposed and present the specialty of adhesiveness to dye molecules, which could help to localize additional dye molecules near the plasmonic NPs, hence increasing the optical absorption consequently the power conversion efficiency (PCE) of the DSCs by 30% from 3.3% to 4.3%. Meanwhile, an irregular Au-Ag alloy popcorn-shaped NPs (popcorn NPs) with plenty of fine structures is also proposed and realized to enhance the light absorption of DSC. A pronounced absorption enhancement in a broadband wavelength range is observed due to the excitation of localized surface plasmon at different wavelengths. The PCE is enhanced by 32% from 5.94% to 7.85%.