Luminol modified polycarbazole and poly(o-anisidine): Theoretical insights compared with experimental data.

PubMed

Jadoun, Sapana; Verma, Anurakshee; Riaz, Ufana

2018-06-07

With the aim to explore the effect of luminol as a multifunctional dopant for conjugated polymers, the present study reports the ultrasound-assisted doping of polycarbazole (PCz) and poly(o-anisidine) (PAnis) with luminol in basic, acidic and neutral media. The synthesized homopolymers and luminol doped polymers were characterized using FT-IR, UV-visible and XRD studies while the photo-physical properties were investigated via fluorescence spectroscopy. Density functional theory (DFT) calculations were performed to get insights into the structural, optical, and electronic properties of homopolymers of polycarbazole (PCz) and poly(o-anisidine) (PAnis). Vibrational bands B3LYP/6-311G (d,p) level, UV-vis spectral bands and electronic properties such as ionization potentials (IP), electron affinities (EA) and HOMO-LUMO band gap energies of the homopolymers and doped polymers were calculated and compared. Results revealed that luminol doped polymers showed different photo-physical characteristics in acidic, basic and neutral media which could be tuned to obtain near infrared (NIR) emitting polymers. Copyright © 2018 Elsevier B.V. All rights reserved.

A comparison of the presumptive luminol test for blood with four non-chemiluminescent forensic techniques.

PubMed

Webb, Joanne L; Creamer, Jonathan I; Quickenden, Terence I

2006-01-01

Presumptive blood detection tests are used by forensic investigators to detect trace amounts of blood or to investigate suspicious stains. Through the years, a number of articles have been published on the popular techniques of the day. However, there is no single paper that critiques and compares the five most common presumptive blood detection tests currently in use: luminol, phenolphthalein (Kastle-Meyer), leucomalachite green, Hemastix and the forensic light source. The present authors aimed to compare the above techniques with regard to their sensitivity, ease of use and safety. The luminol test was determined to be the most sensitive of the techniques, while Hemastix is a suitable alternative when the luminol test is not appropriate. Copyright 2006 John Wiley & Sons, Ltd.

On the use of L-012, a luminol-based chemiluminescent probe, for detecting superoxide and identifying inhibitors of NADPH oxidase: A re-evaluation

PubMed Central

Zielonka, Jacek; Lambeth, J. David; Kalyanaraman, Balaraman

2014-01-01

L-012, a luminol-based chemiluminescent (CL) probe, is widely used in vitro and in vivo to detect NADPH oxidase (Nox)-derived superoxide (O2·−) and identify Nox inhibitors. Yet understanding of the free radical chemistry of L-012 probe is still lacking. We report that peroxidase and H2O2 induce superoxide dismutase (SOD)-sensitive, L-012-derived CL in the presence of oxygen. O2·− alone does not react with L-012 to emit luminescence. Self-generated O2·− during oxidation of L-012 and luminol-analogs artifactually induce CL inhibitable by SOD. These aspects make assays based on luminol analogs less than ideal for specific detection and identification of O2·− and NOX inhibitors. PMID:24080119

The comparative performance of PMI estimation in skeletal remains by three methods (C-14, luminol test and OHI): analysis of 20 cases.

PubMed

Cappella, Annalisa; Gibelli, Daniele; Muccino, Enrico; Scarpulla, Valentina; Cerutti, Elisa; Caruso, Valentina; Sguazza, Emanuela; Mazzarelli, Debora; Cattaneo, Cristina

2015-01-27

When estimating post-mortem interval (PMI) in forensic anthropology, the only method able to give an unambiguous result is the analysis of C-14, although the procedure is expensive. Other methods, such as luminol tests and histological analysis, can be performed as preliminary investigations and may allow the operators to gain a preliminary indication concerning PMI, but they lack scientific verification, although luminol testing has been somewhat more accredited in the past few years. Such methods in fact may provide some help as they are inexpensive and can give a fast response, especially in the phase of preliminary investigations. In this study, 20 court cases of human skeletonized remains were dated by the C-14 method. For two cases, results were chronologically set after the 1950s; for one case, the analysis was not possible technically. The remaining 17 cases showed an archaeological or historical collocation. The same bone samples were also screened with histological examination and with the luminol test. Results showed that only four cases gave a positivity to luminol and a high Oxford Histology Index (OHI) score at the same time: among these, two cases were dated as recent by the radiocarbon analysis. Thus, only two false-positive results were given by the combination of these methods and no false negatives. Thus, the combination of two qualitative methods (luminol test and microscopic analysis) may represent a promising solution to cases where many fragments need to be quickly tested.

Alterations in luminol-enhanced chemiluminescence from nondiluted whole blood in the course of low-level laser therapy of angina pectoris patients

NASA Astrophysics Data System (ADS)

Voeikov, Vladimir L.; Novikov, Cyril N.; Siuch, Natalia I.

1997-05-01

Addition of Luminol to nondiluted blood of healthy donors results in a short and weak increase of chemiluminescence (CL) from it. Contrary to that in 25 cases of stable angina pectoris the intensity of CL from blood of patients sharply increased upon addition of luminol exceeding that form healthy donors' blood 10-100-fold. 24 hours after the 3D intravenous low-level treatment CL burst in patients' blood in the presence of Luminol was in general significantly lower than before the beginning of the treatment. After the 7th treatment the pattern of CL kinetics was in most cases similar to that of healthy donors' blood. However, after the 10th treatment intensity of Luminol-enhanced CL usually increased and for blood of some patients even exceeded its values obtained before the treatment. Some correlation CL from nondiluted blood with neutrophil activity studied by NTB-test and plasma viscosity of same blood was noted. Using highly sensitive single photon counters it is possible to reveal abnormal levels of CL from no more than 0.1-0.2 ml of blood within 3-5 min.

The Development of a Nitrogen Dioxide Sonde

NASA Astrophysics Data System (ADS)

Sluis, Wesley; Allaart, Marc; Piters, Ankie; Gast, Lou

2010-05-01

Nitrogen dioxide is an important pollutant in the atmosphere, it is toxic for living species, it forms photochemical tropospheric ozone, and acid rain. There is a growing number of space-borne instruments to measure nitrogen dioxide concentrations in the atmosphere, but validation of these instruments is hampered by lack of ground-based and in-situ profile measurements. The Royal Netherlands Meteorological Institute (KNMI) has developed a working NO2 sonde. The sonde is attached to a small meteorological balloon and measures a tropospheric NO2 profile. The NO2 sonde has a vertical resolution of 5 meter, and a measurement range between 1 and 100 ppbv. The instrument is light in weight (±300 gram), cheap (disposable), energy efficient and not harmful to the environment or the person who finds the package after use. Therefore the popular molybdenum catalytic converter or a photomultiplier tube can not be used. Instead the sonde uses the chemiluminescent reaction of NO2 in an aqueous luminol solution. The NO2- luminol reaction produces a faint blue/purple light (± 425 nm), which is detected by an array of silicon photodiodes. The instrument is equipped with a reservoir filled with luminol solution. A small piezoelectric diaphragm pump, pumps the luminol solution into a reaction vessel. A Teflon air pump forces the ambient air into the reaction vessel. The NO2 in the ambient air reacts with the luminol solution, and the emitted light is detected by an array of silicon photodiodes which are mounted on the reaction vessel. The generated current in the photodiodes is amplified and relayed to the ground by a Vaisala (RS92) radiosonde. The reaction vessel and the amplifiers are mounted in a tin can, to shield against electrostatic and radio interference, and stray light. All the air tubes used for the instrument are made of Teflon. The luminol solution is optimised to be specific to NO2. Sodium sulphate, sodium EDTA and Triton X-100 are added to the luminol solution to exclude ozone (O3) and PAN (peroxy acetyl nitrate) interference. The efficiency of the NO2 luminol reaction depends on the pH of the solution. To avoid acidification of the system by carbon dioxide, the chemicals are refreshed constantly. Furthermore, treating the luminol solution with clean air for an extended period before the measurement, makes the luminol / NO2 reaction more efficient. The NO2 sonde is compared to a NO2 in-situ monitor with bluelight converter (M200E, BLC) of RIVM. Both instruments measure the same NO2 variations during a certain period of time during the day. During the Cabauw Intercomparison campaign of Nitrogen Dioxide measuring Instruments (CINDI) in June/July 2009 we measured six vertical profiles of NO2 from the ground to 5 km altitude. The NO2 sonde measurements will be compared with the Ozone Monitoring Instrument (OMI) on the EOS-Aura satellite, and other in-situ measurements like LIDAR and MAX Doas.

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.

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.

Study on the luminescence behavior of sulfobutylether-β-cyclodextrin with risperidone and its analytical application.

PubMed

Wu, Min; Chen, Donghua; Song, Zhenghua

2012-10-01

The interaction of sulfobutylether-β-cyclodextrin (SBE-β-CD) with risperidone (RISP) was first described with luminol-SBE-β-CD chemiluminescence (CL) system by flow injection analysis (FIA). In luminol-SBE-β-CD CL system, the 1:1 SBE-β-CD···luminol(*) complexation could enhance CL intensity of luminol and produce the effect of complexation enhancement of CL (CEC). It was found that RISP could quench the CL intensity of SBE-β-CD···luminol(*) and caused the effect of complexation enhancement of quenching (CEQ), the formation constant K(R-CD) 3.4×10(4) L mol(-1) and the stoichiometric ratio 1:1 of RISP···SBE-β-CD complex were obtained by the proposed CL model. Association degree α 0.036 of RISP···SBE-β-CD complex was also given by CL method. Based on the linear relationship to the decrement of luminol-SBE-β-CD-RISP CL intensity and the logarithm of RISP concentration, RISP also can be quantified in the linear range of 3.0-500.0 nmol L(-1) with a detection limit of 1.0 nmol L(-1) (3σ). The proposed method was successfully applied to monitoring excreted RISP in human urine. It was found that RISP reached its maximum after oral administration for 1.5 h with the total excretion of 14.26% within 8.5 h; the elimination rate constant k and half-life time t(1/2) were 0.474 and 1.5 h, respectively. Copyright © 2012 Elsevier B.V. All rights reserved.

A novel electrochemiluminescence strategy for ultrasensitive DNA assay using luminol functionalized gold nanoparticles multi-labeling and amplification of gold nanoparticles and biotin-streptavidin system.

PubMed

Chai, Ying; Tian, Dayong; Wang, Wei; Cui, Hua

2010-10-28

Luminol functionalized gold nanoparticles were used as labels for electrochemiluminescence signal amplification and an ultrasensitive, highly selective, convenient, low cost DNA detection strategy was developed.

A study of the chemiluminescence behavior of cephalosporins with luminol and its analytical application.

PubMed

Niu, Lichuan; Song, Zhenghua; He, Xili

2009-08-01

The chemiluminescence intensity of luminol-dissolved oxygen was decreased when cephalosporins were mixed with luminol. The decrease chemiluminescence intensity was linear with the logarithm of cephalosporins concentration over the range from nanogram to microgramme level, with the limits of detection at nanogram level. The sensitivities of determination for cephalosporins were in the order of cefoperazone > ceftriaxone > cefuroxime > cefaclor > cefalexin > cefradine. The proposed method was applied to monitor the excretion of cefradine in human urine after taken cefradine capsules. The possible chemiluminescence mechanism and relationship between the determination sensitivities and generations of cephalosporins were also discussed.

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.

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.

Electrochemiluminescence quenching of luminol by CuS in situ grown on reduced graphene oxide for detection of N-terminal pro-brain natriuretic peptide.

PubMed

Li, Xiaojian; Lu, Peng; Wu, Bin; Wang, Yaoguang; Wang, Huan; Du, Bin; Pang, Xuehui; Wei, Qin

2018-07-30

A novel electrochemiluminescence (ECL) signal-off strategy based on CuS in situ grown on reduced graphene oxide (CuS-rGO) quenching luminol/H 2 O 2 system was firstly proposed. Luminol was grafted on the surface of Au@Fe 3 O 4 -Cu 3 (PO 4 ) 2 nanoflowers (Luminol-Au@Fe 3 O 4 -Cu 3 (PO 4 ) 2 ) which exhibited excellent catalytic effect towards the reduction of H 2 O 2 to enhance the ECL intensity of luminol. Cu 3 (PO 4 ) 2 nanoflowers showed large surface area which can immobilize more Fe 3 O 4 and Au nanoparticles. The quenching mechanism of CuS-rGO was due to ECL resonance energy transfer (RET). The spectral overlap between fluorescence spectrum of Luminol-Au@Fe 3 O 4 -Cu 3 (PO 4 ) 2 and UV-vis absorption spectrum of CuS-rGO revealed that resonance energy transfer was possible. Au nanoparticles were immobilized on the surface of CuS-rGO to capture secondary antibodies. After a sandwich-type immunoreaction, a remarkable decrease of ECL signal was observed. Under the optimal conditions, the immunosensor showed excellent performance for N-terminal pro-brain natriuretic peptide (NT-proBNP) detection with a wide detection range from 0.5 pg mL -1 to 20 ng mL -1 and a low detection limit of 0.12 pg mL -1 (S/N = 3). The prepared NT-proBNP immunosensor displayed high sensitivity, excellent stability and good specificity. Copyright © 2018 Elsevier B.V. All rights reserved.

[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.

Several methods for concentrating bacteria in fluid samples

NASA Technical Reports Server (NTRS)

Thomas, R. R.

1976-01-01

The sensitivities of the firefly luciferase - ATP flow system and luminol flow system were established as 300,000 E. coli per milliliter and 10,000 E. coli per milliliter respectively. To achieve the detection limit of 1,000 bacteria per milliliter previously established, a method of concentrating microorganisms using a sartorius membrane filter system is investigated. Catalase in 50% ethanol is found to be a stable luminol standard and can be used up to 24 hours with only a 10% loss of activity. The luminol reagent is also stable over a 24 hour period. A method of preparing relatively inexpensive luciferase from desiccated firefly tails is developed.

An ultrasensitive luminol cathodic electrochemiluminescence immunosensor based on glucose oxidase and nanocomposites: graphene-carbon nanotubes and gold-platinum alloy.

PubMed

Jiang, Xinya; Chai, Yaqin; Yuan, Ruo; Cao, Yaling; Chen, Yingfeng; Wang, Haijun; Gan, Xianxue

2013-06-14

In the present study, a novel and ultrasensitive electrochemiluminescence (ECL) immunosensor based on luminol cathodic ECL was fabricated by using Au nanoparticles and Pt nanoparticles (nano-AuPt) electrodeposited on graphene-carbon nanotubes nanocomposite as platform for the detection of carcinoembryonic antigen (CEA). For this introduced immunosensor, graphene (GR) and single wall carbon nanotubes (CNTs) dispersed in chitosan (Chi-GR-CNTs) were firstly decorated on the bare gold electrode (GE) surface. Then nano-AuPt were electrodeposited (DpAu-Pt) on the Chi-GR-CNTs modified electrode. Subsequently, glucose oxidase (GOD) was employed to block the non-specific sites of electrode surface. When glucose was present in the working buffer solution, GOD immediately catalyzed the oxidation of glucose to in situ generate hydrogen peroxide (H2O2), which could subsequently promote the oxidation of luminol with an amplified cathodic ECL signal. The proposed immunosensor was performed at low potential (-0.1 to 0.4V) and low concentration of luminol. The CEA was determined in the range of 0.1 pg mL(-1) to 40 ng mL(-1) with a limit of detection down to 0.03 pg mL(-1) (SN(-1)=3). Moreover, with excellent sensitivity, selectivity, stability and simplicity, the as-proposed luminol-based ECL immunosensor provided great potential in clinical applications. Copyright © 2013 Elsevier B.V. All rights reserved.

Improvement of mimetic peroxidase activity of gold nanoclusters on the luminol chemiluminescence reaction by surface modification with ethanediamine.

PubMed

Han, Lu; Li, Ying; Fan, Aiping

2018-06-01

Peroxidase is a commonly used catalyst in luminol-H 2 O 2 chemiluminescence (CL) reactions. Natural peroxidase has a sophisticated separation process, short shelf life and unstable activity, therefore it is important to develop peroxidases that have both high catalytic activity and good stability as alternatives to the natural enzyme. Gold nanoclusters (Au NCs) are an alternative peroxidase with catalytic activity in the luminol-H 2 O 2 CL reaction. In the present study, ethanediamine was modified on the surface of Au NCs forming cationic Au NCs. The zeta potential of the cationic Au NCs maintained its positive charge when the pH of the solution was between 4 and 9. The cationic Au NCs showed higher catalytic activity in the luminol-H 2 O 2 CL reaction than did unmodified Au NCs. A mechanism study showed that the better performance of cationic Au NCs may be attributed to the generation of 1 O 2 on the surface of cationic Au NCs and a positive surface charge, for better affinity to luminol. Cationic Au NC, acting as a peroxidase mimic, has much better stability than horseradish peroxidase over a wide range of temperatures. We believe that cationic Au NCs may be useful as an artificial peroxidase for a wide range of potential applications in CL and bioanalysis. Copyright © 2018 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.

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.

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.

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.

[Development and Application of Catalytic Tyrosine Modification].

PubMed

Sato, Shinichi; Tsushima, Michihiko; Nakamura, Kosuke; Nakamura, Hiroyuki

2018-01-01

 The chemical labeling of proteins with synthetic probes is a key technique used in chemical biology, protein-based therapy, and material science. Much of the chemical labeling of native proteins, however, depends on the labeling of lysine and cysteine residues. While those methods have significantly contributed to native protein labeling, alternative methods that can modify different amino acid residues are still required. Herein we report the development of a novel methodology of tyrosine labeling, inspired by the luminol chemiluminescence reaction. Tyrosine residues are often exposed on a protein's surface and are thus expected to be good targets for protein functionalization. In our studies so far, we have found that 1) hemin oxidatively activates luminol derivatives as a catalyst, 2) N-methyl luminol derivative specifically forms a covalent bond with a tyrosine residue among the 20 kinds of natural amino acid residues, and 3) the efficiency of tyrosine labeling with N-methyl luminol derivative is markedly improved by using horseradish peroxidase (HRP) as a catalyst. We were able to use molecular oxygen as an oxidant under HRP/NADH conditions. By using these methods, the functionalization of purified proteins was carried out. Because N-methyl luminol derivative is an excellent protein labeling reagent that responds to the activation of peroxidase, this new method is expected to open doors to such biological applications as the signal amplification of HRP-conjugated antibodies and the detection of protein association in combination with peroxidase-tag technology.

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.

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.

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.

Ultrasensitive luminol electrochemiluminescence for protein detection based on in situ generated hydrogen peroxide as coreactant with glucose oxidase anchored AuNPs@MWCNTs labeling.

PubMed

Cao, Yaling; Yuan, Ruo; Chai, Yaqin; Mao, Li; Niu, Huan; Liu, Huijing; Zhuo, Ying

2012-01-15

In this study, an ultrasensitive luminol electrochemiluminescence (ECL) immunosensor was constructed using carboxyl group functionalized multi-walled carbon nanotubes (MWCNTs) as platform and glucose oxidase (GOD) supported on Au nanoparticles (AuNPs) decorated MWCNTs (AuNPs@MWCNTs-GOD) as labels. Firstly, using poly(ethylenimine) (PEI) as linkage reagents, AuNPs@MWCNTs were prepared and introduced for binding of the secondary antibody (Ab(2)) and glucose oxidase (GOD) with high loading amount and good biological activity due to the improved surface area of AuNPs@MWCNTs and excellent biocompatibility of AuNPs. Then the GOD and Ab(2) labeled AuNPs@MWCNTs were linked to the electrode surface via sandwich immunoreactions. These localized GOD and AuNPs amplified luminol ECL signals dramatically, which was achieved by efficient catalysis of the GOD and AuNPs towards the oxidation of glucose to in situ generate improved amount of hydrogen peroxide (H(2)O(2)) as coreactant and the enhancement of AuNPs to the ECL reaction of luminol-H(2)O(2). The experimental results demonstrated that the proposed immunosensor exhibited sensitive and stable response for the detection of α-1-fetoprotein (AFP), ranging from 0.0001 to 80 ng mL(-1) with a limit of detection down to 0.03 pg mL(-1) (S/N=3). With excellent stability, sensitivity, selectivity and simplicity, the proposed luminol ECL immunosensor showed great potential in clinical applications. Copyright © 2011 Elsevier B.V. All rights reserved.

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.

Forensic Luminol Blood Test for Preventing Cross-contamination in Dentistry: An Evaluation of a Dental School Clinic.

PubMed

Bortoluzzi, Marcelo Carlos; Cadore, Peterson; Gallon, Andrea; Imanishi, Soraia Almeida Watanabe

2014-10-01

More than 200 different diseases may be transmitted from exposure to blood in the dental setting. The aim of this study is to identify possible faults in the crosscontamination chain control in a dental school clinic searching for traces of blood in the clinical contact surfaces (CCS) through forensic luminol blood test. Traces of invisible blood where randomly searched in CCS of one dental school clinic. Forty eight surfaces areas in the CCS were tested and the presence of invisible and remnant blood was identified in 28 (58.3%) items. We suggest that the luminol method is suitable for identifying contamination with invisible blood traces and this method may be a useful tool to prevent cross-contamination in the dental care setting.

Ceria Doped Zinc Oxide Nanoflowers Enhanced Luminol-Based Electrochemiluminescence Immunosensor for Amyloid-β Detection.

PubMed

Wang, Jing-Xi; Zhuo, Ying; Zhou, Ying; Wang, Hai-Jun; Yuan, Ruo; Chai, Ya-Qin

2016-05-25

In this work, ceria doped ZnO nanomaterials with flower-structure (Ce:ZONFs) were prepared to construct a luminol-based electrochemiluminescence (ECL) immunosensor for amyloid-β protein (Aβ) detection. Herein, carboxyl groups (-COOH) covered Ce:ZONFs were synthesized by a green method with lysine as reductant. After that, Ce:ZONFs-based ECL nanocomposite was prepared by combining the luminophore of luminol and Ce:ZONFs via amidation and physical absorption. Luminol modified on Ce:ZONFs surface could generate a strong ECL signal under the assistance of reactive oxygen species (ROSs) (such as OH(•) and O2(•-)), which were produced by a catalytic reaction between Ce:ZONFs and H2O2. It was worth noticing that a quick Ce(4+) ↔ Ce(3+) reaction in this doped material could increase the rate of electron transfer to realize the signal amplification. Subsequently, the luminol functionalized Ce:ZONFs (Ce:ZONFs-Lum) were covered by secondary antibody (Ab2) and glucose oxidase (GOD), respectively, to construct a novel Ab2 bioconjugate (Ab2-GOD@Ce:ZONFs-Lum). The wire-structured silver-cysteine complex (AgCys NWs) with a large number of -COOH, which was synthesized by AgNO3 and l-cysteine, was used as substrate of the immunosensor to capture the primary antibody (Ab1). Under the optimal conditions, this proposed ECL immunosensor had exhibited high sensitivity for Aβ detection with a wide linear range from 80 fg/mL to 100 ng/mL and an ultralow detection limit of 52 fg/mL. Meanwhile, this biosensor had good specificity for Aβ, indicating that the provided strategy had a promising potential in the detection of Aβ.

Pharmacokinetic of pseudoephedrine in rat serum with luminol-pepsin chemiluminescence system by flow injection analysis.

PubMed

Luo, Kai; Li, Yajuan; Zheng, Xiaohui; Song, Zhenghua

2015-02-01

Pepsin (Pep) accelerated the electron transferring rate of excited 3-aminophathlate and enhanced luminol-dissolved oxygen chemiluminescence (CL) intensity, and the flow injection (FI) luminol-Pep CL system was first developed. It was found that the CL intensity of luminol-Pep reaction could be remarkably inhibited by pseudoephedrine (PE); the decrement of CL intensity was linear to the logarithm of PE concentration in the range of 0.1∼100.0 nmol L(-1) with a detection limit of 0.03 nmol mL(-1) (3σ). At a flow rate of 2.0 mL min(-1), the complete process including washing and sampling was performed within 40 s, offering a sample throughput of 90 h(-1). This proposed method was successfully applied to determining PE in rat serum for 18 h after intragastric administration with the elimination ratio of 42.34 % and recoveries from 90.3 to 110.6 %. The pharmacokinetic results showed that PE could be rapidly absorbed into serum with peak concentration (C max) of 1.45 ± 0.18 g L(-1) at the time (T max) of 1.49 ± 0.02 h; the absorption half-life (0.35 ± 0.04 h), elimination half-life (1.86 ± 0.24 h), the area under curve (109.81 ± 6.03 mg L(-1) h(-1)), mean residence time (3.82 ± 0.27 h), and elimination rate constant (2.26 ± 0.23 L g(-1) h(-1)) in rats vivo were derived, respectively. The possible CL mechanism of luminol-Pep-PE reaction was discussed by FI-CL, fluorescence, and molecular docking (MD) methods.

Application of response surface methodology (RSM) to the optimization of a post-column luminol chemiluminescence analysis of silyl peroxides.

PubMed

Baj, Stefan; Słupska, Roksana; Krawczyk, Tomasz

2013-01-15

The possibility of the utilization of chemiluminescence post-column luminol oxidation (CL) in a HPLC system for silyl peroxides analysis has been investigated. The conditions of HPLC separation for 12 silyl peroxides, representing bissilyl and alkyl-silyl peroxides, as well as their potential impurities, were established. Optimal chemiluminescent post-column reaction conditions were found using central composite design (CCD) and response surface methodology (RSM). The interaction effects of four of the most important operating variables - the concentrations of luminol, hemin, sodium hydroxide and the post-column solution flow rate - on the light intensity were evaluated. The optimized conditions for analysis were the same for bissilyl and alkyl-silyl peroxides for the base concentration (0.03 M), the luminol concentration (0.4 g L(-1)) and the hemin concentration (0.3 g L(-1)). The only differences occurred in a reagent flow rate (for bissilyl peroxide -0.3 mL min(-1) and for alkyl-silyl peroxides -0.9 mL min(-1)). Under optimal conditions, the detection limits were in the 0.07-0.16 nM range for bissilyl, and 0.53-1.01 for alkyl-silyl peroxides. The calibration curves were linear in the 0.25-3 nM range for bissilyl and the 2.5-25 range for alkyl-silyl peroxides. Intra-day and inter-day precision was lower than 5.5% for each tested concentration level. A mechanism of luminol oxidation by silyl peroxides involving a hydrolysis step with the formation of hydrogen peroxide or hydroperoxide was proposed. Copyright © 2012 Elsevier B.V. All rights reserved.

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.

Forensic Luminol Blood Test for Preventing Cross-contamination in Dentistry: An Evaluation of a Dental School Clinic

PubMed Central

Bortoluzzi, Marcelo Carlos; Cadore, Peterson; Gallon, Andrea; Imanishi, Soraia Almeida Watanabe

2014-01-01

Background: More than 200 different diseases may be transmitted from exposure to blood in the dental setting. The aim of this study is to identify possible faults in the crosscontamination chain control in a dental school clinic searching for traces of blood in the clinical contact surfaces (CCS) through forensic luminol blood test. Methods: Traces of invisible blood where randomly searched in CCS of one dental school clinic. Results: Forty eight surfaces areas in the CCS were tested and the presence of invisible and remnant blood was identified in 28 (58.3%) items. Conclusions: We suggest that the luminol method is suitable for identifying contamination with invisible blood traces and this method may be a useful tool to prevent cross-contamination in the dental care setting. PMID:25400895

Synthesis, characterization of dihydrolipoic acid capped gold nanoparticles, and functionalization by the electroluminescent luminol.

PubMed

Roux, Stéphane; Garcia, Bruno; Bridot, Jean-Luc; Salomé, Murielle; Marquette, Christophe; Lemelle, Laurence; Gillet, Phillipe; Blum, Loïc; Perriat, Pascal; Tillement, Olivier

2005-03-15

The use of gold nanoparticles as biological probes requires the improvement of colloidal stability. Dihydrolipoic acid (DHLA), a dithiol obtained by the reduction of thioctic acid, appears therefore very attractive for the stabilization and the further functionalization of gold nanoparticles because DHLA is characterized by a carboxylic acid group and two thiol functions. The ionizable carboxylic acid groups ensure, for pH > or = 8, the water solubility of DHLA-capped gold (Au@DHLA) nanoparticles, prepared by the Brust protocol, and the stability of the resulting colloid by electrostatic repulsions. Moreover almost all DHLA, adsorbed onto gold, adopts a conformation allowing their immobilization by both sulfur ends. It is proved by sulfur K-edge X-ray absorption near edge structure spectroscopy, which appears as an appropriate tool for determining the chemical form of sulfur atoms present in the organic monolayer. Such a grafting renders the DHLA monolayers more resistant to displacement by dithiothreitol than mercaptoundecanoic acid monolayers. The presence of DHLA on gold particles allows their functionalization by the electroluminescent luminol through amine coupling reactions assisted by 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide. As a luminol-functionalized particle is nine times as bright as a single luminol molecule, the use of the particles as a biological probe with a lower threshold of detection is envisaged.

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.

Co-metal-organic-frameworks with pure uniform crystal morphology prepared via Co2 + exchange-mediated transformation from Zn-metallogels for luminol catalysed chemiluminescence

NASA Astrophysics Data System (ADS)

Tang, Xue Qian; Xiao, Bo Wen; Li, Chun Mei; Wang, Dong Mei; Huang, Cheng Zhi; Li, Yuan Fang

2017-03-01

Cation exchange-mediated transformation from Zn-metallogels (MOGs), which was a mild facile strategy relative to the demanding hydrothermal method, was employed to develop Co2 + metal-organic frameworks (Co-MOFs) at room temperature. The obtained Co-MOFs was of uniform octahedral morphology and possessed high activity to catalyze luminol chemiluminescence without extra oxidants. By adding cysteine, the CL emission of luminol-Co-MOFs system was further enhanced. Based on this phenomenon, Co-MOFs was utilized to build a practical sensing platform for cysteine determination. Under the optimized conditions, the relative CL intensity (ΔI) was proportional to the concentration of cysteine in the range of 2-10 μM, and the detection limit was 0.49 μM (3S/N). Moreover, the established method was applied to the determination of cysteine in commercially available pharmaceutical injections.

Electrochemical Visualization of Intracellular Hydrogen Peroxide at Single Cells.

PubMed

He, Ruiqin; Tang, Huifen; Jiang, Dechen; Chen, Hong-yuan

2016-02-16

In this Letter, the electrochemical visualization of hydrogen peroxide inside one cell was achieved first using a comprehensive Au-luminol-microelectrode and electrochemiluminescence. The capillary with a tip opening of 1-2 μm was filled with the mixture of chitosan and luminol, which was coated with the thin layers of polyvinyl chloride/nitrophenyloctyl ether (PVC/NPOE) and gold as the microelectrode. Upon contact with the aqueous hydrogen peroxide, hydrogen peroxide and luminol in contact with the gold layer were oxidized under the positive potential resulting in luminescence for the imaging. Due to the small diameter of the electrode, the microelectrode tip was inserted into one cell and the bright luminescence observed at the tip confirmed the visualization of intracellular hydrogen peroxide. The further coupling of oxidase on the electrode surface could open the field in the electrochemical imaging of intracellular biomolecules at single cells, which benefited the single cell electrochemical detection.

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.

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.

Actinometric measurement of j(O3-O(1D)) using a luminol detector

NASA Technical Reports Server (NTRS)

Bairai, Solomon T.; Stedman, Donald H.

1992-01-01

The photolysis frequency of ozone to singlet D oxygen atoms has been measured by means of a chemical actinometer using a luminol based detector. The instrument measures j(O3-O(1D)) with a precision of 10 percent. The data collected in winter and spring of 1991 is in agreement with model predictions and previously measured values. Data from a global solar radiometer can be used to estimate the effects of local cloudiness on j(O3-O(1D)).

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.

Co-metal-organic-frameworks with pure uniform crystal morphology prepared via Co2+ exchange-mediated transformation from Zn-metallogels for luminol catalysed chemiluminescence.

PubMed

Tang, Xue Qian; Xiao, Bo Wen; Li, Chun Mei; Wang, Dong Mei; Huang, Cheng Zhi; Li, Yuan Fang

2017-03-15

Cation exchange-mediated transformation from Zn-metallogels (MOGs), which was a mild facile strategy relative to the demanding hydrothermal method, was employed to develop Co 2+ metal-organic frameworks (Co-MOFs) at room temperature. The obtained Co-MOFs was of uniform octahedral morphology and possessed high activity to catalyze luminol chemiluminescence without extra oxidants. By adding cysteine, the CL emission of luminol-Co-MOFs system was further enhanced. Based on this phenomenon, Co-MOFs was utilized to build a practical sensing platform for cysteine determination. Under the optimized conditions, the relative CL intensity (ΔI) was proportional to the concentration of cysteine in the range of 2-10μM, and the detection limit was 0.49μM (3S/N). Moreover, the established method was applied to the determination of cysteine in commercially available pharmaceutical injections. Copyright © 2016 Elsevier B.V. All rights reserved.

Efficient generation of cavitation bubbles and reactive oxygen species using triggered high-intensity focused ultrasound sequence for sonodynamic treatment

NASA Astrophysics Data System (ADS)

Yasuda, Jun; Yoshizawa, Shin; Umemura, Shin-ichiro

2016-07-01

Sonodynamic treatment is a method of treating cancer using reactive oxygen species (ROS) generated by cavitation bubbles in collaboration with a sonosensitizer at a target tissue. In this treatment method, both localized ROS generation and ROS generation with high efficiency are important. In this study, a triggered high-intensity focused ultrasound (HIFU) sequence, which consists of a short, extremely high intensity pulse immediately followed by a long, moderate-intensity burst, was employed for the efficient generation of ROS. In experiments, a solution sealed in a chamber was exposed to a triggered HIFU sequence. Then, the distribution of generated ROS was observed by the luminol reaction, and the amount of generated ROS was quantified using KI method. As a result, the localized ROS generation was demonstrated by light emission from the luminol reaction. Moreover, it was demonstrated that the triggered HIFU sequence has higher efficiency of ROS generation by both the KI method and the luminol reaction emission.

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.

Observation of chemiluminescence induced by hydrodynamic cavitation in microchannels.

PubMed

Podbevsek, D; Colombet, D; Ledoux, G; Ayela, F

2018-05-01

We have performed hydrodynamic cavitation experiments with an aqueous luminol solution as the working fluid. Light emission, together with the high frequency noise which characterizes cavitation, was emitted by the two-phase flow, whereas no light emission from luminol was recorded in the single phase liquid flow. Light emission occurs downstream transparent microdiaphragms. The maximum level of the recorded signal was around 180 photons per second with flow rates of 380 µl/s, that corresponds to a real order of magnitude of the chemiluminescence of 75,000 photons per second. The yield of emitted photons increases linearly with the pressure drop, which is proportional to the square of the total flow rate. Chemiluminescence of luminol is a direct and a quantitative demonstration of the presence of OH hydroxyl radicals created by hydrodynamic cavitation. The presented method could be a key to optimize channel geometry for processes where radical production is essential. Copyright © 2018 Elsevier B.V. All rights reserved.

A new luminol chemiluminescence sensor for glucose based on pH-dependent graphene oxide.

PubMed

Hao, Minjia; Liu, Na; Ma, Zhanfang

2013-08-07

In this study, graphene oxide (GO) was found to catalyze the luminol-O2 reaction, which yielded a novel chemiluminescence (CL). Remarkably, the CL emission could be tuned by modulating the pH of the GO dispersion. Transmission electron microscopy, CL spectra, electron spin resonance spectra studies were carried out to investigate the CL mechanism. The results indicate that the CL emission was attributed to the intrinsic catalytic effect of GO acting as the radical generation proliferators and electron transfer accelerators. Based on the GO catalyzed luminol-O2 system, we successfully developed a new CL sensor to detect glucose. Under the optimized conditions, glucose could be assayed in the range of 0.05 mM to 5 mM with a detection limit of 0.044 mM. For the detection of clinical serum samples, it is well consistent with the data determined by commercially available method in hospital, indicating that the new CL method provides a possible application for the detection of glucose in clinical diagnostics.

Highly Efficient Intramolecular Electrochemiluminescence Energy Transfer for Ultrasensitive Bioanalysis of Aflatoxin M1.

PubMed

Liu, Jia-Li; Zhao, Min; Zhuo, Ying; Chai, Ya-Qin; Yuan, Ruo

2017-02-03

The intermolecular electrochemiluminescence resonance energy transfer (ECL-RET) between luminol and Ru(bpy) 3 2+ was studied extensively to achieve the sensitive bioanalysis owing to the perfect spectral overlap of the donor and acceptor, but it still suffers from the challenging issue of low energy-transfer efficiency. The intramolecular ECL-RET towards the novel ECL compound containing the donor of luminol and the acceptor of Ru(bpy) 2 (mcpbpy) 2+ (Lum-Ru) was designed and investigated. With the high-efficient ECL-RET in one molecule, the highly intense ECL signal of Lum-Ru was obtained owing to the short path of energy transmission and less energy loss between luminol and Ru(bpy) 2 (mcpbpy) 2+ . Lum-Ru was further applied to construct a signal-off electrochemiluminescence (ECL) aptasensor for ultrasensitive detection of a harsh carcinogen of Aflatoxin M1 (AFM1). This sensing platform also provides a significant boost for the trace detection of other biomolecules in clinical analysis. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Assay of picogram level isocarbophos residue on tangerines and oranges with luminol-albumin chemiluminescence system.

PubMed

Chen, Donghua; Song, Zhenghua; Lv, Hairu

2012-12-15

A sensitive flow injection-chemiluminescence (FI-CL) method for the determination of isocarbophos (ICP) residue on tangerines and oranges was proposed. It was found that the CL intensity from luminol-albumin CL reaction could be obviously quenched in the presence of ICP and the decrease in CL intensity was proportional to the logarithm of ICP concentrations ranging from 1.0 to 1000 pmol L(-1), giving the limit of detection of 0.3 pmol L(-1) (3σ). The proposed procedure was successfully applied to the determination of ICP residue on tangerines and oranges with recoveries varying from 92.0 to 111.0% and RSDs less than 5.0%. The possible CL mechanism of luminol-albumin-ICP reaction was discussed, and ICP to albumin's binding constant (K(D)=1.00 × 10(6) L mol(-1)) and the number of binding sites (n=1.00) were given by the homemade FI-CL model. Copyright © 2012 Elsevier Ltd. All rights reserved.

Flow-injection chemiluminescence method to detect a β2 adrenergic agonist.

PubMed

Zhang, Guangbin; Tang, Yuhai; Shang, Jian; Wang, Zhongcheng; Yu, Hua; Du, Wei; Fu, Qiang

2015-02-01

A new method for the detection of β2 adrenergic agonists was developed based on the chemiluminescence (CL) reaction of β2 adrenergic agonist with potassium ferricyanide-luminol CL. The effect of β2 adrenergic agonists including isoprenaline hydrochloride, salbutamol sulfate, terbutaline sulfate and ractopamine on the CL intensity of potassium ferricyanide-luminol was discovered. Detection of the β2 adrenergic agonist was carried out in a flow system. Using uniform design experimentation, the influence factors of CL were optimized. The optimal experimental conditions were 1 mmol/L of potassium ferricyanide, 10 µmol/L of luminol, 1.2 mmol/L of sodium hydroxide, a flow speed of 2.6 mL/min and a distance of 1.2 cm from 'Y2 ' to the flow cell. The linear ranges and limit of detection were 10-100 and 5 ng/mL for isoprenaline hydrochloride, 20-100 and 5 ng/mL for salbutamol sulfate, 8-200 and 1 ng/mL for terbutaline sulfate, 20-100 and 4 ng/mL for ractopamine, respectively. The proposed method allowed 200 injections/h with excellent repeatability and precision. It was successfully applied to the determination of three β2 adrenergic agonists in commercial pharmaceutical formulations with recoveries in the range of 96.8-98.5%. The possible CL reaction mechanism of potassium ferricyanide-luminol-β2 adrenergic agonist was discussed from the UV/vis spectra. Copyright © 2014 John Wiley & Sons, Ltd.

Gold nanoparticles based chemiluminescent resonance energy transfer for immunoassay of alpha fetoprotein cancer marker.

PubMed

Huang, Xiangyi; Ren, Jicun

2011-02-07

In this paper, we report a new strategy of chemiluminescence resonance energy transfer (CRET) by using gold nanoparticles (AuNPs) as efficient long-range energy acceptor in sandwich immunoassays. In the design of CRET system, we chose the highly sensitive chemiluminescence (CL) reaction of luminol and hydrogen peroxide catalysed by horseradish peroxidase (HRP) because the CL spectrum of luminol (λ(max) 425 nm) partially overlaps with the visible absorption bands of AuNPs. On the basis of CRET strategy, we developed a sandwich immunoassay of alpha fetoprotein (AFP) cancer marker. In immunoassay, two antibodies (anti-AFP-1 and anti-AFP-2) were conjugated to AuNPs and horseradish peroxidase (HRP), respectively. The sandwich-type immunoreactions between the AFP (antigen) and the two different antibodies bridged the donors (luminol) and acceptors (AuNPs), which led to the occurrence of CRET from luminol to AuNPs upon chemiluminescent reaction. We observed that the quenching of chemiluminescence signal depended linearly on the AFP concentration within a range of concentration from 5 to 70 ng mL(-1) and the detection limit of AFP was 2.5 ng mL(-1). Our method was successfully applied for determination of AFP levels in sera from cancer patients, and the results were in good agreement with ELISA assays. This approach is expected to be extended to other assay designs, that is, using other antibodies, analytes, chemiluminescent substance, and even other metallic nanoparticles. Copyright © 2010 Elsevier B.V. All rights reserved.

Inhibition of peripheral blood neutrophil oxidative burst in periodontitis patients with a homeopathic medication Traumeel S

PubMed Central

žilinskas, Juozas; žekonis, Jonas; žekonis, Gediminas; Šadzevičienė, Renata; Sapragonienė, Marija; Navickaitė, Justina; Barzdžiukaitė, Ingrida

2011-01-01

Summary Background The anti-inflammatory effects of a homeopathic remedy, Traumeel S, have been observed in experimental and clinical studies; however, its antioxidant properties have not been elucidated. The aim of the present study was to evaluate the antioxidant effects of Traumeel S on peripheral blood neutrophils in patients with periodontitis. Material/Methods The study was performed using venous blood of 22 individuals with chronic periodontitis and 21 healthy subjects. The antioxidant effects of Traumeel S on the production of reactive oxygen species by unstimulated and stimulated with unopsonized E. coli neutrophils were investigated using luminol- and lucigenin-dependent chemiluminescence (CL). Results Polymorphonuclear leukocytes of periodontitis patients produced higher levels (p<0.01) of light output of lucigenin-dependent chemiluminescence and significantly reduced (p<0.01) light output of luminol-dependent chemiluminescence than analogous cells of healthy subjects. Highly diluted (10−4 of the stem solution) Traumeel S significantly (by approximately 50%) reduced superoxide-induced oxidation of lucigenin by unstimulated and stimulated with unopsonized E. coli polymorphonuclear leukocytes of periodontitis patients and had a tendency to intensify luminol-dependent chemiluminescence. Preincubation of the unstimulated and stimulated with unopsonized E. coli polymorphonuclear leukocytes of healthy subjects with Traumeel S exerts no inhibitory action on the luminol- and lucigenin-dependent chemiluminescence of the above-mentioned cells. Conclusions This study indicates that Traumeel S may significantly reduce production of superoxide anion by unstimulated and stimulated peripheral blood polymorphonuclear neutrophils of periodontitis patients. PMID:21525811

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.

Electrochemiluminescence of luminol enhanced by the synergetic catalysis of hemin and silver nanoparticles for sensitive protein detection.

PubMed

Jiang, Xinya; Chai, Yaqin; Wang, Haijun; Yuan, Ruo

2014-04-15

A novel and ultrasensitive electrochemiluminescence (ECL) immunosensor, which was based on the amplifying ECL of luminol by hemin-reduced graphene oxide (hemin-rGO) and Ag nanoparticles (AgNPs) decorated reduced graphene oxide (Ag-rGO), was constructed for the detection of carcinoembryonic antigen (CEA). For this proposed sandwich-type ECL immunosensor, Au nanoparticles electrodeposited (DpAu) onto hemin-rGO (DpAu/hemin-rGO) constructed the base of the immunosensor. DpAu had outstanding electrical conductivity to promote the electron transfer at the electrode interface and had good biocompatibility to load large amounts of primary antibody (Ab1), which provided an excellent platform for this immunosensor. Moreover, AgNPs and glucose oxidase (GOD) functionalized graphene labeled secondary antibody (Ag-rGO-Ab2-GOD) was designed as the signal probe for the sandwiched immunosensor. Not only did the hemin-rGO improve the electron transfer of the electrode surface, but hemin also further amplified the ECL signal of luminol in the presence of hydrogen peroxide (H2O2). With the aid of Ag-rGO-Ab2-GOD, enhanced signal was obtained by in situ generation of H2O2 and catalysis of AgNPs to ECL reaction of the luminol-H2O2 system. The as-prepared ECL immunosensor exhibited excellent analytical property for the detection of CEA in the range from 0.1 pg mL(-1) to 160 ng mL(-1) with a detection limit of 0.03 pg mL(-1) (SN(-1)=3). © 2013 Published by Elsevier B.V.

In vitro screening of Fe2+-chelating effect by a Fenton's reaction-luminol chemiluminescence system.

PubMed

Wada, Mitsuhiro; Komatsu, Hiroaki; Ikeda, Rie; Aburjai, Talal A; Alkhalil, Suleiman M; Kuroda, Naotaka; Nakashima, Kenichiro

2014-11-01

In vitro screening of a Fe(2+) -chelating effect using a Fenton's reaction-luminol chemiluminescence (CL) system is described. The luminescence between the reactive oxygen species generated by the Fenton's reaction and luminol was decreased on capturing Fe(2+) using a chelator. The proposed method can prevent the consumption of expensive seed compounds (drug discovery candidates) owing to the high sensitivity of CL detection. Therefore, the assay could be performed using small volumes of sample solution (150 μL) at micromolar concentrations. After optimization of the screening conditions, the efficacies of conventional chelators such as ethylenediaminetetraacetic acid (EDTA), diethylentriaminepentaacetic acid (DETAPAC), deferoxamine, deferiprone and 1,10-phenanthroline were examined. EC50 values for these compounds (except 1,10-phenanthroline) were in the range 3.20 ± 0.87 to 9.57 ± 0.64 μM (n = 3). Rapid measurement of the Fe(2+)-chelating effect with an assay run time of a few minutes could be achieved using the proposed method. In addition, the specificity of the method was discussed. Copyright © 2014 John Wiley & Sons, Ltd.

Study on a Luminol-based Electrochemiluminescent Sensor for Label-Free DNA Sensing

PubMed Central

Chu, Hai-Hong; Yan, Ji-Lin; Tu, Yi-Feng

2010-01-01

Automatic, inexpensive, simple and sensitive methods for DNA sensing and quantification are highly desirable for biomedical research. The rapid development of both the fundamentals and applications of electrochemiluminescence (ECL) over the past years has demonstrated its potential for analytical and bio-analytical chemistry. This paper reports the quenching effect of DNA on the ECL of luminol and the further development of a DNA sensing device. With the pre-functionalization by a composite of carbon nano-tubes (CNTs) and Au nanoparticles (AuNPs), the sensor provides a novel and valuable label-free approach for DNA sensing. Here the ECL intensity was remarkably decreased when more than 1.0 × 10−12 molar of DNA were adsorbed on the sensor. Linearity of the DNA amount with the reciprocal of ECL intensity was observed. A saturated sensor caused a 92.8% quenching effect. The research also proposes the mechanism for the quenching effect which could be attributed to the interaction between luminol and DNA and the elimination of reactive oxygen species (ROSs) by DNA. PMID:22163421

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.

Self-assembly of organogels via new luminol imide derivatives: diverse nanostructures and substituent chain effect

PubMed Central

2013-01-01

Luminol is considered as an efficient sycpstem in electrochemiluminescence (ECL) measurements for the detection of hydrogen peroxide. In this paper, new luminol imide derivatives with different alkyl substituent chains were designed and synthesized. Their gelation behaviors in 26 solvents were tested as novel low molecular mass organic gelators. It was shown that the length and number of alkyl substituent chains linked to a benzene ring in gelators played a crucial role in the gelation behavior of all compounds in various organic solvents. Longer alkyl chains in molecular skeletons in present gelators are favorable for the gelation of organic solvents. Scanning electron microscope and atomic force microscope observations revealed that the gelator molecules self-assemble into different micro/nanoscale aggregates from a dot, flower, belt, rod, and lamella to wrinkle with change of solvents. Spectral studies indicated that there existed different H-bond formations and hydrophobic forces, depending on the alkyl substituent chains in molecular skeletons. The present work may give some insight to the design and characteristic of new versatile soft materials and potential ECL biosensors with special molecular structures. PMID:23758979

Self-assembly of organogels via new luminol imide derivatives: diverse nanostructures and substituent chain effect

NASA Astrophysics Data System (ADS)

Jiao, Tifeng; Huang, Qinqin; Zhang, Qingrui; Xiao, Debao; Zhou, Jingxin; Gao, Faming

2013-06-01

Luminol is considered as an efficient sycpstem in electrochemiluminescence (ECL) measurements for the detection of hydrogen peroxide. In this paper, new luminol imide derivatives with different alkyl substituent chains were designed and synthesized. Their gelation behaviors in 26 solvents were tested as novel low molecular mass organic gelators. It was shown that the length and number of alkyl substituent chains linked to a benzene ring in gelators played a crucial role in the gelation behavior of all compounds in various organic solvents. Longer alkyl chains in molecular skeletons in present gelators are favorable for the gelation of organic solvents. Scanning electron microscope and atomic force microscope observations revealed that the gelator molecules self-assemble into different micro/nanoscale aggregates from a dot, flower, belt, rod, and lamella to wrinkle with change of solvents. Spectral studies indicated that there existed different H-bond formations and hydrophobic forces, depending on the alkyl substituent chains in molecular skeletons. The present work may give some insight to the design and characteristic of new versatile soft materials and potential ECL biosensors with special molecular structures.

On the interaction of luminol with human serum albumin: Nature and thermodynamics of ligand binding

NASA Astrophysics Data System (ADS)

Moyon, N. Shaemningwar; Mitra, Sivaprasad

2010-09-01

The mechanism and thermodynamic parameters for the binding of luminol (LH 2) with human serum albumin was explored by steady state and picosecond time-resolved fluorescence spectroscopy. It was shown that out of two possible LH 2 conformers present is solution, only one is accessible for binding with HSA. The thermodynamic parameters like enthalpy (Δ H) and entropy (Δ S) change corresponding to the ligand binding process were also estimated by performing the experiment at different temperatures. The ligand replacement experiment with bilirubin confirms that LH 2 binds into the sub-domain IIA of the protein.

Pyrophosphate as substrate for alkaline phosphatase activity: A convenient flow-injection chemiluminescence assay.

PubMed

Zhang, Qingfeng; Zhang, Cuiyun; Yang, Meiding; Yu, Donghong; Yu, Cong

2017-11-01

A sensitive and convenient flow-injection chemiluminescence (FI-CL) turn-on assay for alkaline phosphatase (ALP) activity without any label and synthesis is developed. Cu 2+ can catalyze the luminol-H 2 O 2 CL reaction. Pyrophosphate (PPi) can chelate Cu 2+ and therefore the Cu 2+ -mediated luminol-H 2 O 2 CL reaction is inhibited. The addition of ALP can catalyze the hydrolysis of PPi into phosphate ions, Cu 2+ is released and the chemiluminescence recovers. A detection limit of 1 mU/mL ALP is obtained. Copyright © 2017 John Wiley & Sons, Ltd.

Switch-on fluorescence scheme for antibiotics based on a magnetic composite probe with aptamer and hemin/G-quadruplex coimmobilized nano-Pt-luminol as signal tracer.

PubMed

Miao, Yang-Bao; Gan, Ning; Ren, Hong-Xia; Li, Tianhua; Cao, Yuting; Hu, Futao; Chen, Yinji

2016-01-15

A selective and facile fluorescence "switch-on" scheme is developed to detect antibiotics residues in food, using chloramphenicol (CAP) as model, based on a novel magnetic aptamer probe (aptamer-Pt-luminol nanocomposite labeled with hemin/G-quadruplex). Firstly, the composite probe is prepared through the immuno-reactions between the capture beads (anti-dsDNA antibody labeled on magnetic Dynabeads) and the nanotracer (nano-Pt-luminol labeled with double-strand aptamer, as ds-Apt, and hemin/G-quadruplex). When the composite probe is mixed with CAP, the aptamer preferentially reacted with CAP to decompose the double-strand aptamer to ssDNA, which cannot be recognized by the anti-dsDNA antibody on the capture probes. Thus, after magnetic separation, the nanotracer can be released into the supernatant. Because the hemin/G-quadruplex and PtNPs in nanotracer can catalyze luminol-H2O2 system to emit fluorescence. Thus a dual-amplified "switch-on" signal appeared, of which intensity is proportional to the concentration of CAP between 0.001 and 100ng mL(-1) with detection limit of 0.0005ng mL(-1) (S/N=3). Besides, our method has good selectivity and was employed for CAP detection in real milk samples. The results agree well with those from conventional gas chromatograph-mass spectrometer (GC-MS). The switch-on signal is produced by one-step substitution reaction between aptamer in nanotracer and target. When the analyte is changed, the probe can be refabricated only by changing the corresponding aptamer. Thus, all features above prove our strategy to be a facile, feasible and selective method in antibiotics screening for food safety. Copyright © 2015 Elsevier B.V. All rights reserved.

Study of chemiluminescence measured by luminometry and its application in the estimation of postmortem interval of bone remains.

PubMed

Sarabia, Jesús; Pérez-Martínez, Cristina; Hernández Del Rincón, Juan Pedro; Luna, Aurelio

2018-05-05

A substantial challenge faced by forensic medicine is determining the postmortem interval (PMI) of skeletonized remains. Currently, the luminol method is of limited forensic usefulness, since it uses qualitative and subjective methods to estimate PMI by the naked eye assessing the degree of chemiluminescence (CL) emitted by bone remains, a technique which is not sensitive enough to distinguish between historical or forensically significant time intervals. The aim of the present study was to use a direct and accurate measurement of the CL by luminol technique in relative light units (RLU) using a luminometer to establish this method as a possible complementary and low cost tool for the determination of the PMI for distinguishing between remains of medical-legal (<20 years) and historical (≥20 years) interest in 102 femur remains with a range of PMI between 15 and 64 years. The results suggest that, under favorable conditions, the luminol technique can detect haemoglobin in the bone in a PMI range of 0-65 years, finding significant differences in the CL intensity among samples with PMI < 20 years and PMI ≥ 20 years. In addition, the intensities of CL measured at 10 s, 15 s and 20 s after reaction with luminol show a statistically significant inverse relationship with PMI in the bone studied, following a decreasing logarithmic model. The conclusion is that this quantitative, objective and contrastable technique could be very useful for determining the PMI in bone remains, since it allows a good degree of precision and eliminates the subjectivity introduced by qualitative techniques. Copyright © 2018 Elsevier B.V. All rights reserved.

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.

Highly specific detection of H2O2-dependent luminol chemiluminescence in stimulated human leukocytes using polyvinyl films.

PubMed

Moriguchi, K; Ohno, N; Ogawa, T; Hirai, K

1999-01-01

When human polymorphonuclear leukocytes (PMN) were attached to glass coverslips, cells always spread and formed reactive oxygen species prior to any experimental stimulation. To avoid this, a polyvinylidine chloride film was used as an inactive substance to place the cells. Cells engaged in phagocytosis on the film exhibited a specific H2O2-mediated luminol chemiluminescence (LCL) at the cell-particle interface; the cells stimulated with 12-O-tetradecanoylphorbol-13-acetate became aggregated and the LCL was observed at the cell-cell contact. These results corresponded well with those obtained by an electron microscopic H2O2-demonstration method.

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.

Effect of bacterial stimulants on release of reactive oxygen metabolites from peripheral blood neutrophils in periodontitis.

PubMed

Zekonis, Gediminas; Zekonis, Jonas

2004-01-01

The aim of the present investigation was to explore the oxidative activity of peripheral blood polymorphonuclear neutrophils of periodontitis patients and of healthy subjects stimulated with non-opsonized E. coli and lipopolysaccharide of E. coli. The leukocytes for this study were obtained from peripheral venous blood of 22 parodontitis patients and 16 healthy subjects. Oxidative activity of peripheral blood polymorphonuclear neutrophils was measured by method of the luminol-dependent chemiluminescence. The luminol-dependent chemiluminescence of stimulated neutrophils of periodontitis patients with non-opsonized E. coli increased less significantly (p<0.001) as compared to analogous chemiluminescence of control subjects (147126+/-8386 cpm and 189247+/-9134 cpm, respectively). However, the luminol-dependent chemiluminescence of stimulated neutrophils of periodontitis patients with lipopolysaccharide was five times higher than that of the subjects with intact periodontal tissues and comprised 13261+/-1251 cpm and 2627+/-638 cpm, respectively. Our study results show a complex dependence of oxidative function of peripheral polymorphonuclear neutrophils of periodontitis patients upon the nature of stimulants. Therefore further attempts should be made to evaluate its significance in the etiopathogenesis of periodontal tissue diseases of inflammatory origin.

Luminol testing in detecting modern human skeletal remains: a test on different types of bone tissue and a caveat for PMI interpretation.

PubMed

Caudullo, Giorgio; Caruso, Valentina; Cappella, Annalisa; Sguazza, Emanuela; Mazzarelli, Debora; Amadasi, Alberto; Cattaneo, Cristina

2017-01-01

When forensic pathologists and anthropologists have to deal with the evaluation of the post-mortem interval (PMI) in skeletal remains, luminol testing is frequently performed as a preliminary screening method. However, the repeatability of this test on the same bone, as well as comparative studies on different bones of the same individual, has never been performed. Therefore, with the aim of investigating the influence that different types of bones may exert on the response to the luminol test, the present study analysed three different skeletal elements (femoral diaphysis, vertebra and cranial vault), gathered from ten recent exhumed skeletons (all with a 20-year PMI). The analysis was performed twice on the same bone after 2 months: the analysis at time 0 concerned the whole bone, whereas the second concerned only a part of the same bone taken during the first test (which already had been broken). The overall results showed different responses, depending on the type of bone and on the integrity of the samples. Negative results at the first analysis (6.6% out of the total of samples) are consistent with what is reported in the literature, whilst at the second analysis, the increase of about 20% of false-negative results highlights that the luminol test ought to be performed with caution in case of broken bones or elements which are taphonomically altered. Results have thus proven that the exposition to environmental agents might result in haemoglobin (Hb) loss, as detected even after only 2 months. The study also focused on the crucial issue of the type of bone subjected to testing, remarking the suitability of the femoral diaphysis (100% of positive responses at the first analysis vs only 18% of false-negative results at the second test, corresponding to 5% of total false-negative results) as opposed to other bone elements that showed a low yield. In particular, the cranial vault gave poor results, with 40% of discrepancy between results from the two analyses, which suggests caution in choosing the type of bone sample to test. In conclusion, luminol testing should be used with caution on bones different from long bones or on non-intact bones.

Fiber-Optic Chemiluminescent Biosensors for Monitoring Aqueous Alcohols and Other Water Quality Parameters

NASA Technical Reports Server (NTRS)

Verostko, Charles E. (Inventor); Atwater, James E. (Inventor); Akse, James R. (Inventor); DeHart, Jeffrey L. (Inventor); Wheeler, Richard R. (Inventor)

1998-01-01

A "reagentless" chemiluminescent biosensor and method for the determination of hydrogen peroxide, ethanol and D-glucose in water is disclosed. An aqueous stream is basified by passing it through a solid phase base bed. Luminol is then dissolved in the basified effluent at a controlled rate. Oxidation of the luminol is catalyzed by the target chemical to produce emitted light. The intensity of the emitted light is detected as a measure of the target chemical concentration in the aqueous stream. The emitted light can be transmitted by a fiber optic bundle to a remote location from the aqueous stream for a remote reading of the target chemical concentration.

Chemiluminescence studies between aqueous phase synthesized mercaptosuccinic acid capped cadmium telluride quantum dots and luminol-H2O2

NASA Astrophysics Data System (ADS)

Kaviyarasan, Kulandaivelu; Anandan, Sambandam; Mangalaraja, Ramalinga Viswanathan; Asiri, Abdullah M.; Wu, Jerry J.

2016-08-01

Mercaptosuccinic acid capped Cadmium telluride quantum dots have been successfully synthesized via aqueous phase method. The products were well characterized by a number of analytical techniques, including FT-IR, XRD, HRTEM, and a corrected particle size analysis by the statistical treatment of several AFM measurements. Chemiluminescence experiments were performed to explore the resonance energy transfer between chemiluminescence donor (luminol-H2O2 system) and acceptor CdTe QDs. The combination of such donor and acceptor dramatically reduce the fluorescence while compared to pristine CdTe QDs without any exciting light source, which is due to the occurrence of chemiluminescence resonance energy transfer (CRET) processes.

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.

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.

Pre-evaluation of metal ions as a catalyst on chemiluminometric sequential injection analysis with luminol-H2O2 system.

PubMed

Takayanagi, Toshio; Inaba, Yuya; Kanzaki, Hiroyuki; Jyoichi, Yasutaka; Motomizu, Shoji

2009-09-15

Catalytic effect of metal ions on luminol chemiluminescence (CL) was investigated by sequential injection analysis (SIA). The SIA system was set up with two solenoid micropumps, an eight-port selection valve, and a photosensor module with a fountain-type chemiluminescence cell. The SIA system was controlled and the CL signals were collected by a LabVIEW program. Aqueous solutions of luminol, H(2)O(2), and a sample solution containing metal ion were sequentially aspirated to the holding coil, and the zones were immediately propelled to the detection cell. After optimizing the parameters using 1 x 10(-5)M Fe(3+) solution, catalytic effect of some metal species was compared. Among 16 metal species examined, relatively strong CL responses were obtained with Fe(3+), Fe(2+), VO(2+), VO(3)(-), MnO(4)(-), Co(2+), and Cu(2+). The limits of detection by the present SIA system were comparable to FIA systems. Permanganate ion showed the highest CL sensitivity among the metal species examined; the calibration graph for MnO(4)(-) was linear at the concentration level of 10(-8)M and the limit of detection for MnO(4)(-) was 4.0 x 10(-10)M (S/N=3).

Highly sensitive luminol electrochemiluminescence immunosensor based on ZnO nanoparticles and glucose oxidase decorated graphene for cancer biomarker detection.

PubMed

Cheng, Yinfeng; Yuan, Ruo; Chai, Yaqin; Niu, Huan; Cao, Yaling; Liu, Huijing; Bai, Lijuan; Yuan, Yali

2012-10-01

In this work, we reported a sandwiched luminol electrochemiluminescence (ECL) immunosensor using ZnO nanoparticles (ZnONPs) and glucose oxidase (GOD) decorated graphene as labels and in situ generated hydrogen peroxide as coreactant. In order to construct the base of the immunosensor, a hybrid architecture of Au nanoparticles and graphene by reduction of HAuCl(4) and graphene oxide (GO) with ascorbic acid was prepared. The resulted hybrid architecture modified electrode provided an excellent platform for immobilization of antibody with good bioactivity and stability. Then, ZnONPs and GOD functionalized graphene labeled secondary antibody was designed for fabricating a novel sandwiched ECL immunosensor. Enhanced sensitivity was obtained by in situ generating hydrogen peroxide with glucose oxidase and the catalysis of ZnONPs to the ECL reaction of luminol-H(2)O(2) system. The as-prepared ECL immunosensor exhibited excellent analytical property for the detection of carcinoembryonic antigen (CEA) in the range from 10 pg mL(-1) to 80 ng mL(-1) and with a detection limit of 3.3 pg mL(-1) (SN(-1)=3). The amplification strategy performed good promise for clinical application of screening of cancer biomarkers. Copyright © 2012 Elsevier B.V. All rights reserved.

Measurement of peroxy radicals in the urban atmosphere by PERCA-LIF technique

NASA Astrophysics Data System (ADS)

Sadanaga, Y.; Matsumoto, J.; Sakurai, K.; Kato, S.; Nomaguchi, T.; Bandow, H.; Kajii, Y.

2002-12-01

A new instrument has been developed for measuring peroxy radicals (RO2) using the Chemical Amplifier-Laser Induced Fluorescence (PERCA-LIF) technique. RO2 was converted to NO2 via a chain reaction by the addition of NO and CO in a 1/4" Teflon tube. NO2 was detected by LIF using Nd:YAG laser (532 nm, 5W at 10kHz). More selective detection of NO2 is enabled by the LIF than by luminol chemiluminescence because of free from the interference by other oxidants when using luminol. LIF technique can be more sensitive detection of NO2 than the luminol detector. Optimum conditions were investigated by varying reaction time (i.e. the length of reaction tube) and the concentrations of NO and CO. Maximum chain length of approximately 300 was obtained in dry conditions using a H2O/O2 simultaneous photolysis method. Experiments were performed to characterize the dependence of the chain length on humidity for this instrument. In August 2002, RO2 measurements were performed in Osaka using this method. Maximum concentrations of RO2 in the daytime were approximately 100 pptv. Nighttime observations were also conducted and significant concentrations of RO2 were detected just after the sunset. Existence of formation processes in the dark condition was investigated.

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.

Detection of reactive oxygen metabolites in malignant and adjacent normal tissues of patients with lung cancer.

PubMed

Okur, Hacer Kuzu; Yuksel, Meral; Lacin, Tunc; Baysungur, Volkan; Okur, Erdal

2013-01-17

Different types of reactive oxygen metabolites (ROMs) are known to be involved in carcinogenesis. Several studies have emphasized the formation of ROMs in ischemic tissues and in cases of inflammation. The increased amounts of ROMs in tumor tissues can either be because of their causative effects or because they are produced by the tumor itself. Our study aimed to investigate and compare the levels of ROMs in tumor tissue and adjacent lung parenchyma obtained from patients with lung cancer. Fifteen patients (all male, mean age 63.6 ± 9 years) with non-small cell lung cancer were enrolled in the study. All patients were smokers. Of the patients with lung cancer, twelve had epidermoid carcinoma and three had adenocarcinoma. During anatomical resection of the lung, tumor tissue and macroscopically adjacent healthy lung parenchyma (control) that was 5 cm away from the tumor were obtained. The tissues were freshly frozen and stored at -20°C. The generation of ROMs was monitored using luminol- and lucigenin-enhanced chemiluminescence (CL) techniques. Both luminol (specific for (.)OH, H(2)O(2), and HOCl(-)) and lucigenin (selective for O(2)(.)(-)) CL measurements were significantly higher in tumor tissues than in control tissues (P <0.001). Luminol and lucigenin CL measurements were 1.93 ± 0.71 and 2.5 ± 0.84 times brighter, respectively, in tumor tissues than in the adjacent parenchyma (P = 0.07). In patients with lung cancer, all ROM levels were increased in tumor tissues when compared with the adjacent lung tissue. Because the increase in lucigenin concentration, which is due to tissue ischemia, is higher than the increase in luminol, which is directly related to the presence and severity of inflammation, ischemia may be more important than inflammation for tumor development in patients with lung cancer.

A competitive immunoassay for sensitive detection of small molecules chloramphenicol based on luminol functionalized silver nanoprobe.

PubMed

Yu, Xiuxia; He, Yi; Jiang, Jie; Cui, Hua

2014-02-17

Chloramphenicol (CHL) as a broad-spectrum antibiotic has a broad action spectrum against Gram-positive and Gram-negative bacteria, as well as anaerobes. The use of CHL is strictly restricted in poultry because of its toxic effect. However, CHL is still illegally used in animal farming because of its accessibility and low cost. Therefore, sensitive methods are highly desired for the determination of CHL in foodstuffs. The immunoassays based on labeling as an important tool have been reported for the detection of CHL residues in food-producing animals. However, most of the labeling procedures require multi-step reactions and purifications and thus they are complicated and time-consuming. Recently, in our previous work, luminol functionalized silver nanoparticles have been successfully synthesized, which exhibits higher CL efficiency than luminol functionalized gold nanoparticles. In this work, the new luminol functionalized silver nanoparticles have been used for the labeling of small molecules CHL for the first time and a competitive chemiluminescent immunoassay has been developed for the detection of CHL. Owing to the amplification of silver nanoparticles, high sensitivity for CHL could be achieved with a low detection limit of 7.6×10(-9) g mL(-1) and a wide linear dynamic range of 1.0×10(-8)-1.0×10(-6) g mL(-1). This method has also been successfully applied to determine CHL in milk and honey samples with a good recoveries (92% and 102%, 99% and 107% respectively), indicating that the method is feasible for the determination of CHL in real milk and honey samples. The labeling procedure is simple, convenient and fast, superior to previously reported labeling procedures. The immunoassay is also simple, fast, sensitive and selective. It is of application potential for the determination of CHL in foodstuffs. Copyright © 2014 Elsevier B.V. All rights reserved.

Excited state complex formation between methyl glyoxal and some aromatic bio-molecules: a fluorescence quenching study

NASA Astrophysics Data System (ADS)

Banerjee, D.; Mandal, A.; Mukherjee, S.

2003-01-01

Fluorescence quenching of some important aromatic bio-molecules (ABM) such as 3-aminophthalhydrazide (luminol), tryptophan (Try), phenylalanine and tyrosine (Tyr) by methyl glyoxal (MG) has been studied employing different spectroscopic techniques. The interaction of MG with ABM in the excited state has been analysed using Stern-Volmer (S-V) mechanism. In the case of MG-luminol system time correlated single photon counting (TCSPC) technique has also been applied to explain the S-V mechanism. The bimolecular rate constants obtained are found to be higher than the rate constant for diffusion controlled process. A plausible explanation of the quenching mechanism has been discussed on the basis of hydrogen bonding, charge transfer and energy transfer interaction between the colliding species.

Tested Demonstrations.

ERIC Educational Resources Information Center

Gilbert, George L., Ed.

1987-01-01

Presented are three demonstrations for chemical education. The activities include: (1) demonstration of vapor pressure; (2) a multicolored luminol-based chemiluminescence demonstration; and (3) a Charles's Law/Vapor pressure apparatus. (RH)

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 sniffer-camera for imaging of ethanol vaporization from wine: the effect of wine glass shape.

PubMed

Arakawa, Takahiro; Iitani, Kenta; Wang, Xin; Kajiro, Takumi; Toma, Koji; Yano, Kazuyoshi; Mitsubayashi, Kohji

2015-04-21

A two-dimensional imaging system (Sniffer-camera) for visualizing the concentration distribution of ethanol vapor emitting from wine in a wine glass has been developed. This system provides image information of ethanol vapor concentration using chemiluminescence (CL) from an enzyme-immobilized mesh. This system measures ethanol vapor concentration as CL intensities from luminol reactions induced by alcohol oxidase and a horseradish peroxidase (HRP)-luminol-hydrogen peroxide system. Conversion of ethanol distribution and concentration to two-dimensional CL was conducted using an enzyme-immobilized mesh containing an alcohol oxidase, horseradish peroxidase, and luminol solution. The temporal changes in CL were detected using an electron multiplier (EM)-CCD camera and analyzed. We selected three types of glasses-a wine glass, a cocktail glass, and a straight glass-to determine the differences in ethanol emission caused by the shape effects of the glass. The emission measurements of ethanol vapor from wine in each glass were successfully visualized, with pixel intensity reflecting ethanol concentration. Of note, a characteristic ring shape attributed to high alcohol concentration appeared near the rim of the wine glass containing 13 °C wine. Thus, the alcohol concentration in the center of the wine glass was comparatively lower. The Sniffer-camera was demonstrated to be sufficiently useful for non-destructive ethanol measurement for the assessment of food characteristics.

Inhibition of chemiluminescence and chemotactic activity of phagocytes in vitro by the extracts of selected medicinal plants.

PubMed

Jantan, Ibrahim; Harun, Nurul Hikmah; Septama, Abdi Wira; Murad, Shahnaz; Mesaik, M A

2011-04-01

The methanol extracts of 20 selected medicinal plants were investigated for their effects on the respiratory burst of human whole blood, isolated human polymorphonuclear leukocytes (PMNs) and isolated mice macrophages using a luminol/lucigenin-based chemiluminescence assay. We also tested the effect of the extracts on chemotactic migration of PMNs using the Boyden chamber technique. The extracts of Curcuma domestica L., Phyllanthus amarus Schum & Thonn and C. xanthorrhiza Roxb. were the samples producing the strongest oxidative burst of PMNs with luminol-based chemiluminescence, with IC(50) values ranging from 0.5 to 0.7 μg/ml. For macrophage cells, the extracts which showed strong suppressive activity for luminol-based chemiluminescence were C. xanthorrhiza and Garcinia mangostana L. Among the extracts studied, C. mangga Valton & Vazsjip, Piper nigrum L. and Labisia pumila var. alata showed strong inhibitory activity on lucigenin-amplified oxidative burst of PMNs, with IC(50) values ranging from 0.9 to 1.5 μg/ml. The extracts of Zingiber officinale Rosc., Alpinia galangal (L.) Willd and Averrhoa bilimbi Linn showed strong inhibition on the chemotaxic migration of cells, with IC(50) values comparable to that of ibuprofen (1.5 μg/ml). The results suggest that some of these plants were able to modulate the innate immune response of phagocytes at different steps, emphasizing their potential as a source of new immunomodulatory agents.

Ultrasensitive peroxynitrite-based luminescence with L-012 as a screening system for antioxidative/antinitrating substances, e.g. Tylenol (acetaminophen), 4-OH tempol, quercetin and carboxy-PTIO.

PubMed

Van Dyke, Knox; Ghareeb, Erica; Van Dyke, Mark; Van Thiel, David H

2007-01-01

Previously our group developed a water-soluble antioxidant screening system using the luminescence of the reaction of peroxynitrite and luminol. In the present study we replaced luminol with the luminol-like compound L-012. This increases the production of luminescence approximately 100-fold and therefore, with a higher signal:noise ratio, this new system can detect antioxidation and antinitration effects at lower doses of the inhibitor. We studied acetaminophen (Tylenol) and its metabolite 3-nitroacetaminophen, tyrosine and nitrotyrosine and all these substances were inhibitory in a dose-responsive manner and below micromolar amounts. In addition quercetin, a polyphenol, was highly active (below micromolar amounts) as an antioxidant and antinitrating compound. 4-OH tempol, the stable free radical, superoxide dismutase (SOD) mimetic, was inhibitory in a dose-responsive manner and below micromolar amounts. Carboxy-PTIO was inhibitory at 10 times micromolar amount but not below that dose, which may be related to colour quenching, since the drug is deeply blue, or possibly it is an inhibitor with a slow kinetic profile. Finally, the amino acid tyrosine has been found to be inhibitory in micromolar amounts, similar to acetaminophen. This indicates that tyrosine can act as an antioxidant and antinitration target alone or conjugated in protein, e.g. insulin. (c) 2007 John Wiley & Sons, Ltd.

Detection of gamma irradiated pepper and papain by chemiluminescence

NASA Astrophysics Data System (ADS)

Sattar, Abdus; Delincée, H.; Diehl, J. F.

Chemiluminescence (CL) measurements of black pepper and of papain using luminol and lucigenin reactions were studied. Effects of grinding, irradiation (5-20 kGy) and particle size (750-140 μm) on CL of pepper, and of irradiation (10-30 kGy) on CL of papain, were investigated. All the tested treatments affected the luminescence response in both the luminol and lucigenin reactions; however, the pattern of changes in each case, was inconsistent. Optimum pepper size for maximum luminescence was 560 μm, and optimum irradiation doses were >15 kGy for pepper and >20 kGy for papain. Chemiluminescence may possibly be used as an indicator or irradiation treatment for pepper and papain at a dose of 10 kGy or higher, but further research is needed to establish the reliability of this method.

Cu2+ -Modified Metal-Organic Framework Nanoparticles: A Peroxidase-Mimicking Nanoenzyme.

PubMed

Chen, Wei-Hai; Vázquez-González, Margarita; Kozell, Anna; Cecconello, Alessandro; Willner, Itamar

2018-02-01

The synthesis and characterization of UiO-type metal-organic framework nanoparticles (NMOFs) composed of Zr 4+ ions bridged by 2,2'-bipyridine-5,5'-dicarboxylic acid ligands and the postmodification of the NMOFs with Cu 2+ ions are described. The resulting Cu 2+ -modified NMOFs, Cu 2+ -NMOFs, exhibit peroxidase-like catalytic activities reflected by the catalyzed oxidation of Amplex-Red to the fluorescent Resorufin by H 2 O 2 , the catalyzed oxidation of dopamine to aminochrome by H 2 O 2 , and the catalyzed generation of chemiluminescence in the presence of luminol/H 2 O 2 . Also, the Cu 2+ -NMOFs mimic NADH peroxidase functions and catalyze the oxidation of dihydronicotinamide adenine dinucleotide, NADH, to nicotinamide adenine dinucleotide, NAD + , in the presence of H 2 O 2 . The Cu 2+ -NMOFs-catalyzed generation of chemiluminescence in the presence of luminol/H 2 O 2 is used to develop a glucose sensor by monitoring the H 2 O 2 formed by the aerobic oxidation of glucose to gluconic acid in the presence of glucose oxidase. Furthermore, loading the Cu 2+ -NMOFs with fluorescein and activating the catalyzed generation of chemiluminescence in the presence of luminol/H 2 O 2 yield an efficient chemiluminescence resonance energy transfer (CRET) process to the fluorescein reflected by the activation of the fluorescence of the dye (λ = 520 nm, CRET efficiency 35%). © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Chitosan-induced Au/Ag nanoalloy dispersed in IL and application in fabricating an ultrasensitive glucose biosensor based on luminol-H₂O₂-Cu²⁺/IL chemiluminescence system.

PubMed

Chaichi, M J; Alijanpour, S O

2014-11-01

A novel glucose biosensor based on the chemiluminescence (CL) detection of enzymatically generated hydrogen peroxide (H₂O₂) was constructed by one covalent immobilization of glucose oxidase (GOD) in glutaraldehyde-functionalized glass cell. In following, chitosan-induced Au/Ag nanoparticles dispersed in ion liquid (IL) were synthesised and immobilized on it. Herein, chitosan molecules acted as both the reducing and stabilizing agent for the preparation of NPs and also, as a coupling agent GOD and Au/Ag alloy NPs. In addition to catalyze luminol CL reaction, these NPs offered excellent catalytic activity toward hydrogen peroxide generation in enzymatic reaction between GOD and glucose. The used IL in fabrication of biosensor increased its stability. Also, IL alongside Cu(2+) accelerated enzymatic and CL reaction kinetic, and decreased luminol CL reaction optimum pH to 7.5 which would enable sensitive and precision determination of glucose. Under optimum condition, linear response range of glucose was found to be 1.0 × 10(-6)-7.5 × 10(-3)M, and detection limit was 4.0 × 10(-7)M. The CL biosensor exhibited good storage stability, i.e., 90% of its initial response was retained after 2 months storage at pH 7.0. The present CL biosensor has been applied satisfactory to analysis of glucose in real serum and urine samples. Copyright © 2014 Elsevier B.V. All rights reserved.

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.

CdS nanoparticles-enhanced chemiluminescence and determination of baicalin in pharmaceutical preparations.

PubMed

Chen, Xiaolan; Tan, Xinmei; Wang, Jianxiu

2013-01-01

CdS nanoparticles (CdS NPs) of different sizes were synthesized by the citrate reduction method. It was found that CdS NPs could enhance the chemiluminescence (CL) of the luminol-potassium ferricyanide system and baicalin could inhibit CdS NPs-enhanced luminol-potassium ferricyanide CL signals in alkaline solution. Based on this inhibition, a flow-injection CL method was established for determination of baicalin in pharmaceutical preparations and human urine samples. Under optimized conditions, the linear range for determination of baicalin was 5.0 x 10(-6) to 1.0 x 10(-3) g/L. The detection limit at a signal-to-noise ratio of 3 was 1.7 x 10(-6) g/L. CL spectra, UV-visible spectra and transmission electron microscopy (TEM) were used to investigate the CL mechanism. The method described is simple, selective and obviates the need of extensive sample pretreatment. Copyright © 2012 John Wiley & Sons, Ltd.

Rapid determination of isoamyl nitrite in pharmaceutical preparations by flow injection analysis with on-line UV irradiation and luminol chemiluminescence detection.

PubMed

Kishikawa, Naoya; Kondo, Naoko; Amponsaa-Karikari, Abena; Kodamatani, Hitoshi; Ohyama, Kaname; Nakashima, Kenichiro; Yamazaki, Shigeo; Kuroda, Naotaka

2014-02-01

Isoamyl nitrite is used as a therapeutic reagent for cardiac angina and as an antidote for cyanide poisoning, but it is abused because of its euphoric properties. Therefore, a method to determine isoamyl nitrite is required in many fields, including pharmaceutical and forensic studies. In this study, a simple, rapid and sensitive method for the determination of isoamyl nitrite was developed using a flow injection analysis system equipped with a chemiluminescence detector and on-line photoreactor. This method is based on on-line ultraviolet irradiation of isoamyl nitrite and subsequent luminol chemiluminescence detection without the addition of an oxidant. A linear standard curve was obtained up to 1.0 μM of isoamyl nitrite with a detection limit (blank + 3SD) of 0.03 μM. The method was successfully applied to determine isoamyl nitrite content in pharmaceutical preparations. Copyright © 2013 John Wiley & Sons, Ltd.

Artemisinin-Luminol Chemiluminescence for Forensic Bloodstain Detection Using a Smart Phone as a Detector.

PubMed

Gao, Wenyue; Wang, Chao; Muzyka, Kateryna; Kitte, Shimeles Addisu; Li, Jianping; Zhang, Wei; Xu, Guobao

2017-06-06

Forensic luminol chemiluminescence test is one of the most sensitive and popular methods for the determination of latent bloodstains. It mainly uses hydrogen peroxide or sodium perborate as coreactants. The easy decomposition of hydrogen peroxide and sodium perborate in the presence of many ions significantly affects the selectivity. Artemisinin is a natural peroxide that is quite stable in the presence of common ions. In the present study, artemisinin has been exploited for the forensic bloodstain chemiluminescence detection for the first time. Using smart phone as cost-effective portable detector, the visual detection of bloodstains has been achieved with a dilution factor of blood up to 100 000. Moreover, this system shows excellent selectivity against many common species. It can well differentiate bloodstains from other stains, such as coffee, brown sugar, and black tea. Both favorable sensitivity and selectivity makes the present method promising in forensic detection.

In situ Visualization of Electrocatalytic Reaction Activity at Quantum Dots for Water Oxidation.

PubMed

Chen, Ying; Fu, Jiaju; Cui, Chen; Jiang, Dechen; Chen, Zixuan; Chen, Hong-Yuan; Zhu, Jun-Jie

2018-06-11

Exploring electrocatalytic reactions on nanomaterial surface can give crucial information for the development of robust catalysts. Here, electrocatalytic reaction activity at single quantum dots (QDs) loaded silica micro-particles involved in water oxidation is visualized using electrochemiluminescence (ECL) microscopy. Under positive potential, the active redox centers at QDs induce the generation of hydroperoxide surface intermediates as coreactant to remarkably enhance ECL emission from luminol derivative for imaging. For the first time, in situ visualization of catalytic activity in water oxidation at QDs catalyst was achieved, supported by a linear relation between ECL intensity and turn over frequency. A very slight diffusion trend attributed to only luminol species proved in situ capture of hydroperoxide surface intermediates at catalytic active sites of QDs. This work provides tremendous potential in on-line imaging of electrocatalytic reaction and visual evaluation of catalyst performance.

Development of a chemiluminescent and bioluminescent system for the detection of bacteria in wastewater effluent

NASA Technical Reports Server (NTRS)

Thomas, R. R.

1975-01-01

Automated chemiluminescent and bioluminescent sensors were developed for continuous monitoring of microbial levels in wastewater effluent. Development of the chemiluminescent system included optimization of reagent concentrations as well as two new techniques which will allow for increased sensitivity and specificity. The optimal reagent concentrations are 0.0025 M luminol and 0.0125 M sodium perborate in 0.75N sodium hydroxide before addition of sample. The methods developed to increase specificity include (1) extraction of porphyrins from bacteria collected in a filter using 0.1N NaOH - 50 percent Ethanol, and (2) use of the specific reaction rate characteristics for the different luminol catalysts. Since reaction times are different for each catalyst, the reaction can be made specific for bacteria by measuring only the light emission from the particular reaction time zone specific for bacteria. Developments of the bioluminescent firefly luciferase system were in the area of flow system design.

Cavitation occurrence around ultrasonic dental scalers.

PubMed

Felver, Bernhard; King, David C; Lea, Simon C; Price, Gareth J; Damien Walmsley, A

2009-06-01

Ultrasonic scalers are used in dentistry to remove calculus and other contaminants from teeth. One mechanism which may assist in the cleaning is cavitation generated in cooling water around the scaler. The vibratory motion of three designs of scaler tip in a water bath has been characterised by laser vibrometry, and compared with the spatial distribution of cavitation around the scaler tips observed using sonochemiluminescence from a luminol solution. The type of cavitation was confirmed by acoustic emission analysed by a 'Cavimeter' supplied by NPL. A node/antinode vibration pattern was observed, with the maximum displacement of each type of tip occurring at the free end. High levels of cavitation activity occurred in areas surrounding the vibration antinodes, although minimal levels were observed at the free end of the tip. There was also good correlation between vibration amplitude and sonochemiluminescence at other points along the scaler tip. 'Cavimeter' analysis correlated well with luminol observations, suggesting the presence of primarily transient cavitation.

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

Polyluminol/hydrogel composites as new electrochemiluminescent-active sensing layers.

PubMed

Leca-Bouvier, Béatrice D; Sassolas, Audrey; Blum, Loïc J

2014-09-01

This paper reports on electrochemiluminescent sensors and biosensors based on polyluminol/hydrogel composite sensing layers using chemical or biological membranes as hydrogel matrices. In this work, luminol is electropolymerized under near-neutral conditions onto screen-printed electrode (SPE)-supported hydrogel films. The working electrode coated with a hydrogel film is soaked in a solution containing monomeric luminol units, allowing the monomeric luminol units to diffuse inside the porous matrix to the electrode surface where they are electropolymerized by cyclic voltammetry (CV). Sensors and enzymatic biosensors for H2O2 and choline detection, respectively, have been developed, using choline oxidase (ChOD) as a model enzyme. In this case, hydrogel is used both as the enzymatic immobilization matrix and as a template for the electrosynthesis of polyluminol. The enzyme was immobilized by entrapment in the gel matrix during its formation before electropolymerization of the monomer. Several parameters have been optimized in terms of polymerization conditions, enzyme loading, and average pore size. Using calcium alginate or tetramethoxysilane (TMOS)-based silica as porous matrix, H2O2 and choline detection are reported down to micromolar concentrations with three orders of magnitude wide dynamic ranges starting from 4 × 10(-7) M. Polyluminol/hydrogel composites appear as suitable electrochemiluminescence (ECL)-active sensing layers for the design of new reagentless and disposable easy-to-use optical sensors and biosensors, using conventional TMOS-based silica gel or the more original and easier to handle calcium alginate, reported here for the first time in such a configuration, as the biocompatible hydrogel matrix.

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.

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

Atari, N.A.; Ettinger, K.V.

When some irradiated solids are dissolved in water or certain other solvents light emission occurs, which is termed lyoluminescence''. In the case of inorganic materials, such as alkali halides, reactions of trapped electrons from F-centers are responsible for the light emission, and with organic materials, such as saccharides, trapped free radicals are involved. Application of lyoluminescence'' to dosimetry is described. It is possible to measure doses of between 1 and 10/sup 7/is way with an accuracy of 5% using NaCl with water as solvent. The stored lyoluminescent energy in NaCl decreases by only 15% after seven months of storage, butmore » is sensitive to optical and thermal bleaching. Furthermore, the effective ntomic numbers of NaCl is approximately 16, differing considerably from that of human tissue (above 7.5). Study of monosaccarides, including glucose, xylose and mannose, has demonstrated the stability of the trapped free radicals, and no decrease in their lyoluminescence was observed over 7 months. As regards their use for dosimetry they show linear dependence with dose up to 100 kR, and the lowest dose indicated under test was 100 R. It is considered possible to use the lyoluminescence of saccharides for clinical dosimetry if the sensitivity of the systems could be improved, and to this end tests were carried out using luminol solution. Using a /sup 60/Co gamma -source irradiated saccharides give bright blue light when dissolved in luminol solution, and the light enhancement was about 10/sup 6/ compared with water. It seems likely that the oxidizing species responsible for exciting the luminol are formed as a result of free radical reactions with dissolved or adsorbed O/sub 2/ in the system. Trehalose, which is a fairly true tissue equivalent material, appears to be a good candidate for lyoluminescence dosimetry. (UK)« less

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).

Decrease of neutrophils chemiluminescence during exposure to low-power laser infrared radiation

NASA Astrophysics Data System (ADS)

Czuba, Zenon P.; Adamek, Mariusz; Krol, Wojciech; Sieron, Aleksander; Cieslar, Grzegorz

1995-01-01

The neutrophil is the cell in which phagocyting and transforming of some exogeneous agents results in marked stimulation of nonmitochondrial respiratory chain activity (respiratory burst). In our experiment we focused on determining the level of chemiluminescence (CL) of stimulated neurotrophils during and after irradiation, measuring the photon emission intensity in 6 second's intervals. We used Ga-Al-As pulsed laser (wavelength 904 nm, mean power 8,9 mW, Alpha-Electronics GmbH, Germany) which was placed over the tube containing the suspension of guinea pig peritoneal neurotrophils (2X106 cells/ml). The sensitivity range of used photomultiplier (9514s, THORN EMI, Middlesex, England) was 300-600 nm, which allowed us to measure the CL of neutrophils while being irradiated. The neutrophils were stimulated by phorbol myristate acetate (PMA) and CL intensified by luminol. The decay of luminol-dependent CL of neutrophils may be described by hyperbolic function curve. We switched the laser radiation on for 20 s, 60 s and 300 s and each time we observed the same reaction: the about 20% decrease of intensity of CL immediately after beginning the irradiation. The CL remained on decreased level during the whole period of irradiation reaching immediately the level of CL intensity characteristic for decay curve (20% increase), just after switching off the laser. Only after the longest irradiation time (300 s) we observed CL being higher and inconsistent with decay curve for several minutes. The type of reaction was always the same, regardless to the point of CL decay curve at which laser radiation was applied. The same changes of Cl we obtained irradiating the enzymatic system: horseradish peroxidase (HRP)-luminol - H2O2.

Graphene oxide@gold nanorods-based multiple-assisted electrochemiluminescence signal amplification strategy for sensitive detection of prostate specific antigen.

PubMed

Cao, Jun-Tao; Yang, Jiu-Jun; Zhao, Li-Zhen; Wang, Yu-Ling; Wang, Hui; Liu, Yan-Ming; Ma, Shu-Hui

2018-01-15

A novel and competitive electrochemiluminescence (ECL) aptasensor for prostate specific antigen (PSA) assay was constructed using gold nanorods functionalized graphene oxide (GO@AuNRs) multilabeled with glucose oxidase (GOD) and streptavidin (SA) toward luminol-based ECL system. A strong initial ECL signal was achieved by electrodeposited gold (DpAu) on the electrode because of gold nanoparticles (AuNPs) motivating the luminol ECL signal. The signal probes prepared by loading GOD and SA-biotin-DNA on GO@AuNRs were used for achieving multiple signal amplification. In the absence of PSA, the signal probes can be attached on the electrode by hybridization reaction between PSA aptamer and biotin-DNA. In this state, the GOD loaded on the probe could catalyze glucose to in situ produce H 2 O 2 and then AuNRs catalyze H 2 O 2 to generate abundant reactive oxygen species (ROSs) in luminol ECL reaction. Both the high-content GOD and AuNRs in the signal probe amplified the ECL signal in the ECL system. Moreover, the combination of SA with biotin-DNA further expands ECL intensity. The integration of such amplifying effects in this protocol endows the aptasensor with high sensitivity and good selectivity for PSA detection. This aptasensor exhibits a linear relation in the range of 0.5pgmL -1 to 5.0ngmL -1 with the detection limit of 0.17pgmL -1 (S/N = 3). Besides, the strategy was successfully applied in determination of human serum samples with recovery of 81.4-116.0%. Copyright © 2017 Elsevier B.V. All rights reserved.

Multifunctional reduced graphene oxide trigged chemiluminescence resonance energy transfer: Novel signal amplification strategy for photoelectrochemical immunoassay of squamous cell carcinoma antigen.

PubMed

Zhang, Yan; Sun, Guoqiang; Yang, Hongmei; Yu, Jinghua; Yan, Mei; Song, Xianrang

2016-05-15

Herein, a photoelectrochemical (PEC) immunoassay is constructed for squamous cell carcinoma antigen (SCCA) detection using zinc oxide nanoflower-bismuth sulfide (Bi2S3) composites as photoactive materials and reduced graphene oxide (rGO) as signal labels. Horseradish peroxidase is used to block sites against nonspecific binding, and then participated in luminol-based chemiluminescence (CL) system. The induced CL emission is acted as an inner light source to excite photoactive materials, simplifying the instrument. A novel signal amplification strategy is stem from rGO because of the rGO acts as an energy acceptor, while luminol serves as a donor to rGO, triggering the CL resonance energy transfer phenomenon between luminol and rGO. Thus, the efficient CL emission to photoactive materials decreases. Furthermore, the signal amplification caused by rGO labeled signal antibodies is related to photogenerated electron-hole pairs: perfect matching of energy levels between rGO and Bi2S3 makes rGO a sink to capture photogenerated electrons from Bi2S3; the increased steric hindrance hinders the electron donor to the surface of Bi2S3 for reaction with the photogenerated holes. On the basis of the novel signal amplification strategy, the proposed immunosensor exhibits excellent analytical performance for PEC detection of SCCA, ranging from 0.8 pg mL(-1) to 80 ng mL(-1) with a low detection limit of 0.21 pg mL(-1). Meanwhile, the designed signal amplification strategy provides a general format for future development of PEC assays. Copyright © 2015 Elsevier B.V. All rights reserved.

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 degradation of matrix in arthritis.

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.

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.

Applications of Chemiluminescence in the Teaching of Experimental Design

ERIC Educational Resources Information Center

Krawczyk, Tomasz; Slupska, Roksana; Baj, Stefan

2015-01-01

This work describes a single-session laboratory experiment devoted to teaching the principles of factorial experimental design. Students undertook the rational optimization of a luminol oxidation reaction, using a two-level experiment that aimed to create a long-lasting bright emission. During the session students used only simple glassware and…

STIMULATION OF OXIDANT PRODUCTION IN ALVEOLAR MACROPHAGES BY POLLUTANT AND LATEX PARTICLES

EPA Science Inventory

Air pollutant dusts as well as chemically defined particles were examined for their activating effect on oxidant production (O2- and H2O2) in guinea pig alveolar macrophages (AM). Oxidant production was measured as chemiluminescence of albumin-bound luminol. All particles examine...

A hot-spot-active magnetic graphene oxide substrate for microRNA detection based on cascaded chemiluminescence resonance energy transfer

NASA Astrophysics Data System (ADS)

Bi, Sai; Chen, Min; Jia, Xiaoqiang; Dong, Ying

2015-02-01

Herein, a cascaded chemiluminescence resonance energy transfer (C-CRET) process was demonstrated from horseradish peroxidase (HRP)-mimicking DNAzyme-catalyzed luminol-H2O2 to fluorescein and further to graphene oxide (GO) when HRP-mimicking DNAzyme/fluorescein was in close proximity to the GO surface. The proposed C-CRET system was successfully implemented to construct three modes of C-CRET hot-spot-active substrates (modes I, II and III) by covalently immobilizing HRP-mimicking DNAzyme/fluorescein-labeled hairpin DNAs (hot-spot-generation probes) on magnetic GO (MGO), resulting in a signal ``off'' state due to the quenching of the luminol/H2O2/HRP-mimicking DNAzyme/fluorescein CRET system by GO. Upon the introduction of microRNA-122 (miRNA-122), the targets (mode I) or the new triggers that were generated through a strand displacement reaction (SDR) initiated by miRNA-122 (modes II and III) hybridized with the loop domains of hairpin probes on MGO to form double-stranded (modes I and II) or triplex-stem structures (mode III), causing an ``open'' configuration of the hairpin probe and a CRET signal ``on'' state, thus achieving sensitive and selective detection of miRNA-122. More importantly, the substrate exhibited excellent controllability, reversibility and reproducibility through SDR and magnetic separation (modes II and III), especially sequence-independence for hairpin probes in mode III, holding great potential for the development of a versatile platform for optical biosensing.Herein, a cascaded chemiluminescence resonance energy transfer (C-CRET) process was demonstrated from horseradish peroxidase (HRP)-mimicking DNAzyme-catalyzed luminol-H2O2 to fluorescein and further to graphene oxide (GO) when HRP-mimicking DNAzyme/fluorescein was in close proximity to the GO surface. The proposed C-CRET system was successfully implemented to construct three modes of C-CRET hot-spot-active substrates (modes I, II and III) by covalently immobilizing HRP-mimicking DNAzyme/fluorescein-labeled hairpin DNAs (hot-spot-generation probes) on magnetic GO (MGO), resulting in a signal ``off'' state due to the quenching of the luminol/H2O2/HRP-mimicking DNAzyme/fluorescein CRET system by GO. Upon the introduction of microRNA-122 (miRNA-122), the targets (mode I) or the new triggers that were generated through a strand displacement reaction (SDR) initiated by miRNA-122 (modes II and III) hybridized with the loop domains of hairpin probes on MGO to form double-stranded (modes I and II) or triplex-stem structures (mode III), causing an ``open'' configuration of the hairpin probe and a CRET signal ``on'' state, thus achieving sensitive and selective detection of miRNA-122. More importantly, the substrate exhibited excellent controllability, reversibility and reproducibility through SDR and magnetic separation (modes II and III), especially sequence-independence for hairpin probes in mode III, holding great potential for the development of a versatile platform for optical biosensing. Electronic supplementary information (ESI) available: Sequences of RNA and DNA used in this study, relationship of the proposed three modes, CRET mechanism of the luminol/H2O2/HRP-mimicking DNAzyme/fluorescein system, calculation of the surface coverage of hairpin probe I-1 on MGO, control experiment, comparison between different modes for microRNA detection, and advantages of the proposed strategy. See DOI: 10.1039/c4nr06603k

Monosodium Luminol for Improving Brain Function in Gulf War Illness

DTIC Science & Technology

2015-10-01

Jain et al., PLoS One, 7: e46340, 2012; McAvoy et al., Front Syst Neurosci , 9:120. eCollection 2015; Oomen et al., Wiley Interdiscip Rev Cogn Sci...2007; Yassa and Stark, Trends Neurosci , 34: 515-525). In this test, each rat successively explored two different sets of identical objects (object

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.

A novel green analytical procedure for monitoring of azoxystrobin in water samples by a flow injection chemiluminescence method with off-line ultrasonic treatment.

PubMed

Yang, Xin-an; Zhang, Wang-bing

2013-01-01

A simple and green flow injection chemiluminescence (FI-CL) method for determination of the fungicide azoxystrobin was described for the first time. CL signal was generated when azoxystrobin was injected into a mixed stream of luminol and KMnO4 . The CL signal of azoxystrobin could be greatly improved when an off-line ultrasonic treatment was adopted. Meanwhile, the signal intensity increases with the analyte concentration proportionally. Several variables, such as the ultrasonic parameters, flow rate of reagents, concentrations of sodium hydroxide solution and CL reagents (potassium permanganate, luminol) were investigated, and the optimal CL conditions were obtained. Under optimal conditions, the linear range of 1-100 ng/mL for azoxystrobin was obtained and the detection limit (3σ) was determined as 0.13 ng/mL. The relative standard deviation was 1.5% for 10 consecutive measurements of 20 ng/mL azoxystrobin. The method has been applied to the determination of azoxystrobin residues in water samples. Copyright © 2012 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.

Fe3O4 and metal-organic framework MIL-101(Fe) composites catalyze luminol chemiluminescence for sensitively sensing hydrogen peroxide and glucose.

PubMed

Qian Tang, Xue; Dan Zhang, Yi; Wei Jiang, Zhong; Mei Wang, Dong; Zhi Huang, Cheng; Fang Li, Yuan

2018-03-01

In this work, Fe 3 O 4 and metal-organic framework MIL-101(Fe) composites (Fe 3 O 4 /MIL-101(Fe)) was demonstrated to possess excellent catalytic property to directly catalyze luminol chemiluminescence without extra oxidants. We utilized Fe 3 O 4 /MIL-101(Fe) to develop a ultra-sensitive quantitative analytical method for H 2 O 2 and glucose. The possible mechanism of the chemiluminescence reaction had been investigated. Under optimal conditions, the relative chemiluminescence intensity was linearly proportional to the logarithm of H 2 O 2 concentration in the range of 5-150nM with a limit of detection of 3.7nM (signal-to-noise ratio = 3), and glucose could be linearly detected in the range from 5 to 100nM and the detection limit was 4.9nM (signal-to-noise ratio = 3). Furthermore, the present approach was successfully applied to quantitative determination of H 2 O 2 in medical disinfectant and glucose in human serum samples. Copyright © 2017 Elsevier B.V. All rights reserved.

An electrochemiluminescent biosensor for glucose based on the electrochemiluminescence of luminol on the nafion/glucose oxidase/poly(nickel(II)tetrasulfophthalocyanine)/multi-walled carbon nanotubes modified electrode.

PubMed

Qiu, Bin; Lin, Zhenyu; Wang, Jian; Chen, Zhihuang; Chen, Jinhua; Chen, Guonan

2009-04-15

A poly(nickel(II) tetrasulfophthalocyanine)/multi-walled carbon nanotubes composite modified electrode (polyNiTSPc/MWNTs) was fabricated by electropolymerization of NiTSPc on MWNTs-modified glassy carbon electrode (GCE). The modified electrode was found to be able to greatly improve the emission of luminol electrochemiluminescence (ECL) in a solution containing hydrogen peroxide. Glucose oxidase (GOD) was immobilized on the surface of polyNiTSPc/MWNTs modified GC electrode by Nafion to establish an ECL glucose sensor. Under the optimum conditions, the linear response range of glucose was 1.0x10(-6) to 1.0x10(-4) mol L(-1) with a detection limit of 8.0x10(-8) mol L(-1) (defined as the concentration that could be detected at the signal-to-noise ratio of 3). The ECL sensor showed an outstanding well reproducibility and long-term stability. The established method has been applied to determine the glucose concentrations in real serum samples with satisfactory results.

Luminol-dependent chemiluminescence in antibody-sensitized neutrophils stimulated with protein A-bearing staphylococci.

PubMed

Nishihara, S; Seki, K; Ikigai, H; Masuda, S

1988-01-01

When mouse polymorphonuclear leukocytes (PMNs) sensitized with rabbit antibody to mouse Ehrlich ascites tumor cells were stimulated by Staphylococcus aureus Cowan I cells, a conspicuous luminol-dependent chemiluminescence was observed in the absence of opsonin. The profile of the chemiluminescence (CL) response evoked by staphylococcal cells from antibody-sensitized PMNs had two peaks. An initial peak, observed within 1 min after stimulation, was sharp and high and a second peak, observed about 5 min after stimulation, was low and extended. The CL response of antibody-sensitized PMNs stimulated by S. aureus Cowan I cells was dose-dependently blocked by preincubation with soluble SpA. Cells of a mutant derived from S. aureus Cowan I strain with trace amounts of cell-bound SpA failed to stimulate the antibody-sensitized PMNs to generate the CL response. The antibody-sensitized PMNs were found to phagocytize SpA-bearing S. aureus cells even in the absence of opsonic serum. These results suggest that the observation presented here might provide a useful tool for the investigation of CL response of PMNs.

Biocompatible electrochemiluminescent biosensor for choline based on enzyme/titanate nanotubes/chitosan composite modified electrode.

PubMed

Dai, Hong; Chi, Yuwu; Wu, Xiaoping; Wang, Youmei; Wei, Mingdeng; Chen, Guonan

2010-02-15

A new biocompatible ECL biosensor based on enzyme/titanate nanotubes/chitosan composite film was developed for the determination of analytes in biological samples. In the fabrication of the new ECL biosensor, biocompatible titanate nanotubes (TNTs) and a model enzyme, i.e., choline oxidase (ChOX), were immobilized on a chitosan modified glassy carbon electrode (GCE) via electrostatic adsorption and covalent interaction, respectively. By this ECL biosensor, choline was enzymatically oxidized to hydrogen peroxide and detected by a sensitive luminol ECL system. The use of TNTs not only provided a biocompatible microenvironment for the immobilized enzyme, which resulted in an excellent stability and long lifetime of the ECL biosensor, but also exhibited great enhancement towards luminol ECL and thus led to a significant improvement in sensitivity of ECL biosensor. Satisfactory results were obtained when employing this biosensor in assaying the total choline in milk samples. The work would provide a common platform to develop various sensitive, selective and biocompatible ECL biosensors based on using enzyme/TNTs/CHIT composite films. Copyright 2009 Elsevier B.V. All rights reserved.

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.

Evaluation of six presumptive tests for blood, their specificity, sensitivity, and effect on high molecular-weight DNA.

PubMed

Tobe, Shanan S; Watson, Nigel; Daéid, Niamh Nic

2007-01-01

Luminol, leuchomalachite green, phenolphthalein, Hemastix, Hemident, and Bluestar are all used as presumptive tests for blood. In this study, the tests were subjected to dilute blood (from 1:10,000 to 1:10,000,000), many common household substance, and chemicals. Samples were tested for DNA to determine whether the presumptive tests damaged or destroyed DNA. The DNA loci tested were D2S1338 and D19S433. Leuchomalachite green had a sensitivity of 1:10,000, while the remaining tests were able to detect blood to a dilution of 1:100,000. Substances tested include saliva, semen, potato, tomato, tomato sauce, tomato sauce with meat, red onion, red kidney bean, horseradish, 0.1 M ascorbic acid, 5% bleach, 10% cupric sulfate, 10% ferric sulfate, and 10% nickel chloride. Of all the substances tested, not one of the household items reacted with every test; however, the chemicals did. DNA was recovered and amplified from luminol, phenolphthalein, Hemastix, and Bluestar, but not from leuchomalachite green or Hemident.

Quantitation of immunoadsorbed flavoprotein oxidases by luminol-mediated chemiluminescence.

PubMed

Hinkkanen, A; Maly, F E; Decker, K

1983-04-01

The detection of the flavoenzymes 6-hydroxy-L-nicotine oxidase and 6-hydroxy-D-nicotine oxidase at the sub-femtomol level was achieved by coupling the reaction of the immunoadsorbed proteins to the peroxidase-catalysed oxidation of luminol. The H2O2-producing oxidases retained their full activity when bound to the respective immobilized antibodies. This fact allowed the concentration of the enzymes from very dilute solutions and the quantitative assay of their activities in the microU range. Due to strict stereoselectivity and the absence of immunological cross-reactivity, the two flavoproteins could be determined in the same solution. This method was used to measure the 6-hydroxy-D-nicotine oxidase and 6-hydroxy-L-nicotine oxidase activities in Escherichia coli RR1 and different Arthrobacter strains cultured under non-inducing conditions. The same activity ratio of 6-hydroxy-L-nicotine oxidase/6-hydroxy-D-nicotine oxidase as in D L-nicotine-induced cells of A. oxidans was observed in non-induced wild type and in riboflavin-requiring (rf-) mutant cells of this aerob.

[Effect of smoking on neutrophil oxidative metabolism].

PubMed

Zasimauskas, Darius; Zekonis, Gediminas

2008-01-01

Alterations in neutrophil function by tobacco products may play a central role in the pathogenesis of periodontal diseases and several smoking-related systemic diseases. The aim of the study was to evaluate the effect of smoking on neutrophil oxidative metabolism. The study included 17 smoking men free of systemic diseases who were referred for treatment of various odontological diseases to outpatient department of Kaunas University of Medicine Hospital. The age of subjects varied from 22 to 43 years. All subjects answered the questions about smoking habits. Clinical examination included assessment of oral hygiene status according to the OHI-s index and periodontal status according to Russell and Ramfjord indices. To evaluate the oxidative metabolism of neutrophils, luminol- and liucigenin-dependent chemiluminescence and nitroblue tetrazolium test were used. After smoking, extracellular liucigenin-dependent chemiluminescence response was higher as compared to the response before smoking, but total (intra- and extracellular) luminol-dependent chemiluminescence response was the same both before and after smoking. Exposure of neutrophils to smoking caused a significant increase in nitroblue tetrazolium reduction. The release of reactive oxygen species in neutrophils exposed to smoking may alter the pathogenic processes in periodontal diseases.

Phytochemical Characteristics, Free Radical Scavenging Activities, and Neuroprotection of Five Medicinal Plant Extracts

PubMed Central

Chang, Chia Lin; Lin, Che San; Lai, Guia Hung

2012-01-01

The objective of this study was to determine phytochemical characteristics, chemiluminescence antioxidant capacities, and neuroprotective effects on PC12 cells for methanol extracts of Spatholobus suberectus, Uncaria rhynchophylla, Alpinia officinarum, Drynaria fortunei, and Crataegus pinnatifida. The C. pinnatifida extract (CPE) afforded the greatest yield and total phenolic content. The S. suberectus extract (SSE) yielded the greatest total flavonoid content. The U. rhynchophylla extract (URE) produced the greatest total tannin content, and the A. officinarum extract (AOE) produced the greatest total triterpenoid content. The D. fortunei extract, assayed using horseradish peroxidase-luminol-hydrogen peroxide (H2O2), and AOE using pyrogallol-luminol assay each exhibited better antioxidant activity than the L-ascorbic acid and 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid did. The CPE, SSE, and URE presented neurogrowth effects and neuroprotective activities on H2O2-induced PC12 cell death at 0.5–5.0 μg/mL. The CPE represents a promising medicinal plant source for the treatment of H2O2-induced neurodegenerative disease, because of its useful phytochemical characteristics. PMID:21845204

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.

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.

Detection of iron-porphyrin proteins with a biochemiluminescent method in search of extraterrestrial life.

PubMed

Sotnikov, G G

1970-01-01

Iron-porphyrin proteins (catalase, peroxidase, hemoglobin, cytochrome C) represent an important group of redoxenzymes which have vitally important functions in micro-organisms. A biochemiluminescent method was employed for the detection of iron-porphyrin proteins. The reaction of luminol oxidation with H2O2 is accompanied by chemiluminescence. The rate of hydrogen peroxide decomposition increased 10(5)-10(7) -fold in the presence of the above enzymes as compared with ferrous (or ferric) ions. Possible application of this reaction for the detection of iron-porphyrin proteins of microbial origin was studied. Other authors have suggested this reaction for the detection of extraterrestrial life. Kinetics of the above reaction in the presence of iron-porphyrin proteins were shown to differ both in amplitude and duration of the signal from the pattern observed in the presence of non-hemin catalysts. The reaction pattern in the presence of mixed-soil populations is similar to those observed with pure bacterial cultures and individual iron-porphyrin proteins. Photometric tests revealed that among preparations studied the addition of 0.01% lysozyme was the most effective in destroying cell walls in microbial populations. However, removal of cell walls is not a necessary prerequisite for the detection of iron porphyrin since, for effective luminol oxidation with H2O2 the medium should be kept at pH 12.0. Pretreatment of microbial suspensions with ultrasound increased 2-fold the total signal due to iron porphyrins. The above method gives a reproducible signal indicating the presence of iron porphyrins when sterile nutrient media were innoculated with desert soil samples (Repeteck, Kara-Kum) and incubated for 13 hr. The device was able to detect the presence of no less than 10(5) - 10(6) cells per ml. The addition of limonite (Fe2O3 X nH2O) does not result in the appearance of an appreciable signal in the luminol + H2O2 system.

Determination of 2-methoxyestradiol in serum samples and pharmaceutical preparations by silver nanoparticles-enhanced chemiluminescence.

PubMed

Zhang, Min; Xiao, Xiangqin; Zeng, Wenyuan; Zeng, Xiaoying; Yao, Hanchun

2014-03-01

Silver nanoparticles (AgNPs) exhibited better chemiluminescence (CL) catalysis activity and smaller nanoparticles have stronger catalysis ability in luminol-K3Fe(CN)6 system among the synthesized AgNPs of different size. 10±2 nm nanoparticles was used as catalysts to enhance the reaction sensitivity. It was found that the CL intensity of AgNPs-luminol-K3Fe(CN)6 was strongly inhibited in the presence of 2-methoxyestradiol (2-ME) and the relative CL intensity was in linear correlation with the concentration of 2-ME. Thus, the silver nanoparticles-enhanced CL method for the determination of 2-ME was developed. The proposed method has a detection limit (3 Sb/K) of 5.0×10(-10) mol L(-1) with a relative standard deviation of 0.75% for 5.0×10(-8) mol L(-1) 2-ME. The method was successfully applied for determination of 2-ME in human serum and pharmaceutical preparations. The possible CL reaction mechanism was also discussed briefly. Oxygen radicals played an important role in the catalytic process. Copyright © 2013 Elsevier B.V. All rights reserved.

Detection of ochratoxin A (OTA) in coffee using chemiluminescence resonance energy transfer (CRET) aptasensor.

PubMed

Jo, Eun-Jung; Mun, Hyoyoung; Kim, Su-Ji; Shim, Won-Bo; Kim, Min-Gon

2016-03-01

We report a chemiluminescence resonance energy transfer (CRET) aptasensor for the detection of ochratoxin A (OTA) in roasted coffee beans. The aptamer sequences used in this study are 5'-DNAzyme-Linker-OTA aptamer-3'-dabcyl. Dabcyl at the end of the OTA aptamer region plays as a quencher in CRET aptasensor. When hemin and OTA are added, the dabcyl-labeled OTA aptamer approaches to the G-quadruplex-hemin complex by formation of the G-quadruplex-OTA complex. The G-quadruplex-hemin complexes possess horseradish peroxidase (HRP)-like activity, and therefore, the HRP-mimicking DNAzyme (HRPzyme) catalyzes peroxidation in the presence of luminol and H2O2. Resonance energy transfer between luminol (donor) and dabcyl (acceptor) enables quenching of chemiluminescence signals. The signal decreases with increasing the concentration of OTA within the range of 0.1-100ngmL(-1) (limit of detection 0.22ngmL(-1)), and the level of recovery of the respective 1ngmL(-1) and 10ngmL(-1) spiked coffee samples was 71.5% and 93.3%. These results demonstrated the potential of the proposed method for OTA analysis in diverse foods. Copyright © 2015 Elsevier Ltd. All rights reserved.

Influence of quantum dot's quantum yield to chemiluminescent resonance energy transfer.

PubMed

Wang, Hai-Qiao; Li, Yong-Qiang; Wang, Jian-Hao; Xu, Qiao; Li, Xiu-Qing; Zhao, Yuan-Di

2008-03-03

The resonance energy transfer between chemiluminescence donor (luminol-H2O2 system) and quantum dots (QDs, emission at 593 nm) acceptors (CRET) was investigated. The resonance energy transfer efficiencies were compared while the oil soluble QDs, water soluble QDs (modified with thioglycolate) and QD-HRP conjugates were used as acceptor. The fluorescence of QD can be observed in the three cases, indicating that the CRET occurs while QD acceptor in different status was used. The highest CRET efficiency (10.7%) was obtained in the case of oil soluble QDs, and the lowest CRET efficiency (2.7%) was observed in the QD-HRP conjugates case. This result is coincident with the quantum yields of the acceptors (18.3% and 0.4%). The same result was observed in another similar set of experiment, in which the amphiphilic polymer modified QDs (emission at 675 nm) were used. It suggests that the quantum yield of the QD in different status is the crucial factor to the CRET efficiency. Furthermore, the multiplexed CRET between luminol donor and three different sizes QD acceptors was observed simultaneously. This work will offer useful support for improving the CRET studies based on quantum dots.

Investigation of iron(III) reduction and trace metal interferences in the determination of dissolved iron in seawater using flow injection with luminol chemiluminescence detection.

PubMed

Ussher, Simon J; Milne, Angela; Landing, William M; Attiq-ur-Rehman, Kakar; Séguret, Marie J M; Holland, Toby; Achterberg, Eric P; Nabi, Abdul; Worsfold, Paul J

2009-10-12

A detailed investigation into the performance of two flow injection-chemiluminescence (FI-CL) manifolds (with and without a preconcentration column) for the determination of sub-nanomolar dissolved iron (Fe(II)+Fe(III)), following the reduction of Fe(III) by sulphite, in seawater is described. Kinetic experiments were conducted to examine the efficiency of reduction of inorganic Fe(III) with sulphite under different conditions and a rigorous study of the potential interference caused by other transition metals present in seawater was conducted. Using 100microM concentrations of sulphite a reduction time of 4h was sufficient to quantitatively reduce Fe(III) in seawater. Under optimal conditions, cobalt(II) and vanadium(IV)/(III) were the major positive interferences and strategies for their removal are reported. Specifically, cobalt(II) was masked by the addition of dimethylglyoxime to the luminol solution and vanadium(IV) was removed by passing the sample through an 8-hydroxyquinoline column in a low pH carrier stream. Manganese(II) also interfered by suppression of the CL response but this was not significant at typical open ocean concentrations.

Porphyrin-induced photogeneration of hydrogen peroxide determined using the luminol chemiluminescence method in aqueous solution: A structure-activity relationship study related to the aggregation of porphyrin.

PubMed

Komagoe, Keiko; Katsu, Takashi

2006-02-01

A luminol chemiluminescence method was used to evaluate the porphyrin-induced photogeneration of hydrogen peroxide (H2O2). This method enabled us to detect H202 in the presence of a high concentration of porphyrin, which was not possible using conventional colorimetry. The limit of detection was about 1 microM. We compared the ability to generate H2O2, using uroporphyrin (UP), hexacarboxylporphyrin (HCP), coproporphyrin (CP), hematoporphyrin (HP), mesoporphyrin (MP), and protoporphyrin (PP). The amount of H2O2 photoproduced was strongly related to the state of the porphyrin in the aqueous solution. UP and HCP, which existed predominantly in a monomeric form, had a good ability to produce H2O2. HP and MP, existing as dimers, showed weak activity. CP, forming a mixture of monomer and dimer, had a moderate ability to produce H2O2. PP, which was highly aggregated, had a good ability. These results demonstrated that the efficiency of porphyrins to produce H2O2 was strongly dependent on their aggregated form, and the dimer suppressed the production of H2O2.

Tape Cassette Bacteria Detection System

NASA Technical Reports Server (NTRS)

1973-01-01

The design, fabrication, and testing of an automatic bacteria detection system with a zero-g capability and based on the filter-capsule approach is described. This system is intended for monitoring the sterility of regenerated water in a spacecraft. The principle of detection is based on measuring the increase in chemiluminescence produced by the action of bacterial porphyrins (i.e., catalase, cytochromes, etc.) on a luminol-hydrogen peroxide mixture. Since viable as well as nonviable organisms initiate this luminescence, viable organisms are detected by comparing the signal of an incubated water sample with an unincubated control. Higher signals for the former indicate the presence of viable organisms. System features include disposable sealed sterile capsules, each containing a filter membrane, for processing discrete water samples and a tape transport for moving these capsules through a processing sequence which involves sample concentration, nutrient addition, incubation, a 4 Molar Urea wash and reaction with luminol-hydrogen peroxide in front of a photomultiplier tube. Liquids are introduced by means of a syringe needle which pierces a rubber septum contained in the wall of the capsule. Detection thresholds obtained with this unit towards E. coli and S. marcescens assuming a 400 ml water sample are indicated.

JPRS Report, Science & Technology, Japan, 1989 ERATO Symposia.

DTIC Science & Technology

1990-03-20

urchin eggs in fertilization. In fertilization of sea urchin eggs with seminal fluid, ovoperoxidase is secreted from the eggs causing a hardening of the...amphibians, chickens, sea urchins and other species. Simultaneously, molecular biologists have been trying to understand living organisms at the molecular...Cypridina luciferin analogues and luminol). Our group is also continuing the biochemical study of the mechanism of biophoton emission from Japanese sea

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 had an operational stability of at least 8 h, but with a half-life of 2-3 days.

Antioxidant activity of Citrus paradisi seeds glyceric extract.

PubMed

Giamperi, Laura; Fraternale, Daniele; Bucchini, Anahi; Ricci, Donata

2004-03-01

The antioxidant activity of Citrus paradisi (grapefruit) seeds glyceric extract dissolved in ethanol and in aqueous media was evaluated using three different methods: evaluation by DPPH assay, by 5-lipoxygenase assay and by luminol/xanthine/xanthine oxidase chemiluminescence assay. The total phenolic content was determined by the Prussian Blue method opportunely modified. The grapefruit seeds glyceric extract utilized as aqueous solutions demonstrated antioxidant properties better than those displayed by alcoholic solutions.

Monosodium Luminol for Improving Brain Function in Gulf War Illness

DTIC Science & Technology

2016-10-01

Specific Aim 2 studies are focused on examining whether long - term administration of an apt dose of MSL-GVT would alleviate mood and memory dysfunction...and inflammation. 15. SUBJECT TERMS DEET, Gulf war illness, hippocampal neurogenesis, Memory dysfunction, Mood dysfunction, neuroinflammation...doses of MSL-GVT, in comparison to age-matched naive control rats. Thus, short - term (3 weeks of) MSL-GVT treatment is not efficacious for enhancing

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.

A highly sensitive NADH sensor based on a mycelium-like nanocomposite using graphene oxide and multi-walled carbon nanotubes to co-immobilize poly(luminol) and poly(neutral red) hybrid films.

PubMed

Chiang Lin, Kuo; Yu Lai, Szu; Ming Chen, Shen

2014-08-21

Hybridization of poly(luminol) (PLM) and poly(neutral red) (PNR) has been successfully performed and further enhanced by a conductive and steric hybrid nanotemplate using graphene oxide (GO) and multi-walled carbon nanotubes (MWCNTs). The morphology of the PLM-PNR-MWCNT-GO mycelium-like nanocomposite is studied by SEM and AFM and it is found to be electroactive, pH-dependent, and stable in the electrochemical system. It shows electrocatalytic activity towards NADH with a high current response and low overpotential. Using amperometry, it has been shown to have a high sensitivity of 288.9 μA mM(-1) cm(-2) to NADH (Eapp. = +0.1 V). Linearity is estimated in a concentration range of 1.33 × 10(-8) to 1.95 × 10(-4) M with a detection limit of 1.33 × 10(-8) M (S/N = 3). Particularly, it also shows another linear range of 2.08 × 10(-4) to 5.81 × 10(-4) M with a sensitivity of 151.3 μA mM(-1) cm(-2). The hybridization and activity of PLM and PNR can be effectively enhanced by MWCNTs and GO, resulting in an active hybrid nanocomposite for determination of NADH.

Multicommuted flow system for the determination of glucose in animal blood serum exploiting enzymatic reaction and chemiluminescence detection

PubMed Central

Pires, Cherrine K.; Martelli, Patrícia B.; Lima, José L. F. C.; Saraiva, Maria Lúcia M. F. S.

2003-01-01

An automatic flow procedure based on multicommutation dedicated for the determination of glucose in animal blood serum using glucose oxidase with chemiluminescence detection is described. The flow manifold consisted of a set of three-way solenoid valves assembled to implement multicommutation. A microcomputer furnished with an electronic interface and software written in Quick BASIC 4.5 controlled the manifold and performed data acquisition. Glucose oxidase was immobilized on porous silica beads (glass aminopropyl) and packed in a minicolumn (15 × 5 mm). The procedure was based on the enzymatic degradation of glucose, producing hydrogen peroxide, which oxidized luminol in the presence of hexacyanoferrate(III), causing the chemiluminescence. The system was tested by analysing a set of serum animal samples without previous treatment. Results were in agreement with those obtained with the conventional method (LABTEST Kit) at the 95% confidence level. The detection limit and variation coefficient were estimated as 12.0 mg l−1 (99.7% confidence level) and 3.5% (n = 20), respectively. The sampling rate was about 60 determinations h−1 with sample concentrations ranging from 50 to 600 mg l−1 glucose. The consumptions of serum sample, hexacyanoferrate(III) and luminol were 46 μl, 10.0 mg and 0.2 mg/determination, respectively. PMID:18924619

Active oxygen doctors the evidence

NASA Astrophysics Data System (ADS)

Castelló, Ana; Francès, Francesc; Corella, Dolores; Verdú, Fernando

2009-02-01

Investigation at the scene of a crime begins with the search for clues. In the case of bloodstains, the most frequently used reagents are luminol and reduced phenolphthalein (or phenolphthalin that is also known as the Kastle-Meyer colour test). The limitations of these reagents have been studied and are well known. Household cleaning products have evolved with the times, and new products with active oxygen are currently widely used, as they are considered to be highly efficient at removing all kinds of stains on a wide range of surfaces. In this study, we investigated the possible effects of these new cleaning products on latent bloodstains that may be left at a scene of a crime. To do so, various fabrics were stained with blood and then washed using cleaning agents containing active oxygen. The results of reduced phenolphthalein, luminol and human haemoglobin tests on the washed fabrics were negative. The conclusion is that these new products alter blood to such an extent that it can no longer be detected by currently accepted methods employed in criminal investigations. This inability to locate bloodstains means that highly important evidence (e.g. a DNA profile) may be lost. Consequently, it is important that investigators are aware of this problem so as to compensate for it.

Paramecium caudatum as a source of nitric oxide: Chemiluminescent detection based on Bluestar® Forensic reagent connected with microdialysis.

PubMed

Bancirova, Martina

2017-11-01

Nitric oxide (NO) chemistry inside the body is the most interesting part of its behavior. NO is involved in controlling blood pressure, and in transmitting nerve signals and a variety of other signaling processes. To explain the behavior of NO, it is necessary to determine its immediate concentration or observe time-dependent changes in its concentration. In Paramecium caudatum, NO is formed by calcium-dependent nNOS (NOS1)-like protein, which is distributed in the cytoplasm. NO synthesis affects the ciliary beat and consequent motility of cells and blocked NO synthesis reduces the ability of cells to move. The possibility of online coupling of microdialysis (of P. caudatum solution) with NO detection is demonstrated. Direct measurement of NO is carried out using dilute Bluestar ® Forensic reagent (luminol-H 2 O 2 system; one of the NO detections is based upon the chemiluminescent reaction between NO and the luminol-H 2 O 2 system, which is specifically reactive to NO). The effect of a nitric oxide synthase inhibitor, NG-nitro-l-arginine methyl ester was observed. NO production was inhibited and the movement of P. caudatum was restricted. These effects were time dependent and after a specific time were reversed. Copyright © 2017 John Wiley & Sons, Ltd.

Measurements of peroxyacetyl nitrate (PAN) and NO2 at the South Pacific Ocean

NASA Astrophysics Data System (ADS)

Yeon, J.; Song, D.; Lee, J. S.; Rhee, T. S.; Park, K.; Lee, G.

2014-12-01

We measured peroxyacetyl nitrate (PAN) and NO2 in remote marine boundary area during the SHIPPO (Shipborne Pole to Pole Observation). The measurements were made on the R/V Araon from Christ church, New Zealand to Gwangyang, South Korea along the western Pacific Ocean from March 30th to April 25th, 2014. Both PAN and NO2 were analyzed every 2 minute by a fast chromatograph with luminol-based chemiluminescence detection. In order to improve their detection limits, random noise from PMT has been successfully reduced by ensembled chromatograms with every 30 samples. Additionally, we replaced Nylon membrane surface with reflective aluminum surface and applied the new Luminol solution, which enhanced the signals significantly with detection limits of 6 pptv and 40 ppbv for PAN and NO2, respectively. Average concentrations of PAN and NO2 were 8 pptv for PAN and 80 pptv for NO2 during the experiment. The back trajectory analysis showed that the directly influenced air masses from anthropogenic activities were rare except the latitudes higher than 20°N. Relatively good correlations between PAN and NO2 were consistently observed, while PAN and O3 were not clearly correlated except in the air masses recently originated from land masses.

Active oxygen doctors the evidence.

PubMed

Castelló, Ana; Francès, Francesc; Corella, Dolores; Verdú, Fernando

2009-02-01

Investigation at the scene of a crime begins with the search for clues. In the case of bloodstains, the most frequently used reagents are luminol and reduced phenolphthalein (or phenolphthalin that is also known as the Kastle-Meyer colour test). The limitations of these reagents have been studied and are well known. Household cleaning products have evolved with the times, and new products with active oxygen are currently widely used, as they are considered to be highly efficient at removing all kinds of stains on a wide range of surfaces. In this study, we investigated the possible effects of these new cleaning products on latent bloodstains that may be left at a scene of a crime. To do so, various fabrics were stained with blood and then washed using cleaning agents containing active oxygen. The results of reduced phenolphthalein, luminol and human haemoglobin tests on the washed fabrics were negative. The conclusion is that these new products alter blood to such an extent that it can no longer be detected by currently accepted methods employed in criminal investigations. This inability to locate bloodstains means that highly important evidence (e.g. a DNA profile) may be lost. Consequently, it is important that investigators are aware of this problem so as to compensate for it.

Fructose and tagatose protect against oxidative cell injury by iron chelation.

PubMed

Valeri, F; Boess, F; Wolf, A; Göldlin, C; Boelsterli, U A

1997-01-01

To further investigate the mechanism by which fructose affords protection against oxidative cell injury, cultured rat hepatocytes were exposed to cocaine (300 microM) or nitrofurantoin (400 microM). Both drugs elicited massively increased lactate dehydrogenase release. The addition of the ketohexoses D-fructose (metabolized via glycolysis) or D-tagatose (poor glycolytic substrate) significantly attenuated cocaine- and nitrofurantoin-induced cell injury, although both fructose and tagatose caused a rapid depletion of ATP and compromised the cellular energy charge. Furthermore, fructose, tagatose, and sorbose all inhibited in a concentration-dependent manner (0-16 mM) luminolenhanced chemiluminescence (CL) in cell homogenates, indicating that these compounds inhibit the iron-dependent reactive oxygen species (ROS)-mediated peroxidation of luminol. Indeed, both Fe2+ and Fe3+ further increased cocaine-stimulated CL, which was markedly quenched following addition of the ketohexoses. The iron-independent formation of superoxide anion radicals (acetylated cytochrome c reduction) induced by the prooxidant drugs remained unaffected by fructose or tagatose. The iron-chelator deferoxamine similarly protected against prooxidant-induced cell injury. In contrast, the nonchelating aldohexoses D-glucose and D-galactose did not inhibit luminol CL nor did they protect against oxidative cell injury. These data indicate that ketohexoses can effectively protect against prooxidant-induced cell injury, independent of their glycolytic metabolism, by suppressing the iron-catalyzed formation of ROS.

Quantitative Monitoring of Cefradine in Human Urine Using a Luminol/Sulfobutylether-β-Cyclodextrin Chemiluminescence System

NASA Astrophysics Data System (ADS)

Shen, M. X.; Tan, X. J.; Song, Zh. H.

2018-05-01

In this paper, a sensitive, rapid, and simple flow-injection chemiluminescence (FI-CL) technique is described for determining cefradine in human urine and capsule samples at the picogram level. The results show that cefradine within 0.1-100.0 nmol/L quantitatively quenches the CL intensity of the luminol/sulfo butylether-β-cyclodextrin (SBE-β-CD) system, with a relative correlation coefficient r of 0.9931. Subsequently, the possible mechanism for the quenching phenomenon is discussed in detail using the FI-CL and molecular docking methods. The proposed CL method, with a detection limit of 0.03 nmol/L (3σ) and relative standard deviations <3.0% (N = 7), is then implemented to monitor the excretion of cefradine in human urine. After orally administration, the cefradine reaches a maximum value of 1.37 ± 0.02 mg/mL at 2.0 h in urine, and the total excretion is 4.41 ± 0.03 mg/mL within 8.0 h. The absorption rate constant ka, the elimination rate constant ke, and the half-life t1/2 are 0.670 ± 0.008 h-1, 0.744 ± 0.005 h-1, and 0.93 ± 0.05 h, respectively.

A novel strategy for synthesis of hollow gold nanosphere and its application in electrogenerated chemiluminescence glucose biosensor.

PubMed

Zhong, Xia; Chai, Ya-Qin; Yuan, Ruo

2014-10-01

Well-distributed hollow gold nanospheres (Aushell@GOD) (20 ± 5 nm) were synthesized using the glucose oxidase (GOD) cross-linked with glutaraldehyde as a template. A glucose biosensor was prepared based on Aushell@GOD nanospheres for catalyzing luminol electrogenerated chemiluminescence (ECL). Firstly, chitosan was modified in a glassy carbon electrode which offered an interface of abundant amino-groups to assemble Aushell@GOD nanospheres. Then, glucose oxidase was adsorbed on the surface of Aushell@GOD nanospheres via binding interactions between Aushell and amino groups of GOD to construct a glucose biosensor. The Aushell@GOD nanospheres were investigated with TEM and UV-vis. The ECL behaviors of the biosensor were also investigated. Results showed that, the obtained Aushell@GOD nanospheres exhibited excellent catalytic effect towards the ECL of luminol-H2O2 system. The response of the prepared biosensor to glucose was linear with the glucose concentration in the range of 1.0 μM to 4.3mM (R=0.9923) with a detection limit of 0.3 μM (signal to noise=3). This ECL biosensor exhibited short response time and excellent stability for glucose. At the same time the prepared ECL biosensor showed good reproducibility, sensitivity and selectivity. 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.

Development of a reagentless electrochemiluminescent electrode for flow injection analysis using copolymerised luminol/aniline on nano-TiO2 functionalised indium-tin oxide glass.

PubMed

Liu, Chao; Wei, Xiuhua; Tu, Yifeng

2013-07-15

In this study, a nano-structured copolymer of luminol/aniline (PLA) was deposited onto nano-TiO2-functionalised indium tin oxide (ITO)-coated glass by electrochemical polymerisation using cyclic voltammetry (CV). The resulting reagentless electrochemiluminescent (ECL) electrode (ECLode) can be used for flow injection analysis (FIA). The properties of the ECLode were characterised by CV, electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). The ECLode has high background ECL emission as well as excellent stability and reproducibility, and yielding sensitive response towards target analytes. The ECL emissions of the ECLode were 50 times higher than PLA/ITO, and 500 times higher than polyluminol (PL)/ITO. The ECLode showed sensitive responses to reactive oxygen species (ROSs), permitting its application for determination of antioxidants by quenching. Under optimised conditions, an absolute detection limit of 69.9 pg was obtained for resveratrol, comparable to the highest levels of sensitivity achieved by other methods. Thus, the gross antioxidant content of red wine was determined, with satisfactory recoveries between 87.6% and 108.3%. These results suggest a bright future for the use of the ECLode for single-channel FIA due to its high sensitivity, accuracy and reproducibility. Copyright © 2013 Elsevier B.V. All rights reserved.

Effect of nicotine, cotinine and cigarette smoke extract on the neutrophil respiratory burst.

PubMed

Matthews, John B; Chen, Fa-Ming; Milward, Michael R; Wright, Helen J; Carter, Kevin; McDonagh, Anna; Chapple, Iain L C

2011-03-01

To determine the effect of nicotine, cotinine and cigarette smoke extract (CSE) on the neutrophil respiratory burst and their effect on activation of the nuclear factor-κB (NFκB) pathway in oral epithelium. Neutrophils from periodontally healthy individuals were treated with nicotine, cotinine and CSE before stimulation with Fusobacterium nucleatum, IgG-opsonized Staphylococcus aureus and Escherichia coli lipopolysaccharide. Total and extracellular reactive oxygen species (ROS) generation was determined by luminol/isoluminol chemiluminescence. Activation of NFκB in oral epithelial cells was determined by immunocytochemistry. Smoke extract alone caused increased neutrophil extracellular isoluminol-dependent chemiluminescence, not detectable with luminol. However, pre-treatment with smoke extract reduced both total and extracellular ROS generation in response to all stimuli. Nicotine and cotinine had no effect on the neutrophil respiratory burst. Smoke extract, nicotine and cotinine did not induce oral epithelial cell NFκB activation. These data demonstrate that smoke extract reduces the ability of neutrophils to generate ROS after stimulation with F. nucleatum and IgG-opsonized S. aureus but, at high concentrations, stimulates extracellular ROS generation. During periodontitis, cigarette smoking may differentially affect neutrophil function, generally preventing elimination of periodontal pathogens but, in heavy smokers, also stimulating ROS release and oxidative stress mediated tissue damage. © 2011 John Wiley & Sons A/S.

Effect of desensitizing agents on dentin permeability.

PubMed

Ishihata, Hiroshi; Kanehira, Masafumi; Nagai, Tomoko; Finger, Werner J; Shimauchi, Hidetoshi; Komatsu, Masashi

2009-06-01

To investigate the in vitro efficacy of two dentin desensitizing products at reducing liquid permeability through human dentin discs. The tested hypothesis was that the products, in spite of different chemical mechanisms were not different at reducing or eliminating flow through dentin discs. Dentin slices (1 mm thick) were prepared from 16 extracted human third molars and their permeability was indirectly recorded in a split chamber model, using a chemiluminescence technique, after EDTA treatment (control), after soaking with albumin, and after desensitizer application. Two products were studied: MS Coat, a self-curing resin-containing oxalate product, and Gluma Desensitizer, a glutaraldehyde/HEMA-based agent without initiator. The dentin slices were mounted between an upper chamber, filled with an aqueous solution of 1% potassium ferricyanide and 0.3% hydrogen peroxide, and a lower chamber filled with 1% sodium hydroxide solution and 0.02% luminol. The upper solution was pressurized, and upon contact with the luminol solution a photochemical signal was generated and recorded as a measure of permeability throughout two consecutive pressurizing cycles at 2.5 and 13 kPa (26 and 133 cm H2O), respectively. The permeability of the control and albumin-soaked samples was similarly high. After application of the desensitizing agents, dentin permeability was reduced to virtually zero at both pressure levels (P < 0.001).

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.

Development of a new procedure for the determination of captopril in pharmaceutical formulations employing chemiluminescence and a multicommuted flow analysis approach.

PubMed

Lima, Manoel J A; Fernandes, Ridvan N; Tanaka, Auro A; Reis, Boaventura F

2016-02-01

This paper describes a new technique for the determination of captopril in pharmaceutical formulations, implemented by employing multicommuted flow analysis. The analytical procedure was based on the reaction between hypochlorite and captopril. The remaining hypochlorite oxidized luminol that generated electromagnetic radiation detected using a homemade luminometer. To the best of our knowledge, this is the first time that this reaction has been exploited for the determination of captopril in pharmaceutical products, offering a clean analytical procedure with minimal reagent usage. The effectiveness of the proposed procedure was confirmed by analyzing a set of pharmaceutical formulations. Application of the paired t-test showed that there was no significant difference between the data sets at a 95% confidence level. The useful features of the new analytical procedure included a linear response for captopril concentrations in the range 20.0-150.0 µmol/L (r = 0.997), a limit of detection (3σ) of 2.0 µmol/L, a sample throughput of 164 determinations per hour, reagent consumption of 9 µg luminol and 42 µg hypochlorite per determination and generation of 0.63 mL of waste. A relative standard deviation of 1% (n = 6) for a standard solution containing 80 µmol/L captopril was also obtained. Copyright © 2015 John Wiley & Sons, Ltd.

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.

Cavitation and non-cavitation regime for large-scale ultrasonic standing wave particle separation systems--In situ gentle cavitation threshold determination and free radical related oxidation.

PubMed

Johansson, Linda; Singh, Tanoj; Leong, Thomas; Mawson, Raymond; McArthur, Sally; Manasseh, Richard; Juliano, Pablo

2016-01-01

We here suggest a novel and straightforward approach for liter-scale ultrasound particle manipulation standing wave systems to guide system design in terms of frequency and acoustic power for operating in either cavitation or non-cavitation regimes for ultrasound standing wave systems, using the sonochemiluminescent chemical luminol. We show that this method offers a simple way of in situ determination of the cavitation threshold for selected separation vessel geometry. Since the pressure field is system specific the cavitation threshold is system specific (for the threshold parameter range). In this study we discuss cavitation effects and also measure one implication of cavitation for the application of milk fat separation, the degree of milk fat lipid oxidation by headspace volatile measurements. For the evaluated vessel, 2 MHz as opposed to 1 MHz operation enabled operation in non-cavitation or low cavitation conditions as measured by the luminol intensity threshold method. In all cases the lipid oxidation derived volatiles were below the human sensory detection level. Ultrasound treatment did not significantly influence the oxidative changes in milk for either 1 MHz (dose of 46 kJ/L and 464 kJ/L) or 2 MHz (dose of 37 kJ/L and 373 kJ/L) operation. Copyright © 2015 Elsevier B.V. All rights reserved.

Ultrasound-mediated drug delivery by gas bubbles generated from a chemical reaction.

PubMed

Lee, Sungmun; Al-Kaabi, Leena; Mawart, Aurélie; Khandoker, Ahsan; Alsafar, Habiba; Jelinek, Herbert F; Khalaf, Kinda; Park, Ji-Ho; Kim, Yeu-Chun

2018-02-01

Highly echogenic and ultrasound-responsive microbubbles such as nitrogen and perfluorocarbons have been exploited as ultrasound-mediated drug carriers. Here, we propose an innovative method for drug delivery using microbubbles generated from a chemical reaction. In a novel drug delivery system, luminol encapsulated in folate-conjugated bovine serum albumin nanoparticles (Fol-BSAN) can generate nitrogen gas (N 2 ) by chemical reaction when it reacts with hydrogen peroxide (H 2 O 2 ), one of reactive oxygen species (ROS). ROS plays an important role in the initiation and progression of cancer and elevated ROS have been observed in cancer cells both in vitro and in vivo. High-intensity focussed ultrasound (HIFU) is used to burst the N 2 microbubbles, causing site-specific delivery of anticancer drugs such as methotrexate. In this research, the drug delivery system was optimised by using water-soluble luminol and Mobil Composition of Matter-41 (MCM-41), a mesoporous material, so that the delivery system was sensitive to micromolar concentrations of H 2 O 2 . HIFU increased the drug release from Fol-BSAN by 52.9 ± 2.9% in 10 minutes. The cytotoxicity of methotrexate was enhanced when methotrexate is delivered to MDA-MB-231, a metastatic human breast cancer cell line, using Fol-BSAN with HIFU. We anticipate numerous applications of chemically generated microbubbles for ultrasound-mediated drug delivery.

Blood eosinophils from asymptomatic allergics have a reduced capacity to produce oxygen-free radicals.

PubMed

Woschnagg, C; Rak, S; Venge, P

1998-12-01

The eosinophil granulocyte is an inflammatory cell that plays an active part in diseases such as asthma and rhinitis. This study aimed to investigate oxidative metabolism by blood eosinophils taken from allergic rhinitis patients, asthmatics, and nonallergic controls before and during the birch-pollen season. Twenty patients with allergy to birch pollen and seasonal symptoms of rhinitis, some of whom were also asthmatic, were followed before and during the birch-pollen season in Sweden. The cells were purified using a Percoll gradient and the MACS system. Eosinophil purity in all samples was > 95%. Oxidative metabolism was measured by a chemiluminescence (CL) assay, with luminol and lucigenin acting as enhancers, and PMA, serum-treated zymosan (STZ), interleukin (IL)-5, or RANTES as stimuli. The allergic subjects showed reduced luminol CL when activated before the season with PMA (P = 0.040) or STZ (P = 0.0055). This was not seen during pollen exposure. STZ-activated lucigenin CL was also reduced before the season (P = 0.0027). The reduction was most evident in the group with asymptomatic rhinitis. In terms of eosinophil stimulation, IL-5 and RANTES were equally effective in allergic and nonallergic subjects, both before and during the pollen season. Blood eosinophils from asymptomatic allergics may have a lower capacity to produce oxygen-free radicals than eosinophils from nonallergics.

DNA tetrahedral scaffolds-based platform for the construction of electrochemiluminescence biosensor.

PubMed

Feng, Qiu-Mei; Zhou, Zhen; Li, Mei-Xing; Zhao, Wei; Xu, Jing-Juan; Chen, Hong-Yuan

2017-04-15

Proximal metallic nanoparticles (NPs) could quench the electrochemiluminescence (ECL) emission of semiconductor quantum dots (QDs) due to Förster energy transfer (FRET), but at a certain distance, the coupling of light-emission with surface plasmon resonance (SPR) result in enhanced ECL. Thus, the modification strategies and distances control between QDs and metallic NPs are critical for the ECL intensity of QDs. In this strategy, a SPR enhanced ECL sensor based on DNA tetrahedral scaffolds modified platform was reported for the detection of telomerase activity. Due to the rigid three-dimensional structure, DNA tetrahedral scaffolds grafting on the electrode surface could accurately modulate the distance between CdS QDs and luminol labelled gold nanoparticles (L-Au NPs), meanwhile provide an enhanced spatial dimension and accessibility for the assembly of multiple L-Au NPs. The ECL intensities of both CdS QDs (-1.25V vs. SCE) and luminol (+0.33V vs. SCE) gradually increased along with the formation of multiple L-Au NPs at the vertex of DNA tetrahedral scaffolds induced by telomerase, bringing in a dual-potential ECL analysis. The proposed method showed high sensitivity for the identification of telomerase and was successfully applied for the differentiation of cancer cells from normal cells. This work suggests that DNA tetrahedral scaffolds could serve as an excellent choice for the construction of SPR-ECL system. Copyright © 2016 Elsevier B.V. All rights reserved.

Luminol-based electrochemiluminescent biosensors for highly sensitive medical diagnosis and rapid antioxidant detection

NASA Astrophysics Data System (ADS)

Tamiya, Eiichi; Inoue, Yuki; Saito, Masato

2018-03-01

We present a review of luminol-based electrochemiluminescence (ECL) biosensors that perform enzymatic reactions and bioanalysis using antioxidant molecules by controlling the spatiotemporal production of a luminescent substrate, catalase activity, and glycated albumin (GA). The ECL intensity depends on the antioxidant capacity because radicals are neutralized by the antioxidants, which suppresses the luminescence. The antioxidant capacities of 22 types beverages were evaluated by comparison with a standard curve of Trolox. The time necessary for the ECL measurement of the antioxidant capacity is only 2 min with screen-printed electrodes and a portable ECL measurement system. Our system was also used to monitor reactive oxygen species released from neutrophils, which play an important role in the immune system, defending against viral and bacterial infections. The quenching of ECL imaging by catalase reaction localized in the multichamber electrode using the electrogenerated substrate was examined as a potential candidate for a sensitive reporting system. The substrate was successfully generated at applied potentials between -1 and -0.4 V in multichamber electrodes and the substrate confinement within the chamber was observed within 60 s of generation. The microchamber electrode system demonstrated a detection limit of 90 fM catalase. We also demonstrated a detection limit of 0.1 µM GA in human serum albumin, which is an improvement of about 70 times over colorimetric methods.

Selective, Specific, and Versatile Personal Biosensors to Organophosphate Chemical Toxins Composed of Polyurethane Immobilized Enzymes

DTIC Science & Technology

2002-01-01

cuvette containing a stir bar and the biosensor. RESULTS ACh ChE Acetate + Choline Betaine aldehyde+H2O2 Choline oxidase O2+ Choline oxidase...O2+ H2O2 Betaine + 2H2O2 carbon electrode electrochemical detection luminol fluorescent adducts visible adducts chemiluminescence fluorescence (CPM...soluble BChE and biosensor BChE at different tem- peratures relative to 30oC. Figure 7. Top: Immobilized choline oxidase and soluble form of the

Antioxidant potential of six pine species.

PubMed

Guri, Anilda; Kefalas, Panagiotis; Roussis, Vassilios

2006-04-01

The aim of the study was to evaluate the antioxidant efficacy of extracts obtained from six Pinus species (P. pinea, P. brutia, P. radiata, P. halepensis, P. attenuata, P. nigra) growing in natural forests in Southern Greece. Specimens of fresh, dry needles and pine bark were extracted and fractionated with a variety of organic solvents and the efficient concentration and their radical scavenging activity was evaluated by the Co(II)/EDTA induced luminol plateau chemiluminescence assay. Copyright 2006 John Wiley & Sons, Ltd.

Utility of gold nanoparticles in luminescence determination of trovafloxacin: comparison of chemiluminescence and fluorescence detection.

PubMed

Alarfaj, Nawal A; El-Tohamy, Maha F

2015-12-01

Two novel sensitive sequential injection chemiluminescence analysis and fluorescence methods for trovafloxacin mesylate detection have been developed. The methods were based on the enhancement effect of gold nanoparticles on luminol-ferricyanide-trovafloxacin and europium(III)-trovafloxacin complex systems. The optimum conditions for both detection methods were investigated. The chemiluminescence signal was emitted due to the enhanced effect of gold nanoparticles on the reaction of luminol-ferricyanide-trovafloxacin in an alkaline medium. The response was linear over a concentration range of 1.0 × 10(-9) to 1.0 × 10(-2) mol/L (%RSD = 1.3), (n = 9, r = 0.9991) with a detection limit of 1.7 × 10(-10) mol/L (S/N = 3). The weak fluorescence intensity signal of the oxidation complex of europium(III)-trovafloxacin was strongly enhanced by gold nanoparticles and detected at λex = 330 and λem = 540 nm. Fluorescence detection enabled the determination of trovafloxacin mesylate over a linear range of 1.0 × 10(-8) to 1.0 × 10(-3) mol/L (%RSD = 1.2), (n = 6, r = 0.9993) with a detection limit of 3.3 × 10(-9) mol/L. The proposed methods were successfully applied to the determination of the studied drug in its bulk form and in pharmaceutical preparations. The results were treated statistically and compared with those obtained from other reported methods. Copyright © 2015 John Wiley & Sons, Ltd.

Revealing interaction between sulfobutylether-β-cyclodextrin and reserpine by chemiluminescence and site-directed molecular docking.

PubMed

Xiong, Xunyu; Wu, Min; Zhao, Xinfeng; Song, Zhenghua

2014-09-01

The host-guest interaction between sulfobutylether-β-cyclodextrin (SBE-β-CD) and reserpine (RSP) is described using flow injection-chemiluminescence (FI-CL) and site-directed molecular docking methods. It was found that RSP could inhibit the CL intensity produced by a luminol/SBE-β-CD system. The decrease in CL intensity was logarithmic over an RSP concentration range of 0.03 to 700.0 nM, giving a regression equation of ∆I = 107.1lgCRES  + 186.1 with a detection limit of 10 pM (3σ). The CL assay was successfully applied in the determination of RSP in injection, saliva and urine samples with recoveries in the range 93.5-106.1%. Using the proposed CL model, the binding constant (KCD-R ) and the stoichiometric ratio of SBE-β-CD/RSP were calculated to be 7.4 × 10(6)  M(-1) and 1 : 1, respectively. Using molecular docking, it was confirmed that luminol binds to the small cavity of SBE-β-CD with a nonpolar interaction, while RSP targeted the larger cavity of SBE-β-CD and formed a 1 : 1 complex with hydrogen bonds. The proposed new CL method has the potential to become a powerful tool for revealing the host-guest interaction between CDs and drugs, as well as monitoring drugs with high sensitivity. Copyright © 2013 John Wiley & Sons, Ltd.

CE with chemiluminescence detection for the determination of thyroxine in human serum.

PubMed

Mu, Xiaomei; Li, Shuting; Lu, Xin; Zhao, Shulin

2014-04-01

A sensitive and rapid approach to perform thyroxine (T4) assay by CE with chemiluminescence (CL) detection was developed. The sensitive detection was based on the enhancement effect of T4 on the CL reaction between luminol and potassium permanganate (KMnO4 ) in alkaline solution. A laboratory-built reaction flow cell and a photon counter were deployed for the CL detection. Experimental conditions for CL detection were studied in detail to achieve maximum assay sensitivity. Optimal conditions were found to be 5.0 × 10(-4) M luminol added to the CE running buffer and 9.2 × 10(-5) M KMnO4 in 0.072 M NaOH solution introduced postcolumn. In the optimized experimental conditions, the linear range for T4 detection was 6.0 × 10(-8) -6.0 × 10(-6) M, with the detection limit of 2.0 × 10(-8) M (S/N = 3). Six human serum samples from healthy subjects, hyperthyroid patients and hypothyroid patients were analyzed by the presented method. The serum level of T4 in healthy subjects was found be 9.0 × 10(-8) M, whereas the T4 level was found to be 15.6 × 10(-8) M in hyperthyroid patients and 1.3 × 10(-8) M in hypothyroid patients. The results suggested a potential application of the proposed assay in rapid primary diagnosis of diseases such as hyperthyroid and hypothyroid. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A hot-spot-active magnetic graphene oxide substrate for microRNA detection based on cascaded chemiluminescence resonance energy transfer.

PubMed

Bi, Sai; Chen, Min; Jia, Xiaoqiang; Dong, Ying

2015-02-28

Herein, a cascaded chemiluminescence resonance energy transfer (C-CRET) process was demonstrated from horseradish peroxidase (HRP)-mimicking DNAzyme-catalyzed luminol-H2O2 to fluorescein and further to graphene oxide (GO) when HRP-mimicking DNAzyme/fluorescein was in close proximity to the GO surface. The proposed C-CRET system was successfully implemented to construct three modes of C-CRET hot-spot-active substrates (modes I, II and III) by covalently immobilizing HRP-mimicking DNAzyme/fluorescein-labeled hairpin DNAs (hot-spot-generation probes) on magnetic GO (MGO), resulting in a signal "off" state due to the quenching of the luminol/H2O2/HRP-mimicking DNAzyme/fluorescein CRET system by GO. Upon the introduction of microRNA-122 (miRNA-122), the targets (mode I) or the new triggers that were generated through a strand displacement reaction (SDR) initiated by miRNA-122 (modes II and III) hybridized with the loop domains of hairpin probes on MGO to form double-stranded (modes I and II) or triplex-stem structures (mode III), causing an "open" configuration of the hairpin probe and a CRET signal "on" state, thus achieving sensitive and selective detection of miRNA-122. More importantly, the substrate exhibited excellent controllability, reversibility and reproducibility through SDR and magnetic separation (modes II and III), especially sequence-independence for hairpin probes in mode III, holding great potential for the development of a versatile platform for optical biosensing.

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.

Effect of resonance frequency, power input, and saturation gas type on the oxidation efficiency of an ultrasound horn.

PubMed

Rooze, Joost; Rebrov, Evgeny V; Schouten, Jaap C; Keurentjes, Jos T F

2011-01-01

The sonochemical oxidation efficiency (η(ox)) of a commercial titanium alloy ultrasound horn has been measured using potassium iodide as a dosimeter at its main resonance frequency (20 kHz) and two higher resonance frequencies (41 and 62 kHz). Narrow power and frequency ranges have been chosen to minimise secondary effects such as changing bubble stability, and time available for radical diffusion from the bubble to the liquid. The oxidation efficiency, η(ox), is proportional to the frequency and to the power transmitted to the liquid (275 mL) in the applied power range (1-6 W) under argon. Luminol radical visualisation measurements show that the radical generation rate increases and a redistribution of radical producing zones is achieved at increasing frequency. Argon, helium, air, nitrogen, oxygen, and carbon dioxide have been used as saturation gases in potassium iodide oxidation experiments. The highest η(ox) has been observed at 5 W under air at 62 kHz. The presence of carbon dioxide in air gives enhanced nucleation at 41 and 62 kHz and has a strong influence on η(ox). This is supported by the luminol images, the measured dependence of η(ox) on input power, and bubble images recorded under carbon dioxide. The results give insight into the interplay between saturation gas and frequency, nucleation, and their effect on η(ox). Copyright © 2010 Elsevier B.V. All rights reserved.

New electrochemiluminescent biosensors combining polyluminol and an enzymatic matrix.

PubMed

Sassolas, Audrey; Blum, Loïc J; Leca-Bouvier, Béatrice D

2009-06-01

Performant reagentless electrochemiluminescent (ECL) (bio)sensors have been developed using polymeric luminol as the luminophore. The polyluminol film is obtained by cyclic voltammetry (CV) on a screen-printed electrode either in a commonly used H(2)SO(4) medium or under more original near-neutral buffered conditions. ECL responses obtained after performing polymerization either at acidic pH or at pH 6 have been compared. It appears that polyluminol formed in near-neutral medium gives the best responses for hydrogen peroxide detection. Polymerization at pH 6 by cyclic voltammetry gives a linear range extending from 8 x 10(-8) to 1.3 x 10(-4) M H(2)O(2) concentrations. Based on this performant sensor for hydrogen peroxide detection, an enzymatic biosensor has been developed by associating the polyluminol film with an H(2)O(2)-producing oxidase. Here, choline oxidase (ChOD) has been chosen as a model enzyme. To develop the biosensor, luminol has been polymerized at pH 6 by CV, and then an enzyme-entrapping matrix has been formed on the above modified working electrode. Different biological (chitosan, agarose, and alginate) and chemical (silica gels, photopolymers, or reticulated matrices) gels have been tested. Best performances have been obtained by associating a ChOD-immobilizing photopolymer with the polyluminol film. In this case, choline can be detected with a linear range extending from 8 x 10(-8) to 1.3 x 10(-4) M.

Investigation of fine chalk dust particles' chemical compositions and toxicities on alveolar macrophages in vitro.

PubMed

Zhang, Yuexia; Yang, Zhenhua; Li, Ruijin; Geng, Hong; Dong, Chuan

2015-02-01

The aim of the study is to investigate chemical compositions of fine chalk dust particles (chalk PM2.5) and examine their adverse effects on alveolar macrophages (AMs) in vitro. Morphologies and element concentrations of individual chalk particles were analyzed by using the quantitative energy-dispersive electron probe X-ray microanalysis (ED-EPMA). The oxidative response of AMs and the potential to generate nitric oxide (NO) by luminol-dependent chemiluminescence (CL) and nitrate reductase method were assessed 4h following the treatment of AMs with differing dosages of fine chalk particles, respectively. Oxidative stress and cytotoxicity elicited by chalk PM2.5 were also examined. The results showed that fine chalk particles were mainly composed of gypsum, calcite, dolomite and a little amount of organic adhesives. Exposure to chalk PM2.5 at 100 μg mL(-1) or 300 μg mL(-1) significantly increased intracellular catalase, malondialdehyde, and NO levels and decreased superoxide dismutase level in AMs, leading to leakage of lactate dehydrogenase (LDH) and reduction of the cell viability. Furthermore, luminol-dependent CL from respiratory burst in AMs was enhanced. It was suggested that chalk PM2.5 could make oxidative damages on AMs and result in cytotoxicity, being likely attributed to excessive reactive oxygen species or reactive nitrogen species induced by mixture of fine gypsum and calcite/dolomite particles. Copyright © 2014 Elsevier Ltd. All rights reserved.

Multilayers enzyme-coated carbon nanotubes as biolabel for ultrasensitive chemiluminescence immunoassay of cancer biomarker.

PubMed

Bi, Sai; Zhou, Hong; Zhang, Shusheng

2009-06-15

A novel and ultrasensitive chemiluminescence immunoassay (CLIA) method based on multiple enzyme layers assembled multiwall carbon nanotubes (MWCNTs) as signal amplification labels was developed by employing luminol-H(2)O(2)-HRP-bromophenol blue (BPB) enhanced chemiluminescence (CL) system for the detection of a cancer biomarker in human serum samples, as exemplified by the measurement of alpha-fetoprotein (AFP) as a model protein. In this study, horseradish peroxidase (HRP) was assembled onto MWCNTs templates layer-by-layer (LBL) through electrostatic interactions with polyion PDDA, and further conjugated with AFP secondary antibodies (Ab(2)) as the enzyme label. The resulting LBL assembly could maximize the ratio of HRP/Ab(2) which could amplify the sensitivity greatly. To the best of our knowledge, it was the first time for this strategy applied in CLIA to date. Under the optimum conditions of luminol-H(2)O(2)-HRP-BPB CL system and the sandwich immunoreactions, a linear range from 0.02 to 2.0 ng/mL (R=0.9980) was obtained with the detection limit of 8.0 pg/mL (3sigma) which was two orders of magnitude lower than standard ELISA method. Furthermore, accurate detection of AFP in human serum samples was also demonstrated by comparison to ELISA assays. From the above results, such signal amplification strategy proposed by the novel CNT-LBL enzyme label showed an excellent promise for ultrasensitive detection of cancer biomarkers in clinical laboratory.

Determination of Sulfonamide Residues in Food by Capillary Zone Electrophoresis with On-Line Chemiluminescence Detection Based on an Ag(III) Complex.

PubMed

Dai, Tingting; Duan, Jie; Li, Xinghua; Xu, Xiangdong; Shi, Hongmei; Kang, Weijun

2017-06-16

The presence of sulfonamide (SA) residues in foods is largely due to the raising of animals with sulfonamide antibiotics added or polluted feedstuff. In this paper, a sensitive method was developed for the determination of the residues of three sulfonamides in animal-derived food; the SAs include sulfadimidine (SDD), sulfadiazine (SDZ), and sulfathiazole (STZ). The method is based on capillary zone electrophoresis (CE) with online chemiluminescence (CL) detection, using an Ag(III) complex as an oxidant. These SAs have an inhibiting effect on the Ag(III)-luminol CL reaction. The electrophoretic buffer is 12.0 mM sodium borate. Under a set of optimized conditions, the linear ranges for the detections were found to be 10.0-200 µg·mL -1 for SDD and SDZ, and 2.0-50.0 µg·mL -1 for STZ. The detection limits were 2.75, 3.14, and 0.65 µg·mL -1 for SDD, SDZ, and STZ, respectively. Relative standard deviations (RSD) for the peak heights were between 2.1% and 2.8% (n = 7). The proposed method was used in the analysis of the SAs in samples from pork meat, chicken meat, and milk, showing satisfactory detection results. A reaction mechanism was also proposed for the Ag(III)-luminol-SA CL reactions. The method has potential applications for the monitoring of residue levels of the three SAs in food, providing food safety data.

Ratiometric electrochemiluminescent strategy regulated by electrocatalysis of palladium nanocluster for immunosensing.

PubMed

Huang, Yin; Lei, Jianping; Cheng, Yan; Ju, Huangxian

2016-03-15

This work designed a novel ratiometric electrochemiluminescence (ECL) immunosensing approach based on two different ECL emitters: CdS quantum dots (QDs) as cathodic emitter and luminol as anodic emitter. The ECL immunosensor was constructed by a layer-by-layer modification of CdS QDs, Au nanoparticles and capture antibody on a glassy carbon electrode. With hydrogen peroxide as ECL coreactant, the immunosensor showed a cathodic ECL emission of CdS QDs at -1.5 V (vs Ag/AgCl) in air-saturated pH 8.0 buffer. Upon the formation of sandwich immunoassay, the lumiol/palladium nanoclusters (Pd NCs)@graphene oxide probe was introduced to the electrode. Therefore, the cathodic ECL intensity decreased and luminol anodic ECL emission was appeared at +0.3 V (vs Ag/AgCl) owing to the competition of the coreactant of hydrogen peroxide. Using carcino-embryonic antigen as model, this ratiometric ECL strategy could be used for immunoassay with a linear range of 1.0-100 pg mL(-1) and a detection limit of 0.62 pg mL(-1). The enhanced ratiometric ECL signal resulted from the high density and excellent electrocatalysis of the loaded Pd NCs. The immunosensor exhibited good stability and acceptable fabrication reproducibility and accuracy, showing a great promising for clinical application. This electrocatalysis-regulated ratiometric ECL provides a new concept for ECL measurement, and could be conveniently extended for detection of other protein biomarkers. Copyright © 2015 Elsevier B.V. All rights reserved.

Cassette bacteria detection system. [for monitoring the sterility of regenerated water in spacecraft

NASA Technical Reports Server (NTRS)

1974-01-01

The design, fabrication, and testing of an automatic bacteria detection system, with a zero-g capability, based on the filter-capable approach, and intended for monitoring the sterility of regenerated water in spacecraft is discussed. The principle of detection is based on measuring the increase in chemiluminescence produced by the action of bacterial porphyrins on a luminol-hydrogen peroxide mixture. Viable organisms are detected by comparing the signal of an incubated water sample with an unincubated control. High signals for the incubated water sample indicate the presence of viable organisms.

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.

Binding study of lysozyme with Al(III) using chemiluminescence analysis.

PubMed

Liu, Jiangman; Luo, Kai; Song, Zhenghua

2014-09-01

The binding behavior of lysozyme with Al(III) is described using luminol as a luminescence probe by flow injection-chemiluminescence (FI-CL) analysis. It was found that the CL intensity of the luminol-lysozyme reaction could be markedly enhanced by Al(III), and the increase in CL intensity was linear with the Al(III) concentration over the range 0.3-30.0  pg  mL(-1) , with a detection limit of 0.1 pg  mL(-1) (3σ). Based on the interaction model of lysozyme with Al(III), lg[(I - I0 )/(2I0  - I)] = lgK + nlg[M], the binding constant K = 6.84 × 10(6)  L mol(-1) and the number of binding sites (n) = 0.76. The relative standard deviations were 3.2, 2.4 and 2.0% for 10.0, 20.0 and 30.0  pg  mL(-1) Al(III) (n = 7), respectively. This new method was successfully applied to continuous, quantitative monitoring of picogram level Al(III) in human saliva following oral intake of compound aluminum hydroxide tablets. It was found that Al(III) in saliva reached a maximum of 101.2  ng  mL(-1) at 3.0 h. The absorption rate constant ka , elimination rate constant k and half-life time t1/2 of Al(III) were 1.378  h(-1) , 0.264  h(-1) and 2.624  h, respectively. Copyright © 2013 John Wiley & Sons, Ltd.

Participation of reactive oxygen species in diabetes-induced endothelial dysfunction.

PubMed

Zúrová-Nedelcevová, Jana; Navarová, Jana; Drábiková, Katarína; Jancinová, Viera; Petríková, Margita; Bernátová, Iveta; Kristová, Viera; Snirc, Vladimír; Nosál'ová, Viera; Sotníková, Ruzena

2006-12-01

In the present study, the relationship between diabetes-induced hyperglycemia, reactive oxygen species production and endothelium-mediated arterial function was examined. The effect of antioxidant on the reactive oxygen species induced damage was tested. Diabetes was induced by streptozotocin (STZ), 3 x 30 mg/kg i.p., administered on three consecutive days. After 10 weeks of diabetes, the functional state of the endothelium of the aorta was tested, endothelemia evaluation was performed and systolic blood pressure was measured. Reactive oxygen species (ROS) formation in blood and the aorta was measured using luminol-enhanced chemiluminescence (CL). Levels of reduced glutathione (GSH) were determined in the aorta, kidney, and plasma. To study the involvement of hyperglycemia in functional impairment of the endothelium, aortal rings incubated in solution with high glucose concentration were tested in in vitro experiments. After 10 weeks of diabetes, endothelial injury was observed, exhibited by diminished endothelium-dependent relaxation of the aorta, increased endothelemia and by elevated systolic blood pressure. Using luminol-enhanced CL, a significant increase of ROS production was found in arterial tissue and blood. GSH levels were significantly increased in the kidney, while there were no GSH changes in plasma and the aorta. Incubation of aortic rings in solution with high glucose concentration led to impairment of endothelium-dependent relaxation. The synthetic antioxidant SMe1EC2 was able to restore reduced endothelium-mediated relaxation. Our results suggest an important role of hyperglycemia-induced ROS production in mediating endothelial dysfunction in experimental diabetes, confirmed by CL and the protective effect of the antioxidant SMe1EC2.

On methods for the detection of reactive oxygen species generation by human spermatozoa: analysis of the cellular responses to catechol oestrogen, lipid aldehyde, menadione and arachidonic acid.

PubMed

Aitken, R J; Smith, T B; Lord, T; Kuczera, L; Koppers, A J; Naumovski, N; Connaughton, H; Baker, M A; De Iuliis, G N

2013-03-01

Oxidative stress is known to have a major impact on human sperm function and, as a result, there is a need to develop sensitive methods for measuring reactive oxygen species (ROS) generation by these cells. A variety of techniques have been developed for this purpose including chemiluminescence (luminol and lucigenin), flow cytometry (MitoSOX Red, dihydroethidium, 4,5-diaminofluorescein diacetate and 2',7'-dichlorodihydrofluorescein diacetate) and spectrophotometry (nitroblue tetrazolium). The relative sensitivity of these assays and their comparative ability to detect ROS generated in different subcellular compartments of human spermatozoa, have not previously been investigated. To address this issue, we have compared the performance of these assays when ROS generation was triggered with a variety of reagents including 2-hydroxyestradiol, menadione, 4-hydroxynonenal and arachidonic acid. The results revealed that menadione predominantly induced release of ROS into the extracellular space where these metabolites could be readily detected by luminol-peroxidase and, to a lesser extent, 2',7'-dichlorodihydrofluorescein. However, such sensitivity to extracellular ROS meant that these assays were particularly vulnerable to interference by leucocytes. The remaining reagents predominantly elicited ROS generation by the sperm mitochondria and could be optimally detected by MitoSOX Red and DHE. Examination of spontaneous ROS generation by defective human spermatozoa revealed that MitoSOX Red was the most effective indicator of oxidative stress, thereby emphasizing the general importance of mitochondrial dysregulation in the aetiology of defective sperm function. © 2013 American Society of Andrology and European Academy of Andrology.

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 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

Scanning laser vibrometry and luminol photomicrography to map cavitational activity around ultrasonic scalers

NASA Astrophysics Data System (ADS)

Felver, Bernhard; King, David C.; Lea, Simon C.; Price, Gareth J.; Walmsley, A. Damien

2008-06-01

Ultrasonic dental scalers are clinically used to remove deposits from tooth surfaces. A metal probe, oscillating at ultrasonic frequencies, is used to chip away deposits from the teeth. To reduce frictional heating, water flows over the operated probe in which a bi-product, cavitation, may be generated. The aim of this study is characterise probe oscillations using scanning laser vibrometry and to relate the recorded data to the occurrence of cavitation that is mapped in the course of this research. Scanning laser vibrometry (Polytec models 300-F/S and 400-3D) was used to measure the movement of various designs of operating probes and to locate vibration nodes / anti-nodes at different generator power settings and contact loads (100g and 200g). Cavitation mapping was performed by photographing the emission from a luminol solution with a digital camera (Artemis ICX285). The scaler design influences the number and location of vibration node / anti-node points. For all ultrasonic probes, the highest displacement amplitude values were recorded at the tip. The highest amounts of cavitation around the probes were recorded at the second anti-node measured from the tip. Broad, beaver-tale shaped probes produced more cavitation than slim shaped ones. The design also influences the amount of inertial cavitation around the operated instrument. The clinical relevance is that broad, beaver-tale shaped probes are unlikely to reach subgingival areas of the tooth. Further research is required to design probes that will be clinically superior to cleaning this area of the tooth.

Disposable electrochemiluminescent biosensor for lactate determination in saliva.

PubMed

Ballesta Claver, J; Valencia Mirón, M C; Capitán-Vallvey, L F

2009-07-01

An electrochemiluminescence-based disposable biosensor for lactate is characterized. The lactate recognition system is based on lactate oxidase (LOx) and the transduction system consists of luminol. All the needed reagents, luminol, LOx, BSA, electrolyte and buffer have been immobilized by a Methocel membrane placed on the working electrode of the screen-printed electrochemical cell. The measurement of the electrochemiluminescence (ECL) is made possible via a photocounting head when 50 microl of sample is placed into the screen-printed cell with a circular container containing the disposable sensing membrane. The compositions of the membrane and reaction conditions have been optimized to obtain adequate sensitivity. The disposable biosensor responds to lactate after 20 s when two 1 s pulses at 0.5 V are applied to obtain the analytical parameter, the ECL initial rate. The linearized double logarithmic dependence for lactate shows a dynamic range from 10(-5) to 5 x 10(-4) M with a detection limit of 5 x 10(-6) M and a sensor-to-sensor repeatability, as relative standard deviation, RSD, of 3.30% at the medium level of the range. The ECL disposable biosensor was applied to the analysis of lactate in human saliva as an alternative procedure for obtaining the lactate level in a non-invasive way. Interferences coming from components of saliva were studied and eliminated in a simple way that was easy to handle. The procedure was validated for use in human saliva, comparing the results against an enzymatic reference procedure. The proposed method is quick, inexpensive, selective and sensitive and uses conventional ECL instrumentation.

Effects of melatonin on colonic anastomosis healing following chemotherapy in rats.

PubMed

Akyuz, Cebrail; Yasar, Necdet Fatih; Uzun, Orhan; Peker, Kıvanc Derya; Sunamak, Oguzhan; Duman, Mustafa; Sehirli, Ahmet Ozer; Yol, Sinan

2018-03-19

This study aimed to investigate the effect of melatonin on the healing of colon anastomosis following chemotherapy. 32 rats were randomised into four groups: (a) control group (Group 1), which underwent sigmoid colon transaction and primary anastomosis; (b) melatonin group (Group 2), which received melatonin daily following anastomosis; (c) 5-fluorouracil (5-FU) group (Group 3), which received 5-FU for five days prior to anastomosis; and (d) 5-FU+melatonin group (Group 4), which received 5-FU for five days prior to anastomosis and melatonin daily following anastomosis. Anastomotic bursting pressures of the rats, which were sacrificed on postoperative day 7, were measured. The anastomotic segment was extracted for hydroxyproline, luminol and lucigenin measurements, and histopathological examination. Blood samples were obtained from the vena cava for measurement of tumour necrosis factor-alpha (TNF-α) and interleukin-1β (IL-1β) plasma levels. Bursting pressures of anastomosis and hydroxyproline levels were significantly higher in Groups 1 and 4 than in Group 3. Luminol and lucigenin levels were significantly lower in Groups 1 and 4 than in Group 3. In addition, TNF-α and IL-1β plasma levels were significantly lower in Groups 1 and 4 than in Group 3. Histopathological examination showed a significant decrease in inflammation and necrosis formation in Group 2 when compared to Group 1. The positive effect of melatonin was also seen in the rats that received 5-FU. Our study results showed that the adverse effects of chemotherapy on the mechanical, biochemical and histopathological parameters of anastomosis healing were attenuated through melatonin treatment.

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.

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.

Chemiluminescence resonance energy transfer imaging on magnetic particles for single-nucleotide polymorphism detection based on ligation chain reaction.

PubMed

Bi, Sai; Zhang, Zhipeng; Dong, Ying; Wang, Zonghua

2015-03-15

A novel ligation chain reaction (LCR) methodology for single-nucleotide polymorphism (SNP) detection was developed based on luminol-H2O2-horseradish peroxidase (HRP)-mimicking DNAzyme-fluorescein chemiluminescence resonance energy transfer (CRET) imaging on magnetic particles. For LCR, four unique target-complement probes (X and X(⁎), YG and Y(⁎)) for the amplification of K-ras (G12C) were designed by modifying G-quadruplex sequence at 3'-end of YG and fluorescein at 5'-end of Y(⁎). After the LCR, the resulting products of XYG/X(⁎)Y(⁎) with biotin-labeled X(⁎) were captured onto streptavidin-coated magnetic particles (SA-MPs) via specific biotin-SA interaction, which stimulated the CRET reaction from hemin/G-quadruplex-catalyzed luminol-H2O2 CL system to fluorescein. By collecting signals by a cooled low-light CCD, a CRET imaging method was proposed for visual detection and quantitative analysis of SNP. As low as 0.86fM mutant DNA was detected by this assay, and positive mutation detection was achieved with a wild-type to mutant ratio of 10,000:1. This high sensitivity and specificity could be attributed to not only the exponential amplification and excellent discrimination of LCR but also the employment of SA-MPs. SA-MPs ensured the feasibility of the proposed strategy, which also simplified the operations through magnetic separation and separated the reaction and detection procedures to improve sensitivity. The proposed LCR-CRET imaging strategy extends the application of signal amplification techniques to SNP detection, providing a promising platform for effective and high-throughput genetic diagnosis. Copyright © 2014 Elsevier B.V. All rights reserved.

Amplified electrochemiluminescence of luminol based on hybridization chain reaction and in situ generate co-reactant for highly sensitive immunoassay.

PubMed

Xiao, Lijuan; Chai, Yaqin; Yuan, Ruo; Cao, Yaling; Wang, Haijun; Bai, Lijuan

2013-10-15

In this work, we described a simple and highly sensitive electrochemiluminescence (ECL) strategy for IgG detection. Firstly, L-cysteine functionalized reduced graphene oxide composite (L-cys-rGO) was decorated on the glassy carbon electrode (GCE) surface. Then anti-IgG was immobilized on the modified electrode surface through the interaction between the carboxylic groups of the L-cys-rGO and the amine groups in anti-IgG. And then biotinylated anti-IgG (bio-anti-IgG) was assembled onto the electrode surface based on the sandwich-type immunoreactions. By the conjunction of biotin and streptavidin (SA), SA was immobilized, which in turn, combined with the biotin labeled initiator strand (S1). In the presence of two single DNA strands of glucose oxidase labeled S2 (GOD-S2) and complementary strand (S3), S1 could trigger the hybridization chain reaction (HCR) among S1, GOD-S2 and S3. Herein, due to HCR, numerous GOD was efficiently immobilizated on the sensing surface and exhibited excellent catalysis towards glucose to in situ generate amounts of hydrogen peroxide (H2O2), which acted as luminol's co-reactant to significantly enhance the ECL signal. The proposed ECL immunosensor presented predominate stability and high sensibility for determination of IgG in the range from 0.1 pg mL(-1) to 100 ng mL(-1) with a detection limit of 33 fg mL(-1) (S/N=3). Additionally, the designed ECL immunosensor exhibited a promising application for other protein detection. Copyright © 2013 Elsevier B.V. All rights reserved.

Cot/tpl2 (MAP3K8) mediates myeloperoxidase activity and hypernociception following peripheral inflammation.

PubMed

Soria-Castro, Irene; Krzyzanowska, Agnieszka; Pelaéz, Marta López; Regadera, Javier; Ferrer, Gema; Montoliu, Lluis; Rodríguez-Ramos, Rosario; Fernández, Margarita; Alemany, Susana

2010-10-29

Cot/tpl2 (also known as MAP3K8) has emerged as a new and potentially interesting therapeutic anti-inflammatory target. Here, we report the first study of Cot/tpl2 involvement in acute peripheral inflammation in vivo. Six hours after an intraplantar injection of zymosan, Cot/tpl2(-/-) mice showed a 47% reduction in myeloperoxidase activity, concomitant with a 46% lower neutrophil recruitment and a 40% decreased luminol-mediated bioluminescence imaging in vivo. Accordingly, Cot/tpl2 deficiency provoked a 25-30% reduction in luminol-mediated bioluminescence and neutrophil recruitment together with a 65% lower macrophage recruitment 4 h following zymosan-induced peritonitis. Significantly impaired levels of G-CSF and GM-CSF and of other cytokines such as TNFα, IL-1β, and IL-6, as well as some chemokines such as MCP-1, MIP-1β, and keratinocyte-derived chemokine, were detected during the acute zymosan-induced intraplantar inflammatory response in Cot/tpl2(-/-) mice. Moreover, Cot/tpl2 deficiency dramatically decreased the production of the hypernociceptive ligand NGF at the inflammatory site during the course of inflammation. Most importantly, Cot/tpl2 deficiency significantly reduced zymosan-induced inflammatory hypernociception in mice, with a most pronounced effect of a 50% decrease compared with wild type (WT) at 24 h following intraplantar injection of zymosan. At this time, Cot/tpl2(-/-) mice showed significantly reduced NGF, TNFα, and prostaglandin E(2) levels compared with WT littermates. In conclusion, our study demonstrates an important role of Cot/tpl2 in the NGF, G-CSF, and GM-CSF production and myeloperoxidase activity in the acute inflammatory response process and its implication in inflammatory hypernociception.

In Vivo Bioluminescence Imaging for Longitudinal Monitoring of Inflammation in Animal Models of Uveitis.

PubMed

Gutowski, Michal B; Wilson, Leslie; Van Gelder, Russell N; Pepple, Kathryn L

2017-03-01

We develop a quantitative bioluminescence assay for in vivo longitudinal monitoring of inflammation in animal models of uveitis. Three models of experimental uveitis were induced in C57BL/6 albino mice: primed mycobacterial uveitis (PMU), endotoxin-induced uveitis (EIU), and experimental autoimmune uveitis (EAU). Intraperitoneal injection of luminol sodium salt, which emits light when oxidized, provided the bioluminescence substrate. Bioluminescence images were captured by a PerkinElmer In Vivo Imaging System (IVIS) Spectrum and total bioluminescence was analyzed using Living Image software. Bioluminescence on day zero was compared to bioluminescence on the day of peak inflammation for each model. Longitudinal bioluminescence imaging was performed in EIU and EAU. In the presence of luminol, intraocular inflammation generates detectable bioluminescence in three mouse models of uveitis. Peak bioluminescence in inflamed PMU eyes (1.46 × 105 photons/second [p/s]) was significantly increased over baseline (1.47 × 104 p/s, P = 0.01). Peak bioluminescence in inflamed EIU eyes (3.18 × 104 p/s) also was significantly increased over baseline (1.09 × 104 p/s, P = 0.04), and returned to near baseline levels by 48 hours. In EAU, there was a nonsignificant increase in bioluminescence at peak inflammation. In vivo bioluminescence may be used as a noninvasive, quantitative measure of intraocular inflammation in animal models of uveitis. Primed mycobacterial uveitis and EIU are both acute models with robust anterior inflammation and demonstrated significant changes in bioluminescence corresponding with peak inflammation. Experimental autoimmune uveitis is a more indolent posterior uveitis and generated a more modest bioluminescent signal. In vivo imaging system bioluminescence is a nonlethal, quantifiable assay that can be used for monitoring inflammation in animal models of uveitis.

Stimulus-response mesoporous silica nanoparticle-based chemiluminescence biosensor for cocaine determination.

PubMed

Chen, Zhonghui; Tan, Yue; Xu, Kefeng; Zhang, Lan; Qiu, Bin; Guo, Longhua; Lin, Zhenyu; Chen, Guonan

2016-01-15

Mesoporous silica nanoparticles (MSN) based controlled release system had been coupled with diverse detection technologies to establish biosensors for different targets. Chemiluminescence (CL) system of luminol/H2O2 owns the characters of simplicity, low cost and high sensitivity, but the targets of which are mostly focused on some oxidants or which can participate in a chemical reaction that yields a product with a role in the CL reaction. In this study, chemiluminescent detection technique had been coupled with mesoporous silica-based controlled released system for the first time to develop a sensitive biosensor for the target which does not cause effect to the CL system itself. Cocaine had been chosen a model target, the MSN support was firstly loaded with glucose, then the positively charged MSN interacted with negatively charged oligonucleotides (the aptamer cocaine) to close the mesopores of MSN. At the present of target, cocaine binds with its aptamer with high affinity; the flexible linear aptamer structured will become stems structured through currently well-defined non-Waston-Crick interactions and causes the releasing of entrapped glucose into the solution. With the assistant of glucose oxidase (GOx), the released glucose can react with the dissolved oxgen to produce gluconic acid and H2O2, the latter can enhance the CL of luminol in the NaOH solution. The enhanced CL intensity has a relationship with the cocaine concentration in the range of 5.0-60μM with the detection limit of 1.43μM. The proposed method had been successfully applied to detect cocaine in serum samples with high selectivity. The same strategy can be applied to develop biosensors for different targets. Copyright © 2015 Elsevier B.V. All rights reserved.

Phagocytosis as a biomarker for stress responses

NASA Astrophysics Data System (ADS)

Huber, K.; Krotz-Fahning, M.; Hock, B.

2005-08-01

An in vitro test has been developed for the detection of immunotoxic events. It will be used within the project "TRIPLE LUX" on the International Space Station to investigate the effects of single and combined space flight conditions on mammalian phagocytes. The intensity of the respiratory burst during phagocytosis can be followed by the luminol-based chemiluminescence response after stimulation with zymosan. We adapted this test system for polymorphonuclear leukocytes, purified from sheep blood and stored by cryoconservation. In this report we show the immunostimulating effect of hydrocortisone and the immunosuppressive impact of cadmium as an example for alterations that can be detected by this test.

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

Comparison of chemiluminescence methods for analysis of hydrogen peroxide and hydroxyl radicals

NASA Astrophysics Data System (ADS)

Pehrman, R.; Amme, M.; Cachoir, C.

2006-01-01

Assessment of alpha radiolysis influence on the chemistry of geologically disposed spent fuel demands analytical methods for radiolytic product determination at trace levels. Several chemiluminescence methods for the detection of radiolytic oxidants hydrogen peroxide and hydroxyl radicals are tested. Two of hydrogen peroxide methods use luminol, catalyzed by either μ-peroxidase or hemin, one uses 10-methyl-9-(p-formylphenyl)-acridinium carboxylate trifluoromethanesulfonate and one potassium periodate. All recipes are tested as batch systems in basic conditions. For hydroxyl radical detection luminophores selected are 3-hydroxyphthalic hydrazide and rutin. Both methods are tested as batch systems. The results are compared and the applicability of the methods for near-field dissolution studies is discussed.

Detection of DNA hybridization by ABEI electrochemiluminescence in DNA-chip compatible assembly.

PubMed

Calvo-Muñoz, M-L; Dupont-Filliard, A; Billon, M; Guillerez, S; Bidan, G; Marquette, C; Blum, L

2005-04-01

The electrochemiluminescence (ECL) of a luminol derivate (ABEI) generated both by a carbon electrode and a polypyrrole-coated carbon electrode was examined. It was found that the polypyrrole film (ppy) did not inhibit the ECL. After that, ABEI anchored on a single stranded DNA target (ODNt) has been used for the ECL detection of the hybridization between a complementary single stranded DNA probe (ODNp) covalently linked to a polypyrrole support and the ODNt. The ECL detection has been performed using a DNA sensor having a low surface concentration of ODNp probes, constituted of a polypyrrole copolymer electrosynthesized from a pyrrole-ODNp/pyrrole monomer ratio of 1/20,000.

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

Chemiluminescence detection of peroxynitrite with flow injection

NASA Astrophysics Data System (ADS)

Kang, Dai; Evmiridis, Nick P.; Vlessidis, Athanasios; Zhou, Yikai

2001-09-01

Peroxynitrite is an important derivative made by nitric oxide in vivo. It can make damages in many kinds of tissue and cells. Its research value in heart disease and cancer is a very high. A sensitive, specific method for analysis of peroxynitrite is described. In this method, chemiluminescence reaction between perodynitrite and luminol was used to detect with flow injection system. The assay has a detection limit of 2 by 10-8 mol L-1, and linear range of 5 by 10-8 mol L-1 to 5 by 10-5 mol L-1. The application o f flow injection system offers the possibility to establish biosensor for real-time detection of perodynitrite.

2D spatiotemporal visualization system of expired gaseous ethanol after oral administration for real-time illustrated analysis of alcohol metabolism.

PubMed

Wang, Xin; Ando, Eri; Takahashi, Daishi; Arakawa, Takahiro; Kudo, Hiroyuki; Saito, Hirokazu; Mitsubayashi, Kohji

2010-08-15

A novel 2-dimensional spatiotemporal visualization system of expired gaseous ethanol after oral administration for real-time illustrated analysis of alcohol metabolism has been developed, which employed a low level light CCD camera to detect chemiluminescence (CL) generated by catalytic reactions of standard gaseous ethanol and expired gaseous ethanol after oral administration. First, the optimization of the substrates for visualization and the concentration of luminol solution for CL were investigated. The cotton mesh and 5.0 mmol L(-1) luminol solution were selected for further investigations and this system is useful for 0.1-20.0 mmol L(-1) of H(2)O(2) solution. Then, the effect of pH condition of Tris-HCl buffer solution was also evaluated with CL intensity and under the Tris-HCl buffer solution pH 10.1, a wide calibration range of standard gaseous ethanol (30-400 ppm) was obtained. Finally, expired air of 5 healthy volunteers after oral administration was measured at 15, 30, 45, 60, 75, 90, 105 and 120 min after oral administration, and this system showed a good sensitivity on expired gaseous ethanol for alcohol metabolism. The peaks of expired gaseous ethanol concentration appeared within 30 min after oral administration. During the 30 min after oral administration, the time variation profile based on mean values showed the absorption and distribution function, and the values onward showed the elimination function. The absorption and distribution of expired gaseous ethanol in 5 healthy volunteers following first-order absorption process were faster than the elimination process, which proves efficacious of this system for described alcohol metabolism in healthy volunteers. This system is expected to be used as a non-invasive method to detect VOCs as well as several other drugs in expired air for clinical purpose. Copyright 2010 Elsevier B.V. All rights reserved.

A novel "dual-potential" electrochemiluminescence aptasensor array using CdS quantum dots and luminol-gold nanoparticles as labels for simultaneous detection of malachite green and chloramphenicol.

PubMed

Feng, Xiaobin; Gan, Ning; Zhang, Huairong; Yan, Qing; Li, Tianhua; Cao, Yuting; Hu, Futao; Yu, Hongwei; Jiang, Qianli

2015-12-15

A novel type of "dual-potential" electrochemiluminescence (ECL) aptasensor array was fabricated on a homemade screen-printed carbon electrode (SPCE) for simultaneous detection of malachite green (MG) and chloramphenicol (CAP) in one single assay. The SPCE substrate consisted of a common Ag/AgCl reference electrode, carbon counter electrode and two carbon working electrodes (WE1 and WE2). In the system, CdS quantum dots (QDs) were modified on WE1 as cathode ECL emitters and luminol-gold nanoparticles (L-Au NPs) were modified on WE2 as anode ECL emitters. Then the MG aptamer complementary strand (MG cDNA) and CAP aptamer complementary strand (CAP cDNA) were attached on CdS QDs and L-Au NPs, respectively. The cDNA would hybridize with corresponding aptamer that was respectively tagged with cyanine dye (Cy5) (as quenchers of CdS QDs) and chlorogenic acid (CA) (as quenchers of l-Au NPs) using poly(ethylenimine) (PEI) as a bridging agent. PEI could lead to a large number of quenchers on the aptamer, which increased the quenching efficiency. Upon MG and CAP adding, the targets could induce strand release due to the highly affinity of analytes toward aptamers. Meanwhile, it could release the Cy5 and CA, which recovered cathode ECL of CdS QDs and anode ECL of L-Au NPs simultaneously. This "dual-potential" ECL strategy could be used to detect MG and CAP with the linear ranges of 0.1-100 nM and 0.2-150 nM, with detection limits of 0.03 nM and 0.07 nM (at 3sB), respectively. More importantly, this designed method was successfully applied to determine MG and CAP in real fish samples and held great potential in the food analysis. Copyright © 2015 Elsevier B.V. All rights reserved.

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.

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.

Determination of tannin in green tea infusion by flow-injection analysis based on quenching the fluorescence of 3-aminophthalate.

PubMed

Chen, Richie L C; Lin, Chun-Hsun; Chung, Chien-Yu; Cheng, Tzong-Jih

2005-11-02

A flow-injection analytical system was developed to determine tannin content in green tea infusions. The flow-injection system is based on measuring the quenching effect of tannin on the fluorescence of 3-aminophthalate. Fluorophore was obtained by auto-oxidation of luminol during solution preparation. System performance was satisfactory for routine analysis (sample throughput >20 h(-1); linear dynamic range for tannic acid, 0.005-0.3 mg/mL; linear dynamic range for green tea tannin, 0.02-1.0 mg/mL; CV < 3%). The flow-injection method is immune from interference by coexisting ascorbate in green tea infusion. Analytical results were verified by the ferrous tartrate method, the Japanese official analytical method.

Rapid, quantitative determination of bacteria in water. [adenosine triphosphate

NASA Technical Reports Server (NTRS)

Chappelle, E. W.; Picciolo, G. L.; Thomas, R. R.; Jeffers, E. L.; Deming, J. W. (Inventor)

1978-01-01

A bioluminescent assay for ATP in water borne bacteria is made by adding nitric acid to a water sample with concentrated bacteria to rupture the bacterial cells. The sample is diluted with sterile, deionized water, then mixed with a luciferase-luciferin mixture and the resulting light output of the bioluminescent reaction is measured and correlated with bacteria present. A standard and a blank also are presented so that the light output can be correlated to bacteria in the sample and system noise can be substracted from the readings. A chemiluminescent assay for iron porphyrins in water borne bacteria is made by adding luminol reagent to a water sample with concentrated bacteria and measuring the resulting light output of the chemiluminescent reaction.

Involvement of adhesion molecules (CD11a-ICAM-1) in vascular endothelial cell injury elicited by PMA-stimulated neutrophils.

PubMed

Fujita, H; Morita, I; Murota, S

1991-06-14

Protective effect of anti-CD11a and anti-ICAM-1 antibodies on the cytotoxicity induced by PMA-stimulated neutrophils was studied using cultured endothelial cells isolated from bovine carotid artery. Anti-CD11a antibody and anti-ICAM-1 antibody inhibited the endothelial cell injury induced by the activated neutrophils in a dose dependent manner. On the other hand, both antibodies themselves had no effect on either the luminol chemiluminescence released out of the activated neutrophils or the adhesion of the neutrophils to the endothelial cell monolayer. These data suggest that these adhesion molecules play some important roles in the vascular endothelial cell injury elicited by activated neutrophils.

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.

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

An end to a rumour.

PubMed

Tuğ, Ayşim; Alakoç, Yeşim Doğan; Hanci, I Hamit

2005-10-29

Mardin, is a city in the southeastern part of Turkey where people from different cultures and religions have been living together peacefully for centuries. The province hosted many valuable historical constructions representing different civilizations. Kasimiye Medresse, one of the most important educational centers of its times, has a sacred value for people in Mardin. The reason is that the stain on the wall of Kasimiye Medresse is considered to be Sultan Kasim's blood. Our study aims to analyze if the stain in question is blood. Serological tests are performed by using "Kastle-Meyer" and "Luminol" reactives on the scrapped samples taken from stained and unstained parts of the wall. At the end of the analysis, the stain is turned out to be a dye made of herbal roots ending the rumour of centuries.

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.

Encapsulation of Hemin in Metal-Organic Frameworks for Catalyzing the Chemiluminescence Reaction of the H2O2-Luminol System and Detecting Glucose in the Neutral Condition.

PubMed

Luo, Fenqiang; Lin, Yaolin; Zheng, Liyan; Lin, Xiaomei; Chi, Yuwu

2015-06-03

Novel metal-organic frameworks (MOFs) based solid catalysts have been synthesized by encapsulating Hemin into the HKUST-1 MOF materials. These have been first applied in the chemiluminescence field with outstanding performance. The functionalized MOFs not only maintain an excellent catalytic activity inheriting from Hemin but also can be cyclically utilized as solid mimic peroxidases in the neutral condition. The synthesized Hemin@HKUST-1 composites have been used to develop practical sensors for H2O2 and glucose with wide response ranges and low detection limits. It was envisioned that catalyst-functionalized MOFs for chemiluminescence sensing would have promising applications in green, selective, and sensitive detection of target analytes in the future.

Neutrophil dysfunction in rats with natural gingivitis.

PubMed

Isogai, E; Wakizaka, H; Miura, H; Isogai, H; Hayashi, M

1993-01-01

The functions of polymorphonuclear neutrophils (PMN) from SUS rats with naturally occurring gingivitis were examined by the luminol-dependent chemiluminescence (CL), adherence and bactericidal tests. SUS rats with pre-gingivitis showed lower CL responses of isolated PMNs and whole blood than control rats (RES rats). After plague formation and progression of gingivitis, the CL response gradually increased in SUS rats. RES rats had healthy gingiva and showed no increase in CL responses. Impaired PMN adherence was observed in SUS rats with pre-gingivitis but not in RES rats. PMNs from SUS rats with pre-gingivitis also showed lower bactericidal activity than those from RES rats. Dysfunction of PMNs might induce gingivitis as a result of decreased protection against periodontal pathogens and an elevated level of CL response can be recognized with progression of gingivitis.

Sonochemical characterisation of ultrasonic dental descalers.

PubMed

Price, Gareth J; Tiong, T Joyce; King, David C

2014-11-01

An ultrasonic dental descaling instrument has been characterised using sonochemical techniques. Mapping the emission from luminol solution revealed the distribution of cavitation produced in water around the tips. Hydroxyl radical production rates arising from water sonolysis were measured using terephthalate dosimetry and found to be in the range of μmolmin(-1), comparable with those from a sonochemical horn. Removal of an ink coating from a glass slide showed that cleaning occurred primarily where the tip contacted the surface but was also observed in regions where cavitation occurred even when the tip did not contact the surface. Differences in behaviour were noted between different tip designs and computer simulation of the acoustic pressure distributions using COMSOL showed the reasons behind the different behaviour of the tip designs. Copyright © 2014 Elsevier B.V. All rights reserved.

Design of molecular beacons as signaling probes for adenosine triphosphate detection in cancer cells based on chemiluminescence resonance energy transfer.

PubMed

Zhang, Shusheng; Yan, Yameng; Bi, Sai

2009-11-01

In the present study, binary and triplex DNA molecular beacons, as signaling probes based on a luminol-H(2)O(2)-horseradish peroxidase (HRP)-fluorescein chemiluminescence resonance energy transfer (CRET) system and structure-switching aptamers for highly sensitive detection of small molecules, are developed using adenosine triphosphate (ATP) as a model analyte to demonstrate the generality of the strategy. This CRET process occurs from donor luminol to acceptor fluorescein, which is oxidized by H(2)O(2) and catalyzed by HRP. DNA aptamer for ATP is first attached on the surface of magnetic nanoparticles (MNPs). The cDNA linker has an extension that hybridizes with two other DNAs (LumAuNP-DNA and F-DNA) or three other DNAs (HRP-DNA, LumAuNP-DNA, and F-DNA) to fabricate CRET-BMBP-MNP or CRET-TMBP-MNP conjugates that provide the CRET signals. Thus, in the absence of ATP, when the MNPs are removed from the solution, they also take with them the linker DNA and the CRET signal probes, and no CRET signal can be detected. However, when ATP is introduced, a competition for the ATP aptamer between ATP and the cDNA linker occurs. As a result, CRET-BMBP and CRET-TMBP are forced to dissociate from the MNP surface based on the structure switching of the aptamer. The CRET signals are proportional to the concentration of ATP. In order to accelerate the rate of the aptamer structure-switching process, an invader DNA is introduced into the proposed strategy. The present CRET system provides a low detection limit of 1.1 x 10(-7) and 3.2 x 10(-7) M for ATP detection by BMBP and TMBP, respectively, which also exhibits a good selectivity for ATP detection. Sample assays of ATP in K562 leukemia cells and 4T1 breast cancer cells confirm the reliability and practicality of the protocol, which reveal a good prospect of this platform for biological sample analysis.

Chamomile decoction extract inhibits human neutrophils ROS production and attenuates alcohol-induced haematological parameters changes and erythrocytes oxidative stress in rat.

PubMed

Jabri, Mohamed-Amine; Sani, Mamane; Rtibi, Kais; Marzouki, Lamjed; El-Benna, Jamel; Sakly, Mohsen; Sebai, Hichem

2016-03-31

The aim of this study was to evaluate the protective effects of subacute pre-treatment with chamomile (Matricaria recutita L.) decoction extract (CDE) against stimulated neutrophils ROS production as well as ethanol (EtOH)-induced haematological changes and erythrocytes oxidative stress in rat. Neutrophils were isolated and ROS generation was measured by luminol-amplified chemiluminescence. Superoxide anion generation was detected by the cytochrome c reduction assay. Adult male wistar rats were used and divided into six groups of ten each: control, EtOH, EtOH + various doses of CDE (25, 50, and 100 mg/kg, b.w.), and EtOH+ ascorbic acid (AA). Animals were pre-treated with CDE extract during 10 days. We found that CDE inhibited (P ≤ 0.0003) luminol-amplified chemiluminescence of resting neutrophils and N-formyl methionylleucyl-phenylalanine (fMLF) or phorbolmyristate acetate (PMA) stimulated neutrophils, in a dose-dependent manner. CDE had no effect on superoxide anion, but it inhibited (P ≤ 0.0004) H2O2 production in cell free system. In vivo, CDE counteracted (P ≤ 0.0034) the effect of single EtOH administration which induced (P < 0.0001) an increase of white blood cells (WBC) and platelets (PLT) counts. Our results also demonstrated that alcohol administration significantly (P < 0.0001) induced erythrocytes lipoperoxidation increase and depletion of sulfhydryl groups (-SH) content as well as antioxidant enzyme activities as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). More importantly, we found that acute alcohol administration increased (P < 0.0001) erythrocytes and plasma hydrogen peroxide (H2O2), free iron, and calcium levels while the CDE pre-treatment reversed increased (P ≤ 0.0051) all these intracellular disturbances. These findings suggest that CDE inhibits neutrophil ROS production and protects against EtOH-induced haematologiacal parameters changes and erythrocytes oxidative stress. The haematoprotection offered by chamomile might involve in part its antioxidant properties as well as its opposite effect on some intracellular mediators such as H2O2, free iron, and calcium.

Anti-inflammatory effects of nesfatin-1 in rats with acetic acid - induced colitis and underlying mechanisms.

PubMed

Ozturk, C C; Oktay, S; Yuksel, M; Akakin, D; Yarat, A; Kasimay Cakir, O

2015-10-01

Mucosal balance impairment, bacterial over-proliferation, cytokines, inflammatory mediators are known as responsible for inflammatory bowel disease. Besides known anorexigenic, neuroprotective, and anti-apoptotic effects, the major effect of nesfatin-1 on colitis is unknown. Our aim was to investigate the possible anti-inflammatory effects of nesfatin-1 in acetic acid induced colitis model and potential underlying mechanisms. Male Spraque-Dawley rats were anesthetized by intraperitoneal ketamine (100 mg/kg) and chlorpromazine (0.75 mg/kg). For nesfatin-1 and antagonist applications some of the rats were intracerebroventricularly (i.c.v.) cannulated. In colitis group, intrarectally (i.r.) 4% acetic acid solution (1 ml) and 10 minutes later i.c.v. nesfatin-1 (0.05 μg/5 μl) or vehicle (5 μl) were administered. Treatments continued for 3 days. In control group, physiological saline solution was used intrarectally. To identify the underlying effective mechanism of nesfatin-1, rats were divided into 3 subgroups, 5 minutes following colitis induction; i.c.v. atosiban (oxytocin receptor antagonist), SHU9119 (melanocortin receptor antagonist) or GHSR-1a antagonist (ghrelin receptor antagonist) were administered, 5 minutes later nesfatin-1 was administered for 3 days. On the fourth day, rats were decapitated, and colon tissues were sampled. Macroscopic and microscopic damage scores of distal colon, and colonic tissue malondialdehyde, glutathione, myeloperoxidase, superoxide dismutase, catalase, luminol and lucigenin chemiluminescence measurements were analysed. The increased myeloperoxidase activity, malondialdehyde levels, luminol and lucigenin chemiluminescence measurements, macroscopic and microscopic damage scores with colitis induction (P < 0.05 - 0.001) were decreased with nesfatin-1 treatment (P < 0.05 - 0.001). Nesfatin-1 may show this effect by inhibiting neutrophil infiltration through tissues and by decreasing formation of free oxygen radicals. Atosiban and GHSR-1a administration alleviated the protective effect of nesfatin-1 from microscopic and oxidant damage parameters and lipid peroxidation (P < 0.05 - 0.001). The results of the study suggest that nesfatin-1 had a protective effect from colitis induction, and the anti-inflammatory and antioxidant effects of nesfatin-1 on colitis might occur via oxytocin and ghrelin receptors.

The chemiluminescent response of human monocytes to red cells sensitized with monoclonal anti-Rh(D) antibodies.

PubMed

Hadley, A G; Kumpel, B M; Merry, A H

1988-01-01

Luminol-enhanced chemiluminescence (CL) was used to assess the metabolic response of human monocytes to red cells sensitized with known amounts of anti-Rh(D). Monoclonal antibodies were used to facilitate a comparison between the functional activities of IgG1 and IgG3 subclasses. The detection of CL provided a simple, rapid and semi-quantitative means of measuring monocyte response to sensitized red cells (IgG-RBC). Monocyte response to IgG3-RBC was quantitatively greater, more rapid and less susceptible to inhibition by fluid phase IgG than monocyte response to IgG1-RBC. The minimum levels of sensitization required to elicit CL from monocytes were approximately 2500 IgG3 molecules per red cell, or approximately 5000 IgG1 molecules per cell.

Electrochemical luminescence determination of hyperin using a sol-gel@graphene luminescent composite film modified electrode for solid phase microextraction

NASA Astrophysics Data System (ADS)

Zou, Xiaojun; Shang, Fang; Wang, Sui

2017-02-01

In this paper, a novel electrochemiluminescence (ECL) sensor of sol-gel@graphene luminescent composite film modified electrode for hyperin determination was prepared using graphene (G) as solid-phase microextraction (SPME) material, based on selective preconcentration of target onto an electrode and followed by luminol ECL detection. Hyperin was firstly extracted from aqueous solution through the modified GCE. Hydrogel, electrogenerated chemiluminescence reagents, pH of working solution, extraction time and temperature and scan rate were discussed. Under the optimum conditions, the change of ECL intensity was in proportion to the concentration of hyperin in the range of 0.02-0.24 μg/mL with a detection limit of 0.01 μg/mL. This method showed good performance in stability, reproducibility and precision for the determination of hyperin.

Development of a highly sensitive chemiluminescence enzyme immunoassay using enhanced luminol as substrate.

PubMed

Tao, Xiaoqi; Wang, Wenjun; Wang, Zhanhui; Cao, Xingyuan; Zhu, Jinghui; Niu, Lanlan; Wu, Xiaoping; Jiang, Haiyang; Shen, Jianzhong

2014-06-01

In this study, a high sensitivity chemiluminescence enzyme immunoassay (CLEIA) based on novel enhancers was developed. Under optimal conditions, we developed an enhanced chemiluminescence reaction (ECR) catalyzed by horseradish peroxidase (HRP-C) in the presence of 3-(10'-phenothiazinyl) propane-1-sulfonate (SPTZ) and 4-morpholinopyridine (MORP) as enhancers. The limit of detection of the newly prepared chemiluminescent cocktail for HRP was 0.33 pg/well, which is lower than that of commercial Super Signal substrate. The results showed that this novel chemiluminescent cocktail can significantly increase the light output of HRP-catalyzed ECR, which can be translated into a corresponding improvement in sensitivity. Similar improvements were observed in CLEIA for the determination of chloramphenicol in milk. In addition, the ECR of N-azoles as secondary enhancer was also presented. Copyright © 2013 John Wiley & Sons, Ltd.

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.

Luminescent chemical waves in the Cu(II)-catalyzed oscillatory oxidation of SCN- ions with hydrogen peroxide.

PubMed

Pekala, Katarzyna; Jurczakowski, Rafał; Lewera, Adam; Orlik, Marek

2007-05-10

The oscillatory oxidation of thiocyanate ions with hydrogen peroxide, catalyzed by Cu2+ ions in alkaline media, was so far observed as occurring simultaneously in the entire space of the batch or flow reactor. We performed this reaction for the first time in the thin-layer reactor and observed the spatiotemporal course of the above process, in the presence of luminol as the chemiluminescent indicator. A series of luminescent patterns periodically starting from the random reaction center and spreading throughout the entire solution layer was reported. For a batch-stirred system, the bursts of luminescence were found to correlate with the steep decreases of the oscillating Pt electrode potential. These novel results open possibilities for further experimental and theoretical investigations of those spatiotemporal patterns, including studies of the mechanism of this chemically complex process.

[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.

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.

The antioxidants curcumin and quercetin inhibit inflammatory processes associated with arthritis.

PubMed

Jackson, J K; Higo, T; Hunter, W L; Burt, H M

2006-04-01

Curcumin and quercetin are antioxidant molecules with anti-proliferative, anti-inflammatory and immunosuppressive activities. The objective of this study was to investigate the inhibitory activity of these agents using four assays of inflammatory aspects of arthritis. Crystal-induced neutrophil activation was measured by luminol-dependent chemiluminescence. Synoviocyte proliferation was measured by an MTS assay using HIG-82 rabbit synoviocytes in cell culture. Chondrocyte (cultured primary cells) expression of the matrix metalloproteinases collagenase and stromelysin was measured by Northern Blot analysis. Angiogenesis was measured using the chorioallantoic membrane of the chick embryo. Both agents inhibited neutrophil activation, synoviocyte proliferation and angiogenesis. Curcumin strongly inhibited collagenase and stromelysin expression at micromolar concentrations whereas quercetin had no effect in this assay. These studies suggest that curcumin and to a lesser extent quercetin may offer therapeutic potential for the treatment of crystal-induced arthritis or rheumatoid arthritis.

Possibility of determination of the level of antioxidants in human body using spectroscopic methods

NASA Astrophysics Data System (ADS)

Timofeeva, E.; Gorbunova, E.

2016-08-01

In this work, the processes of antioxidant defence against aggressive free radicals in human body were investigated theoretically; and the existing methods of diagnosis of oxidative stress and disturbance of antioxidant activity were reviewed. Also, the kinetics of free radical reactions in the oxidation of luminol and interaction antioxidants (such as chlorophyll in the multicomponent system of plant's leaves and ubiquinone) with the UV radiation were investigated experimentally by spectroscopic method. The results showed that this method is effective for recording the luminescence of antioxidants, free radicals, chemiluminescent reactions and fluorescence. In addition these results reveal new opportunities for the study of the antioxidant activity and antioxidant balance in a multicomponent system by allocating features of the individual components in spectral composition. A creation of quality control method for drugs, that are required for oxidative stress diagnosis, is a promising direction in the development of given work.

Artificial enzyme mimics for catalysis and double natural enzyme co-immobilization.

PubMed

Li, Xiaohua; Zhang, Zhujun; Li, Yongbo

2014-02-01

This work presents a new chemiluminescent (CL) probe array assay. The new type CL probe array is based on enzyme mimics of Co3O4-SiO2 mesoporous nanocomposite material, which not only have an excellent catalytic effect on the luminol-H2O2 CL reaction in an alkaline medium but also can be used for the immobilization of enzymes. The linear range of the lactose concentration is 3.0 × 10(-7) to 1.0 × 10(-5) g mL(-1) and the detection limit is 6.9 × 10(-8) g mL(-1). β-Galactosidase and glucose oxidase were selected as a model for enzyme assays to demonstrate the applicability of Co3O4-SiO2 mesoporous nanocomposite material in multienzyme immobilization. The novel bifunctional CL probe array has been successfully applied to the determination of lactose in milk.

Estimation of sonodynamic treatment region with sonochemiluminescence in gel phantom

NASA Astrophysics Data System (ADS)

Mashiko, Daisaku; Nishitaka, Shinya; Iwasaki, Ryosuke; Lafond, Maxime; Yoshizawa, Shin; Umemura, Shin-ichiro

2018-07-01

Sonodynamic treatment is a non-invasive cancer treatment using ultrasound through the generation of reactive oxygen species (ROS) by acoustic cavitation. High-intensity focused ultrasound (HIFU) can generate cavitation bubbles using highly negative pressure in its focal region. When cavitation bubbles are forced to collapse, they generate ROS, which can attack cancer cells, typically assisted by a sonodynamically active antitumor agent. For sonodynamic treatment, both localization and efficiency of generating ROS are important. To improve them, the region of ROS generation was quantitatively estimated in this study using a polyacrylamide gel containing luminol as the target exposed to “Trigger HIFU”, consisting of a highly intense short “trigger pulse” to generate a cavitation cloud followed by a moderate-intensity long “sustaining burst” to keep the cavitation bubbles oscillating. It was found to be important for efficient ROS generation that the focal region of the trigger pulse should be immediately exposed to the sustaining burst.

Phagocytic and chemiluminescent responses of mouse peritoneal macrophages to living and killed Salmonella typhimurium and other bacteria

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

Tomita, T.; Blumenstock, E.; Kanegasaki, S.

1981-06-01

In the presence of luminol, resident as well as thioglycolate-induced and immunized macrophages emitted chemiluminescence more efficiently when the cells were exposed to living Salmonella typhimurium than when they were exposed to the same bacterium killed by ultraviolet light or heat. This phenomenon was observed whether or not the bacterium was opsonized. The different response to living and killed bacteria was also found with Escherichia coli, Pseudomonas aeruginosa, Proteus morganii, and Enterobacter aerogenes, but not with Shigella sonnei, Klebsiella pneumoniae, and Propionibacterium acnes. The results suggest that macrophages respond better to living, motile bacteria than to nonmotile or killed bacteria.more » The experimental results obtained with motility mutants of S. typhimurium, E. coli, and P. aeruginosa confirm that macrophages exposed to the motile bacteria emit chemiluminescence more efficiently and ingest the motile bacteria at a much faster rate than the nonmotile bacteria.« less

Oxygen radical-mediated mutagenic effect of asbestos on human lymphocytes: suppression by oxygen radical scavengers.

PubMed

Korkina, L G; Durnev, A D; Suslova, T B; Cheremisina, Z P; Daugel-Dauge, N O; Afanas'ev, I B

1992-02-01

The mutagenic effect of chrysotile asbestos fibers and zeolite and latex particles on human lymphocytes in whole blood has been studied. It was concluded that their mutagenic activities were mediated by oxygen radicals because they were inhibited by antioxidant enzymes (SOD and catalase) and oxygen radical scavengers (rutin, ascorbic acid, and bemitil). It was proposed that oxygen radicals were released by phagocytes activated upon exposure to mineral dusts and fibers. The study of lucigenin- and luminol-amplified chemiluminescence of peritoneal macrophages stimulated by chrysotile fibers and zeolite and latex particles has shown that their mutagenic action is probably mediated by different oxygen species, namely, by the iron-oxygen complexes (perferryl ions) plus hydrogen peroxide, hydrogen peroxide, and superoxide ion, respectively. From the oxygen radical scavengers studied, rutin was the most effective inhibitor of the mutagenic effect of mineral fibers and dusts.

Chemiluminescence imaging ELISA using an imprinted polymer as the recognition element instead of an antibody.

PubMed

Surugiu, I; Danielsson, B; Ye, L; Mosbach, K; Haupt, K

2001-02-01

An imaging assay analogous to competitive enzyme immunoassays has been developed using a molecularly imprinted polymer instead of an antibody. The antigen 2,4-dichlorophenoxyacetic acid (2,4-D) was labeled with tobacco peroxidase, and the chemiluminescence reaction of luminol was used for detection. Microtiter plates (96 or 384 wells) were coated with polymer microspheres imprinted with 2,4-D, which were fixed in place by using poly(vinyl alcohol) as glue. In a competitive mode, the analyte-peroxidase conjugate was incubated with the free analyte in the microtiter plate, after which the bound fraction of the conjugate was quantified. After addition of the chemiluminescent substrates, light emission was measured in a high-throughput imaging format with a CCD camera. Calibration curves corresponding to analyte concentrations ranging from 0.01 to 100 microg/mL were obtained.

Acetylsalicylic Acid Produces Different Effects on the Production of Active Oxygen Species by Activated Platelets in Different Inflammatory Diseases.

PubMed

Gabbasov, Z A; Kogan-Yasny, V V; Lakhno, D A; Kagan, L G; Ryzhkova, E V; Vasilieva, E Yu; Shpektor, A V

2017-11-01

We studied the effect of acetylsalicylic acid on ROS generation by platelets in patients after surgical interventions and in patients with bronchial asthma was studied. Platelets stimulated with platelet-activating factor are characterized by weak luminol-enhanced chemiluminescence in healthy people and patients after operations with laparoscopic incisions. Addition of platelet activation factor to platelet samples from patients after open abdominal surgery caused intensive chemiluminescence that was suppressed after platelet incubation with acetylsalicylic acid. At the same time, platelets of patients with aspirin-sensitive asthma did not respond to addition of platelet activating factor, but after incubation with acetylsalicylic acid, an intensive burst of chemiluminescence was detected with a maximum in 5-10 sec after the addition of a platelet-activating factor. In patients with bronchial asthma tolerant to aspirin, platelet activation factor did not induce chemiluminescence irrespective of incubation with acetylsalicylic acid.

Chemiluminescence and phagocytic responses of rat polymorphonuclear neutrophils to leptospires.

PubMed

Isogai, E; Isogai, H; Wakizaka, H; Miura, H; Kurebayashi, Y

1989-11-01

The interaction of leptospires with polymorphonuclear neutrophils (PMN) was examined by the luminol-dependent chemiluminescence (CL) test. Whole blood CL changed in relation to the stage of leptospiral infection both in susceptible (SUS) and resistant (RES) rats. The intensity of CL grew with an increasing number of leptospires in the blood. CL responses were observed in isolated PMN upon exposure to living leptospires. In contrast, the same bacteria, having been inactivated by formalin, did not stimulate PMN. A variation was found in the CL response by different living strains of Leptospira. The CL intensity was arranged as follows: L. illini greater than L. biflexa greater than L. interrogans avirulent strains greater than L. interrogans virulent strains. The CL response was markedly enhanced by an opsonization of leptospires. Specific opsonization was shown to increase the rate of phagocytosis of leptospires with relation to the CL response.

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 readout circuit dedicated for the detection of chemiluminescence using a silicon photomultiplier

NASA Astrophysics Data System (ADS)

Baszczyk, M.; Dorosz, P.; Mik, L.; Kucewicz, W.; Reczynski, W.; Sapor, M.

2018-05-01

A readout circuit dedicated for the detection of the chemiluminescence phenomenon using a silicon photomultiplier (SiPM) is presented. During chemiluminescence, light is generated as a result of chemical reaction. Chemiluminescence is used in many applications within medicine, chemistry, biology and biotechnology, and is one of the most important sensing techniques in biomedical science and clinical medicine. The front-end electronics consist of a preamplifier and a fast shaper—this produces pulses, the peaking time which is 3.6 ns for a single photon and the FWHM is 3.8 ns. The system has been optimised to measure chemiluminescence—it is sensitive at the level of single photons, it generates a low number of overlapping pulses and is accurate. Two methods of signal detection are analysed and compared: the counting of events and amplitude detection. The relationship between the chemiluminescence light intensity and the concentration of the chemical compound (luminol) is linear in the range of the tested concentrations and has strong linearity parameters and low prediction intervals.

Deconvoluting heme biosynthesis to target blood-stage malaria parasites

PubMed Central

Sigala, Paul A; Crowley, Jan R; Henderson, Jeffrey P; Goldberg, Daniel E

2015-01-01

Heme metabolism is central to blood-stage infection by the malaria parasite Plasmodium falciparum. Parasites retain a heme biosynthesis pathway but do not require its activity during infection of heme-rich erythrocytes, where they can scavenge host heme to meet metabolic needs. Nevertheless, heme biosynthesis in parasite-infected erythrocytes can be potently stimulated by exogenous 5-aminolevulinic acid (ALA), resulting in accumulation of the phototoxic intermediate protoporphyrin IX (PPIX). Here we use photodynamic imaging, mass spectrometry, parasite gene disruption, and chemical probes to reveal that vestigial host enzymes in the cytoplasm of Plasmodium-infected erythrocytes contribute to ALA-stimulated heme biosynthesis and that ALA uptake depends on parasite-established permeability pathways. We show that PPIX accumulation in infected erythrocytes can be harnessed for antimalarial chemotherapy using luminol-based chemiluminescence and combinatorial stimulation by low-dose artemisinin to photoactivate PPIX to produce cytotoxic reactive oxygen. This photodynamic strategy has the advantage of exploiting host enzymes refractory to resistance-conferring mutations. DOI: http://dx.doi.org/10.7554/eLife.09143.001 PMID:26173178

Sonochemical cleaning efficiencies in dental instruments

NASA Astrophysics Data System (ADS)

Tiong, T. Joyce; Walmsley, A. Damien; Price, Gareth J.

2012-05-01

Ultrasound has been widely used for cleaning purposes in a variety of situations, including in dental practice. Cleaning is achieved through a combination of acoustically driven streaming effects and sonochemical effects arising from the production of inertial cavitation in a liquid. In our work, various dental instruments used for endodontic (root canal) treatment have been evaluated for their efficiency in producing sonochemical effects in an in-vitro cleaning environment. The areas where cavitation was produced were mapped by monitoring chemiluminescence from luminol solutions and this was correlated with their cleaning efficiencies - assessed by the ability to bleach a dye, to form an emulsion by mixing immiscible components and also to remove ink from a glass surface. The results showed good correlation (Pearson's coefficient > 0.9) between the cavitation and cleaning efficiencies, suggesting that the former plays an important role in cleaning. The methods developed and the results will be beneficial in endodontics research in order to optimise future root canal instruments and treatments.

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

Sample Handling and Chemical Kinetics in an Acoustically Levitated Drop Microreactor

PubMed Central

2009-01-01

Accurate measurement of enzyme kinetics is an essential part of understanding the mechanisms of biochemical reactions. The typical means of studying such systems use stirred cuvettes, stopped-flow apparatus, microfluidic systems, or other small sample containers. These methods may prove to be problematic if reactants or products adsorb to or react with the container’s surface. As an alternative approach, we have developed an acoustically-levitated drop reactor eventually intended to study enzyme-catalyzed reaction kinetics related to free radical and oxidative stress chemistry. Microliter-scale droplet generation, reactant introduction, maintenance, and fluid removal are all important aspects in conducting reactions in a levitated drop. A three capillary bundle system has been developed to address these needs. We report kinetic measurements for both luminol chemiluminescence and the reaction of pyruvate with nicotinamide adenine dinucleotide, catalyzed by lactate dehydrogenase, to demonstrate the feasibility of using a levitated drop in conjunction with the developed capillary sample handling system as a microreactor. PMID:19769373

Some dinophycean red tide plankton species generate a superoxide scavenging substance.

PubMed

Sato, Emiko; Niwano, Yoshimi; Matsuyama, Yukihiko; Kim, Daekyung; Nakashima, Takuji; Oda, Tatsuya; Kohno, Masahiro

2007-03-01

Recent studies indicate that some raphidophycean red tide flagellates produce substances able to scavenge superoxide, whereas there have been no reports on superoxide scavenger production by dinophycean red tide flagellates. In this study, we examined the superoxide-scavenging activity of aqueous extracts from dinophycean red tide flagellates, Gymnodinium spp., Scrippsiella trochoidea, and Karenia sp., by a luminol analog L-012-dependent chemiluminescence (CL) method and an electron spin resonance (ESR)-spin trapping method, and compared the activity to that of raphidophycean red tide flagellates, Chattonella spp., Heterosigma akashiwo, and Fibrocapsa japonica. In the experiment applying the L-012-dependent CL method, only the aqueous extracts from raphidophycean red tide flagellates showed superoxide-scavenging activity. On the other hand, applying the ESR-spin trapping method, we found that the aqueous extracts from dinophycean red tide flagellates also showed superoxide-scavenging activity. This is the first report on the production of a superoxide-scavenger by dinophycean red tide flagellates.

A novel flow injection chemiluminescence method for automated and miniaturized determination of phenols in smoked food samples.

PubMed

Vakh, Christina; Evdokimova, Ekaterina; Pochivalov, Aleksei; Moskvin, Leonid; Bulatov, Andrey

2017-12-15

An easily performed fully automated and miniaturized flow injection chemiluminescence (CL) method for determination of phenols in smoked food samples has been proposed. This method includes the ultrasound assisted solid-liquid extraction coupled with gas-diffusion separation of phenols from smoked food sample and analytes absorption into a NaOH solution in a specially designed gas-diffusion cell. The flow system was designed to focus on automation and miniaturization with minimal sample and reagent consumption by inexpensive instrumentation. The luminol - N-bromosuccinimide system in an alkaline medium was used for the CL determination of phenols. The limit of detection of the proposed procedure was 3·10 -8 ·molL -1 (0.01mgkg -1 ) in terms of phenol. The presented method demonstrated to be a good tool for easy, rapid and cost-effective point-of-need screening phenols in smoked food samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

Superoxide scavenging activity of pirfenidone-iron complex

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

Mitani, Yoshihiro; Sato, Keizo; Muramoto, Yosuke

Pirfenidone (PFD) is focused on a new anti-fibrotic drug, which can minimize lung fibrosis etc. We evaluated the superoxide (O{sub 2}{sup {center_dot}}{sup -}) scavenging activities of PFD and the PFD-iron complex by electron spin resonance (ESR) spectroscopy, luminol-dependent chemiluminescence assay, and cytochrome c reduction assay. Firstly, we confirmed that the PFD-iron complex was formed by mixing iron chloride with threefold molar PFD, and the complex was stable in distillated water and ethanol. Secondary, the PFD-iron complex reduced the amount of O{sub 2}{sup {center_dot}}{sup -} produced by xanthine oxidase/hypoxanthine without inhibiting the enzyme activity. Thirdly, it also reduced the amount ofmore » O{sub 2}{sup {center_dot}}{sup -} released from phorbor ester-stimulated human neutrophils. PFD alone showed few such effects. These results suggest the possibility that the O{sub 2}{sup {center_dot}}{sup -} scavenging effect of the PFD-iron complex contributes to the anti-fibrotic action of PFD used for treating idiopathic pulmonary fibrosis.« less

Determination of beta-agonists in swine hair by μFIA and chemiluminescence.

PubMed

Chen, Xu; Luo, Yong; Shi, Bo; Gao, Zhigang; Du, Yuguang; Liu, Xianming; Zhao, Weijie; Lin, Bingcheng

2015-04-01

β-Agonists are a group of illegal feed additives. In this paper, it was found that the light emission produced by the oxidation of luminol by potassium ferricyanide was enhanced by the β-agonists (ractopamine, salbutamol, and terbutaline). Based on chemiluminescence phenomenon, a novel, rapid, and sensitive microflow injection analysis system on a microfluidic glass chip was established for determination of the β-agonists. The chip was fabricated from two glass plates (64 mm × 32 mm) with microchannels of 200 μm width and 100 μm depth. The detection limits were achieved at 2.0 × 10(-8) mol/L of ractopamine, 1.0 × 10(-8) mol/L of terbutaline and 5.0 × 10(-7) mol/L of salbutamol. In this report, our method was applied for determination of the β-agonists in swine hair from three different sources with satisfactory results. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Vertical and horizontal transmission of tilapia larvae encephalitis virus: the bad and the ugly.

PubMed

Sinyakov, Michael S; Belotsky, Sandro; Shlapobersky, Mark; Avtalion, Ramy R

2011-02-05

Impairment of innate immunity in tilapia larvae after vertical and horizontal infection with the newly characterized tilapia larvae encephalitis virus (TLEV) was accessed by evaluation of cell-mediated reactive oxygen species (ROS) production in affected fish with the use of horseradish peroxidase-amplified luminol-dependent chemiluminescence assay. The priming in-vivo infection with TLEV resulted in downregulation of ROS response in both vertically- and horizontally-infected fish; this suppression was further exacerbated by specific in-vitro booster infection with the same virus. Application of Ca ionophore and phorbol myristate acetate as alternative nonspecific boosters enabled restoration of ROS release in vertically-infected but not in horizontally-infected larvae. The results indicate severe TLEV-imposed phagocyte dysfunction in affected larvae. The difference in restoration potential of ROS production after vertical and horizontal virus transmission is interpreted in the frame of principal distinctions between the two modes. Copyright © 2010 Elsevier Inc. All rights reserved.

Triple-Stimuli-Responsive Ferrocene-Containing PEGs in Water and on the Surface.

PubMed

Alkan, Arda; Steinmetz, Christian; Landfester, Katharina; Wurm, Frederik R

2015-12-02

Triple-stimuli-responsive PEG-based materials are prepared by living anionic ring-opening copolymerization of ethylene oxide and vinyl ferrocenyl glycidyl ether and subsequent thiol-ene postpolymerization modification with cysteamine. The hydrophilicity of these materials can be tuned by three stimuli: (i) temperature (depending on the comonomer ratio), (ii) oxidation state of iron centers in the ferrocene moieties, and (iii) pH-value (through amino groups), both in aqueous solution and at the interface after covalent attachment to a glass surface. In such materials, the cloud point temperatures are adjustable in solution by changing oxidation state and/or pH. On the surface, the contact angle increases with increasing pH and temperature and after oxidation, making these smart surfaces interesting for catalytic applications. Also, their redox response can be switched by temperature and pH, making this material useful for catalysis and electrochemistry applications. Exemplarily, the temperature-dependent catalysis of the chemiluminescence of luminol (a typical blood analysis tool in forensics) was investigated with these polymers.

Evaluation of Oxidative Metabolism in Leukocytes during Phagocytosis of Escherichia coli Carrying Genetic Constructs soxS::lux or katG::lux.

PubMed

Karimov, I F; Deryabin, D G; Karimova, D N; Subbotina, T Yu; Manukhov, I V

2016-06-01

We studied ROS generation by human peripheral blood monocytes and granulocytes during phagocytosis of Escherichia coli soxS::lux or katG::lux responding by luminescence (bioluminescence) to the development of oxidative stress. Initially high sensitivity of the bioluminescent reaction of E. coli katG::lux strain to the effects of model ROS (KO2 and H2O2) and pronounced induction of luminescence upon contact with granulocytes, whereas E. coli soxS::lux demonstrated less pronounced reaction to chemical oxidants and bioluminescence was observed primarily upon contact with monocytes. A correlation was found between quantitative characteristics of E. coli katG::lux bioluminescence and luminol-dependent chemiluminescence of leukocytes in some patients, but no dependence of this kind was noted for E. coli soxS::lux. The results can provide experimental substantiation of a new approach for evaluation of ROS production by leukocytes during phagocytosis and choosing the optimal object for these studies.

In situ-synthesized cadmium sulfide nanowire photosensor with a parylene passivation layer for chemiluminescent immunoassays.

PubMed

Im, Ju-Hee; Kim, Hong-Rae; An, Byoung-Gi; Chang, Young Wook; Kang, Min-Jung; Lee, Tae-Geol; Son, Jin Gyeng; Park, Jae-Gwan; Pyun, Jae-Chul

2017-06-15

The direct in situ synthesis of cadmium sulfide (CdS) nanowires (NWs) was presented by direct synthesis of CdS NWs on the gold surface of an interdigitated electrode (IDE). In this work, we investigated the effect of a strong oxidant on the surfaces of the CdS NWs using X-ray photoelectron spectroscopy, transmission electron microscopy, and time-of-flight secondary ion mass spectrometry. We also fabricated a parylene-C film as a surface passivation layer for in situ-synthesized CdS NW photosensors and investigated the influence of the parylene-C passivation layer on the photoresponse during the coating of parylene-C under vacuum using a quartz crystal microbalance and a photoanalyzer. Finally, we used the in situ-synthesized CdS NW photosensor with the parylene-C passivation layer to detect the chemiluminescence of horseradish peroxidase and luminol and applied it to medical detection of carcinoembryonic antigen. Copyright © 2017 Elsevier B.V. All rights reserved.

Enhanced chemiluminescence-based detection on gold substrate after electrografting of diazonium precursor-coated gold nanoparticles.

PubMed

Houmed Adabo, Ali; Zeggari, Rabah; Mohamed Saïd, Nasser; Bazzi, Rana; Elie-Caille, Céline; Marquette, Christophe; Martini, Matteo; Tillement, Olivier; Perriat, Pascal; Chaix, Carole; Boireau, Wilfrid; Roux, Stéphane

2016-04-01

Since it was demonstrated that nanostructured surfaces are more efficient for the detection based on the specific capture of analytes, there is a real need to develop strategies for grafting nanoparticles onto flat surfaces. Among the different routes for the functionalization of a surface, the reduction of diazonium salts appears very attractive for the covalent immobilization of nanoparticles because this method does not require a pre-treatment of the surface. For achieving this goal, gold nanoparticles coated by precursor of diazonium salts were synthesized by reduction of gold salt in presence of mercaptoaniline. These mercaptoaniline-coated gold nanoparticles (Au@MA) were successfully immobilized onto various conducting substrates (indium tin oxide (ITO), glassy carbon (GC) and gold electrodes with flat terraces) after addition of sodium nitrite at fixed potential. When applied onto the gold electrodes, such a grafting strategy led to an obvious enhancement of the luminescence of luminol used for the biodetection. Copyright © 2016 Elsevier Inc. All rights reserved.

The effect of mark enhancement techniques on the subsequent detection of saliva.

PubMed

McAllister, Patricia; Graham, Eleanor; Deacon, Paul; Farrugia, Kevin J

2016-09-01

There appears to be a limited but growing body of research on the sequential analysis/treatment of multiple types of evidence. The development of an integrated forensic approach is necessary to maximise evidence recovery and to ensure that a particular treatment is not detrimental to other types of evidence. This study aims to assess the effect of latent and blood mark enhancement techniques (e.g. fluorescence, ninhydrin, acid violet 17, black iron-oxide powder suspension) on the subsequent detection of saliva. Saliva detection was performed by means of a presumptive test (Phadebas®) in addition to analysis by a rapid stain identification (RSID) kit test and confirmatory DNA testing. Additional variables included a saliva depletion series and a number of different substrates with varying porosities as well as different ageing periods. Examination and photography under white light and fluorescence was carried out prior to and after chemical enhancement. All enhancement techniques (except Bluestar® Forensic Magnum luminol) employed in this study resulted in an improved visualisation of the saliva stains, although the inherent fluorescence of saliva was sometimes blocked after chemical treatment. The use of protein stains was, in general, detrimental to the detection of saliva. Positive results were less pronounced after the use of black iron-oxide powder suspension, cyanoacrylate fuming followed by BY40 and ninhydrin when compared to the respective positive controls. The application of Bluestar® Forensic Magnum luminol and black magnetic powder proved to be the least detrimental, with no significant difference between the test results and the positive controls. The use of non-destructive fluorescence examination provided good visualisation; however, only the first few marks in the depletion were observed. Of the samples selected for DNA analysis only depletion 1 samples contained sufficient DNA quantity for further processing using standard methodology. The 28-day delay between sample deposition and collection resulted in a 5-fold reduction in the amount of useable DNA. When sufficient DNA quantities were recovered, enhancement techniques did not have a detrimental effect on the ability to generate DNA profiles. This study aims to contribute to a strategy for maximising evidence recovery and efficiency for the detection of latent marks and saliva. The results demonstrate that most of the enhancement techniques employed in this study were not detrimental to the subsequent detection of saliva by means of presumptive, confirmative and DNA tests. Copyright © 2016 The Chartered Society of Forensic Sciences. Published by Elsevier Ireland Ltd. All rights reserved.

A competitive chemiluminescence enzyme immunoassay method for β-defensin-2 detection in transgenic mice.

PubMed

Yang, Xi; Zhou, Tao; Yu, Lei; Tan, Wenwen; Zhou, Rui; Hu, Yonggang

2015-03-01

A competitive chemiluminescence enzyme immunoassay (CLEIA) method for porcine β-defensin-2 (pBD-2) detection in transgenic mice was established. Several factors that affect detection, including luminol, p-iodophenol and hydrogen peroxide concentrations, as well as pH, were studied and optimized. The linear range of the proposed method for pBD-2 detection under optimal conditions was 0.05-80 ng/mL with a correlation coefficient of 0.9960. Eleven detections of a 30 ng/mL pBD-2 standard sample were performed. Reproducible results were obtained with a relative standard deviation of 3.94%. The limit of detection of the method for pBD-2 was 3.5 pg/mL (3σ). The proposed method was applied to determine pBD-2 expression levels in the tissues of pBD-2 transgenic mice, and compared with LC-MS/MS and quantitative real-time reverse-transcriptase polymerase chain reaction. This suggests that the CLEIA can be used as a valuable method to detect and quantify pBD-2. Copyright © 2014 John Wiley & Sons, Ltd.

Decadal change in PAN & O3 and their precursors levels in Seoul during May and June

NASA Astrophysics Data System (ADS)

Kim, H.; Rhee, H.; Lee, M.; Lee, G.; Jang, J.; Shin, H. J.

2017-12-01

In Seoul, PAN and O3 concentrations were examined for the two months of May and June, when O3 concentration is the highest of the year. The measurement sets of PAN and O3 are available for 2004, 2005, 2015 and 2016. PAN was measured by a fast GC system coupled with Luminol chemiluminescence. The hourly maximum PAN and O3 concentrations were10 ppbv and 123 ppbv in 2004,8 ppbv and 141 ppbv in 2005, 4.4 ppbv and 143 ppbv in 2015, and 7.5 ppbv and 127 ppbv in 2016, respectively. The total concentrations of NOX and VOCs were evidently decreased but with different proportions in their subclasses. While alkans and aromatics were considerably decreased, biogenic VOC(BVOC) were increased about twice, leading to increased contribution of BVOC to OH reactivity. Although NOX was decreased by 35%, NO2/NOX ratio was increased for the decade. PAN levels were decreased over the years corresponding to decrease in precursor levels. However, the concentration of O3 was increased due to an increase in NO2 / NO ratio and BVOC.

Antiorthostatic suspension for 14 days does not diminish the oxidative response of neutrophils in mice

NASA Technical Reports Server (NTRS)

Smolen, J. E.; Fossett, M. C.; Joe, Y.; Prince, J. E.; Priest, E.; Kanwar, S.; Smith, C. W.

2000-01-01

The effects of long-term spaceflight on inflammatory responses have not been well-studied in either humans or animals. It is thus important to determine if the functions of immune and inflammatory cells are altered in models of spaceflight. One such animal model is antiorthostatic suspension (AOS), in which the experimental animal is subjected to a head-down tilt that mimics both the stress and the cephalad fluid shift experienced in spaceflight. A previous study reported that the peritoneal neutrophils from mice experiencing AOS generated less superoxide than unsuspended controls. We expanded on this study using several different stimuli and measuring the oxidative response of murine neutrophils in a variety of ways. These responses included the rate, lag period, and dose/response characteristics for superoxide generation, FACS analysis with dihydrodichlorofluorescein as a substrate, and a chemiluminescence response with luminol as a substrate. We also examined phagocytosis of three different microorganisms. While some effects of orthostatic suspension (attributable to the stress of the apparatus) were observed, no clear effects of AOS on oxidative function of the peritoneal neutrophils were seen.

A competitive aptamer chemiluminescence assay for ochratoxin A using a single silica photonic crystal microsphere.

PubMed

Shen, Peng; Li, Wei; Ding, Zhi; Deng, Yang; Liu, Yan; Zhu, Xuerui; Cai, Tingting; Li, Jianlin; Zheng, Tiesong

2018-08-01

We designed a competitive aptamer chemiluminescence assay for ochratoxin A (OTA) on the surface of a single silica photonic crystal microsphere (SPCM) in cereal samples. The structural color of SPCMs is used to recognize and trace the microspheres during process of detection. Anti-aptamer was immobilized on the surface of SPCM. OTA and anti-aptamer competed to bind to aptamer when OTA and its aptamer (labeled by biotin at 5'end) were added in the system. The chemiluminescence signal was developed by the horseradish peroxidase (HRP), luminol and H 2 O 2 . The molecules on the single SPCM can produce enough chemiluminescence signal intensity for quantitative detection for OTA. The linear detection range for OTA was from 1 pg/mL to 1 ng/mL and recovery rates were 89%-95%, 81%-92% and 94%-105% in rice, wheat and corn, respectively. The results showed that the developed method for OTA using a single SPCM has a great application potential in cereal samples. Copyright © 2018 Elsevier Inc. All rights reserved.

Molecularly imprinted polymer based microtiter chemiluminescence array for determination of phenothiazines and benzodiazepines in pork.

PubMed

Xia, Wan Qiu; Huang, Jun; Wang, Geng Nan; Liu, Jing; Wang, Jian Ping

2018-05-25

In this study, a molecularly imprinted polymer based chemiluminescence array capable of simultaneous determining phenothiazines and benzodiazepines was first reported. Two polymers were coated in different wells of the conventional 96-well microtiter plate as the recognition reagents, and the added analytes competed with a horseradish peroxidase-labeled bi-hapten conjugate to bind the recognition reagents. The light signal was induced by using a highly effective luminol-H 2 O 2 -IMP system. The assay procedure consisted of only one sample-loading step prior to data acquisition. Then, the array was used to determine 4 phenothiazines and 5 benzodiazepines in pork simultaneously. The limits of detection for the 9 drugs were in a range of 0.001-0.01 ng/mL, and the recoveries from the fortified blank pork were in a range of 63.5%-94.1%. Furthermore, the array could be reused for 8 times. The detection results for some real pork samples were consistent with an ultra performance liquid chromatography method. Copyright © 2018 Elsevier Inc. All rights reserved.

Resistance of Histoplasma capsulatum to killing by human neutrophils. Evasion of oxidative burst and lysosomal-fusion products.

PubMed

Kurita, N; Terao, K; Brummer, E; Ito, E; Nishimura, K; Miyaji, M

1991-09-01

The basis for resistance of yeast form of Histoplasma capsulatum to antifungal activity of human neutrophils was studied. In limiting dilution assays and short term coculture assays human neutrophils were ineffective in killing H. capsulatum whereas Candida albicans was readily killed. By contrast, in a cell free hydrogen peroxide-peroxidase-halide system H. capsulatum was as sensitive to killing as C. albicans. Moreover, lysate of human neutrophils effectively substituted for horse-radish peroxidase in a cell free system for killing H. capsulatum. H. capsulatum elicited significant products of the oxidative burst in human neutrophils as detected by luminol-enhanced chemiluminescence. However, the response was two-fold less (p less than 0.05) than that induced by C. albicans. Transmission electron microscopy studies showed that phagosome-lysosome fusion took place when neutrophils phagocytosed C. albicans or H. capsulatum. Taken together, these findings indicate that, even though H. capsulatum elicits an oxidative burst and phagosome-lysosome fusion within the phagosome, it is capable of evading damage in short term assays.

A Portable Luminometer with a Disposable Electrochemiluminescent Biosensor for Lactate Determination

PubMed Central

Martínez-Olmos, Antonio; Ballesta-Claver, Julio; Palma, Alberto J.; Valencia-Mirón, Maria del Carmen; Capitán-Vallvey, Luis Fermin

2009-01-01

A hand-held luminometer for measuring electrochemiluminescence (ECL) for lactate determination and based on one-shot biosensors fabricated using screen-printed electrodes is described. The lactate recognition system is based on lactate oxidase and the transduction system consists of electro-oxidation of luminol, with all the reagents immobilized in a Methocel membrane. The membrane composition and reaction conditions have been optimized to obtain adequate sensitivity. The luminometer is based on a large silicon photodiode as detector and includes a programmable potentiostat to initialize the chemical reaction and signal processing circuitry, designed to acquire a low level photocurrent with offset cancelation, low pass filtering for noise attenuation and adjustable gain up to 1012 V/A. The one-shot biosensor responds to lactate rapidly, with an acquisition time of 2.5 min, obtaining a linear dependence from 8 × 10−6 to 2 × 10−4 M, a detection limit of 2.4 × 10−6 M and a sensor-to-sensor reproducibility (relative standard deviation, RSD) of around 7–10 % at the medium level of the range. PMID:22408475

Increasing Electrochemiluminescence Intensity of a Wireless Electrode Array Chip by Thousands of Times Using a Diode for Sensitive Visual Detection by a Digital Camera.

PubMed

Qi, Liming; Xia, Yong; Qi, Wenjing; Gao, Wenyue; Wu, Fengxia; Xu, Guobao

2016-01-19

Both a wireless electrochemiluminescence (ECL) electrode microarray chip and the dramatic increase in ECL by embedding a diode in an electromagnetic receiver coil have been first reported. The newly designed device consists of a chip and a transmitter. The chip has an electromagnetic receiver coil, a mini-diode, and a gold electrode array. The mini-diode can rectify alternating current into direct current and thus enhance ECL intensities by 18 thousand times, enabling a sensitive visual detection using common cameras or smart phones as low cost detectors. The detection limit of hydrogen peroxide using a digital camera is comparable to that using photomultiplier tube (PMT)-based detectors. Coupled with a PMT-based detector, the device can detect luminol with higher sensitivity with linear ranges from 10 nM to 1 mM. Because of the advantages including high sensitivity, high throughput, low cost, high portability, and simplicity, it is promising in point of care testing, drug screening, and high throughput analysis.

DNA origami nanorobot fiber optic genosensor to TMV.

PubMed

Torelli, Emanuela; Manzano, Marisa; Srivastava, Sachin K; Marks, Robert S

2018-01-15

In the quest of greater sensitivity and specificity of diagnostic systems, one continually searches for alternative DNA hybridization methods, enabling greater versatility and where possible field-enabled detection of target analytes. We present, herein, a hybrid molecular self-assembled scaffolded DNA origami entity, intimately immobilized via capture probes linked to aminopropyltriethoxysilane, onto a glass optical fiber end-face transducer, thus producing a novel biosensor. Immobilized DNA nanorobots with a switchable flap can then be actuated by a specific target DNA present in a sample, by exposing a hemin/G-quadruplex DNAzyme, which then catalyzes the generation of chemiluminescence, once the specific fiber probes are immersed in a luminol-based solution. Integrating organic nanorobots to inorganic fiber optics creates a hybrid system that we demonstrate as a proof-of-principle can be utilized in specific DNA sequence detection. This system has potential applications in a wide range of fields, including point-of-care diagnostics or cellular in vivo biosensing when using ultrathin fiber optic probes for research purposes. Copyright © 2017 Elsevier B.V. All rights reserved.

[Evaluation of free radical quantity in the anterior chamber following femtosecond laser-assisted capsulotomy].

PubMed

Tóth, Gábor; Sándor, Gábor László; Kleiner, Dénes; Szentmáry, Nóra; Kiss, Huba J; Blázovics, Anna; Nagy, Zoltán Zsolt

2016-11-01

Femtosecond laser is a revolutionary, innovative treatment method used in cataract surgery. To evaluate free radical quantity in the anterior chamber of the eye, during femtosecond laser assisted capsulotomy, in a porcine eye model. Seventy fresh porcine eyes were collected within 2 hours post mortem, were transported at 4 ºC and treated within 7 hours. Thirty-five eyes were used as control and 35 as femtosecond laser assisted capsulotomy group. A simple luminol-dependent chemiluminescence method was used to measure the total scavenger capacity in the aqueous humour, as an indicator of free radical production. The emitted photons were expressed in relative light unit %. The relative light unit % was lower in the control group (median 1%, interquartile range [0.4-3%]) than in the femtosecond laser assisted capsulotomy group (median 4.4%, interquartile range [1.5%-21%]) (p = 0.01). Femtosecond laser assisted capsulotomy decreases the antioxidant defense of the anterior chamber, which refers to a significant free radical production during femtosecond laser assisted capsulotomy. Orv. Hetil., 2016, 157(47), 1880-1883.

Performance of an organic photodiode as an optical detector and its application to fluorometric flow-immunoassay for IgA.

PubMed

Miyake, Mayo; Nakajima, Hizuru; Hemmi, Akihide; Yahiro, Masayuki; Adachi, Chihaya; Soh, Nobuaki; Ishimatsu, Ryoichi; Nakano, Koji; Uchiyama, Katsumi; Imato, Toshihiko

2012-07-15

The performance of an organic thin film photodiode (OPD), fabricated from a hetero-junction comprised of two layers of C(60) and a phthalocyanine-Cu(II) complex was evaluated by detecting the chemiluminescence generated from the reaction of luminol with horseradish peroxidase in the presence of H(2)O(2), and the fluorescence from resorufin, as an optical detector. The photocurrent of the OPD was linear with respect to the power of light from a commercial LED. The sensitivity of the OPD was sufficient for detecting chemiluminescence with a power 0.1μW/cm(2). The OPD was successfully used in a flow-immunoassay for IgA, a marker of human stress, in which a sandwich immunoassay was carried out on the microchip and the fluorescence from resorufin, produced by the enzymatic reaction, was detected. The detection limits for resorufin and IgA were 5.0μM and 16ng/mL, respectively. The photosensitivity of the OPD remained relatively constant for a minimum of one year. Copyright © 2012 Elsevier B.V. All rights reserved.

Utilization of the human cell line HL-60 for chemiluminescence based detection of microorganisms and related substances.

PubMed

Timm, Michael; Hansen, Erik W; Moesby, Lise; Christensen, Jens D

2006-02-01

In this paper we describe a new pyrogen assay using the human leukemia cell line HL-60. The cell line is differentiated using all-trans retinoic acid (ATRA) to generate a cell population that resembles mature granulocytes. The differentiated HL-60 cell is capable of generating reactive oxygen species (ROS) when challenged with pyrogenic substances. In a luminol enhanced chemilumimetric assay the responsiveness of differentiated HL-60 cells is tested towards Salmonella typhimurium, Bacillus subtilis, Saccharomyces cerevisiae, Candida albicans, lipopolysaccharide (LPS) and lipoteichoic acid (LTA). The results show a poor sensitivity to S. typhimurium but displays good sensitivity towards B. subtilis, LTA and LPS. Furthermore, the sensitivity towards the yeasts C. albicans and S. cerevisiae is considerably better than obtained in other in vitro cell systems. Overall these results indicate that the HL-60 cell assay possibly could be evolved to a supplementary assay for the known pyrogenic detection assays. Furthermore, the utilization of the assay for pyrogenic examination of recombinant drugs derived from yeast expression systems would be relevant to examine.

A novel array of chemiluminescence sensors for sensitive, rapid and high-throughput detection of explosive triacetone triperoxide at the scene.

PubMed

Li, Xiaohua; Zhang, Zhujun; Tao, Liang

2013-09-15

Triacetone triperoxide (TATP) is relatively easy to make and has been used in various terrorist acts. Early but easy detection of TATP is highly desired. We designed a new type sensor array for H2O2. The unique CL sensor array was based on CeO2 nanoparticles' membranes, which have an excellent catalytic effect on the luminol-H2O2 CL reaction in alkaline medium. It exhibits a linear range for the detection of H2O2 from 1.0×10(-8) to 5.0×10(-5)M (R(2)=0.9991) with a 1s response time. The detection limit is 1.0×10(-9)M. Notably, the present approach allows the design of CL sensor array assays in a more simple, time-saving, long-lifetime, high-throughput, and economical approach when compared with conventional CL sensor. It is conceptually different from conventional CL sensor assays. The novel sensor array has been successfully applied for the detection of TATP at the scene. Copyright © 2013 Elsevier B.V. All rights reserved.

Chemiluminescent Determination of Oxamyl in Drinking Water and Tomato Using Online Postcolumn UV Irradiation in a Chromatographic System.

PubMed

Murillo Pulgarín, José A; García Bermejo, Luisa F; Durán, Armando Carrasquero

2018-03-07

High-performance liquid chromatography (HPLC) was used to separate oxamyl from other pesticides in drinking water and tomato paste. The eluate emerging from the column tail was mixed with an alkaline solution of Co 2+ in EDTA and irradiated with UV light to induce photolysis of the carbamate in order to obtain free radicals and other reactive species that oxidize luminol and produce chemiluminescence (CL) as a result. The intensity of the CL signal was monitored in the form of chromatographic peaks. Under the optimum operating conditions for the HPLC-UV-CL system, the analyte concentration was linearly related to peak area. The limit of detection as determined in accordance with the IUPAC criterion was 0.17 mg L -1 . Oxamyl was successfully extracted with recoveries of 88.7-103.1% from spiked tomato paste by using a simple QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) sample preparation approach. Similar recoveries were obtained from drinking water samples spiked with oxamyl concentrations above the LOD. The proposed method is a simple, fast, accurate choice for quantifying this pesticide.

Determination of NH(3) gas by combination of nanosized LaCoO(3) converter with chemiluminescence detector.

PubMed

Shi, Jinjun; Yan, Ruoxue; Zhu, Yongfa; Zhang, Xinrong

2003-10-17

Combination of a novel NH(3) converter based on nanosized materials with chemiluminescence (CL) detector for the determination of NH(3) gas was demonstrated in this paper. NH(3) gas is oxidized on different nanosized catalysts to produce NO(x), which can react with luminol to generate CL emission. Eight nanosized materials were investigated as catalyst, and CL was detected from seven of them. The nanosized LaCoO(3) was chosen as the catalyst for preparing the converter because of its higher activity than others. Under the optimized conditions, the linear range of CL intensity versus concentration of NH(3) gas is 0.04-10 ppm (r=0.9951, n=14) with the detection limit of 0.014 ppm. The method offers advantages of long lifetime of the converter, fast response and high selectivity to NH(3). There was no response while the foreign substances, such as hydrogen, oxygen, nitrogen, formaldehyde, acetone and gasoline passing through the CL detection system, and the interference of CCl(4), ethanol, ethylene and toluene was insignificant.

Polydimethylsiloxane microfluidic chemiluminescence immunodevice with the signal amplification strategy for sensitive detection of human immunoglobin G.

PubMed

Li, Huifang; Zhao, Mei; Liu, Wei; Chu, Weiru; Guo, Yumei

2016-01-15

A polydimethylsiloxane (PDMS) microfluidic chemiluminescence (CL) immunodevice for sensitive detection of human immunoglobin G (IgG) with the signal amplification strategy was developed in this work. The immunodevice was prepared by covalently immobilizing capture antibodies (Abs) on the silanized microchannel of microfluidic chip. Gold nanoparticles (AuNPs) functionalized with a high molar ratio of horseradish peroxidase (HRP) were used as an Ab label for signal amplification. Using a sandwich immunoassay, the multi-HRP conjugated AuNPs can catalyze the luminol-H2O2 CL system to achieve the high sensitivity. In addition, the double spiral flow-channel was adopted here, which can still contribute to the high sensitivity. Based on signal amplification strategy, the performance of human IgG tests revealed a lower detection limit (DL) of 0.03ng/mL and showed an increase of 7.4-fold in detection sensitivity compared to a commercial Ab-HRP conjugation. This microfluidic immunodevice can provide an alternative approach for sensitive detection of human IgG in the field of clinic diagnostic and therapeutic. Copyright © 2015 Elsevier B.V. All rights reserved.

Neutrophil hyper-responsiveness in periodontitis.

PubMed

Matthews, J B; Wright, H J; Roberts, A; Ling-Mountford, N; Cooper, P R; Chapple, I L C

2007-08-01

Peripheral neutrophil hyper-responsiveness in chronic periodontitis leads to excessive reactive oxygen species (ROS) production. We aimed to determine whether neutrophil hyper-responsiveness was constitutive or reactive, and to discover the effect of non-surgical therapy. Peripheral blood neutrophils from patients (n = 19), before and 3 months after therapy, and matched control individuals were Fc gamma-receptor-stimulated with/without priming with P. gingivalis and F. nucleatum. Total and extracellular ROS were determined by luminol/isoluminol chemiluminescence. The high total ROS generation of patients' neutrophils compared with that of control individuals (P = 0.016) continued at a reduced level post-therapy (P = 0.059). Reduced activity post-therapy was also seen with priming. Unstimulated total ROS levels did not differ between patients and control individuals before or after therapy. However, the high unstimulated, extracellular ROS production by patients' neutrophils compared with control individuals (P < 0.05) continued post-therapy and was unaffected by priming. Therapy reduced Fc gamma-receptor-stimulated total ROS production, but not unstimulated extracellular radical release, suggesting that constitutive and reactive mechanisms underlie neutrophil hyper-responsiveness.

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.

A sensitive chemiluminescent immunoassay to detect Chromotrope FB (Chr FB) in foods.

PubMed

Xu, Kun; Long, Hao; Xing, Rongge; Yin, Yongmei; Eremin, Sergei A; Meng, Meng; Xi, Rimo

2017-03-01

Chromotrope FB (Chr FB) is a synthetic azo dye permitted for use in foods and medicines. An acceptable daily intake (ADI) of Chr FB was 0-0.5mg/kg in China. In this study, we synthesized a Chr FB hapten with an amino group to prepare its artificial immunogen. Polyclonal antibodies obtained from New Zealand rabbits were applied to develop an indirect competitive chemiluminescent immunoassay (icCLIA) to detect Chr FB in foods. A horseradish peroxidase (HRP)-luminol-H 2 O 2 system was used to yield CL signal with p-iodophenol as an enhancement reagent. The method showed good specificity towards Chr FB and could detect as low as 0.02ngmL -1 Chr FB in buffer, 0.07ngg -1 in yoghurt candy, 0.07ngg -1 in vitamin drink and 0.13ngg -1 in bread. Compared with HPLC method, the proposed method is more sensitive by two orders of magnitude. The accuracy and precision of this method are acceptable and comparable with HPLC method. Therefore, the proposed method could be used for rapid screening of Chr FB in the mentioned foodstuffs. Copyright © 2016. Published by Elsevier B.V.

Highly sensitive microfluidic competitive enzyme immunoassay based on chemiluminescence resonance energy transfer for the detection of neuron-specific enolase.

PubMed

Yang, Tingzhen; Vdovenko, Marina; Jin, Xue; Sakharov, Ivan Yu; Zhao, Shulin

2014-07-01

A microfluidic competitive enzyme immunoassay based on chemiluminescence resonance energy transfer (CRET) was developed for highly sensitive detection of neuron-specific enolase (NSE). The CRET system consisted of horseradish peroxidase (HRP)/luminol as a light donor and fluorescein isothiocyanate as an acceptor. When fluorescein isothiocyanate-labeled antibody binds with HRP-labeled antigen to form immunocomplex, the donor and acceptor are brought close each other and CRET occurs in the immunocomplex. In the MCE, the immunocomplex and excess HRP-NSE were separated, and the chemiluminescense intensity of immunocomplex was used to estimate NSE concentration. The calibration curve showed a linearity in the range of NSE concentrations from 9.0 to 950 pM with a correlation coefficient of 0.9964. Based on a S/N of 3, the detection limit for NSE determination was estimated to be 4.5 pM, which is two-order magnitude lower than that of without CRET detection. This assay was applied for NSE quantification in human serum. The obtained results demonstrated that the proposed immunoassay may serve as an alternative tool for clinical analysis of NSE. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Activation of normal neutrophils by anti-neutrophil cytoplasm antibodies.

PubMed Central

Keogan, M T; Esnault, V L; Green, A J; Lockwood, C M; Brown, D L

1992-01-01

Anti-neutrophil cytoplasm antibodies (ANCA) are markers of systemic vasculitis for which a pathogenetic role has been postulated. We have examined the effect of these autoantibodies on the function of normal human neutrophils in vitro. In the presence of ANCA positive sera luminol-amplified chemiluminescence was significantly increased compared to the values seen in the presence of normal or anti-double stranded DNA positive sera (P < 0.01). Five of six ANCA positive F(ab)2 preparations also produced significant neutrophil activation as demonstrated by the chemiluminescence response. This response was totally abrogated by the addition of neutrophil cytoplasm extract, containing the ANCA antigen. Addition of inhibitors to the chemiluminescence system demonstrated that the chemiluminescence response was inhibited by azide and salicylhydroxamic acid and reduced by histidine, suggesting that the chemiluminescence response was due to activation of myeloperoxidase, with generation of singlet oxygen. The chemotactic response to f-Met-Leu-Phe, a bacterial chemotactic peptide, was significantly augmented in the presence of ANCA. Chemotaxis to zymosan-activated serum and chemokinesis was not affected. Phagocytosis was also unaffected. We propose that neutrophil activation and modulation of neutrophil migration by ANCA may be of pathogenetic significance in systemic vasculitis. PMID:1424279

Platinum(II)-Oligonucleotide Coordination Based Aptasensor for Simple and Selective Detection of Platinum Compounds.

PubMed

Cai, Sheng; Tian, Xueke; Sun, Lianli; Hu, Haihong; Zheng, Shirui; Jiang, Huidi; Yu, Lushan; Zeng, Su

2015-10-20

Wide use of platinum-based chemotherapeutic regimens for the treatment for carcinoma calls for a simple and selective detection of platinum compound in biological samples. On the basis of the platinum(II)-base pair coordination, a novel type of aptameric platform for platinum detection has been introduced. This chemiluminescence (CL) aptasensor consists of a designed streptavidin (SA) aptamer sequence in which several base pairs were replaced by G-G mismatches. Only in the presence of platinum, coordination occurs between the platinum and G-G base pairs as opposed to the hydrogen-bonded G-C base pairs, which leads to SA aptamer sequence activation, resulting in their binding to SA coated magnetic beads. These Pt-DNA coordination events were monitored by a simple and direct luminol-peroxide CL reaction through horseradish peroxidase (HRP) catalysis with a strong chemiluminescence emission. The validated ranges of quantification were 0.12-240 μM with a limit of detection of 60 nM and selectivity over other metal ions. This assay was also successfully used in urine sample determination. It will be a promising candidate for the detection of platinum in biomedical and environmental samples.

In vitro inhibitory effects of Moringa oleifera leaf extract and its major components on chemiluminescence and chemotactic activity of phagocytes.

PubMed

Vongsak, Boonyadist; Gritsanapan, Wandee; Wongkrajang, Yuvadee; Jantan, Ibrahim

2013-11-01

The ethanol extract of Moringa oleifera Lam. leaves and its major constituents, crypto-chlorogenic acid, quercetin 3-O-glucoside and kaempferol 3-O-glucoside, were investigated on the respiratory burst of human whole blood and isolated human polymorphonuclear leukocytes (PMNs) using a luminol-based chemiluminescence assay. The chemotactic migration of PMNs was also investigated using the Boyden chamber technique. The ethanol extract demonstrated inhibitory activities on the oxidative burst and the chemotactic migration of PMNs. Quercetin 3-O-glucoside, crypto-chlorogenic acid, and kaempferol 3-O-glucoside, isolated from the extract, expressed relatively strong inhibitory activity on the oxidative burst of PMNs with IC50 values of 4.1, 6.7 and 7.0 microM, respectively, comparable with that of aspirin. They also demonstrated strong inhibition of chemotatic migration of PMNs with IC50 values of 9.5, 15.9 and 18.2 microM, respectively. The results suggest that M. oleifera leaves could modulate the immune response of human phagocytes, linking to its ethnopharmacological use as an anti-inflammatory agent. The immunomodulating activity of the plant was mainly due to its major components.

Design of a sensitive aptasensor based on magnetic microbeads-assisted strand displacement amplification and target recycling.

PubMed

Li, Ying; Ji, Xiaoting; Song, Weiling; Guo, Yingshu

2013-04-03

A cross-circular amplification system for sensitive detection of adenosine triphosphate (ATP) in cancer cells was developed based on aptamer-target interaction, magnetic microbeads (MBs)-assisted strand displacement amplification and target recycling. Here we described a new recognition probe possessing two parts, the ATP aptamer and the extension part. The recognition probe was firstly immobilized on the surface of MBs and hybridized with its complementary sequence to form a duplex. When combined with ATP, the probe changed its conformation, revealing the extension part in single-strand form, which further served as a toehold for subsequent target recycling. The released complementary sequence of the probe acted as the catalyst of the MB-assisted strand displacement reaction. Incorporated with target recycling, a large amount of biotin-tagged MB complexes were formed to stimulate the generation of chemiluminescence (CL) signal in the presence of luminol and H2O2 by incorporating with streptavidin-HRP, reaching a detection limit of ATP as low as 6.1×10(-10)M. Moreover, sample assays of ATP in Ramos Burkitt's lymphoma B cells were performed, which confirmed the reliability and practicality of the protocol. Copyright © 2013 Elsevier B.V. All rights reserved.

Chemometrics-assisted simultaneous determination of cobalt(II) and chromium(III) with flow-injection chemiluminescence method

NASA Astrophysics Data System (ADS)

Li, Baoxin; Wang, Dongmei; Lv, Jiagen; Zhang, Zhujun

2006-09-01

In this paper, a flow-injection chemiluminescence (CL) system is proposed for simultaneous determination of Co(II) and Cr(III) with partial least squares calibration. This method is based on the fact that both Co(II) and Cr(III) catalyze the luminol-H 2O 2 CL reaction, and that their catalytic activities are significantly different on the same reaction condition. The CL intensity of Co(II) and Cr(III) was measured and recorded at different pH of reaction medium, and the obtained data were processed by the chemometric approach of partial least squares. The experimental calibration set was composed with nine sample solutions using orthogonal calibration design for two component mixtures. The calibration curve was linear over the concentration range of 2 × 10 -7 to 8 × 10 -10 and 2 × 10 -6 to 4 × 10 -9 g/ml for Co(II) and Cr(III), respectively. The proposed method offers the potential advantages of high sensitivity, simplicity and rapidity for Co(II) and Cr(III) determination, and was successfully applied to the simultaneous determination of both analytes in real water sample.

Fast nucleation for silica nanoparticle synthesis using a sol-gel method.

PubMed

Dixit, Chandra K; Bhakta, Snehasis; Kumar, Ajeet; Suib, Steven L; Rusling, James F

2016-12-01

We have developed a method that for the first time allowed us to synthesize silica particles in 20 minutes using a sol-gel preparation. Therefore, it is critically important to understand the synthesis mechanism and kinetic behavior in order to achieve a higher degree of fine tuning ability during the synthesis. In this study, we have employed our ability to modulate the physical nature of the reaction medium from sol-gel to emulsion, which has allowed us to halt the reaction at a particular time; this has allowed us to precisely understand the mechanism and chemistry of the silica polymerization. The synthesis medium is kept quite simple with tetraethyl orthosilicate (TEOS) as a precursor in an equi-volumetric ethanol-water system and with sodium hydroxide as a catalyst. Synthesis is performed under ambient conditions at 20 °C for 20 minutes followed by phasing out of any unreacted TEOS and polysilicic acid chains via their emulsification with supersaturated water. We have also demonstrated that the developed particles with various sizes can be used as seeds for further particle growth and other applications. Luminol, a chemiluminescent molecule, has been entrapped successfully between the layers of silica and was demonstrated for the chemiluminescence of these particles.

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.

Heterogeneity of neutrophil antibodies in patients with primary Sjögren's syndrome.

PubMed

Lamour, A; Le Corre, R; Pennec, Y L; Cartron, J; Youinou, P

1995-11-01

Our aims were to determine the prevalence of neutrophil antibodies in patients with primary Sjögren's syndrome (pSS), identify their target antigen(s), and evaluate their functional significance. Neutrophil antibodies were detected using an indirect immunofluorescence (IIIF) test and an enzyme-linked immunosorbent assay (ELISA), using recombinant human Fc-gamma receptor (Fc gamma RIIIb) as a capture agent. Luminol-dependent chemiluminescence was then measured by an established technique. Antibodies to neutrophils were detected in 30 of 66 patients (45%) and categorized on the basis of positivity for the two assays: IIF+/ELISA+ (group A: five patients), IIF+/ELISA- (group B: five patients), and IFF-/ELISA+ (group C: 20 patients). All positive sera contained antibodies directed to the neutrophil specific Fc gamma RIIIb, and none of them bound to NAnull neutrophils. The titer of neutrophil-reactive antibodies (groups A and B) showed no correlation with the neutrophil count, but these autoantibodies did reduce the cell ability to generate a respiratory burst. Thus, neutrophil antibodies are common in patients with pSS. Their main target appears to be Fc gamma RIII, and this may partly account for the dysfunction in Fc gamma R-mediated clearance by the reticuloendothelial system reported in these patients.

Parameters of oxidative stress in saliva from patients with aggressive and chronic periodontitis.

PubMed

Acquier, Andrea B; De Couto Pita, Alejandra K; Busch, Lucila; Sánchez, Gabriel A

2017-05-01

Free radicals play an important role in the onset and progression of many diseases. The aim of this study was to investigate the contribution of oxidative stress in the pathology of aggressive (AgP) and chronic (CP) periodontitis and its relation with the clinical periodontal status. Eighty subjects were divided into two groups: 20 patients with AgP and 20 patients with CP with their 20 corresponding matched controls, based on clinical attachment loss (CAL), probing pocket depth (PPD), and bleeding on probing (BOP). Saliva reactive oxygen species (ROS), lipid peroxidation, and non-enzymatic antioxidant defences were measured by luminol-dependent chemiluminescence assay, as thiobarbituric acid-reactive substances (TBARs) and total radical-trapping antioxidant potential (TRAP), respectively. Pearson's correlation and multivariate analysis were used to determine the relationship between ROS and TBARs and the clinical parameters. ROS and TBARs were increased in AgP while TRAP was decreased, comparing with CP. In AgP, a strong and positive correlation was observed between ROS and TBARs and they were closely associated with CAL and PPD. In AgP, but not in CP, oxidative stress is a high contributor to periodontal pathology and it is closely associated with the clinical periodontal status.

Mapping cavitation activity around dental ultrasonic tips.

PubMed

Walmsley, A Damien; Lea, Simon C; Felver, Bernhard; King, David C; Price, Gareth J

2013-05-01

Cavitation arising within the water around the oscillating ultrasonic scaler tip is an area that may lead to advances in enhancing biofilm removal. The aim of this study is to map the occurrence of cavitation around scaler tips under loaded conditions. Two designs of piezoelectric ultrasonic scaling probes were evaluated with a scanning laser vibrometer and luminol dosimetric system under loaded (100 g/200 g) and unloaded conditions. Loads were applied to the probe tips via teeth mounted in a load-measuring apparatus. There was a positive correlation between probe displacement amplitude and cavitation production for ultrasonic probes. The position of cavitation at the tip of each probe was greater under loaded conditions than unloaded and for the longer P probe towards the tip. Whilst increasing vibration displacement amplitude of ultrasonic scalers increases the occurrence of cavitation, factors such as the length of the probe influence the amount of cavitation activity generated. The application of load affects the production of cavitation at the most clinically relevant area-the tip. Loading and the design of ultrasonic scalers lead to maximising the occurrence of the cavitation at the tip and enhance the cleaning efficiency of the scaler.

Histological changes and some in vitro biological activities induced by lipopolysaccharide from Bacteroides gingivalis.

PubMed

Isogai, H; Isogai, E; Fujii, N; Oguma, K; Kagota, W; Takano, K

1988-07-01

The biological activities of lipopolysaccharide from Bacteroides gingivalis 381 (B-LPS) were examined in vivo and in vitro. Intra-oral mucosal injection of B-LPS induced an acute inflammation at the injection site. Intravenous injection of B-LPS induced necrotic lesions with many thrombi in the liver and lymphocytic reduction in the spleen. By immunohistochemical examination, B-LPS was detected in macrophages in the liver, spleen and lymph nodes. In vitro analysis showed that B-LPS was a potent activator of both neutrophils and macrophages in luminol-dependent response and IL-1 secretion from macrophages and was mitogenic to the spleen cells not only from BALB/c mice but also from LPS-non-responder C3H/HeJ mice. Interferon production from human peripheral mononuclear leucocytes was induced, in vitro, by stimulation with B-LPS but not with the other enterobacterial LPS. These findings clarified the various biological activities of B-LPS affecting various cells and tissues, especially neutrophils, macrophages and lymphocytes. The potent inflammability of B-LPS shown in the present study indicates that it is one of the effective agents to induce periodontitis.

Sonochemical and high-speed optical characterization of cavitation generated by an ultrasonically oscillating dental file in root canal models.

PubMed

Macedo, R G; Verhaagen, B; Fernandez Rivas, D; Gardeniers, J G E; van der Sluis, L W M; Wesselink, P R; Versluis, M

2014-01-01

Ultrasonically Activated Irrigation makes use of an ultrasonically oscillating file in order to improve the cleaning of the root canal during a root canal treatment. Cavitation has been associated with these oscillating files, but the nature and characteristics of the cavitating bubbles were not yet fully elucidated. Using sensitive equipment, the sonoluminescence (SL) and sonochemiluminescence (SCL) around these files have been measured in this study, showing that cavitation occurs even at very low power settings. Luminol photography and high-speed visualizations provided information on the spatial and temporal distribution of the cavitation bubbles. A large bubble cloud was observed at the tip of the files, but this was found not to contribute to SCL. Rather, smaller, individual bubbles observed at antinodes of the oscillating file with a smaller amplitude were leading to SCL. Confinements of the size of bovine and human root canals increased the amount of SL and SCL. The root canal models also showed the occurrence of air entrainment, resulting in the generation of stable bubbles, and of droplets, near the air-liquid interface and leading eventually to a loss of the liquid. Copyright © 2013 Elsevier B.V. All rights reserved.

An in-fiber integrated optofluidic device based on an optical fiber with an inner core.

PubMed

Yang, Xinghua; Yuan, Tingting; Teng, Pingping; Kong, Depeng; Liu, Chunlan; Li, Entao; Zhao, Enming; Tong, Chengguo; Yuan, Libo

2014-06-21

A new kind of optofluidic in-fiber integrated device based on a specially designed hollow optical fiber with an inner core is designed. The inlets and outlets are built by etching the surface of the optical fiber without damaging the inner core. A reaction region between the end of the fiber and a solid point obtained after melting is constructed. By injecting samples into the fiber, the liquids can form steady microflows and react in the region. Simultaneously, the emission from the chemiluminescence reaction can be detected from the remote end of the optical fiber through evanescent field coupling. The concentration of ascorbic acid (AA or vitamin C, Vc) is determined by the emission intensity of the reaction of Vc, H2O2, luminol, and K3Fe(CN)6 in the optical fiber. A linear sensing range of 0.1-3.0 mmol L(-1) for Vc is obtained. The emission intensity can be determined within 2 s at a total flow rate of 150 μL min(-1). Significantly, this work presents information for the in-fiber integrated optofluidic devices without spatial optical coupling.

A novel biosensor array with a wheel-like pattern for glucose, lactate and choline based on electrochemiluminescence imaging.

PubMed

Zhou, Zhenyu; Xu, Linru; Wu, Suozhu; Su, Bin

2014-10-07

Electrochemiluminescence (ECL) imaging provides a superior approach to achieve array detection because of its ability for ultrasensitive multiplex analysis. In this paper, we reported a novel ECL imaging biosensor array modified with an enzyme/carbon nanotubes/chitosan composite film for the determination of glucose, choline and lactate. The biosensor array was constructed by integrating a patterned indium tin oxide (ITO) glass plate with six perforated poly(dimethylsiloxane) (PDMS) covers. ECL is generated by the electrochemical reaction between luminol and hydrogen peroxide that is produced by the enzyme catalysed oxidation of different substrates with molecular oxygen, and ECL images were captured by a charge-coupled device (CCD) camera. The separated electrochemical micro-cells enabled simultaneous assay of six samples at different concentrations. From the established calibration curves, the detection limits were 14 μM for glucose, 40 μM for lactate and 97 μM for choline, respectively. Moreover, multicomponent assays and cross reactivity were also studied, both of which were satisfied for the analysis. This biosensing platform based on ECL imaging shows many distinct advantages, including miniaturization, low cost, and multi-functionalization. We believe that this novel ECL imaging biosensor platform will have potential applications in clinical diagnostics, medicine and food inspection.

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.

Soil emissions of nitric oxide in a seasonally dry tropical forest of Mexico

NASA Technical Reports Server (NTRS)

Davidson, Eric A.; Vitousek, Peter M.; Riley, Ralph; Matson, Pamela A.; Garcia-Mendez, Georgina; Maass, J. M.

1991-01-01

Soil emissions of NO were measured at the Chamela Biological Station, Mexico, using soil covers and a field apparatus of NO detection based on CrO3 conversion of NO to NO2 and detection of NO2 by chemiluminescence with Luminol. Mean NO fluxes from forest soils ranged from 0.14 to 0.52 ng NO-N/sq cm/hr during the dry season and from 0.73 to 1.27 ng NO-N/sq cm/hr during the wet season. A fertilized floodplain pasture exhibited higher fluxes, but an unfertilized upland pasture, which represents the fastest growing land use in the region, had flux rates similar to the forest sites. Wetting experiments at the end of the dry season caused large pulses of NO flux, equaling 10 percent to 20 percent of the estimated annual NO emissions of 0.5-1.0 kg N/ha from the forest sites. Absence of a forest canopy during the dry season and the first wet season rain probably results in substantial NO(x) export from the forest system that may be important to regional atmospheric chemical processes. Wetting experiments during the wet season and a natural rain event had little or no stimulatory effect on NO flux rates.

Eco-friendly synthesis of gelatin-capped bimetallic Au-Ag nanoparticles for chemiluminescence detection of anticancer raloxifene hydrochloride.

PubMed

Alarfaj, Nawal A; El-Tohamy, Maha F

2016-09-01

This study described the utility of green analytical chemistry in the synthesis of gelatin-capped silver, gold and bimetallic gold-silver nanoparticles (NPs). The preparation of nanoparticles was based on the reaction of silver nitrate or chlorauric acid with a 1.0 wt% aqueous gelatin solution at 50°C. The gelatin-capped silver, gold and bimetallic NPs were characterized using transmission electron microscopy, UV-vis, X-ray diffraction and Fourier transform infrared spectroscopy, and were used to enhance a sensitive sequential injection chemiluminescence luminol-potassium ferricyanide system for determination of the anticancer drug raloxifene hydrochloride. The developed method is eco-friendly and sensitive for chemiluminescence detection of the selected drug in its bulk powder, pharmaceutical injections and biosamples. After optimizing the conditions, a linear relationship in the range of 1.0 × 10(-9) to 1.0 × 10(-1)  mol/L was obtained with a limit of detection of 5.0 × 10(-10)  mol/L and a limit of quantification of 1.0 × 10(-9)  mol/L. Statistical treatment and method validation were performed based on ICH guidelines. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Effect of Grewia asiatica fruit on glycemic index and phagocytosis tested in healthy human subjects.

PubMed

Mesaik, Muhammad Ahmed; Ahmed, Asif; Khalid, Ahmed Shukralla; Jan, Saleem; Siddiqui, Afaq Ahmed; Perveen, Shahida; Azim, Muhammad Kamran

2013-01-01

The Grewia asiatica (commonly known as Phalsa or Fasla) is a shrub or small tree found in southern Asia. It produces purple to black color fruit when ripe. In folk medicine the edible Grewia asiatica fruit is used in a number of pathological conditions. The current study described the effects of Grewia asiatica fruit on glycemic index (GI) and phagocytosis in healthy non-diabetic human subjects. The results showed that Grewia asiatica fruit has low GI value of 5.34 with modest hypoglycemic activity. Luminol-enhanced chemiluminescence assay was carried out to determine the production of reactive oxygen species (ROS) in the oxidative burst activity of whole blood. ROS production was found to be significantly affected, having the 78.3, 58.6 and 30.8% when the subjects were fed with D-glucose, mixture of D-glucose and Grewia asiatica fruit and Grewia asiatica fruit alone respectively as compared to the control. The aqueous, methanolic and butanolic extracts of Grewia asiatica fruits were found to produce a stimulatory effect on ROS production however; the chloroform, hexane and ethanol-acetate extracted exerted significant inhibitory effect. These results demonstrated that Grewia asiatica fruit has desirable effects on blood glucose metabolism manifested as low glycemic response and modulation of ROS production.

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.

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 novel multi-hyphenated analytical method to simultaneously determine xanthine oxidase inhibitors and superoxide anion scavengers in natural products.

PubMed

Qi, Jin; Sun, Li-Qiong; Qian, Steven Y; Yu, Bo-Yang

2017-09-01

Natural products, such as rosmarinic acid and apigenin, can act as xanthine oxidase inhibitors (XOIs) as well as superoxide anion scavengers, and have potential for treatment of diseases associated with high uric acid levels and oxidative stress. However, efficient simultaneous screening of these two bioactivities in natural products has been challenging. We have developed a novel method by assembling a multi-hyphenated high performance liquid chromatography (HPLC) system that combines a photo-diode array, chemiluminescence detector and a HPLC system with a variable wavelength detector, to simultaneously detect components that act as both XOIs and superoxide anion scavengers in natural products. Superoxide anion scavenging activity in the analyte was measured by on-line chemiluminescence chromatography based on pyrogallol-luminol oxidation, while xanthine oxidase inhibitory activity was determined by semi-on-line HPLC analysis. After optimizing multiple elements, including chromatographic conditions (e.g., organic solvent concentration and mobile phase pH), concentrations of xanthine/xanthine oxidase and reaction temperature, our validated analytical method was capable of mixed sample analysis. The final results from our method are presented in an easily understood visual format including comprehensive bioactivity data of natural products. Copyright © 2017. Published by Elsevier B.V.

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.

Glucose impairs aspirin inhibition in platelets through a NAD(P)H oxidase signaling pathway.

PubMed

Kobzar, Gennadi; Mardla, Vilja; Samel, Nigulas

2017-07-01

Hyperglycemia has been suggested to play a role in the increased platelet resistance to antiplatelet therapy in patients with diabetes mellitus. Exposure to high glucose impairs platelet inhibition by aspirin. It has been found that antioxidant agents reduce the effect of glucose, confirming the involvement of reactive oxygen species (ROS) in the effect of glucose. The aim of the study was to examine the mechanism of ROS increase by high glucose in aspirin-treated platelets. Platelet aggregation was measured by the optical method, and the production of ROS was detected using luminol-dependent horseradish peroxidase-enhanced chemiluminescence. We found that glucose did not affect ADP-induced platelet aggregation. However, it reduced the effect of aspirin on platelet aggregation, which was accompanied by an increase in ROS generation. The inhibition of NAD(P)H oxidase (NOX) prevented the glucose effect and ROS generation. The same result was recorded after the inhibition of p38 mitogen-activated protein kinases (p38 MAPK), phospholipase A 2 (PLA 2 ) or 12-lipoxygenase (12-LOX). The inhibition of TxA 2 receptor did not decrease the effect of glucose indicating that the effect was not caused by activation of TxA 2 receptors. Copyright © 2017 Elsevier Inc. All rights reserved.

The application of visible wavelength reflectance hyperspectral imaging for the detection and identification of blood stains.

PubMed

Li, Bo; Beveridge, Peter; O'Hare, William T; Islam, Meez

2014-12-01

Current methods of detection and identification of blood stains rely largely on visual examination followed by presumptive tests such as Kastle-Meyer, Leuco-malachite green or luminol. Although these tests are useful, they can produce false positives and can also have a negative impact on subsequent DNA tests. A novel application of visible wavelength reflectance hyperspectral imaging has been used for the detection and positive identification of blood stains in a non contact and non destructive manner on a range of coloured substrates. The identification of blood staining was based on the unique visible absorption spectrum of haemoglobin between 400 and 500 nm. Images illustrating successful discrimination of blood stains from nine red substances are included. It has also been possible to distinguish between blood and approximately 40 other reddish stains. The technique was also successfully used to detect latent blood stains deposited on white filter paper at dilutions of up to 1 in 512 folds and on red tissue at dilutions of up to 1 in 32 folds. Finally, in a blind trial, the method successfully detected and identified a total of 9 blood stains on a red T-shirt. Copyright © 2014 Forensic Science Society. Published by Elsevier Ireland Ltd. All rights reserved.

Advantages and limitations of common testing methods for antioxidants.

PubMed

Amorati, R; Valgimigli, L

2015-05-01

Owing to the importance of antioxidants in the protection of both natural and man-made materials, a large variety of testing methods have been proposed and applied. These include methods based on inhibited autoxidation studies, which are better followed by monitoring the kinetics of oxygen consumption or of the formation of hydroperoxides, the primary oxidation products. Analytical determination of secondary oxidation products (e.g. carbonyl compounds) has also been used. The majority of testing methods, however, do not involve substrate autoxidation. They are based on the competitive bleaching of a probe (e.g. ORAC assay, β-carotene, crocin bleaching assays, and luminol assay), on reaction with a different probe (e.g. spin-trapping and TOSC assay), or they are indirect methods based on the reduction of persistent radicals (e.g. galvinoxyl, DPPH and TEAC assays), or of inorganic oxidizing species (e.g. FRAP, CUPRAC and Folin-Ciocalteu assays). Yet other methods are specific for preventive antioxidants. The relevance, advantages, and limitations of these methods are critically discussed, with respect to their chemistry and the mechanisms of antioxidant activity. A variety of cell-based assays have also been proposed, to investigate the biological activity of antioxidants. Their importance and critical aspects are discussed, along with arguments for the selection of the appropriate testing methods according to the different needs.

Progress in directed energy control of vectors for microbes and other cells

NASA Astrophysics Data System (ADS)

Kiel, Johnathan L.; Parker, Jill E.; Holwitt, Eric A.; Vivekananda, Jeeva; Sloan, Mark A.; Stribling, Lucille J. V.

2004-07-01

Biosynthetic semiconductor, diazoluminomelanin (DALM), is a polymer of tyrosine, luminol, and nitrite. DALM has a very large cross section of absorption for light from ultraviolet to radio frequencies. This polymer can be made efficiently in a genetically engineered E.coli, JM109/pIC2ORNR1.1 (ATCC# 69905). We have been pursuing ways to couple electromagnetic radiation to vectors using this polymer. DNA capture elements (DCEs; formerly aptamers) have made this possible. We incorporated DCEs into the plasmid of this E. coli to direct binding to whatever microbe or cell desired and to produce DALM attached to the plasmid DNA. Using two other vectors pSV2neoNR101 or pSV2neoNR8005 (ATCC # 69617 and 69618, respectively), both propagated in the E. coli host HB101, we have also inserted genes necessary for DALM production into animal and human cell lines (mouse monocytic leukemia: ATCC # CRL- 11771, -11772, -1173, mouse mammary adenocarcinoma: ATCC# CRL-12184, -12185; and human carcinoma of the cervix: ATCC # CRL-12510). The DCE/DALM vectors can be used to tag target cells, detectable by broad-spectrum light absorbance, luminescence, or fluorescence. DCE/DALM can further be activated with light, microwave energy, or by oxidative chemistry to kill the targeted microbes or other cells.

Production of reactive oxygen species by phagocytic cells after exposure to glass wool and stone wool fibres - effect of fibre preincubation in aqueous solution.

PubMed

Zoller, T; Zeller, W J

2000-04-03

The potential of four man-made vitreous fibres (MMVFs) (glass wool Code A, stone wool Code G, HT-N and MMVF 21) and of two natural mineral fibres (crocidolite, erionite) to induce production of reactive oxygen species (ROS) by differentiated HL-60 cells (HL-60-M cells) was investigated by determination of luminol-enhanced chemiluminescence (CL). Quartz served as positive control. The same system was used to uncover possible influences of fibre preincubation in aqueous solutions on the ROS-generating potential. Following preincubation in unbuffered saline over about 4 weeks, Code A and G fibres showed decreased ROS-generating potential as compared to freshly suspended fibres. On the other hand, MMVF 21 and HT-N fibres as well as crocidolite and erionite showed no decreased CL after incubation in aqueous solutions. The observed decrease of the ROS-generating potential of Code A and G fibres after preincubation may be an expression of fibre surface alterations (leaching, initiation of dissolution) that influences the response of exposed phagocytic cells. After incubation of both fibres in buffered solutions at different pH values (5.0, 7.4) a reduced ROS-generating potential was still discernible as compared to freshly suspended fibres.

Assessment of antioxidant activity of spray dried extracts of Psidium guajava leaves by DPPH and chemiluminescence inhibition in human neutrophils.

PubMed

Fernandes, M R V; Azzolini, A E C S; Martinez, M L L; Souza, C R F; Lucisano-Valim, Y M; Oliveira, W P

2014-01-01

This work evaluated the physicochemical properties and antioxidant activity of spray dried extracts (SDE) from Psidium guajava L. leaves. Different drying carriers, namely, maltodextrin, colloidal silicon dioxide, Arabic gum, and β -cyclodextrin at concentrations of 40 and 80% relative to solids content, were added to drying composition. SDE were characterized through determination of the total phenolic, tannins, and flavonoid content. Antioxidant potential of the SDE was assessed by two assays: cellular test that measures the luminol-enhanced chemiluminescence (LumCL) produced by neutrophils stimulated with phorbol myristate acetate (PMA) and the DPPH radical scavenging (DPPH∗ method). In both assays the antioxidant activity of the SDE occurred in a concentration-dependent manner and showed no toxicity to the cells. Using the CLlum method, the IC50 ranged from 5.42 to 6.50 µg/mL. The IC50 of the SDE ranged from 7.96 to 8.11 µg/mL using the DPPH(•) method. Psidium guajava SDE presented significant antioxidant activity; thus they show high potential as an active phytopharmaceutical ingredient. Our findings in human neutrophils are pharmacologically relevant since they indicate that P. guajava SDE is a potential antioxidant and anti-inflammatory agent in human cells.

Assessment of Antioxidant Activity of Spray Dried Extracts of Psidium guajava Leaves by DPPH and Chemiluminescence Inhibition in Human Neutrophils

PubMed Central

Fernandes, M. R. V.; Azzolini, A. E. C. S.; Martinez, M. L. L.; Souza, C. R. F.; Lucisano-Valim, Y. M.; Oliveira, W. P.

2014-01-01

This work evaluated the physicochemical properties and antioxidant activity of spray dried extracts (SDE) from Psidium guajava L. leaves. Different drying carriers, namely, maltodextrin, colloidal silicon dioxide, Arabic gum, and β-cyclodextrin at concentrations of 40 and 80% relative to solids content, were added to drying composition. SDE were characterized through determination of the total phenolic, tannins, and flavonoid content. Antioxidant potential of the SDE was assessed by two assays: cellular test that measures the luminol-enhanced chemiluminescence (LumCL) produced by neutrophils stimulated with phorbol myristate acetate (PMA) and the DPPH radical scavenging (DPPH∗ method). In both assays the antioxidant activity of the SDE occurred in a concentration-dependent manner and showed no toxicity to the cells. Using the CLlum method, the IC50 ranged from 5.42 to 6.50 µg/mL. The IC50 of the SDE ranged from 7.96 to 8.11 µg/mL using the DPPH• method. Psidium guajava SDE presented significant antioxidant activity; thus they show high potential as an active phytopharmaceutical ingredient. Our findings in human neutrophils are pharmacologically relevant since they indicate that P. guajava SDE is a potential antioxidant and anti-inflammatory agent in human cells. PMID:24822200

Oxidative response of neutrophils to platelet-activating factor is altered during acute ruminal acidosis induced by oligofructose in heifers

PubMed Central

Concha, Claudia; Carretta, María Daniella; Alarcón, Pablo; Conejeros, Ivan; Gallardo, Diego; Hidalgo, Alejandra Isabel; Tadich, Nestor; Cáceres, Dante Daniel; Hidalgo, María Angélica

2014-01-01

Reactive oxygen species (ROS) production is one of the main mechanisms used to kill microbes during innate immune response. D-lactic acid, which is augmented during acute ruminal acidosis, reduces platelet activating factor (PAF)-induced ROS production and L-selectin shedding in bovine neutrophils in vitro. This study was conducted to investigate whether acute ruminal acidosis induced by acute oligofructose overload in heifers interferes with ROS production and L-selectin shedding in blood neutrophils. Blood neutrophils and plasma were obtained by jugular venipuncture, while ruminal samples were collected using rumenocentesis. Lactic acid from plasma and ruminal samples was measured by HPLC. PAF-induced ROS production and L-selectin shedding were measured in vitro in bovine neutrophils by a luminol chemiluminescence assay and flow cytometry, respectively. A significant increase in ruminal and plasma lactic acid was recorded in these animals. Specifically, a decrease in PAF-induced ROS production was observed 8 h after oligofructose overload, and this was sustained until 48 h post oligofructose overload. A reduction in PAF-induced L-selectin shedding was observed at 16 h and 32 h post oligofructose overload. Overall, the results indicated that neutrophil PAF responses were altered in heifers with ruminal acidosis, suggesting a potential dysfunction of the innate immune response. PMID:25013355

Oxidative response of neutrophils to platelet-activating factor is altered during acute ruminal acidosis induced by oligofructose in heifers.

PubMed

Concha, Claudia; Carretta, María Daniella; Alarcón, Pablo; Conejeros, Ivan; Gallardo, Diego; Hidalgo, Alejandra Isabel; Tadich, Nestor; Cáceres, Dante Daniel; Hidalgo, María Angélica; Burgos, Rafael Agustín

2014-01-01

Reactive oxygen species (ROS) production is one of the main mechanisms used to kill microbes during innate immune response. D-lactic acid, which is augmented during acute ruminal acidosis, reduces platelet activating factor (PAF)-induced ROS production and L-selectin shedding in bovine neutrophils in vitro. This study was conducted to investigate whether acute ruminal acidosis induced by acute oligofructose overload in heifers interferes with ROS production and L-selectin shedding in blood neutrophils. Blood neutrophils and plasma were obtained by jugular venipuncture, while ruminal samples were collected using rumenocentesis. Lactic acid from plasma and ruminal samples was measured by HPLC. PAF-induced ROS production and L-selectin shedding were measured in vitro in bovine neutrophils by a luminol chemiluminescence assay and flow cytometry, respectively. A significant increase in ruminal and plasma lactic acid was recorded in these animals. Specifically, a decrease in PAF-induced ROS production was observed 8 h after oligofructose overload, and this was sustained until 48 h post oligofructose overload. A reduction in PAF-induced L-selectin shedding was observed at 16 h and 32 h post oligofructose overload. Overall, the results indicated that neutrophil PAF responses were altered in heifers with ruminal acidosis, suggesting a potential dysfunction of the innate immune response.

Development of a tape transport bacterial detection system

NASA Technical Reports Server (NTRS)

Witz, S.; Hartung, W. H.

1972-01-01

The feasibility of a tape transport chemiluminescence system for bacterial monitoring of regenerated water was demonstrated using a manually operated laboratory breadboard. The principle of detection is based on measuring the increase in chemiluminescence produced by the catalytic action of bacterial porphyrins on a luminol-hydrogen peroxide mixture. Viable organisms are distinguished from nonviable by comparing the signals of incubated and unincubated water samples. Using optimized protocols, sensitivities were obtained with 400 ml suspensions of E. coli and Cl. sporogenes. The sensitivity of the unincubated cycle E. coli (aerobe) was found to be 30 to 35 cells/m1, and that of the Cl. sporogenes (anaerobe) was 1000 to 10,000 cells/m1. The lower sensitivity toward Cl. sporogenes is attributed to several factors, namely the lower cytochrome content, the tendency to sporulate, long lag periods and the lower growth rate of Clostridia in general. The operational procedures used for processing the incubated and unincubated samples involved the following sequence: (1) concentrating the sample by filtration through a membrane filter, (2) washing with Dextrose-Thioglycollate Broth (3) incubating (0 to 4 hrs as required), (4) washing with 4M Urea, and (5) reacting with reagent in front of a photomultiplier tube. The signal output was recorded on a strip chart recorder.

Chlorhexidine markedly potentiates the oxidants scavenging abilities of Candida albicans.

PubMed

Ginsburg, I; Koren, E; Feuerstein, O; Zogakis, I P; Shalish, M; Gorelik, S

2015-10-01

The oxidant scavenging ability (OSA) of catalase-rich Candida albicans is markedly enhanced by chlorhexidine digluconate (CHX), polymyxin B, the bile salt ursodeoxycholate and by lysophosphatidylcholine, which all act as detergents facilitating the penetration of oxidants and their intracellular decomposition. Quantifications of the OSA of Candida albicans were measured by a highly sensitive luminol-dependent chemiluminescence assay and by the Thurman's assay, to quantify hydrogen peroxide (H2O2). The OSA enhancing activity by CHX depends to some extent on the media on which candida grew. The OSA of candida treated by CHX was modulated by whole human saliva, red blood cells, lysozyme, cationic peptides and by polyphenols. Concentrations of CHX, which killed over 95 % of Candida albicans cells, did not affect the cells' abilities to scavenge reactive oxygen species (ROS). The OSA of Candida cells treated by CHX is highly refractory to H2O2 (50 mM) but is strongly inhibited by hypochlorous acid, lecithin, trypan blue and by heparin. We speculate that similarly to catalase-rich red blood cells, Candida albicans and additional catalase-rich microbiota may also have the ability to scavenge oxidants and thus can protect catalase-negative anaerobes and facultative anaerobes cariogenic streptococci against peroxide and thus secure their survival in the oral cavity.

Stimulus specific effect of ibuprofen on chemiluminescence of sheep neutrophils

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

Tahamont, M.V.; Margiotta, M.; Gee, M.H.

1986-03-05

The authors have shown that pretreatment with ibuprofen inhibits free radical release from complement stimulated neutrophils. To further examine the effect of ibuprofen on neutrophil free radical release, they stimulated neutrophils with the synthetic peptide, FMLP, phorbol myristate acetate (PMA), or zymosan-activated plasma (ZAP). Pure (>95%), viable (>95%) sheep neutrophils (2 x 10/sup 6/) were placed in HEPES buffer, luminol, drug or vehicle and stimulated in the luminometer with one of the stimuli. The chemiluminescence (CL) response was recorded and the drug treated samples were compared to vehicle treated controls. Ibuprofen had a dose dependent effect on CL in ZAPmore » stimulated neutrophils. At the highest dose (10/sup -2/M) these cells produced only 37 +/- 7% of the CL response observed in the control cells. In contrast, at the same dose, ibuprofen did not significantly attenuate CL seen in FMLP stimulated cells, with these cells producing 79 +/- 7% of the control cells; nor did ibuprofen effect PMA stimulated CL, as these cells produced a CL response that was 85 +/- 8% of the control cells. Ibuprofen appears to have a stimulus specific effect on free radical release in activated neutrophils. It is also apparent that ibuprofen inhibits complement stimulated free radical release by some mechanism independent of its cyclooxygenase inhibitory effect.« less

Antioxidant effects of herbal therapies used by patients with inflammatory bowel disease: an in vitro study.

PubMed

Langmead, L; Dawson, C; Hawkins, C; Banna, N; Loo, S; Rampton, D S

2002-02-01

Herbal remedies used by patients for treatment of inflammatory bowel disease include slippery elm, fenugreek, devil's claw, Mexican yam, tormentil and wei tong ning, a traditional Chinese medicine. Reactive oxygen metabolites produced by inflamed colonic mucosa may be pathogenic. Aminosalicylates (5-ASA) are antioxidant and other such agents could be therapeutic. To assess the antioxidant effects of herbal remedies in cell-free oxidant-generating systems and inflamed human colorectal biopsies. Luminol-enhanced chemiluminescence in a xanthine/xanthine oxidase cell-free system was used to detect superoxide scavenging by herbs and 5-ASA, and fluorimetry to define peroxyl radical scavenging using a phycoerythrin degradation assay. Chemiluminescence was used to detect herbal effects on generation of oxygen radicals by mucosal biopsies from patients with active ulcerative colitis. Like 5-ASA, all herbs, except fenugreek, scavenged superoxide dose-dependently. All materials tested scavenged peroxyl dose-dependently. Oxygen radical release from biopsies was reduced after incubation in all herbs except Mexican yam, and by 5-ASA. All six herbal remedies have antioxidant effects. Fenugreek is not a superoxide scavenger, while Mexican yam did not inhibit radical generation by inflamed biopsies. Slippery elm, fenugreek, devil's claw, tormentil and wei tong ning merit formal evaluation as novel therapies in inflammatory bowel disease.

A sensitive electrochemiluminescent biosensor based on AuNP-functionalized ITO for a label-free immunoassay of C-peptide.

PubMed

Liu, Xiang; Fang, Chen; Yan, Jilin; Li, Huiling; Tu, Yifeng

2018-05-23

The C-peptide is a co-product of pancreatic β-cells during insulin secretion; its content in body fluid is closely related to diabetes. This paper reports an immune-sensing strategy for a simple and effective assay of C-peptide based on label-free electrochemiluminescent (ECL) signaling, with high sensitivity and specificity. The basal electrode was constructed of an indium tin oxide (ITO) glass as a conductive substrate, which was decorated by Au nanoparticles (AuNPs) with hydrolysed (3-aminopropyl)trimethoxysilane as the linker. The characteristics of the fabricated electrode were investigated by electron microscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. After immobilizing the C-peptide antibody, which takes great advantage of AuNPs' binding capacity, this immunosensor can quantify C-peptide using luminol as the ECL probe. By measuring ECL inhibition, calibration can be established to report the C-peptide concentration between 0.05 ng mL -1 and 100 ng mL -1 with a detection limit of 0.0142 ng mL -1 . As a proof of concept, the proposed strategy is a promising and versatile platform for the clinical diagnosis, classification, and research of diabetes. Copyright © 2018 Elsevier B.V. All rights reserved.

A multipumping flow system for in vitro screening of peroxynitrite scavengers.

PubMed

Ribeiro, Marta F T; Dias, Ana C B; Santos, João L M; Fernandes, Eduarda; Lima, José L F C; Zagatto, Elias A G

2007-09-01

Peroxynitrite anion is a reactive nitrogen species formed in vivo by the rapid, controlled diffusion reaction between nitric oxide and superoxide radicals. By reacting with several biological molecules, peroxynitrite may cause important cellular and tissue deleterious effects, which have been associated with many diseases. In this work, an automated flow-based procedure for the in vitro generation of peroxynitrite and subsequent screening of the scavenging activity of selected compounds is developed. This procedure involves a multipumping flow system (MPFS) and exploits the ability of compounds such as lipoic acid, dihydrolipoic acid, cysteine, reduced glutathione, oxidized glutathione, sulindac, and sulindac sulfone to inhibit the chemiluminescent reaction of luminol with peroxynitrite under physiological simulated conditions. Peroxynitrite was generated in the MPFS by the online reaction of acidified hydrogen peroxide with nitrite, followed by a subsequent stabilization by merging with a sodium hydroxide solution to rapidly quench the developing reaction. The pulsed flow and the timed synchronized insertion of sample and reagent solutions provided by the MPFS ensure the establishment of the reaction zone only inside the flow cell, thus allowing maximum chemiluminescence emission detection. The results obtained for the assayed compounds show that, with the exception of oxidized glutathione, all are highly potent scavengers of peroxynitrite at the studied concentrations.

Biological effects of electrolyzed water in hemodialysis.

PubMed

Nakayama, Masaaki; Kabayama, Shigeru; Nakano, Hirofumi; Zhu, Wan-Jun; Terawaki, Hiroyuki; Nakayama, Keisuke; Katoh, Kiyoshi; Satoh, Toshinobu; Ito, Sadayoshi

2009-01-01

The application of electrolyzed water (EW) at the cathode side to manufacture reverse osmosis (RO) water and hemodialysis (HD) solution can actually lead to less oxidative capacity in chemical terms. The present study examined the biological actions of this water on human polymorphonuclear leukocytes (PMNs), and the clinical feasibility of applying this technology to HD treatment. RO water using EW (e-RO) exhibited less chemiluminescence in luminol-hydrogen peroxide and higher dissolved hydrogen levels (-99.0 ppb) compared with control RO water. The effects of e-RO on PMN viability were tested. HD using e-RO was performed for 12 consecutive sessions in 8 patients for the feasibility test. Basal cellular viability and function to generate superoxide radicals of PMNs were better preserved by e-RO application. In the clinical trial, reductions of blood pressure were noted, but no adverse events were observed. There were no changes in the blood dialysis parameters, although methylguanidine levels were significantly decreased at the end of study. The present study demonstrated the capacity of e-RO to preserve the viability of PMNs, and the clinical feasibility of applying this water for HD treatment. The clinical application of this technology may improve the bio-compatibility of HD treatment. Copyright 2009 S. Karger AG, Basel.

Minocycline affects human neutrophil respiratory burst and transendothelial migration.

PubMed

Parenti, Astrid; Indorato, Boris; Paccosi, Sara

2017-02-01

This study aimed at investigating the in vitro activity of minocycline and doxycycline on human polymorphonuclear (h-PMN) cell function. h-PMNs were isolated from whole venous blood of healthy subjects; PMN oxidative burst was measured by monitoring ROS-induced oxidation of luminol and transendothelial migration was studied by measuring PMN migration through a monolayer of human umbilical vein endothelial cells. Differences between multiple groups were determined by ANOVA followed by Tukey's multiple comparison test; Student's t test for unpaired data for two groups. Minocycline (1-300 µM) concentration dependently and significantly inhibited oxidative burst of h-PMNs stimulated with 100 nM fMLP. Ten micromolar concentrations, which are superimposable to C max following a standard oral dose of minocycline, promoted a 29.8 ± 4 % inhibition of respiratory burst (P < 0.001; n = 6). Doxycycline inhibited ROS production with a lesser extent and at higher concentrations. 10-100 µM minocycline impaired PMN transendothelial migration, with maximal effect at 100 µM (42.5 ± 7 %, inhibition, n = 5, P < 0.001). These results added new insight into anti-inflammatory effects of minocycline exerted on innate immune h-PMN cell function.

Ascorbate and α-tocopherol differentially modulate reactive oxygen species generation by neutrophils in response to FcγR and TLR agonists.

PubMed

Chapple, Iain Lc; Matthews, John B; Wright, Helen J; Scott, Ann E; Griffiths, Helen R; Grant, Melissa M

2013-01-01

Periodontitis, a ubiquitous chronic inflammatory disease, is associated with reduced antioxidant defences and neutrophil hyperactivity in terms of reactive oxygen species (ROS) generation. Its phenotype is thus characterized by oxidative stress. We have determined the effect of antioxidant micronutrients ascorbate and α-tocopherol on neutrophil ROS generation. Peripheral neutrophils from periodontally-healthy individuals (n = 20) were challenged with phorbol myristate acetate, IgG-opsonised Staphylococcus aureus, Fusobacterium nucleatum or PBS in the presence and absence of micronutrients (50 µM). Total and extracellular ROS were measured by luminol and isoluminol chemiluminescence respectively. Total and extracellular unstimulated, baseline ROS generation was unaffected by α-tocopherol, but inhibited by ascorbate and a combination of both micronutrients. Fcγ-receptor (Fcγ-R)-stimulated total or extracellular ROS generation was not affected by the presence of individual micronutrients. However, the combination significantly reduced extracellular FcγR-stimulated ROS release. Neither micronutrient inhibited TLR-stimulated total ROS, but the combination caused inhibition. Ascorbate and the micronutrient combination, but not α-tocopherol, inhibited extracellular ROS release by TLR-stimulated cells. Such micronutrient effects in vivo could be beneficial in reducing collateral tissue damage in chronic inflammatory diseases, such as periodontitis, while retaining immune-mediated neutrophil function.

The effect of storage on whole blood chemiluminescence measurement of equine neutrophils.

PubMed

Krumrych, Wiesław; Skórzewski, Radosław; Malinowski, Edward

2013-01-01

The aim of this study was to determine the effect of duration and temperature of sample storage on whole blood chemiluminescence measurement results. Venous blood from 18 clinically healthy Polish half-bred horses aged 4 to 11 years were used in the study. Luminol dependent chemiluminescence (CL) was used to measure neutrophil oxygen metabolism in whole blood. Blood samples were examined for spontaneous CL and stimulated by a surface receptor stimulus as well as extra-receptor stimulus. The assay was performed in two parallel experimental sets with samples stored at 4 and 22 °C, respectively. Whole blood CL was estimated at 2, 6, 24, 48, 72, 96 and 120 h after collection. The study demonstrated that temperature and duration of sample storage are factors that determine the quality of CL measurements of whole blood in horses. The study concluded that samples should be stored at 4 °C and the assay should be performed as early as possible. It was also shown that the viability period of horse blood for CL assays is relatively long. Material stored at room temperature for 24 h and even up to 48 h at 4 °C did not show any significant decrease in spontaneous or stimulated chemiluminescence. Copyright © 2012 John Wiley & Sons, Ltd.

A Highly Sensitive Chemiluminometric Assay for Real-Time Detection of Biological Hydrogen Peroxide Formation.

PubMed

Zhu, Hong; Jia, Zhenquan; Trush, Michael A; Li, Y Robert

2016-05-01

Hydrogen peroxide (H 2 O 2 ) is a major reactive oxygen species (ROS) produced by various cellular sources, especially mitochondria. At high levels, H 2 O 2 causes oxidative stress, leading to cell injury, whereas at low concentrations, this ROS acts as an important second messenger to participate in cellular redox signaling. Detection and measurement of the levels or rates of production of cellular H 2 O 2 are instrumental in studying the biological effects of this major ROS. While a number of assays have been developed over the past decades for detecting and/or quantifying biological H 2 O 2 formation, none has been shown to be perfect. Perhaps there is no perfect assay for sensitively and accurately quantifying H 2 O 2 as well as other ROS in cells, wherein numerous potential reactants are present to interfere with the reliable measurement of the specific ROS. In this context, each assay has its own advantages and intrinsic limitations. This article describes a highly sensitive assay for real-time detection of H 2 O 2 formation in cultured cells and isolated mitochondria. This assay is based on the luminol/horseradish peroxidase-dependent chemiluminescence that is inhibitable by catalase. The article discusses the usefulness and shortcomings of this chemiluminometric assay in detecting biological H 2 O 2 formation induced by beta-lapachone redox cycling with both cells and isolated mitochondria.

An aptasensor for staphylococcus aureus based on nicking enzyme amplification reaction and rolling circle amplification.

PubMed

Xu, Jingguo; Guo, Jia; Maina, Sarah Wanjiku; Yang, Yumeng; Hu, Yimin; Li, Xuanxuan; Qiu, Jiarong; Xin, Zhihong

2018-05-15

An ultra-sensitive aptamer-based biosensor for the detection of staphylococcus aureus was established by adopting the nicking enzyme amplification reaction (NEAR) and the rolling circle amplification (RCA) technologies. Aptamer-probe (AP), containing an aptamer and a probe sequence, was developed to act as the recognition unit of the biosensor, which was specifically bound to S. aureus. The probe was released from AP and initiated into the subsequent DNA amplification reactions where S. aureus was present, converting the detection of S. aureus to the investigation of probe oligonucleotide. The RCA amplification products contained a G-quadruplex motif and formed a three dimensional structure in presence of hemin. The G4/hemin complex showed horseradish peroxidase (HRP)-mimic activity and catalyzed the chemiluminescence reaction of luminol mediated by H 2 O 2 . The results showed that the established biosensor could detect S. aureus specifically with a good linear correlation at 5-10 4  CFU/mL. The signal values based on NEAR-RCA two-step cycle were boosted acutely, much higher than that relied on one-cycle magnification. The limit of detection (LoD) was determined to be as low as 5 CFU/mL. The established aptasensor exhibited a good discrimination of living against dead S. aureus, and can be applied to detect S. aureus in the food industry. Copyright © 2018 Elsevier Inc. All rights reserved.

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.

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.

Effects of young barley leaf extract and antioxidative vitamins on LDL oxidation and free radical scavenging activities in type 2 diabetes.

PubMed

Yu, Y-M; Chang, W-C; Chang, C-T; Hsieh, C-L; Tsai, C E

2002-04-01

The effects of supplementation of young barley leaf extract (BL) and/or antioxidative vitamins C and E on different low-density lipoprotein (LDL) subfractions susceptibility to oxidation and free radical scavenging activities in patients with type 2 diabetes were evaluated. Thirty-six type 2 diabetic patients were enrolled in this study. The subjects received one of the following supplements daily for 4 weeks: 15 g BL, 200 mg vitamin C and 200 mg vitamin E (CE), or BL plus CE (BL + CE). The lucigenin-chemiluminescence (CL) and luminol-CL levels in blood were significantly reduced in all groups. Vitamin E content of LDL subfractions increased significantly following supplements, especially for BL + CE group. The percent increase of lag times in the BL + CE was significantly higher than those in the BL or CE group. The antioxidative effect of BL + CE was the greatest for small, dense LDL (Sd-LDL) with further increases in percentage of lag times 4 folds compared to BL alone. Our results indicate that supplementation with BL may help to scavenge oxygen free radicals, save the LDL-vitamin E content, and inhibit LDL oxidation. Furthermore, the addition of vitamins C and E to BL can inhibit the Sd-LDL oxidation more effectively, which may protect against vascular diseases in type 2 diabetic patients.

A new strategy for the detection of adenosine triphosphate by aptamer/quantum dot biosensor based on chemiluminescence resonance energy transfer.

PubMed

Zhou, Zi-Ming; Yu, Yong; Zhao, Yuan-Di

2012-09-21

We designed an aptasensor for the detection of adenosine triphosphate (ATP) based on chemiluminescence resonance energy transfer (CRET). An adenosine aptamer was cut into two pieces of ssDNA, which were attached to quantum dots (QDs) and horse radish peroxidase (HRP), respectively. They could reassemble into specific structures in the presence of ATP and then decrease the distance of HRP and QDs. ATP detection can be easily realized according to the fluorescent intensity of QDs, which is excited by CRET between luminol and QDs. Results show that the concentration of ATP is linear relation with the fluorescent intensity of the peak of QDs emission and the linear range for the linear equation is from 50 μM to 231 μM and the detection limit was 185 nM. When the concentration of ATP was 2 mM, the efficiency of CRET is 13.6%. Good specificity for ATP had been demonstrated compared to thymidine triphosphate (TTP), cytidine triphosphate (CTP) and guanosine triphosphate (GTP), when 1 mM of each was added, respectively. This method needs no external light source and can avoid autofluorescence and photobleaching, and ATP can be detected selectively, specifically, and sensitively in a low micromolar range, which means that the strategy reported here can be applicable to the detection of several other target molecules.

Reduced graphene oxide decorated with gold nanoparticle as signal amplification element on ultra-sensitive electrochemiluminescence determination of caspase-3 activity and apoptosis using peptide based biosensor

PubMed Central

Khalilzadeh, Balal; Shadjou, Nasrin; Afsharan, Hadi; Eskandani, Morteza; Nozad Charoudeh, Hojjatollah; Rashidi, Mohammad-Reza

2016-01-01

Introduction:Growing demands for ultrasensitive biosensing have led to the development of numerous signal amplification strategies. In this report, a novel electrochemiluminescence (ECL) method was developed for the detection and determination of caspase-3 activity based on reduced graphene oxide sheets decorated by gold nanoparticles as signal amplification element and horseradish peroxidase enzyme (HRP) as ECL intensity enhancing agent. Methods: The ECL intensity of the luminol was improved by using the streptavidin coated magnetic beads and HRP in the presence of hydrogen peroxide. The cleavage behavior of caspase-3 was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) techniques using biotinylated peptide (DEVD containing peptide) which was coated on reduced graphene oxide decorated with gold nanoparticle. The surface modification of graphene oxide was successfully confirmed by FTIR, UV-vis and x-ray spectroscopy. Results: ECL based biosensor showed that the linear dynamic range (LDR) and the lower limit of quantification (LLOQ) were 0.5-100 and 0.5 femtomolar (fM), respectively. Finally, the performance of the engineered peptide based biosensor was validated in the A549 cell line as real samples. Conclusion: The prepared peptide based biosensor could be considered as an excellent candidate for early detection of apoptosis, cell turnover, and cancer related diseases. PMID:27853677

Energetic balance in an ultrasonic reactor using focused or flat high frequency transducers.

PubMed

Hallez, L; Touyeras, F; Hihn, J Y; Klima, J

2007-09-01

In order to undertake irradiation of polymer blocks or films by ultrasound, this paper deals with the measurements of ultrasonic power and its distribution within the cell by several methods. The electric power measured at the transducer input is compared to the ultrasonic power input to the cell evaluated by calorimetry and radiation force measurement for different generator settings. Results obtained in the specific case of new transducer types (composites and focused composites i.e., HIFU: high intensity focused ultrasound) provide an opportunity to conduct a discussion about measurement methods. It has thus been confirmed that these measurement techniques can be applied to HIFU transducers. For all cases, results underlined the fact that measurement of radiation pressure for power evaluation is more adapted to low powers (<15 W) and that measurement by calorimetry is a valid technique for global energy measurements. Composites and monocomponent transducers were compared and it appears that the presence of an adaptation glass plate reduces the efficiency of the monocomponent transducers. The distribution of ultrasonic intensity is qualitatively depicted by sono-chemiluminescence of luminol. Finally, the quantity of energy absorbed by samples placed in the sound field is determined and the temperature distribution monitored as a function of wall distance. This energetic balance allows us to understand the global behaviour of all experimental set-ups made up of a generator-transducer-liquid and sample.

Measurement of hydroxyl radical production in ultrasonic aqueous solutions by a novel chemiluminescence method.

PubMed

Hu, Yufei; Zhang, Zhujun; Yang, Chunyan

2008-07-01

Measurement methods for ultrasonic fields are important for reasons of safety. The investigation of an ultrasonic field can be performed by detecting the yield of hydroxyl radicals resulting from ultrasonic cavitations. In this paper, a novel method is introduced for detecting hydroxyl radicals by a chemiluminescence (CL) reaction of luminol-hydrogen peroxide (H2O2)-K5[Cu(HIO6)2](DPC). The yield of hydroxyl radicals is calculated directly by the relative CL intensity according to the corresponding concentration of H2O2. This proposed CL method makes it possible to perform an in-line and real-time assay of hydroxyl radicals in an ultrasonic aqueous solution. With flow injection (FI) technology, this novel CL reaction is sensitive enough to detect ultra trace amounts of H2O2 with a limit of detection (3sigma) of 4.1 x 10(-11) mol L(-1). The influences of ultrasonic output power and ultrasonic treatment time on the yield of hydroxyl radicals by an ultrasound generator were also studied. The results indicate that the amount of hydroxyl radicals increases with the increase of ultrasonic output power (< or = 15 W mL(-1)). There is a linear relationship between the time of ultrasonic treatment and the yield of H2O2. The ultrasonic field of an ultrasonic cleaning baths has been measured by calculating the yield of hydroxyl radicals.

Aspergillus-induced superoxide production by cystic fibrosis phagocytes is associated with disease severity.

PubMed

Brunel, Shan F; Willment, Janet A; Brown, Gordon D; Devereux, Graham; Warris, Adilia

2018-04-01

Aspergillus fumigatus infects up to 50% of cystic fibrosis (CF) patients and may play a role in progressive lung disease. As cystic fibrosis transmembrane conductance regulator is expressed in cells of the innate immune system, we hypothesised that impaired antifungal immune responses play a role in CF-related Aspergillus lung disease. Peripheral blood mononuclear cells, polymorphonuclear cells (PMN) and monocytes were isolated from blood samples taken from CF patients and healthy volunteers. Live-cell imaging and colorimetric assays were used to assess antifungal activity in vitro . Production of reactive oxygen species (ROS) was measured using luminol-induced chemiluminescence and was related to clinical metrics as collected by case report forms. CF phagocytes are as effective as those from healthy controls with regards to phagocytosis, killing and restricting germination of A. fumigatus conidia. ROS production by CF phagocytes was up to four-fold greater than healthy controls (p<0.05). This effect could not be replicated in healthy phagocytes by priming with lipopolysaccharide or serum from CF donors. Increased production of ROS against A. fumigatus by CF PMN was associated with an increased number of clinical exacerbations in the previous year (p=0.007) and reduced lung function (by forced expiratory volume in 1 s) (p=0.014). CF phagocytes mount an intrinsic exaggerated release of ROS upon A. fumigatus stimulation which is associated with clinical disease severity.

Aspergillus-induced superoxide production by cystic fibrosis phagocytes is associated with disease severity

PubMed Central

Brunel, Shan F.; Brown, Gordon D.; Devereux, Graham; Warris, Adilia

2018-01-01

Aspergillus fumigatus infects up to 50% of cystic fibrosis (CF) patients and may play a role in progressive lung disease. As cystic fibrosis transmembrane conductance regulator is expressed in cells of the innate immune system, we hypothesised that impaired antifungal immune responses play a role in CF-related Aspergillus lung disease. Peripheral blood mononuclear cells, polymorphonuclear cells (PMN) and monocytes were isolated from blood samples taken from CF patients and healthy volunteers. Live-cell imaging and colorimetric assays were used to assess antifungal activity in vitro. Production of reactive oxygen species (ROS) was measured using luminol-induced chemiluminescence and was related to clinical metrics as collected by case report forms. CF phagocytes are as effective as those from healthy controls with regards to phagocytosis, killing and restricting germination of A. fumigatus conidia. ROS production by CF phagocytes was up to four-fold greater than healthy controls (p<0.05). This effect could not be replicated in healthy phagocytes by priming with lipopolysaccharide or serum from CF donors. Increased production of ROS against A. fumigatus by CF PMN was associated with an increased number of clinical exacerbations in the previous year (p=0.007) and reduced lung function (by forced expiratory volume in 1 s) (p=0.014). CF phagocytes mount an intrinsic exaggerated release of ROS upon A. fumigatus stimulation which is associated with clinical disease severity. PMID:29651422

Cold Environment Exacerbates Brain Pathology and Oxidative Stress Following Traumatic Brain Injuries: Potential Therapeutic Effects of Nanowired Antioxidant Compound H-290/51.

PubMed

Sharma, Aruna; Muresanu, Dafin F; Lafuente, José Vicente; Sjöquist, Per-Ove; Patnaik, Ranjana; Ryan Tian, Z; Ozkizilcik, Asya; Sharma, Hari S

2018-01-01

The possibility that traumatic brain injury (TBI) occurring in a cold environment exacerbates brain pathology and oxidative stress was examined in our rat model. TBI was inflicted by making a longitudinal incision into the right parietal cerebral cortex (2 mm deep and 4 mm long) in cold-acclimatized rats (5 °C for 3 h daily for 5 weeks) or animals at room temperature under Equithesin anesthesia. TBI in cold-exposed rats exhibited pronounced increase in brain lucigenin (LCG), luminol (LUM), and malondialdehyde (MDA) and marked pronounced decrease in glutathione (GTH) as compared to identical TBI at room temperature. The magnitude and intensity of BBB breakdown to radioiodine and Evans blue albumin, edema formation, and neuronal injuries were also exacerbated in cold-exposed rats after injury as compared to room temperature. Nanowired delivery of H-290/51 (50 mg/kg) 6 and 8 h after injury in cold-exposed group significantly thwarted brain pathology and oxidative stress whereas normal delivery of H-290/51 was neuroprotective after TBI at room temperature only. These observations are the first to demonstrate that (i) cold aggravates the pathophysiology of TBI possibly due to an enhanced production of oxidative stress, (ii) and in such conditions, nanodelivery of antioxidant compound has superior neuroprotective effects, not reported earlier.

Ultrasensitive determination of DNA sequences by flow injection chemiluminescence using silver ions as labels.

PubMed

Zheng, Lichun; Liu, Xiuhui; Zhou, Min; Ma, Yongjun; Wu, Guofan; Lu, Xiaoquan

2014-10-27

We presented a new strategy for ultrasensitive detection of DNA sequences based on the novel detection probe which was labeled with Ag(+) using metallothionein (MT) as a bridge. The assay relied on a sandwich-type DNA hybridization in which the DNA targets were first hybridized to the captured oligonucleotide probes immobilized on Fe3O4@Au composite magnetic nanoparticles (MNPs), and then the Ag(+)-modified detection probes were used to monitor the presence of the specific DNA targets. After being anchored on the hybrids, Ag(+) was released down through acidic treatment and sensitively determined by a coupling flow injection-chemiluminescent reaction system (Ag(+)-Mn(2+)-K2S2O8-H3PO4-luminol) (FI-CL). The experiment results showed that the CL intensities increased linearly with the concentrations of DNA targets in the range from 10 to 500 pmol L(-1) with a detection limit of 3.3 pmol L(-1). The high sensitivity in this work may be ascribed to the high molar ratio of Ag(+)-MT, the sensitive determination of Ag(+) by the coupling FI-CL reaction system and the perfect magnetic separation based on Fe3O4@Au composite MNPs. Moreover, the proposed strategy exhibited excellent selectivity against the mismatched DNA sequences and could be applied to real samples analysis. Copyright © 2014 Elsevier B.V. All rights reserved.

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.

Lipopolysaccharides elicit an oxidative burst as a component of the innate immune system in the seagrass Thalassia testudinum.

PubMed

Loucks, Kyle; Waddell, David; Ross, Cliff

2013-09-01

This study represents the first report characterizing the biological effects of a lipopolysaccharide (LPS) immune modulator on a marine vascular plant. LPS was shown to serve as a strong elicitor of the early defense response in the subtropical seagrass Thalassia testudinum Banks ex König and was capable of inducing an oxidative burst identified at the single cell level. The formation of reactive oxygen species (ROS), detected by a redox-sensitive fluorescent probe and luminol-based chemiluminescence, included a diphenyleneiodonium sensitive response, suggesting the involvement of an NADPH oxidase. A 900 bp cDNA fragment coding for this enzyme was sequenced and found to encode a NAD binding pocket domain with extensive homology to the Arabidopsis thaliana rbohF (respiratory burst oxidase homolog) gene. The triggered release of ROS occurred at 20 min post-elicitation and was dose-dependent, requiring a minimal threshold of 50 μg/mL LPS. Pharmacological dissection of the early events preceding ROS emission indicated that the signal transduction chain of events involved extracellular alkalinization, G-proteins, phospholipase A2, as well as K(+), Ca(2+), and anion channels. Despite exclusively thriving in a marine environment, seagrasses contain ROS-generating machinery and signal transduction components that appear to be evolutionarily conserved with the well-characterized defense response systems found in terrestrial plants. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

The control of vascular endothelial cell injury.

PubMed

Murota, S; Morita, I; Suda, N

1990-01-01

The mechanism by which MCI-186 showed a potent cytoprotective effect on the in vitro endothelial cell injury due to 15-HPETE was studied. Stimulation of human leukocytes with various chemical mediators such as TPA, f-Met-Leu-Phe, LTB4, etc. elicited the production of active oxygens, which could be detected by luminol-dependent chemiluminescence. Among the chemical mediators tested, TPA elicited the chemiluminescence the most, and f-Met-Leu-Phe and LTB4 came next. When the leukocytes were directly placed on a monolayer of cultured endothelial cells, followed by stimulating the leukocytes with TPA, severe endothelial cell injury was observed. The effect of TPA was dose dependent. There was good correlation between the active oxygen releasing activity and the cytotoxic activity. When the leukocytes were placed on a filter which was set apart from the monolayer of endothelial cell in a culture dish, and stimulated the leukocytes with TPA, no cytotoxicity was observed. These data strongly suggest that the substance responsible for the cytotoxicity must be a very labile and short-lived substance, presumably active oxygens. On the other hand, MCI-186 was found to have a complete quenching activity to the chemiluminescence due to active oxygens in the TPA-leukocyte system. Taken together, these factors indicate that the potent cytoprotective effect of MCI-186 may be due to its specific radical scavenging activity.

Responses of human neutrophils to nicotine and/or Porphyromonas gingivalis.

PubMed

Al-Shibani, Nouf K; Labban, Nawaf Y; Kowolik, Michael J; Ruby, John D; Windsor, L Jack

2011-10-01

Tobacco smoking is considered a major modifiable risk factor for periodontal disease. Nicotine is the addictive ingredient in tobacco and has been shown to affect multiple cellular processes. Neutrophils are the first line of host defense and are critical cells in the maintenance of periodontal health through their role in the control of bacteria, but they can also contribute to the progression of periodontal disease by the production and release of reactive oxygen species (ROS). Virulence factors from periodontal pathogens, such as Porphyromonas gingivalis (Pg), stimulate the respiratory burst of neutrophils. The objective of this study is to explore the oxidative activity of neutrophils when stimulated with Pg, nicotine, or both. Neutrophils were separated from buffy coats by the double dextran gradient method. The generation of ROS by neutrophils was determined using luminol-dependent chemiluminescence assays. The reaction was followed for 90 minutes, and the neutrophil activation was recorded as the total integrated energy output. The Pg and Pg plus nicotine groups had a significantly higher active and peak chemiluminescence than the nicotine group (all with P <0.0001). The Pg and Pg with nicotine groups were not significantly different (P = 0.90). In the presence of Pg, the nicotine did not further enhance the ROS release by the neutrophils, suggesting that the bacteria induced the maximum ROS release in this model system.

Effects of iron and iron chelation in vitro on mucosal oxidant activity in ulcerative colitis.

PubMed

Millar, A D; Rampton, D S; Blake, D R

2000-09-01

Reactive oxygen species may be pathogenic in ulcerative colitis. Oral iron supplements anecdotally exacerbate inflammatory bowel disease and iron levels are elevated in the inflamed mucosa. Mucosal iron may enhance hydroxyl ion production via Fenton chemistry. Conversely, the iron chelator, desferrioxamine, is reportedly beneficial in Crohn's disease. To assess the in vitro effects of exogenous iron and of iron chelators on the production of reactive oxygen species by colonic biopsies from normal control subjects and patients with ulcerative colitis. Luminol-amplified chemiluminescence was used to measure mucosal reactive oxygen species production both before and after addition in vitro of ferric citrate (100 microM), desferrioxamine (1 mM) and 1,10-phenanthroline (1 mM). Ferric citrate had no effect on the chemiluminescence produced by human colonic mucosa. However, desferrioxamine and phenanthroline reduced chemiluminescence by 47% (n=7, P=0.018) and by 26% (n=10, P=0.005), respectively, in inactive ulcerative colitis, and by 44% (n=9, P=0. 008) and 42% (n=11, P=0.006) in active disease. The lack of effect of ferric citrate suggests that sufficient free iron is already present in inflamed biopsies to drive the Fenton reaction maximally. The effects of desferrioxamine and 1,10-phenanthroline on the chemiluminescence of biopsies from patients with ulcerative colitis suggest that a clinical trial of topical iron chelation in active disease is indicated.

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.

A functional glycoprotein competitive recognition and signal amplification strategy for carbohydrate-protein interaction profiling and cell surface carbohydrate expression evaluation

NASA Astrophysics Data System (ADS)

Wang, Yangzhong; Chen, Zhuhai; Liu, Yang; Li, Jinghong

2013-07-01

A simple and sensitive carbohydrate biosensor has been suggested as a potential tool for accurate analysis of cell surface carbohydrate expression as well as carbohydrate-based therapeutics for a variety of diseases and infections. In this work, a sensitive biosensor for carbohydrate-lectin profiling and in situ cell surface carbohydrate expression was designed by taking advantage of a functional glycoprotein of glucose oxidase acting as both a multivalent recognition unit and a signal amplification probe. Combining the gold nanoparticle catalyzed luminol electrogenerated chemiluminescence and nanocarrier for active biomolecules, the number of cell surface carbohydrate groups could be conveniently read out. The apparent dissociation constant between GOx@Au probes and Con A was detected to be 1.64 nM and was approximately 5 orders of magnitude smaller than that of mannose and Con A, which would arise from the multivalent effect between the probe and Con A. Both glycoproteins and gold nanoparticles contribute to the high affinity between carbohydrates and lectin. The as-proposed biosensor exhibits excellent analytical performance towards the cytosensing of K562 cells with a detection limit of 18 cells, and the mannose moieties on a single K562 cell were determined to be 1.8 × 1010. The biosensor can also act as a useful tool for antibacterial drug screening and mechanism investigation. This strategy integrates the excellent biocompatibility and multivalent recognition of glycoproteins as well as the significant enzymatic catalysis and gold nanoparticle signal amplification, and avoids the cell pretreatment and labelling process. This would contribute to the glycomic analysis and the understanding of complex native glycan-related biological processes.A simple and sensitive carbohydrate biosensor has been suggested as a potential tool for accurate analysis of cell surface carbohydrate expression as well as carbohydrate-based therapeutics for a variety of diseases and infections. In this work, a sensitive biosensor for carbohydrate-lectin profiling and in situ cell surface carbohydrate expression was designed by taking advantage of a functional glycoprotein of glucose oxidase acting as both a multivalent recognition unit and a signal amplification probe. Combining the gold nanoparticle catalyzed luminol electrogenerated chemiluminescence and nanocarrier for active biomolecules, the number of cell surface carbohydrate groups could be conveniently read out. The apparent dissociation constant between GOx@Au probes and Con A was detected to be 1.64 nM and was approximately 5 orders of magnitude smaller than that of mannose and Con A, which would arise from the multivalent effect between the probe and Con A. Both glycoproteins and gold nanoparticles contribute to the high affinity between carbohydrates and lectin. The as-proposed biosensor exhibits excellent analytical performance towards the cytosensing of K562 cells with a detection limit of 18 cells, and the mannose moieties on a single K562 cell were determined to be 1.8 × 1010. The biosensor can also act as a useful tool for antibacterial drug screening and mechanism investigation. This strategy integrates the excellent biocompatibility and multivalent recognition of glycoproteins as well as the significant enzymatic catalysis and gold nanoparticle signal amplification, and avoids the cell pretreatment and labelling process. This would contribute to the glycomic analysis and the understanding of complex native glycan-related biological processes. Electronic supplementary information (ESI) available: Experimental details; characterization of probes; the influence of electrolyte pH; probe concentration and glucose concentration on the electrode ECL effect. See DOI: 10.1039/c3nr01598j

Rebamipide, a novel antiulcer agent, attenuates Helicobacter pylori induced gastric mucosal cell injury associated with neutrophil derived oxidants.

PubMed Central

Suzuki, M; Miura, S; Mori, M; Kai, A; Suzuki, H; Fukumura, D; Suematsu, M; Tsuchiya, M

1994-01-01

The effect of rebamipide, a novel antiulcer compound, on Helicobacter pylori activated neutrophil dependent in vitro gastric epithelial cell injury was investigated. Luminol dependent chemiluminescence (ChL), which detects toxic oxidants from neutrophils exhibited a 12-fold increase when the bacterial suspension of H pylori was added to the isolated human neutrophils. This change was significantly attenuated by rebamipide at a concentration less than 1 mM, showing that rebamipide may inhibit oxidant production from H pylori elicited neutrophils. To assess whether rebamipide attenuates gastric mucosal injury, we tested its inhibitory action on H pylori induced gastric mucosal damage associated with neutrophils in vitro. Rabbit gastric mucosal cells were monolayered in culture wells and coincubated with human neutrophils and H pylori, and the cytotoxicity index was then calculated. Cultured gastric cells were significantly damaged when they were incubated with human neutrophils activated by H pylori. This cellular damage was attenuated by rebamipide in a dose-dependent manner. Furthermore, spectrophotometrical measurement showed that rebamipide (1 mM) inhibits urease activity by 21.7%. As monochloramine (an oxidant yielded by reaction of neutrophil derived chlorinated oxidant and ammonia) is proposed as an important toxic molecule in this model, the current findings suggest that the preventive effect of rebamipide on H pylori elicited neutrophil induced gastric mucosal injury may result from its inhibitory actions on the neutrophilic oxidative burst as well as H pylori derived urease activity. PMID:7959190

Hydrogen peroxide in deep waters from the Mediterranean Sea, South Atlantic and South Pacific Oceans

NASA Astrophysics Data System (ADS)

Hopwood, Mark J.; Rapp, Insa; Schlosser, Christian; Achterberg, Eric P.

2017-03-01

Hydrogen peroxide (H2O2) is present ubiquitously in marine surface waters where it is a reactive intermediate in the cycling of many trace elements. Photochemical processes are considered the dominant natural H2O2 source, yet cannot explain nanomolar H2O2 concentrations below the photic zone. Here, we determined the concentration of H2O2 in full depth profiles across three ocean basins (Mediterranean Sea, South Atlantic and South Pacific Oceans). To determine the accuracy of H2O2 measurements in the deep ocean we also re-assessed the contribution of interfering species to ‘apparent H2O2’, as analysed by the luminol based chemiluminescence technique. Within the vicinity of coastal oxygen minimum zones, accurate measurement of H2O2 was not possible due to interference from Fe(II). Offshore, in deep (>1000 m) waters H2O2 concentrations ranged from 0.25 ± 0.27 nM (Mediterranean, Balearics-Algeria) to 2.9 ± 2.2 nM (Mediterranean, Corsica-France). Our results indicate that a dark, pelagic H2O2 production mechanism must occur throughout the deep ocean. A bacterial source of H2O2 is the most likely origin and we show that this source is likely sufficient to account for all of the observed H2O2 in the deep ocean.

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.

Characteristics of PAN (Peroxyacetyl Nitrate) in Outflow Plumes Over the Yellow Sea During KORUS-AQ Campaign

NASA Astrophysics Data System (ADS)

Seo, J.; Inae, K.; Lee, M.; Shin, B.; Ryoo, S.; Jung, J.; Kim, S. W.

2017-12-01

Peroxyacetyl nitrate (PAN) is a secondary atmospheric pollutant which is generated by photochemical reaction of VOCs (Volatile Organic Compounds) and NOx (NO+NO2). While PAN has been known as an indicator of photochemical smog in urban areas, it serves as a robust tracer for long-range transport in remote regions. Research vessel Gisang 1 explored the Yellow Sea during May and June 2016, measuring reactive gases including PAN, O3, and NOx. The research area covers the region between 31° 38°N and 124° 127°E. PAN was measured using GC-LCD (Gas Chromatography Luminol Chemiluminescence Detection) every 2 minutes. The average mixing ratio of PAN was the highest (1.1 ppbv) in the second shift (May 17-30) and lower in the first (0.92 ppbv) and third (0.48 ppbv) shift. The PAN concentrations higher than the 95th percentile (2.19 ppbv) were observed on May 21 and 22 in air mass passing through Seoul Metropolitan Areas. In contrast, on May 4 and 29, both PAN and O3 were high under influence of Chinese outflows. On May 6 when dust storm passed through the Yellow Sea, both PAN and O3 concentrations were at their minimum levels. It is noteworthy that PAN concentration was higher with low O3 level near the west coast of Korean peninsula, which was likely to be the influence of ship emissions.

Superoxide and peroxynitrite generation from inducible nitric oxide synthase in macrophages

PubMed Central

Xia, Yong; Zweier, Jay L.

1997-01-01

Superoxide (O2⨪) and nitric oxide (NO) act to kill invading microbes in phagocytes. In macrophages NO is synthesized by inducible nitric oxide synthase (iNOS, NOS 2) from l-arginine (l-Arg) and oxygen; however, O2⨪ was thought to be produced mainly by NADPH oxidase. Electron paramagnetic resonance (EPR) spin trapping experiments performed in murine macrophages demonstrate a novel pathway of O2⨪ generation. It was observed that depletion of cytosolic l-Arg triggers O2⨪ generation from iNOS. This iNOS-mediated O2⨪ generation was blocked by the NOS inhibitor N-nitro-l-arginine methyl ester or by l-Arg, but not by the noninhibitory enantiomer N-nitro-d-arginine methyl ester. In l-Arg-depleted macrophages iNOS generates both O2⨪ and NO that interact to form the potent oxidant peroxynitrite (ONOO−), which was detected by luminol luminescence and whose formation was blocked by superoxide dismutase, urate, or l-Arg. This iNOS-derived ONOO− resulted in nitrotyrosine formation, and this was inhibited by iNOS blockade. iNOS-mediated O2⨪ and ONOO− increased the antibacterial activity of macrophages. Thus, with reduced l-Arg availability iNOS produces O2⨪ and ONOO− that modulate macrophage function. Due to the existence of l-Arg depletion in inflammation, iNOS-mediated O2⨪ and ONOO− may occur and contribute to cytostatic/cytotoxic actions of macrophages. PMID:9192673

Bifunctional fusion proteins containing the sequence of the bradykinin homologue maximakinin: activities at the rat bradykinin B2 receptor.

PubMed

Charest-Morin, Xavier; Lodge, Robert; Marceau, François

2018-05-01

To support bradykinin (BK) B 2 receptor (B 2 R) detection and therapeutic stimulation, we developed and characterized fusion proteins consisting of the BK homolog maximakinin (MK), or variants, positioned at the C-terminus of functional proteins (enhanced green fluorescent protein (EGFP), the peroxidase APEX2, or human serum albumin (HSA)). EGFP-MK loses its reactivity with anti-BK antibodies and molecular mass as it progresses in the endosomal tract of cells expressing rat B 2 Rs (immunoblots, epifluorescence microscopy). APEX2-(NG) 15 -MK is a bona fide agonist of the rat, but not of the human B 2 R (calcium and c-Fos signaling) and is compatible with the cytochemistry reagent TrueBlue (microscopy), a luminol-based reagent, or 3,3',5,5'-tetramethylbenzidine (luminescence or colourimetric B 2 R detection, cell well plate format). APEX2-(NG) 15 -MK is a non-isotopic ligand suitable for drug discovery via binding competition. Affinity-purified secreted forms of HSA fused with peptides possessing the C-terminal MK or BK sequence failed to stimulate the rat B 2 R in the concentration range of 50-600 nmol/L. However, the non-secreted construction myc-HSA-MK is a B 2 R agonist, indicating that protein denaturation made the C-terminal sequence available for receptor binding. Fusion protein ligands of the B 2 R are stable but subjected to slow intracellular inactivation, strong species specificity, and possible steric hindrance between the receptor and large proteins.

The effect of dissolve gas concentration in the initial growth stage of multi cavitation bubbles. Differences between vacuum degassing and ultrasound degassing.

PubMed

Yanagida, Hirotaka

2008-04-01

The sonochemical luminescence intensity from luminol was measured at a sampling rate of several kilohertz. This was noted at three different periods: first, the latent period in which no light emission occurs at all; second, the increased emission period from the start of light emission to the time when a steady state is reached; and third, the steady state period in which light emission occurs at the steady state value. When irradiated with ultrasound of different intensities, the times of the latent period and increased emission period are shorter for higher ultrasound intensities. To know how the dissolved oxygen content is involved in early-stage cavitation growth, an experiment was conducted using solutions with varying dissolved oxygen contents from 100% to 37%. For dissolved air content of 50% or less, it was found that the latent period was 30 times longer in a saturated condition. It was also found that the increased emission period was 10 times longer. However, the emission intensity in the steady state did not change at all even when the initial dissolved gas concentration of the sample was changed. From this, it was found that the reuse of collapsed bubbles takes place efficiently in the steady state. Dissolved oxygen was reduced by the use of a vacuum pump and by the degassing action of ultrasound, and it was discovered that the behavior of transient emission differed for the two ways of degassing.

Hydrogen peroxide in deep waters from the Mediterranean Sea, South Atlantic and South Pacific Oceans

PubMed Central

Hopwood, Mark J.; Rapp, Insa; Schlosser, Christian; Achterberg, Eric P.

2017-01-01

Hydrogen peroxide (H2O2) is present ubiquitously in marine surface waters where it is a reactive intermediate in the cycling of many trace elements. Photochemical processes are considered the dominant natural H2O2 source, yet cannot explain nanomolar H2O2 concentrations below the photic zone. Here, we determined the concentration of H2O2 in full depth profiles across three ocean basins (Mediterranean Sea, South Atlantic and South Pacific Oceans). To determine the accuracy of H2O2 measurements in the deep ocean we also re-assessed the contribution of interfering species to ‘apparent H2O2’, as analysed by the luminol based chemiluminescence technique. Within the vicinity of coastal oxygen minimum zones, accurate measurement of H2O2 was not possible due to interference from Fe(II). Offshore, in deep (>1000 m) waters H2O2 concentrations ranged from 0.25 ± 0.27 nM (Mediterranean, Balearics-Algeria) to 2.9 ± 2.2 nM (Mediterranean, Corsica-France). Our results indicate that a dark, pelagic H2O2 production mechanism must occur throughout the deep ocean. A bacterial source of H2O2 is the most likely origin and we show that this source is likely sufficient to account for all of the observed H2O2 in the deep ocean. PMID:28266529

Effects of Phytochemically Characterized Extracts From Syringa vulgaris and Isolated Secoiridoids on Mediators of Inflammation in a Human Neutrophil Model.

PubMed

Woźniak, Marta; Michalak, Barbara; Wyszomierska, Joanna; Dudek, Marta K; Kiss, Anna K

2018-01-01

Aim of the study: The aim of the present study was to investigate the effects of phytochemically characterized extracts connected with the traditional use (infusions and ethanolic extracts) of different parts of Syringa vulgaris (common lilac) on the pro-inflammatory functions of neutrophils. Active compounds were isolated from the most promising extract(s) using bioassay-guided fractionation, and their activity and molecular mechanisms of action were determined. Methods: The extracts were characterized using a HPLC-DAD- MS n method. The effects on ROS, MMP-9, TNF-α, IL-8, and MCP-1 production by neutrophils were measured using luminol-dependent chemiluminescence and enzyme-linked immunosorbent assay (ELISA) methods. The effects on p38MAPK, ERK1/2, JNK phosphorylation, and NF- k B p65 translocation were determined using western blots. Results: The major compounds detected in the extracts and infusions belong to structural groups, including caffeic acid derivatives, flavonoids, and iridoids. All extracts and infusions were able to significantly reduce ROS and IL-8 production. Bioassay-guided fractionation led to the isolation of the following secoiridoids: 2″-epiframeroside, oleonuezhenide, oleuropein, ligstroside, neooleuropein, hydroxyframoside, and framoside. Neooleuropein appeared to be the most active compound in the inhibition of cytokine production by attenuating the MAP kinase pathways. Conclusion: The present study demonstrated that common lilac, which is a traditionally used medicinal plant in Europe, is a valuable source of active compounds, especially neooleuropein.

LC-DAD-MS (ESI+) analysis and antioxidant capacity of crocus sativus petal extracts.

PubMed

Termentzi, Aikaterini; Kokkalou, Eugene

2008-04-01

In this study, various fractions isolated from the petals of Crocus sativus were assessed at first for their phenolic content both qualitatively and quantitatively and secondly for their antioxidant activity. The phytochemical analysis was carried out by LC-DAD-MS (ESI (+)) whereas the antioxidant potential was evaluated by applying two methodologies, the DPPH. radical scavenging activity test and the Co(II)-induced luminol chemiluminescence procedure. According to data obtained from these antioxidant tests, the diethyl ether, ethyl acetate and aqueous fractions demonstrated the strongest antioxidant capacity. Interestingly, the major constituents identified in these fractions correspond to kaempferol, quercetin, naringenin and some flavanone and flavanol derivatives glycosylated and esterified with phenylpropanoic acids. In addition, the presence of some nitrogen-containing substances, as well as other phenolics and phenylpropanoic derivatives was also traced. The identification and structural elucidation of all substances isolated in this study was achieved by both comparing available literature data and by proposed fragmentation mechanisms based on evaluating the LC-DAD-MS (ESI (+)) experimental data. The quantitative analysis data obtained thus far have shown that Crocus sativus petals are a rich source of flavonoids. Such a fact suggests that the good antioxidant capacity detected in the various fractions of Crocus sativus petals could be attributed to the presence of flavonoids, since it is already known that these molecules exert antioxidant capability. The latter, along with the use of Crocus sativus in food and pharmaceutical industry is discussed.

Rapid method for monitoring N-nitrosodimethylamine in drinking water at the ng/L level without pre-concentration using high-performance liquid chromatography-chemiluminescence detection.

PubMed

Kodamatani, Hitoshi; Yamasaki, Hitomi; Sakaguchi, Takeru; Itoh, Shinya; Iwaya, Yoshimi; Saga, Makoto; Saito, Keiitsu; Kanzaki, Ryo; Tomiyasu, Takashi

2016-08-19

As a contaminant in drinking water, N-nitrosodimethylamine (NDMA) is of great concern because of its carcinogenicity; it has been limited to levels of ng/L by regulatory bodies worldwide. Consequently, a rapid and sensitive method for monitoring NDMA in drinking water is urgently required. In this study, we report an improvement of our previously proposed HPLC-based system for NDMA determination. The approach consists of the HPLC separation of NDMA, followed by NDMA photolysis to form peroxynitrite and detection with a luminol chemiluminescence reaction. The detection limit for the improved HPLC method was 0.2ng/L, which is 10 times more sensitive than our previously reported system. For tap water measurements, only the addition of an ascorbic acid solution to eliminate residual chlorine and passage through an Oasis MAX solid-phase extraction cartridge are needed. The proposed NDMA determination method requires a sample volume of less than 2mL and a complete analysis time of less than 15min per sample. The method was utilized for the long-term monitoring of NDMA in tap water. The NDMA level measured in the municipal water survey was 4.9ng/L, and a seasonal change of the NDMA concentration in tap water was confirmed. The proposed method should constitute a useful NDMA monitoring method for protecting drinking water quality. Copyright © 2016 Elsevier B.V. All rights reserved.

Direct-injection chemiluminescence detector. Properties and potential applications in flow analysis.

PubMed

Koronkiewicz, Stanislawa; Kalinowski, Slawomir

2015-02-01

We present a novel chemiluminescence detector, with a cone-shaped detection chamber where the analytical reaction takes place. The sample and appropriate reagents are injected directly into the chamber in countercurrent using solenoid-operated pulse micro-pumps. The proposed detector allows for fast measurement of the chemiluminescence signal in stop-flow conditions from the moment of reagents mixing. To evaluate potential applications of the detector the Fenton-like reaction with a luminol-H2O2 system and several transition metal ions (Co(2+), Cu(2+), Cr(3+), Fe(3+)) as a catalyst were investigated. The results demonstrate suitability of the proposed detector for quantitative analysis and for investigations of reaction kinetics, particularly rapid reactions. A multi-pumping flow system was designed and optimized. The developed methodology demonstrated that the shape of the analytical signals strongly depends on the type and concentration of the metal ions. The application of the detector in quantitative analysis was assessed for determination of Fe(III). The direct-injection chemiluminescence detector allows for a sensitive and repeatable (R.S.D. 2%) determination. The intensity of chemiluminescence increased linearly in the range from about 0.5 to 10 mg L(-1) Fe(III) with the detection limit of 0.025 mg L(-1). The time of analysis depended mainly on reaction kinetics. It is possible to achieve the high sampling rate of 144 samples per hour. Copyright © 2014 Elsevier B.V. All rights reserved.

Beneficial Effects of Trillium govanianum Rhizomes in Pain and Inflammation.

PubMed

Ur Rahman, Shafiq; Adhikari, Achyut; Ismail, Muhammad; Raza Shah, Muhammad; Khurram, Muhammad; Shahid, Muhammad; Ali, Farman; Haseeb, Abdul; Akbar, Fazal; Iriti, Marcello

2016-08-20

Trillium govanianum rhizome is used as an analgesic and anti-inflammatory remedy in traditional medicine in northern Pakistan. In an attempt to establish its medicinal value, the present research evaluated the analgesic and anti-inflammatory potential of T. govanianum. The in vivo anti-inflammatory activity of extract and fractions was investigated in the carrageenan induced paw edema assay. The in vitro suppression of oxidative burst of extract, fractions and isolated compounds was assessed through luminol-enhanced chemiluminescence assay. The in vivo analgesic activity was assayed in chemical and thermal induced nociceptive pain models. The crude methanol extract and its solvent fractions showed anti-inflammatory and analgesic responses, exhibited by significant amelioration of paw edema and relieve of the tonic visceral chemical and acute phasic thermal nociception. In the oxidative burst assay, based on IC50, the crude methanol extract and n-butanol soluble fraction produced a significant inhibition, followed by chloroform and hexane soluble fractions as compared to ibuprofen. Similarly, the isolated compounds pennogenin and borassoside E exhibited significant level of oxidative burst suppressive activity. The in vivo anti-inflammatory and analgesic activities as well as the in vitro inhibition of oxidative burst validated the traditional use of T. govanianum rhizomes as a phytotherapeutic remedy for both inflammatory conditions and pain. The observed activities might be attributed to the presence of steroids and steroid-based compounds. Therefore, the rhizomes of this plant species could serve as potential novel source of compounds effective for alleviating pain and inflammation.

Simple and rapid chemiluminescence aptasensor for Hg2+ in contaminated samples: A new signal amplification mechanism.

PubMed

Qi, Yingying; Xiu, Fu-Rong; Yu, Gending; Huang, Lili; Li, Baoxin

2017-01-15

Detection of ultralow concentration of heavy metal ion Hg 2+ is important for human health protection and environment monitoring because of the gradual accumulation in environmental and biological fields. Herein, we report a convenient chemiluminescence (CL) biosensing platform for ultrasensitive Hg 2+ detection by signal amplification mechanism from positively charged gold nanoparticles ((+)AuNPs). It is based on (+)AuNPs charge effect and aptamer conformation change induced by target to stimulate the generation of CL in the presence of H 2 O 2 and luminol without high salt medium. Notably particularly, the typical problem of the high salt medium from (-) AuNPs system, like influencing aptamers' bind with target and hindering CL reaction can be effectively addressed through the direct introduction of (+)AuNPs. Therefore, the proposed biosensing exhibits a high sensitivity toward target Hg 2+ with a detection limit of 16 pM, which is far below the limit (10nM) defined by the U.S. Environmental Protection Agency in drinkable water, and is about 10-fold lower than the previously reported aptamer-based assays for Hg 2+ . This sensing platform provides a simple, rapid, and cost-effective approach for label-free sensitive detection of Hg 2+ . Moreover, it is universal for the detection of other targets. Undoubtedly, such a direct utilizing of (+)AuNPs' charge effect will provide a new signal amplification way for label-free aptamer-based CL analysis. Copyright © 2016 Elsevier B.V. All rights reserved.

Correlation Between Metabolic Syndrome, Periodontitis and Reactive Oxygen Species Production. A Pilot Study.

PubMed

Patini, Romeo; Gallenzi, Patrizia; Spagnuolo, Gianrico; Cordaro, Massimo; Cantiani, Monica; Amalfitano, Adriana; Arcovito, Alessandro; Callà, Cinzia; Mingrone, Gertrude; Nocca, Giuseppina

2017-01-01

Metabolic syndrome (MetS) is associated with an increased risk of periodontitis even if the mechanism is unknown. Since both MetS and periodontitis are characterized by an alteration of inflammation status, the aim of this pilot study was to determine if differences in ROS metabolism of phagocytes isolated from (A) patients with MetS, (B) patients with both MetS and mild periodontitis, (C) healthy subjects and (D) normal weight subjects with mild periodontitis, were present. ROS metabolism was studied by a Chemiluminescence (CL) technique: the system was made up of luminol (100 nmol/L) and cells (1 × 10 5 ) in the presence or absence of stimulus constituted by opsonized zymosan (0.5 mg). The final volume (1.0 mL) was obtained using modified KRP buffer. ROS production was measured at 25°C for 2 h, using an LB 953 luminometer (Berthold, EG & G Co, Germany). All the experiments were performed in triplicate. All results are mean ± standard deviation (SD). The group of means was compared by the analysis of variance "(ANOVA)". A value of p < 0.05 was considered significant. Results showed that basal ROS production (both from PMNs and from PBMs) of groups A, B and D was increased with respect to that obtained from group C ( p <0.05). These results are congruent with literature data, although the actual clinical relevance of the phenomenon remains to be evaluated.

A method of determining the presence of blood in and on a dental needle after the administration of local anesthetic.

PubMed

Kotze, Marthinus J; Labuschagne, Willemien

2014-06-01

In the study reported in this article, the authors aimed to demonstrate the presence of blood on the surface and in the lumen of two gauges of dental needles after administration of local anesthetic (LA) by using three LA-administering techniques normally used for the extraction of teeth. The authors obtained standardized photographs of 200 urine dipsticks after moistening the dipstick's chemical pads for blood with the first drop of liquid discharged from the needle lumen after LA administration. Using the histogram function of a software program, the authors analyzed differences in gray-scale values of the different blood parameters for the presence of blood. They used luminol spray to expose small quantities of blood on the surface of the needle after LA administration. Blood was identified at 39 percent in the lumen and at 16 percent on the surface of the needles when analyzed after LA administration. With the method used, it was possible to demonstrate and quantify the percentage of blood present in the lumen of needles (39 percent) after the administration of dental LA. Furthermore, the technique was adequately sensitive for demonstrating the quantity of blood in two needles of different diameters. By demonstrating the presence, as well as quantifying the percentage, of blood on two dental needles of different gauges after the administration of LA, dental health care workers can be motivated to report needlestick injuries and to follow the approved protocols recommended by their institutions.

Correlation Between Metabolic Syndrome, Periodontitis and Reactive Oxygen Species Production. A Pilot Study

PubMed Central

Patini, Romeo; Gallenzi, Patrizia; Spagnuolo, Gianrico; Cordaro, Massimo; Cantiani, Monica; Amalfitano, Adriana; Arcovito, Alessandro; Callà, Cinzia; Mingrone, Gertrude; Nocca, Giuseppina

2017-01-01

Background and Objective: Metabolic syndrome (MetS) is associated with an increased risk of periodontitis even if the mechanism is unknown. Since both MetS and periodontitis are characterized by an alteration of inflammation status, the aim of this pilot study was to determine if differences in ROS metabolism of phagocytes isolated from (A) patients with MetS, (B) patients with both MetS and mild periodontitis, (C) healthy subjects and (D) normal weight subjects with mild periodontitis, were present. Methods: ROS metabolism was studied by a Chemiluminescence (CL) technique: the system was made up of luminol (100 nmol/L) and cells (1 × 105) in the presence or absence of stimulus constituted by opsonized zymosan (0.5 mg). The final volume (1.0 mL) was obtained using modified KRP buffer. ROS production was measured at 25°C for 2 h, using an LB 953 luminometer (Berthold, EG & G Co, Germany). All the experiments were performed in triplicate. Statistical Analysis: All results are mean ± standard deviation (SD). The group of means was compared by the analysis of variance "(ANOVA)". A value of p < 0.05 was considered significant. Results: Results showed that basal ROS production (both from PMNs and from PBMs) of groups A, B and D was increased with respect to that obtained from group C (p <0.05). Conclusion: These results are congruent with literature data, although the actual clinical relevance of the phenomenon remains to be evaluated. PMID:29290840

Antioxidant and antiradical properties of esculin, and its effect in a model of epirubicin-induced bone marrow toxicity.

PubMed

Biljali, Sefedin; Hadjimitova, Vera A; Topashka-Ancheva, Margarita N; Momekova, Denitsa B; Traykov, Trayko T; Karaivanova, Margarita H

2012-01-01

To evaluate the effect of esculin, a plant coumarin glucoside, on free radicals and against epirubicin-induced toxicity on bone marrow cells. Antioxidant activity was assessed by a luminol-dependent chemiluminescence method or NBT test in a xanthine-xanthine oxidase system, and two iron-dependent lipid peroxidation systems. In vivo experiments were carried out in epirubicin-treated mice, alone or in a combination with esculin. Genotoxicity of the anthracycline drug was assessed by cytogenetic analysis and an autoradiographic assay. Esculin inactivated superoxide anion radicals in both systems we used. It exerted SOD-mimetic effect and reduced the level of superoxide radicals generated in a xanthine-xanthine oxidase system by 30%. Esculin also showed an antioxidant effect in a model of Fe2+-induced lipid peroxidation. Cytogenetic analysis showed that epirubicin had a marked influence on the structure of metaphase chromosomes of normal bone marrow cells. Inclusion of esculin in the treatment protocol failed to ameliorate the epirubicin-induced antiproliferative effects and genotoxicity in bone marrow cells. In this study the ability of the coumarin glucoside esculin to scavenge superoxide radicals and to decrease Fe-induced lipid peroxidation was documented. However, despite the registered antioxidant effects the tested compound failed to exert cytoprotection in models of anthracycline-induced genotoxicity in bone marrow cells. The results of this study warrant for more precise further evaluation of esculin, employing different test systems and end-points and a wider range of doses to more precisely appraise its potential role as a chemoprotective/resque agent.

Flow injection analysis of organic peroxide explosives using acid degradation and chemiluminescent detection of released hydrogen peroxide.

PubMed

Mahbub, Parvez; Zakaria, Philip; Guijt, Rosanne; Macka, Mirek; Dicinoski, Greg; Breadmore, Michael; Nesterenko, Pavel N

2015-10-01

The applicability of acid degradation of organic peroxides into hydrogen peroxide in a pneumatically driven flow injection system with chemiluminescence reaction with luminol and Cu(2+) as a catalyst (FIA-CL) was investigated for the fast and sensitive detection of organic peroxide explosives (OPEs). The target OPEs included hexamethylene triperoxide diamine (HMTD), triacetone triperoxide (TATP) and methylethyl ketone peroxide (MEKP). Under optimised conditions maximum degradations of 70% and 54% for TATP and HMTD, respectively were achieved at 162 µL min(-1), and 9% degradation for MEKP at 180 µL min(-1). Flow rates were precisely controlled in this single source pneumatic pressure driven multi-channel FIA system by model experiments on mixing of easily detectable component solutions. The linear range for detection of TATP, HMTD and H2O2 was 1-200 µM (r(2)=0.98-0.99) at both flow rates, while that for MEKP was 20-200 µM (r(2)=0.97) at 180 µL min(-1). The detection limits (LODs) obtained were 0.5 µM for TATP, HMTD and H2O2 and 10 µM for MEKP. The detection times varied from 1.5 to 3 min in this FIA-CL system. Whilst the LOD for H2O2 was comparable with those reported by other investigators, the LODs and analysis times for TATP and HMTD were superior, and significantly, this is the first time the detection of MEKP has been reported by FIA-CL. Copyright © 2015 Elsevier B.V. All rights reserved.

Decoupling peroxyacetyl nitrate from ozone in Chinese outflows observed at Gosan Climate Observatory

NASA Astrophysics Data System (ADS)

Han, Jihyun; Lee, Meehye; Shang, Xiaona; Lee, Gangwoong; Emmons, Louisa K.

2017-09-01

We measured peroxyacetyl nitrate (PAN) and other reactive species such as O3, NO2, CO, and SO2 with aerosols including mass, organic carbon (OC), and elemental carbon (EC) in PM2. 5 and K+ in PM1. 0 at Gosan Climate Observatory in Korea (33.17° N, 126.10° E) during 19 October-6 November 2010. PAN was determined through fast gas chromatography with luminol chemiluminescence detection at 425 nm every 2 min. The PAN mixing ratios ranged from 0.1 (detection limit) to 2.4 ppbv with a mean of 0.6 ppbv. For all measurements, PAN was unusually better correlated with PM2. 5 (Pearson correlation coefficient, γ = 0.79) than with O3 (γ = 0.67). In particular, the O3 level was highly elevated with SO2 at midnight, along with a typical midday peak when air was transported rapidly from the Beijing areas. The PAN enhancement was most noticeable during the occurrence of haze under stagnant conditions. In Chinese outflows slowly transported over the Yellow Sea, PAN gradually increased up to 2.4 ppbv at night, in excellent correlation with a concentration increase in PM2. 5 OC and EC, PM2. 5 mass, and PM1. 0 K+. The high K+ concentration and OC / EC ratio indicated that the air mass was impacted by biomass combustion. This study highlights PAN decoupling with O3 in Chinese outflows and suggests PAN as a useful indicator for diagnosing continental outflows and assessing their perturbation of regional air quality in northeast Asia.

PAN and O3 enhancement at Taehwa Research Forest in Korea

NASA Astrophysics Data System (ADS)

Gil, J.; Lee, M.; Rhee, H.; Lee, Y.; Park, H.; Kim, S.

2017-12-01

PAN (Peroxyacetyl Nitrate) is one of the most important secondary pollutant produced by the reaction of NOx (= NO + NO2) and oxygenated VOCs (Volatile Organic Compounds). It is considered more reliable indicator of photochemical pollution than O3 in urban area. To observe the evolution of biogenic emission being mixed with urban pollutants, measurement was conducted at TRF (Taehwa Research Forest) near SMA (Seoul Metropolitan Area) in Korea during 2012, and 2013. PAN with reactive gases (O3, NOx, CO, SO2) were measured at six heights (4.1, 9.5, 15, 20, 31, 39 m) of a 41m tower along with BVOCs (Biogenic Volatile Organic Compounds). PAN was measured using a fast GC-LCD (Gas Chromatography with Luminol-based Chemiluminescence Detection). For PAN and O3, the 5%ile, 50%ile, and 95%ile were 0.12 ppbv, 0.46 ppbv, and 2.09 ppbv, and 18.4 ppbv, 44.7 ppbv, and 66.6 ppbv respectively. PAN was visibly higher during warm seasons (0.69 ppbv) than cold seasons (0.35 ppbv) and their monthly mean concentrations were the highest in June. The PAN maxima (7.78 ppbv) was observed in August 2013 with the elevation of O3 and NOx. It is noteworthy that there were enhancement of PAN and O3 around 6 PM, along with isoprene emission and a sudden increase of NO2 near the time for enhancement. A F0AM (Framework for 0-D Atmospheric Modeling) was used to identify the contribution of BVOCs and NOx to PAN and O3 enhancement.

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.

The exploitation of inflammation in photodynamic therapy of pleural cancer (Conference Presentation)

NASA Astrophysics Data System (ADS)

Davis, Richard W.; Miller, Joann; Houser, Cassandra L.; Klampatsa, Astero; Jenkins, Tim; Cengel, Keith A.; Albelda, Steven M.; Busch, Theresa M.

2017-02-01

The onset of inflammation is a well-known physiology in tumors treated with photodynamic therapy (PDT). After PDT, the release of danger signals causes an influx of neutrophils, activation of dendritic cells, and an eventual initiation of the adaptive immune response. However, inflammation also lies at a crucial fulcrum for treatment outcome, as it can stimulate the expression of resistance factors. Therefore, effective treatment with PDT requires an understanding of the holistic contribution of inflammation. Within, we outline two means of studying tumor inflammation in the setting of PDT. Experiments are conducted in murine models of mesothelioma, including those that incorporate surgery prior to PDT or pleural propagation of the disease. First, we use a chemiluminescent agent, luminol, to detect the influx of neutrophils by in vivo molecular imaging. This longitudinal approach allows for the repeated non-invasive monitoring of PDT-induced neutrophil influx. Data clearly identify protocol-specific differences in tumor-associated neutrophil activity. Second, we describe the application of cone-beam CT to detect the fibrosis associated with murine orthotropic mesothelioma models. This approach incorporates novel methods in image segmentation to accurately identify diffuse disease in the thoracic cavity. These studies lay the foundation for future research to correlate long-term response with local PDT-induced inflammation. Such methods in monitoring of inflammation or tumor burden will enable characterization of the consequences of combinatorial therapy (e.g., intraoperative PDT). Resulting data will guide the selection of pharmacological agents or molecular imaging techniques that respectively exploit inflammation for therapeutic or monitoring purposes.

Decreased activity of neutrophils in the presence of diferuloylmethane (curcumin) involves protein kinase C inhibition.

PubMed

Jancinová, Viera; Perecko, Tomás; Nosál, Radomír; Kostálová, Daniela; Bauerová, Katarína; Drábiková, Katarína

2009-06-10

Diferuloylmethane (curcumin) has been shown to act beneficially in arthritis, particularly through downregulated expression of proinflammatory cytokines and collagenase as well as through the modulated activities of T lymphocytes and macrophages. In this study its impact on activated neutrophils was investigated both in vitro and in experimental arthritis. Formation of reactive oxygen species in neutrophils was recorded on the basis of luminol- or isoluminol-enhanced chemiluminescence. Phosphorylation of neutrophil protein kinases C alpha and beta II was assessed by Western blotting, using phosphospecific antibodies. Adjuvant arthritis was induced in Lewis rats by heat-killed Mycobacterium butyricum. Diferuloylmethane or methotrexate was administered over a period of 28 days after arthritis induction. Under in vitro conditions, diferuloylmethane (1-100 microM) reduced dose-dependently oxidant formation both at extra- and intracellular level and it effectively reduced protein kinase C activation. Adjuvant arthritis was accompanied by an increased number of neutrophils in blood and by a more pronounced spontaneous as well as PMA (phorbol myristate acetate) stimulated chemiluminescence. Whereas the arthritis-related alterations in neutrophil count and in spontaneous chemiluminescence were not modified by diferuloylmethane, the increased reactivity of neutrophils to PMA was less evident in diferuloylmethane-treated animals. The effects of diferuloylmethane were comparable with those of methotrexate. Diferuloylmethane was found to be a potent inhibitor of neutrophil functions both in vitro and in experimental arthritis. As neutrophils are considered to be cells with the greatest capacity to inflict damage within diseased joints, the observed effects could represent a further mechanism involved in the antirheumatic activity of diferuloylmethane.

Sonochemiluminescence of lucigenin: Evidence of superoxide radical anion formation by ultrasonic irradiation

NASA Astrophysics Data System (ADS)

Matsuoka, Masanori; Takahashi, Fumiki; Asakura, Yoshiyuki; Jin, Jiye

2016-07-01

The sonochemiluminescence (SCL) behavior of lucigenin (Luc2+) has been studied in aqueous solutions irradiated with 500 kHz ultrasound. Compared with the SCL of a luminol system, a tremendously increased SCL intensity is observed from 50 µM Luc2+ aqueous solution (pH =11) when small amounts of coreactants such as 2-propanol coexist. It is shown that SCL intensity strongly depends on the presence of dissolved gases such as air, O2, N2, and Ar. The highest SCL intensity is obtained in an O2-saturated solution, indicating that molecular oxygen is required to generate SCL. Since SCL intensity is quenched completely in the presence of superoxide dismutase (SOD), an enzyme that can catalyze the disproportionation of O2 •-, the generation of O2 •- in the ultrasonic reaction field is important in the SCL of Luc2+. In this work, the evidence of O2 •- production is examined by a spectrofluorometric method using 2-(2-pyridyl)benzothiazoline as the fluorescent probe. The results indicate that the yield of O2 •- is markedly increased in the O2-saturated solutions when a small amount of 2-propanol coexists, which is consistent with the results of SCL measurements. 2-Propanol in the interfacial region of a cavitation bubble reacts with a hydroxyl radical (•OH) to form a 2-propanol radical, CH3C•(OH)CH3, which can subsequently react with dissolved oxygen to generate O2 •-. The most likely pathways for SCL as well as the spatial distribution of SCL in a microreactor are discussed in this study.

Expression of IL-17A concentration and effector functions of peripheral blood neutrophils in food allergy hypersensitivity patients.

PubMed

Żbikowska-Gotz, Magdalena; Pałgan, Krzysztof; Gawrońska-Ukleja, Ewa; Kuźmiński, Andrzej; Przybyszewski, Michał; Socha, Ewa; Bartuzi, Zbigniew

2016-03-01

Lymphocytes Th17 and other types of immune system cells produce IL17. By induction of cytokines and chemokines, the IL17 cytokine is involved in mechanisms of allergic reaction with participation of neutrophil granulocytes. It affects activation, recruitment, and migration of neutrophils to the tissues, regulating inflammatory reaction intensity. Excited neutrophils secrete inter alia elastase and reactive oxygen species (ROS)--significant mediators of inflammation process responsible for tissues damage.The aim of the study was to evaluate the concentrations of serum interleukin 17A, serum neutrophil elastase, and ROS production by neutrophils in patients with food allergy.The study included 30 patients with food allergy diagnosed based on interview, clinical symptoms, positive SPT, placebo controlled double-blind oral provocation trial, and the presence of asIgE in blood serum against selected food allergens using fluoro-immuno-enzymatic method FEIA UNICap 100. The control group consisted of 10 healthy volunteers. The concentrations of IL17A were determined in all patients using ELISA method with eBioscience kits, and elastase using BenderMed Systems kits. Chemiluminescence of non-stimulated neutrophils was evaluated using luminol-dependent kinetic method for 40 min on Luminoskan (Labsystems luminometer).The results of serum IL-17A concentrations and the values of chemiluminescence obtained by non-activated neutrophils, as well as elastase concentrations, were higher in patients with food allergic hypersensitivity compared to healthy volunteers.This study demonstrates a significance of IL-17A and activated neutrophil granulocytes in the course of diseases with food allergic hypersensitivity. © The Author(s) 2015.

In Situ Generation and Consumption of H2O2 by Bienzyme-Quantum Dots Bioconjugates for Improved Chemiluminescence Resonance Energy Transfer.

PubMed

Xu, Shuxia; Li, Xianming; Li, Chaobi; Li, Jialin; Zhang, Xinfeng; Wu, Peng; Hou, Xiandeng

2016-06-21

Exploration of quantum dots (QDs) as energy acceptors revolutionizes the current chemiluminescence resonance energy transfer (CRET), since QDs possess large Stokes shifts and high luminescence efficiency. However, the strong and high concentration of oxidant (typically H2O2) needed for luminol chemiluminescence (CL) reaction could cause oxidative quenching to QDs, thereby decreasing the CRET performance. Here we proposed the use of bienzyme-QDs bioconjugate as the energy acceptor for improved CRET sensing. Two enzymes, one for H2O2 generation (oxidase) and another for H2O2 consumption (horseradish peroxidase, HRP), were bioconjugated onto the surface of QDs. The bienzyme allowed fast in situ cascaded H2O2 generation and consumption, thus alleviating fluorescence quenching of QDs. The nanosized QDs accommodate the two enzymes in a nanometric range, and the CL reaction was confined on the surface of QDs accordingly, thereby amplifying the CL reaction rate and improving CRET efficiency. As a result, CRET efficiency of 30-38% was obtained; the highest CRET efficiency by far was obtained using QDs as the energy acceptor. The proposed CRET system could be explored for ultrasensitive sensing of various oxidase substrates (here exemplified with cholesterol, glucose, and benzylamine), allowing for quantitative measurement of a spectrum of metabolites with high sensitivity and specificity. Limits of detection (LOD, 3σ) for cholesterol, glucose, and benzylamine were found to be 0.8, 3.4, and 10 nM, respectively. Furthermore, multiparametric blood analysis (glucose and cholesterol) is demonstrated.

Dual switchable CRET-induced luminescence of CdSe/ZnS quantum dots (QDs) by the hemin/G-quadruplex-bridged aggregation and deaggregation of two-sized QDs.

PubMed

Hu, Lianzhe; Liu, Xiaoqing; Cecconello, Alessandro; Willner, Itamar

2014-10-08

The hemin/G-quadruplex-catalyzed generation of chemiluminescence through the oxidation of luminol by H2O2 stimulates the chemiluminescence resonance energy transfer (CRET) to CdSe/ZnS quantum dots (QDs), resulting in the luminescence of the QDs. By the cyclic K(+)-ion-induced formation of the hemin/G-quadruplex linked to the QDs, and the separation of the G-quadruplex in the presence of 18-crown-6-ether, the ON-OFF switchable CRET-induced luminescence of the QDs is demonstrated. QDs were modified with nucleic acids consisting of the G-quadruplex subunits sequences and of programmed domains that can be cross-linked through hybridization, using an auxiliary scaffold. In the presence of K(+)-ions, the QDs aggregate through the cooperative stabilization of K(+)-ion-stabilized G-quadruplex bridges and duplex domains between the auxiliary scaffold and the nucleic acids associated with the QDs. In the presence of 18-crown-6-ether, the K(+)-ions are eliminated from the G-quadruplex units, leading to the separation of the aggregated QDs. By the cyclic treatment of the QDs with K(+)-ions/18-crown-6-ether, the reversible aggregation/deaggregation of the QDs is demonstrated. The incorporation of hemin into the K(+)-ion-stabilized G-quadruplex leads to the ON-OFF switchable CRET-stimulated luminescence of the QDs. By the mixing of appropriately modified two-sized QDs, emitting at 540 and 610 nm, the dual ON-OFF activation of the luminescence of the QDs is demonstrated.

Grape seed extract reduces oxidative stress and fibrosis in experimental biliary obstruction.

PubMed

Dulundu, Ender; Ozel, Yahya; Topaloglu, Umit; Toklu, Hale; Ercan, Feriha; Gedik, Nursal; Sener, Goksel

2007-06-01

The aim of this study was to assess the protective effect of grape seed extract (GSE) against oxidative liver injury and fibrosis induced by biliary obstruction in rats. Wistar albino rats were divided into four groups; control (C), GSE-treated, bile duct ligated (BDL), and BDL and GSE-treated (BDL + GSE) groups. GSE was administered at a dose of 50 mg/kg a day orally for 28 days. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) levels were determined to assess liver function and tissue damage, respectively. Tumor necrosis factor-alpha (TNF-alpha) and antioxidant capacity (AOC) were assayed in plasma samples. Liver tissues were taken for determination of the hepatic malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase (MPO) activity and collagen content. Production of reactive oxidants was monitored by chemiluminescence (CL) assay. Serum AST, ALT, LDH and plasma TNF-alpha were elevated in the BDL group as compared to the control group and were significantly decreased with GSE treatment. Plasma AOC and hepatic GSH level, depressed by BDL, was elevated back to the control level in the GSE-treated BDL group. Increases in tissue MDA level, MPO activity and collagen content due to BDL were also attenuated by GSE treatment. Furthermore, luminol and lucigenin CL values in the BDL group increased dramatically compared to the control and were reduced by GSE treatment. These results suggest that GSE protects the liver from oxidative damage following bile duct ligation in rats. This effect possibly involves the inhibition of neutrophil infiltration and lipid peroxidation; thus, restoration of oxidant and antioxidant status in the tissue.

[Vasaprostan treatment of fibrosing alveolitis in patients with pulmonary hypertension].

PubMed

Popova, E N; Bolevich, S B; Litvitskiĭ, P F; Arkhipova, D V; Osipenko, V I; Kogan, E A; Kornev, B M; Mukhin, N A

2004-01-01

To study clinical efficacy of vasaprostan in patients with fibrosing alveolitis (FA) complicated by pulmonary hypertension (PH), its effect on functional activity of platelets and endothelium, intensity of free radical processes. Seven FA patients were examined. They had either idiopathic FA or FA with diffuse diseases of the connective tissues. The following methods were used to assess the effect: standard clinical tests, high resolution computer tomography, Doppler echocardiography, definition of the complex thrombin-antithrombin (TAT) and thrombocytic factor 4 (TF-4). Generation of oxygen active forms by leukocytes was measured by luminol-dependent chemiluminescence. Morphological verification of the diagnosis was made by the results of open pulmonary biopsies. Vasaprostan reduced pressure in the pulmonary artery from 31.6 +/- 2.31 to 19.58 +/- 3.90 mm Hg (p < 0.05) and coagulation parameters. TAT decreased after 2 and 8 weeks of treatment from 15.25 +/- 4.5 to 5.1 +/- 0.33 and 2.4 +/- 0.31 pg/ml (p < 0.05). Initially low TF-4 (2.11 +/- 0.39 pg/ml) elevated to the end of the treatment and reached values close to control (4.37 +/- 0.25 pg/ml, p < 0.05). Moreover, vasaprostan enhanced the ability of platelets to inhibit generation of active oxygen forms (from 0.9 +/- 0.18 to 1.23 +/- 0.16 r. u., p < 0.05) and thus depressed activity of lipid peroxidation. Good effect of vasaprostan on platelet activity, free radical processes validates its use in combined treatment of various FA forms for correction of PH, its complications and as an antifibrogenic agent.

Ergothioneine prevents endothelial dysfunction induced by mercury chloride.

PubMed

Gökçe, Göksel; Arun, Mehmet Zuhuri; Ertuna, Elif

2018-06-01

Exposure to mercury has detrimental effects on the cardiovascular system, particularly the vascular endothelium. The present study aimed to investigate the effects of ergothioneine (EGT) on endothelial dysfunction induced by low-dose mercury chloride (HgCl 2 ). Agonist-induced contractions and relaxations were evaluated in isolated aortic rings from 3-month-old male Wistar rats treated by intra-muscular injection to caudal hind leg muscle with HgCl 2 (first dose, 4.6 µg/kg; subsequent doses, 0.07 µg/kg/day for 15 days) and optionally with EGT (2 µg/kg for 30 days). Reactive oxygen species (ROS) in aortic rings were measured by means of lucigenin- and luminol-enhanced chemiluminescence. The protein level of endothelial nitric oxide synthase was evaluated by ELISA. Blood glutathione (GSH) and catalase levels, lipid peroxidation and total nitrite were measured spectrophotometrically. The results indicated that low-dose HgCl 2 administration impaired acetylcholine (ACh)-induced relaxation and potentiated phenylephrine- and serotonin-induced contractions in rat aortas. In addition, HgCl 2 significantly increased the levels of ROS in the aortic tissue. EGT prevented the loss of ACh-induced relaxations and the increase in contractile responses. These effects were accompanied by a significant decrease in ROS levels. EGT also improved the ratio of reduced GSH to oxidized GSH and catalase levels with a concomitant decrease in lipid peroxidation. In conclusion, to the best of our knowledge, the present study was the first to report that EGT prevents endothelial dysfunction induced by low-dose HgCl 2 administration. EGT may serve as a therapeutic tool to reduce mercury-associated cardiovascular complications via improving the antioxidant status.

Comparative antioxidant activity of cultivated and wild Vaccinium species investigated by EPR, human neutrophil burst and COMET assay.

PubMed

Braga, P C; Antonacci, R; Wang, Y Y; Lattuada, N; Dal Sasso, M; Marabini, L; Fibiani, M; Lo Scalzo, R

2013-01-01

The Vaccinium (V.) spp. berries are considered a source of antioxidants, mainly belonging to polyphenols, specifically flavonoids and anthocyanins. Wild genotypes generally contain more antioxidants than cultivated counterparts. So, seven different antioxidants assays on extracts from cultivated and wild Vaccinium berries were performed, to evaluate their difference in terms of bioactivity on oxidative protection and minimum dosage to have a significant action. Four cell-free antioxidant assays (ABTS radical scavenging and electronic paramagnetic resonance using Fremy's salt, superoxide anion and hydroxyl radical), and three assays on human cells (two luminol amplified chemiluminescence, LACL, one on DNA damage, COMET) were used to measure the effects of cultivated blueberry (V. corymbosum) and wild bilberry (V. myrtillus) on the differently induced oxidative stress. Concentrations vs activity patterns were obtained by successive dilutions of extracts in order to identify both EC50 and minimum significant activity (MSA). All the assays (except for the hydroxyl radical scavenging) showed a good relationship mainly with anthocyanin and polyphenol content and the significant greater activity of wild Vaccinium extracts. In fact, LACL data gave an EC50 of 11.8 and an MSA of 5.2 g were calculated as fresh weight dosage in cultivated berries, compared with lower doses in wild berries, EC50 of 5.7 g and MSA of 3.4 g. Wild Vaccinium extracts averaged 3.04 and 2.40 fold more activity than cultivated extracts by EC50 and MSA, respectively. COMET assay confirmed the stronger action on DNA protection in wild samples.

Effects of coarse chalk dust particles (2.5-10 μm) on respiratory burst and oxidative stress in alveolar macrophages.

PubMed

Zhang, Yuexia; Yang, Zhenhua; Feng, Yan; Li, Ruijin; Zhang, Quanxi; Geng, Hong; Dong, Chuan

2015-08-01

The main aim of the present study was to examine in vitro responses of rat alveolar macrophages (AMs) exposed to coarse chalk dust particles (particulate matter in the size range 2.5-10 μm, PM(coarse)) by respiratory burst and oxidative stress. Chalk PM(coarse)-induced respiratory burst in AMs was measured by using a luminol-dependent chemiluminescence (CL) method. Also, the cell viability; lactate dehydrogenase (LDH) release; levels of cellular superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), malondialdehyde (MDA), and acid phosphatase (ACP); plasma membrane ATPase; and extracellular nitric oxide (NO) level were determined 4 h following the treatment with the different dosages of chalk PM(coarse). The results showed that chalk PM(coarse) initiated the respiratory burst of AMs as indicated by strong CL, which was inhibited by diphenyleneiodonium chloride and L-N-nitro-L-arginine methyl ester hydrochloride. It suggested that chalk PM(coarse) induced the production of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in AMs. This hypothesis was confirmed by the fact that chalk PM(coarse) resulted in a significant decrease of intracellular SOD, GSH, ACP, and ATPase levels and a notable increase of intracellular CAT, MDA content, and extracellular NO level, consequently leading to a decrease of the cell viability and a increase of LDH release. It was concluded that AMs exposed to chalk PM(coarse) can suffer from cytotoxicity which may be mediated by generation of excessive ROS/RNS. Graphical Abstract The possible mechanism of coarse chalk particles-induced adverse effects in AMs.

Determination of Sulfonamide Residues in Food by Capillary Zone Electrophoresis with On-Line Chemiluminescence Detection Based on an Ag(III) Complex

PubMed Central

Dai, Tingting; Duan, Jie; Li, Xinghua; Xu, Xiangdong; Shi, Hongmei; Kang, Weijun

2017-01-01

The presence of sulfonamide (SA) residues in foods is largely due to the raising of animals with sulfonamide antibiotics added or polluted feedstuff. In this paper, a sensitive method was developed for the determination of the residues of three sulfonamides in animal-derived food; the SAs include sulfadimidine (SDD), sulfadiazine (SDZ), and sulfathiazole (STZ). The method is based on capillary zone electrophoresis (CE) with online chemiluminescence (CL) detection, using an Ag(III) complex as an oxidant. These SAs have an inhibiting effect on the Ag(III)–luminol CL reaction. The electrophoretic buffer is 12.0 mM sodium borate. Under a set of optimized conditions, the linear ranges for the detections were found to be 10.0–200 µg·mL−1 for SDD and SDZ, and 2.0–50.0 µg·mL−1 for STZ. The detection limits were 2.75, 3.14, and 0.65 µg·mL−1 for SDD, SDZ, and STZ, respectively. Relative standard deviations (RSD) for the peak heights were between 2.1% and 2.8% (n = 7). The proposed method was used in the analysis of the SAs in samples from pork meat, chicken meat, and milk, showing satisfactory detection results. A reaction mechanism was also proposed for the Ag(III)–luminol–SA CL reactions. The method has potential applications for the monitoring of residue levels of the three SAs in food, providing food safety data. PMID:28621728

Design parameters of stainless steel plates for maximizing high frequency ultrasound wave transmission.

PubMed

Michaud, Mark; Leong, Thomas; Swiergon, Piotr; Juliano, Pablo; Knoerzer, Kai

2015-09-01

This work validated, in a higher frequency range, the theoretical predictions made by Boyle around 1930, which state that the optimal transmission of sound pressure through a metal plate occurs when the plate thickness equals a multiple of half the wavelength of the sound wave. Several reactor design parameters influencing the transmission of high frequency ultrasonic waves through a stainless steel plate were examined. The transmission properties of steel plates of various thicknesses (1-7 mm) were studied for frequencies ranging from 400 kHz to 2 MHz and at different distances between plates and transducers. It was shown that transmission of sound pressure through a steel plate showed high dependence of the thickness of the plate to the frequency of the sound wave (thickness ratio). Maximum sound pressure transmission of ∼ 60% of the incident pressure was observed when the ratio of the plate thickness to the applied frequency was a multiple of a half wavelength (2 MHz, 6mm stainless steel plate). In contrast, minimal sound pressure transmission (∼ 10-20%) was measured for thickness ratios that were not a multiple of a half wavelength. Furthermore, the attenuation of the sound pressure in the transmission region was also investigated. As expected, it was confirmed that higher frequencies have more pronounced sound pressure attenuation than lower frequencies. The spatial distribution of the sound pressure transmitted through the plate characterized by sonochemiluminescence measurements using luminol emission, supports the validity of the pressure measurements in this study. Copyright © 2015 Elsevier B.V. All rights reserved.

Antioxidant effects of aminosalicylates and potential new drugs for inflammatory bowel disease: assessment in cell-free systems and inflamed human colorectal biopsies.

PubMed

Simmonds, N J; Millar, A D; Blake, D R; Rampton, D S

1999-03-01

The therapeutic efficacy of 5-aminosalicylic acid in inflammatory bowel disease may be related to its antioxidant properties. To compare in vitro the antioxidant effects of conventional drugs (5-aminosalicylic acid, corticosteroids, metronidazole), with new aminosalicylates (4-aminosalicylic acid, balsalazide) and other potential therapies (ascorbate, N-acetylcysteine, glutathione, verapamil). Compounds were assessed for efficacy in reducing the in vitro production of reactive oxygen species by cell-free systems (using xanthine/xanthine oxidase, with or without myeloperoxidase) and by colorectal biopsies from patients with ulcerative colitis using luminol-amplified chemiluminescence. 5-aminosalicylic acid and balsalazide were more potent antioxidants than 4-aminosalicylic acid or N-acetyl-5-aminosalicylic acid in cell-free systems. 5-aminosalicylic acid (20 mM) and balsalazide (20 mM) inhibited rectal biopsy chemiluminescence by 93% and 100%, respectively, compared with only 59% inhibition by 4-aminosalicylic acid (20 mM). Hydrocortisone, metronidazole and verapamil had no significant effect on chemiluminescence in any system. Ascorbate (20 mM) inhibited chemiluminescence by 100% in cell-free systems and by 60% in rectal biopsies. N-acetyl cysteine (10 mM), and both oxidized and reduced glutathione (10 mM), completely inhibited chemiluminescence in cell-free systems, but not with rectal biopsies. The antioxidant effects of compounds varies between cell-free systems and inflamed colorectal biopsies. The effect of drugs on the chemiluminescence produced by these two assay systems is useful for screening potentially new antioxidant treatments for inflammatory bowel disease. Ascorbate seems worth further study as a novel therapy.

Shaken, not stirred: bioanalytical study of the antioxidant activities of martinis.

PubMed

Trevithick, C C; Chartrand, M M; Wahlman, J; Rahman, F; Hirst, M; Trevithick, J R

Moderate consumption of alcoholic drinks seems to reduce the risks of developing cardiovascular disease, stroke, and cataracts, perhaps through antioxidant actions of their alcohol, flavonoid, or polyphenol contents. "Shaken, not stirred" routinely identifies the way the famous secret agent James Bond requires his martinis. As Mr Bond is not afflicted by cataracts or cardiovascular disease, an investigation was conducted to determine whether the mode of preparing martinis has an influence on their antioxidant capacity. Stirred and shaken martinis were assayed for their ability to quench luminescence by a luminescent procedure in which hydrogen peroxide reacts with luminol bound to albumin. Student's t test was used for statistical analysis. Shaken martinis were more effective in deactivating hydrogen peroxide than the stirred variety, and both were more effective than gin or vermouth alone (0.072% of peroxide control for shaken martini, 0.157% for stirred v 58.3% for gin and 1.90% for vermouth). The reason for this is not clear, but it may well not involve the facile oxidation of reactive martini components: control martinis through which either oxygen or nitrogen was bubbled did not differ in their ability to deactivate hydrogen peroxide (0.061% v 0. 057%) and did not differ from the shaken martini. Moreover, preliminary experiments indicate that martinis are less well endowed with polyphenols than Sauvignon white wine or Scotch whisky (0.056 mmol/l (catechin equivalents) shaken, 0.060 mmol/l stirred v 0.592 mmol/l wine, 0.575 mmol/l whisky). 007's profound state of health may be due, at least in part, to compliant bartenders.

Photoluminescence, chemiluminescence and anodic electrochemiluminescence of hydrazide-modified graphene quantum dots

NASA Astrophysics Data System (ADS)

Dong, Yongqiang; Dai, Ruiping; Dong, Tongqing; Chi, Yuwu; Chen, Guonan

2014-09-01

Single-layer graphene quantum dots (SGQDs) were refluxed with hydrazine (N2H4) to prepare hydrazide-modified SGQDs (HM-SGQDs). Compared with SGQDs, partial oxygen-containing groups have been removed from HM-SGQDs. At the same time, a lot of hydrazide groups have been introduced into HM-SGQDs. The introduced hydrazide groups provide HM-SGQDs with a new kind of surface state, and give HM-SGQDs unique photoluminescence (PL) properties such as blue-shifted PL emission and a relatively high PL quantum yield. More importantly, the hydrazide-modification made HM-SGQDs have abundant luminol-like units. Accordingly, HM-SGQDs exhibit unique and excellent chemiluminescence (CL) and anodic electrochemiluminescence (ECL). The hydrazide groups of HM-SGQDs can be chemically oxidized by the dissolved oxygen (O2) in alkaline solutions, producing a strong CL signal. The CL intensity is mainly dependent on the pH value and the concentration of O2, implying the potential applications of HM-SGQDs in pH and O2 sensors. The hydrazide groups of HM-SGQDs can also be electrochemically oxidized in alkaline solutions, producing a strong anodic ECL signal. The ECL intensity can be enhanced sensitively by hydrogen peroxide (H2O2). The enhanced ECL intensity is proportional to the concentration of H2O2 in a wide range of 3 μM to 500 μM. The detection limit of H2O2 was calculated to be about 0.7 μM. The results suggest the great potential applications of HM-SGQDs in the sensors of H2O2 and bio-molecules that are able to produce H2O2 in the presence of enzymes.Single-layer graphene quantum dots (SGQDs) were refluxed with hydrazine (N2H4) to prepare hydrazide-modified SGQDs (HM-SGQDs). Compared with SGQDs, partial oxygen-containing groups have been removed from HM-SGQDs. At the same time, a lot of hydrazide groups have been introduced into HM-SGQDs. The introduced hydrazide groups provide HM-SGQDs with a new kind of surface state, and give HM-SGQDs unique photoluminescence (PL) properties such as blue-shifted PL emission and a relatively high PL quantum yield. More importantly, the hydrazide-modification made HM-SGQDs have abundant luminol-like units. Accordingly, HM-SGQDs exhibit unique and excellent chemiluminescence (CL) and anodic electrochemiluminescence (ECL). The hydrazide groups of HM-SGQDs can be chemically oxidized by the dissolved oxygen (O2) in alkaline solutions, producing a strong CL signal. The CL intensity is mainly dependent on the pH value and the concentration of O2, implying the potential applications of HM-SGQDs in pH and O2 sensors. The hydrazide groups of HM-SGQDs can also be electrochemically oxidized in alkaline solutions, producing a strong anodic ECL signal. The ECL intensity can be enhanced sensitively by hydrogen peroxide (H2O2). The enhanced ECL intensity is proportional to the concentration of H2O2 in a wide range of 3 μM to 500 μM. The detection limit of H2O2 was calculated to be about 0.7 μM. The results suggest the great potential applications of HM-SGQDs in the sensors of H2O2 and bio-molecules that are able to produce H2O2 in the presence of enzymes. Electronic supplementary information (ESI) available: AFM images of SGQDs and HM-SGQDs (Fig. S1), FT-IR spectra of SGQDs and HM-SGQDs (Fig. S2), UV-vis and PL emission spectra of R-SGQDs (Fig. S3), cathodic ECL responses of SGQD, R-SGQDs and HM-SGQDs (Fig. S4), and the pH effect on the anodic ECL responses of HM-SGQDs (Fig. S5). See DOI: 10.1039/c4nr02539c

Escherichia coli LF82 differentially regulates ROS production and mucin expression in intestinal epithelial T84 cells: implication of NOX1.

PubMed

Elatrech, Imen; Marzaioli, Viviana; Boukemara, Hanane; Bournier, Odile; Neut, Christel; Darfeuille-Michaud, Arlette; Luis, José; Dubuquoy, Laurent; El-Benna, Jamel; My-Chan Dang, Pham; Marie, Jean-Claude

2015-05-01

Increased reactive oxygen species (ROS) production is associated with inflamed ileal lesions in Crohn's disease colonized by pathogenic adherent-invasive Escherichia coli LF82. We investigated whether such ileal bacteria can modulate ROS production by epithelial cells, thus impacting on inflammation and mucin expression. Ileal bacteria from patients with Crohn's disease were incubated with cultured epithelial T84 cells, and ROS production was assayed using the luminol-amplified chemiluminescence method. The gentamicin protection assay was used for bacterial invasion of T84 cell. The expression of NADPH oxidase (NOX) subunits, mucin, and IL-8 was analyzed by quantitative real-time PCR and Western blots. Involvement of NOX and ROS was analyzed using diphenyleneiodonium (DPI) and N-acetylcysteine (NAC). Among different bacteria tested, only LF82 induced an increase of ROS production by T84 cells in a dose-dependent manner. This response was inhibited by DPI and NAC. Heat- or ethanol-attenuated LF82 bacteria and the mutant LF82ΔFimA, which does not express pili type 1 and poorly adheres to epithelial cells, did not induce the oxidative response. The LF82-induced oxidative response coincides with its invasion in T84 cells, and both processes were inhibited by DPI. Also, we observed an increased expression of NOX1 and NOXO1 in response to LF82 bacteria versus the mutant LF82ΔFimA. Furthermore, LF82 inhibited mucin gene expression (MUC2 and MUC5AC) in T84 cells while increasing the chemotactic IL-8 expression, both in a DPI-sensitive manner. Adherent-invasive E. coli LF82 induced ROS production by intestinal NADPH oxidase and altered mucin and IL-8 expression, leading to perpetuation of inflammatory lesions in Crohn's disease.

Evaluation of Streptococcus pneumoniae Type XIV Opsonins by Phagocytosis-Associated Chemiluminescence and a Bactericidal Assay

PubMed Central

Gardner, Susan E.; Anderson, Donald C.; Webb, Bette J.; Stitzel, Ann E.; Edwards, Morven S.; Spitzer, Roger E.; Baker, Carol J.

1982-01-01

The relative roles of serum factors required for opsonization of type XIV Streptococcus pneumoniae were investigated by means of luminol-enhanced chemiluminescence (CL), bactericidal, and immunofluorescence assays employing adult sera containing high (>1,000 ng of antibody nitrogen per ml) or low (<200 ng of antibody nitrogen per ml) antibody concentrations as determined by radioimmunoassay. Specific antibody concentration correlated directly with both total and heat-labile CL activity (P < 0.005) and with the bactericidal index (P < 0.05) at a serum concentration of 10%. The importance of specific antibody as an opsonin was confirmed by the abolition of CL activity and immunoglobulin immunofluorescence observed after absorption of heated sera with type XIV pneumococcal cells and by the dose response in CL and bactericidal activity observed with the addition of immunoglobulin G to hypogammaglobulinemic serum. A role for the classical complement pathway in opsonization was indicated by significantly greater CL integrals for high-antibody sera than for low-antibody sera depleted of factor D and by the bactericidal activity noted for untreated, but not magnesium ethylene glycol-bis(β-aminoethyl ether)-N,N-tetraacetic acid-chelated low-antibody sera. The alternative pathway contributed more than half of the CL activity of both high- and low-antibody sera. However, after magnesium ethylene glycol-bis(β-aminoethyl ether)-N,N-tetraacetic acid chelation, only sera with high antibody concentrations or agammaglobulinemic serum reconstituted with immunoglobulin G with high specific antibody levels supported significant bactericidal activity. Therefore, type-specific antibody and complement promote opsonization of type XIV S. pneumoniae, and this may occur via either complement pathway. These results suggest that CL is a suitable tool to delineate serum factors and their contribution to opsonization, but results must be related to other functional assays. PMID:6802760

Organic Exudates Enhance Iron Bioavailability to Trichodesmium (IMS101) by Modifying Fe Speciation

NASA Astrophysics Data System (ADS)

Tohidi Farid, H.; Rose, A.; Schulz, K.

2016-02-01

Although ferrous iron (Fe (II)) is believed to be the most readily absorbed form of Fe by cells, under alkaline and oxygenated conditions typical of marine environments, the thermodynamically stable Fe(III) state dominates. In marine environments, this Fe(III) is primarily presents as organic Fe(III)L complexes whose bioavailability is highly variable. However, it has been demonstrated that some eukaryotic marine algae are able to release organic ligands into their surrounding environments that change Fe bioavailability through complexation and/or redox reactions. Nevertheless, it is unclear how Fe(II) oxidation and Fe(III) reduction rates might be modified by these exudates and how this might increase or decrease iron bioavailability to microorganisms. Here, the role of natural organic ligands excreted by the cyanobacterium Trichodesmium erythraeum on the oxidation kinetics of Fe(II) was studied using the luminol chemiluminescence technique. The oxidation kinetics of Fe(II) were examined at nanomolar Fe concentrations in presence of different concentrations of EDTA and dissolved organic carbon exuded by Trichodesmium cells. The results indicated that an increase in the concentration of exuded organic matter, and consequently L:Fe(II) ratio, resulted in decreasing rates of Fe(II) oxidation by oxygen, primarily due to formation of Fe(II) complexes. Moreover, the results demonstrated that the exudates from Trichodesmium may be able to reduce Fe(III) to the more bioavailable Fe(II) state under some circumstances. This study therefore supports the ability of microorganisms to manipulate Fe bioavailability by releasing organic compounds into the extracellular environment that retard Fe(II) oxidation rates or reducing Fe(III) species to Fe(II). It also provides new insight into the potential mechanism(s) by which Trichdesmium may acquire Fe under conditions where Fe bioavailability is otherwise limited.

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.

The inhibitory effect of vitamin E on cigarette smoke-induced oxidative damage to the rat urothelium: can it prevent transitional cell carcinoma?

PubMed

Onol, Fikret Fatih; Demir, Aslan; Temiz, Yusuf; Yüksel, Meral; Eren, Funda; Türkeri, Levent N

2007-01-01

We aimed to detect reactive oxygen species (ROS) and assess subsequent carcinogenesis in terms of cellular proliferation in the bladder and kidney epithelial tissues of rats exposed to cigarette smoke (CS), and to investigate the changes following vitamin E treatment. Twenty-four male Sprague-Dawley rats were divided into 3 groups: group 1 was kept intact; group 2 was subjected to CS exposure for 8 weeks, and group 3 received intraperitoneal vitamin E injections (200 mg/kg/week) for 8 weeks in addition to CS exposure. Histological examination and Ki67 antigen expression measurements were made from bladder and renal pelvic tissue sections. Luminol-amplified chemiluminescence was used to measure ROS levels. All results were compared using a one-way ANOVA test. In CS-exposed rats, light microscopy of renal and bladder tissues revealed nonspecific epithelial changes; however, Ki67 expression was significantly increased in bladder tissues compared to other groups (17.5 +/- 4.7, 35 +/- 2.9 and 18.7 +/- 5.1% in groups 1, 2 and 3, respectively, p < 0.05). Chemiluminescence levels in bladder and renal tissues were also significantly higher in the CS-exposed animals (78.1 +/- 11.4, 148 +/- 13.3, 97.8 +/- 6.1 rlu/mg for the bladder, and 99.8 +/- 12.2, 176.1 +/- 27.9, 67.1 +/- 9 rlu/mg, for renal pelvic tissues, respectively, p < 0.05). Vitamin E can alleviate CS-induced oxidative damage in rat bladder and kidney epithelium suggesting a potential role for vitamin E in the prevention of CS-mediated carcinogenesis. 2007 S. Karger AG, Basel

Importance of allochthonous and autochthonous dissolved organic matter in Fe(II) oxidation: A case study in Shizugawa Bay watershed, Japan.

PubMed

Lee, Ying Ping; Fujii, Manabu; Kikuchi, Tetsuro; Natsuike, Masafumi; Ito, Hiroaki; Watanabe, Toru; Yoshimura, Chihiro

2017-08-01

Ferrous iron (Fe[II]) oxidation by dissolved oxygen was investigated in the Shizugawa Bay watershed with particular attention given to the effect of dissolved organic matter (DOM) properties on Fe(II) oxidation. To cover a wide spectrum of DOM composition, water samples were collected from various water sources including freshwater (e.g., river water and wastewater effluent) and coastal seawater. Measurement of nanomolar Fe(II) oxidation by using luminol chemiluminescence under dark, air-saturated conditions at 25 °C indicated that spatio-temporal variation of the second-order rate constant (6.7-74.5 M -1  s -1 ) was partially explained by the variation of the sample pH (7.5-8.6). However, at comparable pH values, the oxidation rates for freshwater were generally greater than those for coastal seawater. The substantial decline in oxidation rate constant after the removal of humic-type (allochthonous) DOM suggested that this hydrophobic DOM is a key factor that accelerates the Fe(II) oxidation in the freshwater samples. Observed lower oxidation rates for coastal seawater compared with freshwater and organic ligand-free seawater were likely associated with microbially derived autochthonous DOM, and the variation of Fe(II) oxidation at a fixed pH was best described by fluorescence index that represents the proportion of autochthonous and allochthonous DOM in natural waters. Consistently, Fe(II) oxidation was found to be slower in the presence of cellular exudates from phytoplankton. The present study highlighted the significant effect of DOM composition on the Fe(II) oxidation in inland and coastal waters. Copyright © 2017 Elsevier Ltd. All rights reserved.

Characterisation of the antioxidant effects of Aesculus hippocastanum L. bark extract on the basis of radical scavenging activity, the chemiluminescence of human neutrophil bursts and lipoperoxidation assay.

PubMed

Braga, P C; Marabini, L; Wang, Y Y; Lattuada, N; Calò, R; Bertelli, A; Falchi, M; Dal Sasso, M; Bianchi, T

2012-07-01

Oxidative stress is increasingly recognised as a pivotal factor that plays a number of roles in the inflammatory response to environmental signals. It has been claimed that Aesculus hippocastanum extracts have antioxidant and anti-inflammatory activity, but these claims are mainly based on the results of chemical reactions and folk-medicine. The aim of this study was to examine whether a bark extract of Aesculus hippocastanum interferes with reactive oxygen/nitrogen species (ROS/RNS) during the course of human neutrophil respiratory bursts, and to establish the lowest concentration at which it still has antioxidant activity by means of luminol amplified chemiluminescence (LACL). We also studied its ability to counteract lipid peroxidation (LPO) in human cells. Before investigating its antioxidant effects on human cells, we analysed its scavenging activity against ABTS*+, hydroxyl radical, superoxide anion, and Fremy's salt (those last three by means of electron paramagnetic resonance (EPR) spectrometry). The extract of Aesculus hippocastanum exerted its anti-ROS/RNS activity in a concentration-dependent manner with significant effects being observed for even very low concentrations: 10 microg/ml without L-Arg, and 5 microg/ml when L-Arg was added to the fMLP test. The LPO assay confirmed these results, which were paralleled by the EPR study. These findings are interesting for improving the antioxidant network and restoring redox balance in human cells, and extend the possibility of using plant-derived molecules to antagonise the oxidative stress generated in living organisms when the balance is in favour of free radicals as a result of the depletion of cell antioxidants.

Dual-Readout Immunochromatographic Assay by Utilizing MnO 2 Nanoflowers as the Unique Colorimetric/Chemiluminescent Probe

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

Ouyang, Hui; Lu, Qian; Wang, Wenwen

Manganese dioxide nanoflowers (MnO2 NFs) were synthesized and utilized as a dual readout probe to develop a novel immunochromatographic test strip (ITS) for detecting pesticide residues using chlorpyrifos as the model analyte. MnO2 NFs-labeled antibody for chlorpyrifos was employed as the signal tracer for conducting the ITS. After 10-min competitive immunoreaction, the tracer antibody was captured by the immobilized immunogen on test line in the test strip, resulting in the accumulation of MnO2 NFs. The accumulation of MnO2 NFs led to the appearance of brown color on the test line, which could be easily observed by the naked eye asmore » a qualitative readout. Moreover, MnO2 NFs showed a remarkably enhancing effect on the luminol-H2O2 chemiluminescent (CL) system. Unlike peroxidase-like nanomaterials, the enhancing mechanism of MnO2 NFs was based on its oxidant activity to decompose H2O2 for forming reactive oxygen species. After initiating the CL system in the test zone, strong CL signal was collected as a quantitative readout to sensitively detect chlorpyrifos. Under optimal conditions, the linear range of chlorpyrifos was 0.1–50 ng/mL with a low detection limit of 0.033 ng/mL (S/N = 3). The reliability of the dual-readout ITS was successfully demonstrated by the application on traditional Chinese medicine and environmental water samples. Due to the simultaneous rapid-qualitative and sensitive-quantitative detection, the dual-readout protocol provides a promising strategy for rapid screening and field assay on various areas such as environmental monitoring, food safety and point-of-care testing.« less

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.

D-lactic acid interferes with the effects of platelet activating factor on bovine neutrophils.

PubMed

Alarcón, P; Conejeros, I; Carretta, M D; Concha, C; Jara, E; Tadich, N; Hidalgo, M A; Burgos, R A

2011-11-15

D-lactic acidosis occurs in ruminants, such as cattle, with acute ruminal acidosis caused by ingestion of excessive amounts of highly fermentable carbohydrates. Affected animals show clinical signs similar to those of septic shock, as well as acute laminitis and liver abscesses. It has been proposed that the inflammatory response and susceptibility to infection could both be caused by the inhibition of phagocytic mechanisms. To determine the effects of d-lactic acid on bovine neutrophil functions, we pretreated cells with different concentrations of D-lactic acid and measured intracellular pH using 2',7'-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein acetoxymethyl ester (BCECF-AM) and calcium flux using FLUO-3 AM-loaded neutrophils. Reactive oxygen species (ROS) production was measured using a luminol chemiluminescence assay, and MMP-9/gelatinase-B granule release was measured by zymography. CD11b and CD62L/l-selectin expression, changes in cell shape, superoxide anion production, phagocytosis of Escherichia coli-Texas red bioparticles, and apoptosis were all measured using flow cytometry. Our results demonstrated that D-lactic acid reduced ROS production, CD11b upregulation and MMP-9 release in bovine neutrophils treated with 100 nM platelet-activating factor (PAF). D-lactic acid induced MMP-9 release and, at higher concentrations, upregulated CD11b expression, decrease L-selectin expression, and induces late apoptosis. We concluded that D-lactic acid can interfere with neutrophil functions induced by PAF, leading to reduced innate immune responses during bacterial infections. Moreover, the increase of MMP-9 release and CD11b expression induced by 10mM D-lactic acid could promote an nonspecific neutrophil-dependent inflammatory reaction in cattle with acute ruminal acidosis. Copyright © 2011 Elsevier B.V. All rights reserved.

Internal Light Source-Driven Photoelectrochemical 3D-rGO/Cellulose Device Based on Cascade DNA Amplification Strategy Integrating Target Analog Chain and DNA Mimic Enzyme.

PubMed

Lan, Feifei; Liang, Linlin; Zhang, Yan; Li, Li; Ren, Na; Yan, Mei; Ge, Shenguang; Yu, Jinghua

2017-11-01

In this work, a chemiluminescence-driven collapsible greeting card-like photoelectrochemical lab-on-paper device (GPECD) with hollow channel was demonstrated, in which target-triggering cascade DNA amplification strategy was ingeniously introduced. The GPECD had the functions of reagents storage and signal collection, and the change of configuration could control fluidic path, reaction time and alterations in electrical connectivity. In addition, three-dimentional reduced graphene oxide affixed Au flower was in situ grown on paper cellulose fiber for achieving excellent conductivity and biocompatibility. The cascade DNA amplification strategy referred to the cyclic formation of target analog chain and its trigger action to hybridization chain reaction (HCR), leading to the formation of numerous hemin/G-quadruplex DNA mimic enzyme with the presence of hemin. Subjected to the catalysis of hemin/G-quadruplex, the strong chemiluminiscence of luminol-H 2 O 2 system was obtained, which then was used as internal light source to excite photoactive materials realizing the simplification of instrument. In this analyzing process, thrombin served as proof-of-concept, and the concentration of target was converted into the DNA signal output by the specific recognition of aptamer-protein and target analog chain recycling. The target analog chain was produced in quantity with the presence of target, which further triggered abundant HCR and introduced hemin/G-quadruplex into the system. The photocurrent signal was obtained after the nitrogen-doped carbon dots sensitized ZnO was stimulated by chemiluminescence. The proposed GPECD exhibited excellent specificity and sensitivity toward thrombin with a detection limit of 16.7 fM. This judiciously engineered GPECD paved a luciferous way for detecting other protein with trace amounts in bioanalysis and clinical biomedicine.

Determination of the post mortem interval in skeletal remains by the comparative use of different physico-chemical methods: Are they reliable as an alternative to 14C?

PubMed

Amadasi, Alberto; Cappella, Annalisa; Cattaneo, Cristina; Cofrancesco, Pacifico; Cucca, Lucia; Merli, Daniele; Milanese, Chiara; Pinto, Andrea; Profumo, Antonella; Scarpulla, Valentina; Sguazza, Emanuela

2017-05-01

The determination of the post-mortem interval (PMI) of skeletal remains is a challenging aspect in the forensic field. Previous studies focused their attention on different macroscopic and morphological aspects but a thorough and complete evaluation of the potential of chemical and physical analyses in this field of research has not been performed. In addition to luminol test and Oxford histology index (OHI) reported in a recent paper, widely spread and accessible methods based on physical aspect and chemical characteristics of skeletal remains have been investigated as potential alternatives to dating by determination of 14 C. The investigation was performed on a total of 24 archeological and forensic bone samples with known PMI, with inductively coupled plasma optical emission spectrometer (ICP-OES), inductively coupled plasma quadruple mass spectrometry (ICP-MS), Fourier transform infrared (FT-IR) spectroscopy, energy dispersive X-ray analysis (EDX), powder X-ray diffraction analysis (XRPD) and scanning electron microscopy (SEM). Finally, the feasibility of such alternative methods was discussed. Some results such as carbonates/phosphates ratio from FT-IR, the amounts of organic and inorganic matter by EDX, crystallite sizes with XRPD, and surface morphology obtained by SEM, showed significant trends along with PMI. Though, from a chemical point of view cut-off values and gold-standard methods still present challenges, and rather different techniques together can provide useful information toward the assessment of the PMI of skeletal remains. It is however clear that in a hypothetical flowchart those methods may be placed practically at the same level and a choice should always consider the evaluation of results by each technique, execution times and a costs/benefits relationship. Copyright © 2017 Elsevier GmbH. All rights reserved.

Interaction between Salmonella typhimurium and phagocytic cells in pigs. Phagocytosis, oxidative burst and killing in polymorphonuclear leukocytes and monocytes.

PubMed

Riber, U; Lind, P

1999-02-22

Interactions between Salmonella typhimurium and peripheral blood leucocytes from healthy, Salmonella-free pigs were investigated in vitro. Both granulocytes and monocytes phagocytized FITC-labelled heat-killed Salmonella bacteria as shown by flow cytometry. Phagocytosis in whole blood and isolated leucocytes was measured as acquired fluorescence in the leukocytes and was both time and dose related. Living, serum-opsonized Salmonella bacteria induced a dose-dependent oxidative burst in PMNs and monocytes as measured by luminol-enhanced chemiluminescence (LC). When opsonized in normal serum the Salmonella bacteria, in the range of 2-5 x 10(7) cfu, induced a LC response in monocytes comparable to the level of responses induced by phorbol myristate acetate (PMA) and opsonized zymosan, and the Salmonella-induced response was only marginally reduced by superoxide dismutase (SOD). Intracellular killing of Salmonella by monocytes was assessed from plate colony counts of lysed monocytes and showed that Salmonella typhimurium was able to survive and proliferate in adherent monocytes in vitro despite a reduction in intracellular cfu during the first hour's incubation in cells from some pigs. Experiments with the exhaustion of oxidative burst in non-adherent monocytes were performed by prestimulation with PMA, heat-killed Salmonella or buffer. Prestimulation with PMA led to a strong reduction in oxidative burst induced by living opsonized Salmonella bacteria, whereas prestimulation with heat-killed bacteria gave rise to an enhanced response. In these experiments intracellular killing of the added living Salmonella gave variable results, in that monocytes from two out of three pigs showed no essential change in intracellular bactericidal activity, but with cells from one pig a less pronounced bactericidal activity was found after prestimulation with PMA.

An "off-on" electrochemiluminescent biosensor based on DNAzyme-assisted target recycling and rolling circle amplifications for ultrasensitive detection of microRNA.

PubMed

Zhang, Pu; Wu, Xiaoyan; Yuan, Ruo; Chai, Yaqin

2015-03-17

In this study, an off-on switching of a dual amplified electrochemiluminescence (ECL) biosensor based on Pb(2+)-induced DNAzyme-assisted target recycling and rolling circle amplification (RCA) was constructed for microRNA (miRNA) detection. First, the primer probe with assistant probe and miRNA formed Y junction which was cleaved with the addition of Pb(2+) to release miRNA. Subsequently, the released miRNA could initiate the next recycling process, leading to the generation of numerous intermediate DNA sequences (S2). Afterward, bare glassy carbon electrode (GCE) was immersed into HAuCl4 solution to electrodeposit a Au nanoparticle layer (depAu), followed by the assembly of a hairpin probe (HP). Then, dopamine (DA)-modified DNA sequence (S1) was employed to hybridize with HP, which switching off the sensing system. This is the first work that employs DA to quench luminol ECL signal, possessing the biosensor ultralow background signal. Afterward, S2 produced by the target recycling process was loaded onto the prepared electrode to displace S1 and served as an initiator for RCA. With rational design, numerous repeated DNA sequences coupling with hemin to form hemin/G-quadruplex were generated, which could exhibit strongly catalytic toward H2O2, thus amplified the ECL signal and switched the ON state of the sensing system. The liner range for miRNA detection was from 1.0 fM to 100 pM with a low detection limit down to 0.3 fM. Moreover, with the high sensitivity and specificity induced by the dual signal amplification, the proposed miRNA biosensor holds great potential for analysis of other interesting tumor markers.

Differential Regulatory Role of Pituitary Adenylate Cyclase–Activating Polypeptide in the Serum-Transfer Arthritis Model

PubMed Central

Botz, Bálint; Bölcskei, Kata; Kereskai, László; Kovács, Miklós; Németh, Tamás; Szigeti, Krisztián; Horváth, Ildikó; Máthé, Domokos; Kovács, Noémi; Hashimoto, Hitoshi; Reglődi, Dóra; Szolcsányi, János; Pintér, Erika; Mócsai, Attila; Helyes, Zsuzsanna

2014-01-01

Objective Pituitary adenylate cyclase–activating polypeptide (PACAP) expressed in capsaicin-sensitive sensory neurons and immune cells has divergent functions in inflammatory and pain processes. This study was undertaken to investigate the involvement of PACAP in a mouse model of rheumatoid arthritis. Methods Arthritis was induced in PACAP−/− and wild-type (PACAP+/+) mice by K/BxN serum transfer. General features of the disease were investigated by semiquantitative scoring, plethysmometry, and histopathologic analysis. Mechano- and thermonociceptive thresholds and motor functions were also evaluated. Metabolic activity was assessed by positron emission tomography. Bone morphology was measured by in vivo micro–computed tomography, myeloperoxidase activity and superoxide production by bioluminescence imaging with luminol and lucigenin, respectively, and vascular permeability by fluorescent indocyanine green dye study. Results PACAP+/+ mice developed notable joint swelling, reduced grasping ability, and mechanical (but not thermal) hyperalgesia after K/BxN serum transfer. In PACAP−/− mice clinical scores and edema were significantly reduced, and mechanical hyperalgesia and motor impairment were absent, throughout the 2-week period of observation. Metabolic activity and superoxide production increased in the tibiotarsal joints of wild-type mice but were significantly lower in PACAP−/− animals. Myeloperoxidase activity in the ankle joints of PACAP−/− mice was significantly reduced in the early phase of arthritis, but increased in the late phase. Synovial hyperplasia was also significantly increased, and progressive bone spur formation was observed in PACAP-deficient mice only. Conclusion In PACAP-deficient mice with serum-transfer arthritis, joint swelling, vascular leakage, hyperalgesia, and early inflammatory cell accumulation are reduced; in the later phase of the disease, immune cell function and bone neoformation are increased. Elucidation of the underlying pathways of PACAP activity may open promising new avenues for development of therapy in inflammatory arthritis. PMID:25048575

Antioxidant effects of cultured wild ginseng root extracts on the male reproductive function of boars and guinea pigs.

PubMed

Yun, Suk Jun; Bae, Gui-Seck; Park, Jae Hawn; Song, Tae Ho; Choi, Ahreum; Ryu, Buom-Yong; Pang, Myung-Geol; Kim, Eun Joong; Yoon, Minjung; Chang, Moon Baek

2016-07-01

The main objective of this study was to investigate the effects of cultured wild ginseng root extracts (cWGRE) on the sperm of boars and the reproductive system of guinea pigs. Firstly, semen collected from boars (n=10) were incubated in 38°C for 1h with xanthine and xanthine oxidase to generate ROS. The cWGRE was added to the sperm culture system to test its antioxidant effect on the boar sperm. The amount of Reactive Oxygen Species (ROS) was measured by a chemiluminescence assay using luminol. The results indicated that the addition of cWGRE to boar sperm culture inhibited xanthine and xanthine oxidase-induced ROS concentrations. Treatment with cWGRE also had a positive effect on maintaining sperm motility. Effects of cWGRE administration on vitamin C-deficient guinea pigs were further investigated. Hartley guinea pigs (n=25) at 8 weeks of age were randomly divided into five groups. With the exception of the positive control group, each group was fed vitamin C-deficient feed for 21days (d). Respective groups were also orally administered cWGRE, ginseng extract, or mixed ginsenosides for 21 days. In comparison to the control group, oral administration of cWGRE reduced (P<0.05) amount of lipid peroxidation and increased (P<0.05) both glutathione peroxidase concentrations and the trolox equivalent antioxidant capacity. In addition, administration of cWGRE induced increases (P<0.05) in body weight, testosterone concentrations, and spermatid populations. The results of the present study support our hypothesis that cWGRE has positive effects on male reproductive functions via suppression of ROS production. Copyright © 2016 Elsevier B.V. All rights reserved.

Monitoring of transient cavitation induced by ultrasound and intense pulsed light in presence of gold nanoparticles.

PubMed

Sazgarnia, Ameneh; Shanei, Ahmad; Shanei, Mohammad Mahdi

2014-01-01

One of the most important challenges in medical treatment is invention of a minimally invasive approach in order to induce lethal damages to cancer cells. Application of high intensity focused ultrasound can be beneficial to achieve this goal via the cavitation process. Existence of the particles and vapor in a liquid decreases the ultrasonic intensity threshold required for cavitation onset. In this study, synergism of intense pulsed light (IPL) and gold nanoparticles (GNPs) has been investigated as a means of providing nucleation sites for acoustic cavitation. Several approaches have been reported with the aim of cavitation monitoring. We conducted the experiments on the basis of sonochemiluminescence (SCL) and chemical dosimetric methods. The acoustic cavitation activity was investigated by determining the integrated SCL signal acquired over polyacrylamide gel phantoms containing luminol in the presence and absence of GNPs in the wavelength range of 400-500 nm using a spectrometer equipped with cooled charged coupled devices (CCD) during irradiation by different intensities of 1 MHz ultrasound and IPL pulses. In order to confirm these results, the terephthalic acid chemical dosimeter was utilized as well. The SCL signal recorded in the gel phantoms containing GNPs at different intensities of ultrasound in the presence of intense pulsed light was higher than the gel phantoms without GNPs. These results have been confirmed by the obtained data from the chemical dosimetry method. Acoustic cavitation in the presence of GNPs and intense pulsed light has been suggested as a new approach designed for decreasing threshold intensity of acoustic cavitation and improving targeted therapeutic effects. Copyright © 2013 Elsevier B.V. All rights reserved.

Comparison of PAN and Black Carbon Levels in Mexico City: 1997 and 2003

NASA Astrophysics Data System (ADS)

Gaffney, J. S.; Marley, N. A.

2004-12-01

Peroxyacetyl nitrate (PAN) is a secondary oxidant formed by the oxidation of hydrocarbons in the presence of nitrogen dioxide. PAN is a good indicator compound for hydrocarbon reactivity that leads to ozone formation. Black carbon (BC) is formed by incomplete combustion processes such as diesel soot formation and is a good indicator of primary carbonaceous aerosols in urban areas. We used a fast-response luminol method to measure PAN and BC during the Mexico City Metropolitan Area 2003/Mexico City Megacity 2003 field study in April 2003. We compare these results with our previous PAN measurements in Mexico City during February 1997, made with a gas chromatograph-electron capture detector system. The decreased PAN levels observed in 2003 are consistent with the application of emissions controls on spark ignition gasoline-fueled vehicles, leading to lower levels of the nitrogen oxides and reactive volatile hydrocarbons needed to form PAN. Black carbon data for Mexico City in 2003, taken with a seven-channel aethalometer, are compared with data from 1997, estimated from thermal analyses as elemental carbon (EC). The comparison indicates little change in the levels of BC/EC over the six-year period. This observation is consistent with the application of minimal controls to diesel engines, the likely major source of BC in the Mexico City megacity complex during this period. The authors wish to thank the researchers at Centro Nacional de Investigación en Calidad Ambiental (CENICA), Mexico City. This work was supported by the U.S. Department of Energy, Atmospheric Science Program. We also wish to acknowledge Drs. Mario and Luisa Molina for their help in organizing and directing the Mexico City Metropolitan Area 2003 field study, during which these data were collected.

Role of serotype-specific polysaccharide in the resistance of Streptococcus mutans to phagocytosis by human polymorphonuclear leukocytes.

PubMed

Tsuda, H; Yamashita, Y; Toyoshima, K; Yamaguchi, N; Oho, T; Nakano, Y; Nagata, K; Koga, T

2000-02-01

To clarify the role of cell surface components of Streptococcus mutans in resistance to phagocytosis by human polymorphonuclear leukocytes (PMNs), several isogenic mutants of S. mutans defective in cell surface components were studied with a luminol-enhanced chemiluminescence (CL) assay, a killing assay, and a transmission electron microscope. The CL responses of human PMNs to mutant Xc11 defective in a major cell surface antigen, PAc, and mutant Xc16 defective in two surface glucosyltransferases (GTF-I and GTF-SI) were the same as the response to the wild-type strain, Xc. In contrast, mutant Xc24R, which was defective in serotype c-specific polysaccharide, induced a markedly higher CL response than the other strains. The killing assay showed that human PMNs killed more Xc24R than the parent strain and the other mutants. The transmission electron microscopic observation indicated that Xc24R cells were more internalized by human PMNs than the parental strain Xc. These results may be reflected by the fact that strain Xc24R was more phagocytosed than strain Xc. The CL response of human PMNs to a mutant defective in polysaccharide serotype e or f was similar to the response to Xc24R. Furthermore, mutants defective in serotype-specific polysaccharide were markedly more hydrophobic than the wild-type strains and the other mutants, suggesting that the hydrophilic nature of polysaccharides may protect the bacterium from phagocytosis. We conclude that the serotype-specific polysaccharide, but not the cell surface proteins on the cell surface of S. mutans, may play an important role in the resistance to phagocytosis.

IgA-mediated inhibition of human leucocyte function by interference with Fc gamma and C3b receptors.

PubMed

Saito, K; Kato, C; Katsuragi, H; Komatsuzaki, A

1991-09-01

The inhibitory effects of IgA from human colostrum, and IgA1 and IgA2 from human serum on the chemiluminescence (CL) response and phagocytosis of polymorphonuclear leucocytes (PML) to Staphylococcus epidermidis and the CL response to formylmethionyl-leucyl-phenylalanine (FMLP) were studied. The dose-dependent inhibition of the luminol-mediated CL response of human PML to the bacteria was observed in the presence of more than 0.1 mg/ml IgA from both colostrum and serum. The preincubation of PML with a solution of IgA enhanced the suppressive effect of IgA on the cells. Removal of IgA from the reaction mixture after preincubation resulted in recovery, with time, of the response of PML to the bacteria. The bacteria treated with IgA did not give rise to any inhibition of the response. The CL response of PML to FMLP was not affected by the presence of IgA in the reaction mixture. The decrease of phagocytic activity of PML in the presence of IgA resulted in a decrease of NADPH oxidase activity of PML after stimulation with the bacteria as compared with the absence of IgA. The effect of IgA on the receptors of Fc and C3b (CR1) on the surface of PML was measured by monitoring erythrocyte-antibody (EA) or erythrocyte-antibody-complement (EAC) rosette formation and by direct and indirect immunofluorescence techniques using anti-CR1 antibody and Fc-specific antibodies. The presence of IgA in the reaction mixture led to a quantitative decrease in CR1 and the ability to bind IgG to the surface of PML.

Role of Serotype-Specific Polysaccharide in the Resistance of Streptococcus mutans to Phagocytosis by Human Polymorphonuclear Leukocytes

PubMed Central

Tsuda, Hiromasa; Yamashita, Yoshihisa; Toyoshima, Kuniaki; Yamaguchi, Noboru; Oho, Takahiko; Nakano, Yoshio; Nagata, Kengo; Koga, Toshihiko

2000-01-01

To clarify the role of cell surface components of Streptococcus mutans in resistance to phagocytosis by human polymorphonuclear leukocytes (PMNs), several isogenic mutants of S. mutans defective in cell surface components were studied with a luminol-enhanced chemiluminescence (CL) assay, a killing assay, and a transmission electron microscope. The CL responses of human PMNs to mutant Xc11 defective in a major cell surface antigen, PAc, and mutant Xc16 defective in two surface glucosyltransferases (GTF-I and GTF-SI) were the same as the response to the wild-type strain, Xc. In contrast, mutant Xc24R, which was defective in serotype c-specific polysaccharide, induced a markedly higher CL response than the other strains. The killing assay showed that human PMNs killed more Xc24R than the parent strain and the other mutants. The transmission electron microscopic observation indicated that Xc24R cells were more internalized by human PMNs than the parental strain Xc. These results may be reflected by the fact that strain Xc24R was more phagocytosed than strain Xc. The CL response of human PMNs to a mutant defective in polysaccharide serotype e or f was similar to the response to Xc24R. Furthermore, mutants defective in serotype-specific polysaccharide were markedly more hydrophobic than the wild-type strains and the other mutants, suggesting that the hydrophilic nature of polysaccharides may protect the bacterium from phagocytosis. We conclude that the serotype-specific polysaccharide, but not the cell surface proteins on the cell surface of S. mutans, may play an important role in the resistance to phagocytosis. PMID:10639428

Neutrophils in chronic and aggressive periodontitis in interaction with Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans.

PubMed

Guentsch, A; Puklo, M; Preshaw, P M; Glockmann, E; Pfister, W; Potempa, J; Eick, S

2009-06-01

This study analyzed the interaction of Porphyromonas gingivalis ATCC 33277 and Aggregatibacter actinomycetemcomitans Y4 with peripheral blood polymorphonuclear neutrophils taken from patients with aggressive periodontitis and chronic periodontitis. Peripheral blood polymorphonuclear neutrophils obtained from 12 patients with chronic periodontitis, six patients with aggressive periodontitis and 12 healthy controls were exposed to P. gingivalis and A. actinomycetemcomitans following opsonization of the bacteria using the patient's own serum. Serum immunoglobulin G (IgG) levels against both periodontopathogens were measured. Phagocytosis and killing of the bacteria, as well as the extracellular human neutrophil elastase activity, were quantified. The total amount and the extracellular release of reactive oxygen species were measured using luminol-dependent and isoluminol-dependent chemiluminescence. Polymorphonuclear neutrophils from patients with chronic (62.16 +/- 19.39%) and aggressive (43.26 +/- 26.63%) periodontitis phagocytosed more P. gingivalis than the healthy controls (24.43 +/- 19.87%) at the 30-min time point after exposure to the bacteria (p < 0.05). High serum IgG levels against P. gingivalis and A. actinomycetemcomitans were detected in subjects with periodontitis. Polymorphonuclear neutrophils from subjects with chronic and aggressive periodontitis released significantly more reactive oxygen species and demonstrated greater human neutrophil elastase activity in the absence of any stimulus than polymorphonuclear neutrophils from healthy controls (p < 0.05). Polymorphonuclear neutrophils in chronic periodontitis released significantly more reactive oxygen species when exposed to P. gingivalis and A. actinomycetemcomitans than polymorphonuclear neutrophils in aggressive periodontitis. High serum IgG levels against P. gingivalis and A. actinomycetemcomitans promote phagocytosis in periodontitis. The extracellular release of reactive oxygen species and neutrophil elastase by polymorphonuclear neutrophils may also contribute to damage of the surrounding periodontal tissues.

Influence of heat inactivation of human serum on the opsonization of Streptococcus mutans.

PubMed

Moore, M A; Hakki, Z W; Gregory, R L; Gfell, L E; Kim-Park, W K; Kowolik, M J

1997-12-15

Phagocytosis of bacteria, such as Streptococcus mutans, is important to host defense. One mechanism by which phagocytosis can be enhanced is by antibody or complement-mediated opsonization of bacteria. Many studies utilize opsonization of bacteria to enhance a cellular response, but little information has been found examining methodology or validity of the opsonization process following the denaturization of the serum. Human serum was inactivated by heat in order to disrupt the classical and alternative pathways of the complement cascade. S. mutans isolated from human subjects were opsonized with heat-inactivated human serum before exposing them to viable neutrophils in vitro. Luminol-dependent chemiluminescence (CL) was used to measure neutrophil activation. Human serum used to opsonize the bacteria was denatured by incubation at 57 degrees C for intervals of 30 and 60 min to inactivate complement. The results from the opsonization data indicated that there was significantly increased CL with 60-min inactivation of the serum (34% increase in mean integration mV.min; p < or = 0.05) over the nonopsonized control. This indicated a successful opsonization of the bacteria. In addition, the data demonstrate that the inactivation of serum requires a minimum of 60 min at 57 degrees C to disrupt the complement cascade, while 30- and 15-min inactivations produced no significant increase in CL activity over the control. Standard sandwich ELISA assays, detecting complement binding to S. mutans, confirmed successful heat inactivation of serum showing a significant decrease (p < or = 0.001) in complement binding to S. mutans after 30 min, but could not explain the increased CL response after 60-min heat deactivation of the serum.

A photochemical method for in vitro evaluation of fluid flow in human dentine.

PubMed

Boreak, Nezar; Ishihata, Hiroshi; Shimauchi, Hidetoshi

2015-01-01

To evaluate the flow dynamics of dentine fluid using a chemiluminescence method in vitro. Horizontally sliced coronal dentine specimens with thicknesses of 1.4, 1.6, 1.8, and 2.0mm (n=10 each) were prepared from extracted human third molars. After cleaning with EDTA, a mounted specimen was clamped between 2 acrylic chambers attached to both the occlusal and pulpal sides. The occlusal chamber, which was closed with a glass coverslip, was filled with a chemiluminescent solution (0.02% luminol and 1% sodium hydroxide in water). A trigger solution of 1% hydrogen peroxide and 1% potassium ferricyanide was injected into the pulpal chamber at a constant pressure of 2.5 kPa, and allowed to immediately flow into the patent dentinal tubules. Four consecutive measurements (T1-T4) were performed on each sample by recording the emission of chemiluminescence with a photodetector. The relationship between the crossing time of the liquid through the slice and dentine thickness was examined. An apparent time delay was detected between the starting points of the trigger solution run and photochemical emission at T1. Dt (Dt, s) values of each thickness group were 13.6 ± 4.25 for 1.4mm, 18.1 ± 2.38 for 1.6mm, 28.0 ± 2.46 for 1.8mm, and 39.2 ± 8.61 for 2.0mm, respectively. Dt significantly decreased as dentine became thinner towards the pulp chamber (P<0.001). The velocity of fluid flow increased both with increasing dentine depth or reduction of remaining dentine thickness. Copyright © 2014 Elsevier Ltd. All rights reserved.

Hyperactivity and reactivity of peripheral blood neutrophils in chronic periodontitis.

PubMed

Matthews, J B; Wright, H J; Roberts, A; Cooper, P R; Chapple, I L C

2007-02-01

Some evidence exists that peripheral neutrophils from patients with chronic periodontitis generate higher levels of reactive oxygen species (ROS) after Fcgamma-receptor stimulation than those from healthy controls. We hypothesized that peripheral neutrophils in periodontitis also show both hyper-reactivity to plaque organisms and hyperactivity in terms of baseline, unstimulated generation and release of ROS. Peripheral neutrophils from chronic periodontitis patients and age/sex/smoking-matched healthy controls (18 pairs) were assayed for total ROS generation and extracellular ROS release, with and without stimulation (Fcgamma-receptor and Fusobacterium nucleatum), using luminol and isoluminol chemiluminescence. Assays were performed with and without priming with Escherichia coli lipopolysaccharide (LPS) and granulocyte-macrophage colony-stimulating factor (GM-CSF). Phox gene expression (p22, p47, p67, gp91) was investigated using reverse transcription-polymerase chain reaction (RT-PCR). Neutrophils from patients produced higher mean levels of ROS in all assays. Total generation and extracellular release of ROS by patients' cells were significantly greater than those from controls after FcgammaR-stimulation, with (P = 0.023) and without (P < or = 0.023) priming with GM-CSF. Differences in unstimulated total ROS generation were not significant. By contrast, patients' cells demonstrated greater baseline, extracellular ROS release than those from controls (P = 0.004). This difference was maintained after priming with LPS (P = 0.028) but not GM-CSF (P = 0.217). Phox gene expression was similar in patient and control cells at baseline and stimulation with F. nucleatum (3 h) consistently reduced gp91(PHOX) transcripts. Our data demonstrate that peripheral neutrophils from periodontitis patients exhibit hyper-reactivity following stimulation (Fcgamma-receptor and F. nucleatum) and hyperactivity in terms of excess ROS release in the absence of exogenous stimulation. This hyperactive/-reactive neutrophil phenotype is not associated with elevated phox gene expression.

Live Candida albicans suppresses production of reactive oxygen species in phagocytes.

PubMed

Wellington, Melanie; Dolan, Kristy; Krysan, Damian J

2009-01-01

Production of reactive oxygen species (ROS) is an important aspect of phagocyte-mediated host responses. Since phagocytes play a crucial role in the host response to Candida albicans, we examined the ability of Candida to modulate phagocyte ROS production. ROS production was measured in the murine macrophage cell line J774 and in primary phagocytes using luminol-enhanced chemiluminescence. J774 cells, murine polymorphonuclear leukocytes (PMN), human monocytes, and human PMN treated with live C. albicans produced significantly less ROS than phagocytes treated with heat-killed C. albicans. Live C. albicans also suppressed ROS production in murine bone marrow-derived macrophages from C57BL/6 mice, but not from BALB/c mice. Live C. albicans also suppressed ROS in response to external stimuli. C. albicans and Candida glabrata suppressed ROS production by phagocytes, whereas Saccharomyces cerevisiae stimulated ROS production. The cell wall is the initial point of contact between Candida and phagocytes, but isolated cell walls from both heat-killed and live C. albicans stimulated ROS production. Heat-killed C. albicans has increased surface exposure of 1,3-beta-glucan, a cell wall component that can stimulate phagocytes. To determine whether surface 1,3-beta-glucan exposure accounted for the difference in ROS production, live C. albicans cells were treated with a sublethal dose of caspofungin to increase surface 1,3-beta-glucan exposure. Caspofungin-treated C. albicans was fully able to suppress ROS production, indicating that suppression of ROS overrides stimulatory signals from 1,3-beta-glucan. These studies indicate that live C. albicans actively suppresses ROS production in phagocytes in vitro, which may represent an important immune evasion mechanism.

Neutrophils in chronic and aggressive periodontitis in interaction with Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans

PubMed Central

Guentsch, Arndt; Puklo, Magdalena; Preshaw, Philip M.; Glockmann, Eike; Pfister, Wolfgang; Potempa, Jan; Eick, Sigrun

2014-01-01

AIM The aim of this in vitro study was to study phagocytosis and killing of Porphyromonas gingivalis ATCC 33277 and Aggregatibacter actinomycetemcomitans Y4 by peripheral blood PMNs taken from aggressive and chronic periodontitis patients. Also, the release of reactive oxygen species (ROS) and human neutrophil elastase (HNE) upon the interaction of PMNs with bacteria was measured. METHODS Peripheral blood PMNs obtained from 12 chronic periodontitis patients, 6 aggressive periodontitis patients and 12 healthy controls were exposed to Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans following opsonisation of the bacteria using the patient’s own serum. Phagocytosis and killing of the bacteria as well as the extracellular HNE activity were quantified for up to 2 hours. The total amount and the extracellular release of ROS were measured by luminol and isoluminol dependent chemiluminescence. RESULTS PMNs from chronic (62.16 ± 19.39 %) and aggressive periodontitis (43.26 ± 26.63 %) patients phagocytosed more P. gingivalis than the healthy controls (24.43 ± 19.87 %) at 30 mins after exposure to the bacteria (p < 0.05). PMNs from subjects with chronic and aggressive periodontitis released significantly more ROS and demonstrated greater HNE activity in the absence of any stimulus than PMNs from healthy controls (p < 0.05). The total release of ROS increased in chronic periodontitis PMNs and in the control group PMNs after interaction with P. gingivalis. The interaction with A. actinomycetemcomitans resulted in greater total ROS release in chronic periodontitis PMNs and in the control group PMNs than P. gingivalis. CONCLUSION PMNs in aggressive and chronic periodontitis are hyperactive even without any particular stimulus. The extracellular release of ROS and neutrophil elastase by PMNs may not only affect bacterial virulence and/or viability, but also contribute to damage of the surrounding periodontal tissues. PMID:19210340

Shaken, not stirred: bioanalytical study of the antioxidant activities of martinis

PubMed Central

Trevithick, C C; Chartrand, M M; Wahlman, J; Rahman, F; Hirst, M; Trevithick, J R

1999-01-01

Background Moderate consumption of alcoholic drinks seems to reduce the risks of developing cardiovascular disease, stroke, and cataracts, perhaps through antioxidant actions of their alcohol, flavonoid, or polyphenol contents. “Shaken, not stirred” routinely identifies the way the famous secret agent James Bond requires his martinis. Objectives As Mr Bond is not afflicted by cataracts or cardiovascular disease, an investigation was conducted to determine whether the mode of preparing martinis has an influence on their antioxidant capacity. Design Stirred and shaken martinis were assayed for their ability to quench luminescence by a luminescent procedure in which hydrogen peroxide reacts with luminol bound to albumin. Student's t test was used for statistical analysis. Results Shaken martinis were more effective in deactivating hydrogen peroxide than the stirred variety, and both were more effective than gin or vermouth alone (0.072% of peroxide control for shaken martini, 0.157% for stirred v 58.3% for gin and 1.90% for vermouth). The reason for this is not clear, but it may well not involve the facile oxidation of reactive martini components: control martinis through which either oxygen or nitrogen was bubbled did not differ in their ability to deactivate hydrogen peroxide (0.061% v 0.057%) and did not differ from the shaken martini. Moreover, preliminary experiments indicate that martinis are less well endowed with polyphenols than Sauvignon white wine or Scotch whisky (0.056 mmol/l (catechin equivalents) shaken, 0.060 mmol/l stirred v 0.592 mmol/l wine, 0.575 mmol/l whisky). Conclusions 007's profound state of health may be due, at least in part, to compliant bartenders. PMID:10600955

Live Candida albicans Suppresses Production of Reactive Oxygen Species in Phagocytes▿ †

PubMed Central

Wellington, Melanie; Dolan, Kristy; Krysan, Damian J.

2009-01-01

Production of reactive oxygen species (ROS) is an important aspect of phagocyte-mediated host responses. Since phagocytes play a crucial role in the host response to Candida albicans, we examined the ability of Candida to modulate phagocyte ROS production. ROS production was measured in the murine macrophage cell line J774 and in primary phagocytes using luminol-enhanced chemiluminescence. J774 cells, murine polymorphonuclear leukocytes (PMN), human monocytes, and human PMN treated with live C. albicans produced significantly less ROS than phagocytes treated with heat-killed C. albicans. Live C. albicans also suppressed ROS production in murine bone marrow-derived macrophages from C57BL/6 mice, but not from BALB/c mice. Live C. albicans also suppressed ROS in response to external stimuli. C. albicans and Candida glabrata suppressed ROS production by phagocytes, whereas Saccharomyces cerevisiae stimulated ROS production. The cell wall is the initial point of contact between Candida and phagocytes, but isolated cell walls from both heat-killed and live C. albicans stimulated ROS production. Heat-killed C. albicans has increased surface exposure of 1,3-β-glucan, a cell wall component that can stimulate phagocytes. To determine whether surface 1,3-β-glucan exposure accounted for the difference in ROS production, live C. albicans cells were treated with a sublethal dose of caspofungin to increase surface 1,3-β-glucan exposure. Caspofungin-treated C. albicans was fully able to suppress ROS production, indicating that suppression of ROS overrides stimulatory signals from 1,3-β-glucan. These studies indicate that live C. albicans actively suppresses ROS production in phagocytes in vitro, which may represent an important immune evasion mechanism. PMID:18981256

IgA-mediated inhibition of human leucocyte function by interference with Fc gamma and C3b receptors.

PubMed Central

Saito, K; Kato, C; Katsuragi, H; Komatsuzaki, A

1991-01-01

The inhibitory effects of IgA from human colostrum, and IgA1 and IgA2 from human serum on the chemiluminescence (CL) response and phagocytosis of polymorphonuclear leucocytes (PML) to Staphylococcus epidermidis and the CL response to formylmethionyl-leucyl-phenylalanine (FMLP) were studied. The dose-dependent inhibition of the luminol-mediated CL response of human PML to the bacteria was observed in the presence of more than 0.1 mg/ml IgA from both colostrum and serum. The preincubation of PML with a solution of IgA enhanced the suppressive effect of IgA on the cells. Removal of IgA from the reaction mixture after preincubation resulted in recovery, with time, of the response of PML to the bacteria. The bacteria treated with IgA did not give rise to any inhibition of the response. The CL response of PML to FMLP was not affected by the presence of IgA in the reaction mixture. The decrease of phagocytic activity of PML in the presence of IgA resulted in a decrease of NADPH oxidase activity of PML after stimulation with the bacteria as compared with the absence of IgA. The effect of IgA on the receptors of Fc and C3b (CR1) on the surface of PML was measured by monitoring erythrocyte-antibody (EA) or erythrocyte-antibody-complement (EAC) rosette formation and by direct and indirect immunofluorescence techniques using anti-CR1 antibody and Fc-specific antibodies. The presence of IgA in the reaction mixture led to a quantitative decrease in CR1 and the ability to bind IgG to the surface of PML. PMID:1834550

In vitro immunomodulating properties of selected Sudanese medicinal plants.

PubMed

Koko, W S; Mesaik, M Ahmed; Yousaf, S; Galal, M; Choudhary, M Iqbal

2008-06-19

Ethanolic extracts of 23 medicinal plants, commonly used in Sudanese folk medicines against infectious diseases, were investigated for their immunomodulating activity using luminol/lucigenin-based chemiluminescence assay. Preliminary screenings on whole blood oxidative burst activity showed inhibitory activities of 14 plant extracts, while only one plant, Balanites aegyptiaca fruits exhibited a proinflammatory activity. Further investigation was conducted by monitoring their effects on oxidative burst of isolated polymorphonuclear cells (PMNs) and mononuclear cells (MNCs) by using two different phagocytosis activators (serum opsonizing zymosan-A and PMA). Results obtained showed that the fruits and barks of Acacia nilotica, and leaves and barks of Khaya senegalensis, possess average inhibitory effects in the range of 70.7, 67.1, 69.5 and 67.4% on both types of phagocytes (PMNs and MNCs), respectively, at a 6.25 microg/mL concentration. Moderate inhibitory activity (52.2%) was exerted by the aerial parts of Xanthium brasilicum, while the rest of the plants showed only a weak inhibitory activity. The inhibition of oxidative burst activity was found to be irreversible in most of the extracts, except for Peganum harmala, Tephrosia apollinea, Tinospora bakis, and Vernonia amygdalina. Interestingly, the fruits of Balanites aegyptiaca exhibited a moderate proinflammatory effect (37-40.4% increases in ROS level compared to the control) at 25-100 microg/mL concentration in the case of whole blood along with PMNs phagocyte activity. The Tinospora bakis extract showed proinflammatory response at a low concentration (6.25 microg/mL) during activation with PMA. None of these extracts affected PMNs viability (90-98%) upon 2 h incubation, except of the ethanolic extracts of Acacia nilotica fruits and Balanites aegyptiaca barks.

Relationship between age-dependent changes of bovine neutrophil functions and their intracellular Ca2+ concentrations.

PubMed

Higuchi, H; Nagahata, H; Hiroki, M; Noda, H

1997-04-01

Neutrophil functions and intracellular Ca2+ concentrations ([Ca2+]i) were evaluated in 15 Holstein cattle divided into the following 3 groups: 5 neonatal calves less than 1 week old (group 1), 5 young calves 2 to 4 weeks old (group 2) and 5 cows 2 to 3 years old (group 3). The ability of neutrophils to phagocytose Candida albicans (C. albicans) was significantly higher (p < 0.05) in neonatal and young calves than in cows, whereas the phagocytosis by neutrophils of bovine IgG-coated yeasts (IgG-yeasts) was significantly lower (p < 0.05) in neonatal and young calves than that in cows. The killing activity by neutrophils of C. albicans in neonatal and young calves was significantly lower (p < 0.05) than that in cows. Luminol dependent chemiluminescent (LDCL) responses stimulated with opsonized zymosan (OPZ), heat-aggregated IgG (H-agg.IgG) and phorbol myristate acetate (PMA) were apparently lower in neonatal and young calves than in cows. No clearly different expressions of complement receptor type 3 (CR3) on neutrophils were observed among the 3 groups of cattle, although the values due to the binding of FITC-anti-bovine IgG to neutrophils in neonatal and young calves were lower than those in group 3. The OPZ-induced [Ca2+]i of neutrophils in neonatal and young calves were significantly higher (p < 0.05) than those in cows, but they were lower in neonatal and young calves when stimulated with H-agg.IgG. These results indicate that CR3- and FcR-mediated phagocytic and killing activities of neutrophils in neonatal and young calves are different from those in cows. These phenomena may be associated with age-dependent changes in [Ca2+]i.

The interaction of ruminant IgG with receptor type II for IgG on human phagocytes.

PubMed Central

Jungi, T W; Peterhans, E; Pfister, H; Fey, H

1989-01-01

The interaction of ruminant IgG with human phagocytes was assessed using Fc receptor (FcR)-mediated ingestion and the triggering of a respiratory burst as effector functions indicative of receptor-specific interaction. In monomeric form, ruminant IgG was three to five orders of magnitude less potent than homologous IgG in inhibiting FcR-specific phagocytosis by monocytes. However, when attached to tanned sheep erythrocytes (Es-T), ruminant IgG was opsonic, as it promoted enhanced phagocytosis of Es-T, comparable to ingestion of rabbit IgG-coated Es. This phagocytosis was inhibitable by high concentrations of human IgG in the fluid phase. Moreover, Es-T precoated with ferritin could be opsonized to a similar degree by anti-ferritin IgG from rabbit and cow. However, only bovine IgG1, but not IgG2, was opsonic. Bovine and goat IgG of some, but not other, suppliers were inactive. Similar results were obtained by measuring the respiratory burst triggered by heat-aggregated IgG, using a luminol-enhanced chemiluminescence assay. Thus, human IgG and ruminant IgG stimulated monocytes and, to a lesser extent, polymorphonuclear leucocytes (PMN), to generate CL. Depending on the manufacturer, some preparations of bovine and goat IgG were inactive, and bovine IgG2 failed to induce CL. These findings prove that certain ruminant IgG preparations, including bovine IgG1 interacting weakly with homologous PMN and monocytes, do interact with human PMN, monocytes and macrophages in a FcR-specific manner when offered in complexed form. Inhibition studies suggest that bovine IgG1 interacts mainly with human FcR type II. In contrast, bovine IgG2, regarded as cytophilic for homologous PMN, fails to interact with human PMN, monocytes and macrophages. PMID:15493277

Controlled Release of Dexamethasone from Peptide Nanofiber Gels to Modulate Inflammatory Response

PubMed Central

Webber, Matthew J.; Matson, John B.; Tamboli, Vibha K.; Stupp, Samuel I.

2012-01-01

New biomaterials that have the ability to locally suppress an immune response could have broad therapeutic use in the treatment of diseases characterized by acute or chronic inflammation or as a strategy to facilitate improved efficacy in cell or tissue transplantation. We report here on the preparation of a modular peptide amphiphile (PA) capable of releasing an anti-inflammatory drug, dexamethasone (Dex), by conjugation via a labile hydrazone linkage. This molecule self-assembled in water into long supramolecular nanofibers when mixed with a similar PA lacking the drug conjugate, and the addition of calcium salt to screen electrostatic repulsion between nanofibers promoted gel formation. These nanofiber gels demonstrated sustained release of soluble Dex for over one month in physiologic media. The Dex released from these gels maintained its anti-inflammatory activity when evaluated in vitro using a human inflammatory reporter cell line and furthermore preserved cardiomyocytes viability upon induced oxidative stress. The ability of this gel to mitigate the inflammatory response in cell transplantation strategies was evaluated using cell-surrogate polystyrene microparticles suspended in the nanofiber gel that were then subcutaneously injected in a mouse. Live animal luminescence imaging using the chemiluminescent reporter molecule luminol showed a significant reduction in inflammation at the site where particles were injected with Dex-PA compared to the site of injection for particles within a control PA in the same animal. Histological evidence suggested a marked reduction in the number of infiltrating inflammatory cells when particles were delivered within Dex-PA nanofiber gels and very little inflammation was observed at either 3 days or 21 days post-implantation. The use of Dex-PA could facilitate localized anti-inflammatory activity as a component of biomaterials designed for various applications in regenerative medicine and could specifically be a useful module for PA-based therapies. More broadly, these studies define a versatile strategy for facile synthesis of self-assembling peptide-based materials with the ability to control drug release. PMID:22748768

Development and validation of the first assay method coupling liquid chromatography with chemiluminescence for the simultaneous determination of menadione and its thioether conjugates in rat plasma.

PubMed

Elgawish, Mohamed Saleh; Shimomai, Chikako; Kishikawa, Naoya; Ohyama, Kaname; Wada, Mitsuhiro; Kuroda, Naotaka

2013-09-16

Menadione (2-methyl-1,4-naphthoquinone, MQ), a component of multivitamin drugs with antihemorrhagic, antineoplastic, and antimalarial activity, is frequently used to investigate quinone-induced cytotoxicity. The formation of MQ conjugates with glutathione (GSH) by Michael addition and subsequent biotransformation to yield N-acetyl-l-cysteine conjugates is believed to be an important detoxification process. However, the resulting conjugates, 2-methyl-3-(glutathione-S-yl)-1,4-naphthoquinone (MQ-GS) and 2-methyl-3-(N-acetyl-l-cysteine-S-yl)-1,4-naphthoquinone (MQ-NAC), retain the ability to redox cycle and to arylate cellular nucleophiles. Although the nephrotoxicity and hepatotoxicity of MQ-thiol conjugates have been reported in vitro, methods for their determination in vivo have yet to be published. Herein, a highly sensitive, simple, and selective HPLC-chemiluminescence (HPLC-CL) coupled method is reported, allowing for the first time the simultaneous determination of MQ, MQ-GS, and MQ-NAC in rat plasma after MQ administration. Our method exploits the unique redox characteristics of MQ, MQ-GS, and MQ-NAC to react with dithiothreitol (DTT) to liberate reactive oxygen species (ROS) which are detected by a CL assay using luminol as a CL probe. To verify the proposed mechanism, MQ-GS and MQ-NAC were synthetically prepared. Specimen preparation involved solid-phase extraction on an Oasis HLB cartridge followed by isocratic elution on an ODS column. No interference from endogenous substances was detected. Linearity was observed in the range of 5-120 nM for MQ-GS and MQ-NAC and 10-240 nM for MQ, with detection limits (S/N of 3) of 1.4, 0.8, and 128 fmol for MQ-GS, MQ-NAC, and MQ, respectively. The application of our method reported here is the first to extensively study the stability and reversibility of thiol-quinones.

Dual-Readout Immunochromatographic Assay by Utilizing MnO2 Nanoflowers as the Unique Colorimetric/Chemiluminescent Probe.

PubMed

Ouyang, Hui; Lu, Qian; Wang, Wenwen; Song, Yang; Tu, Xinman; Zhu, Chengzhou; Smith, Jordan N; Du, Dan; Fu, Zhifeng; Lin, Yuehe

2018-04-17

Manganese dioxide nanoflowers (MnO 2 NFs) were synthesized and used as a dual readout probe to develop a novel immunochromatographic test strip (ITS) for detecting pesticide residues using chlorpyrifos as the model analyte. MnO 2 NFs-labeled antibody for chlorpyrifos was employed as the signal tracer for conducting the ITS. After 10 min competitive immunoreaction, the tracer antibody was captured by the immobilized immunogen in the test strip, resulting in the captured MnO 2 NFs on test line. The captured MnO 2 NFs led to the appearance of brown color on the test line, which could be easily observed by the naked eye as a qualitative readout. Due to the very slight colorimetric difference of chlorpyrifos at trace concentrations, the semiquantitative readout by naked eyes could not meet the demand of quantitative analysis. MnO 2 NFs showed a significant effect on the luminol-H 2 O 2 chemiluminescent (CL) system, and the CL signal driven by MnO 2 NFs were used to detect the trace concentration of chlorpyrifos quantitatively. 1,3-Diphenylisobenzofuran quenching studies and TMB-H 2 O 2 coloration assays were conducted for studying the enhancing mechanism of MnO 2 NFs, which was based on the oxidant activity to decompose H 2 O 2 for forming reactive oxygen species. Under optimal conditions, the linear range of chlorpyrifos was 0.1-50 ng/mL with a low detection limit of 0.033 ng/mL (S/N = 3). The reliability of the dual-readout ITS was successfully demonstrated by the application on traditional Chinese medicine and environmental water samples. Due to the simultaneous rapid-qualitative and sensitive-quantitative detection, the dual-readout protocol provides a promising strategy for rapid screening and field assay on various areas such as environmental monitoring and food safety.

Flowers of Clerodendrum volubile exacerbate immunomodulation by suppressing phagocytic oxidative burst and modulation of COX-2 activity.

PubMed

Erukainure, Ochuko L; Mesaik, Ahmed M; Muhammad, Aliyu; Chukwuma, Chika I; Manhas, Neha; Singh, Parvesh; Aremu, Oluwole S; Islam, Md Shahidul

2016-10-01

The immunomodulatory potentials of the crude methanolic extract and fractions [n-hexane (Hex), n-dichloromethane (DCM), ethyl acetate (EtOAc) and n-butanol (BuOH)] of Clerodendrum volubile flowers were investigated on whole blood phagocytic oxidative burst using luminol-amplified chemiluminescence technique. They were also investigated for their free radicals scavenging activities. The DCM fraction showed significant (p<0.05) anti-oxidative burst and free radical scavenging activities indicating high immunomodulatory and antioxidant potencies respectively. Cytotoxicity assay of the DCM fraction revealed a cytotoxic effect on CC-1 normal cell line. GCMS analysis revealed the presence of triacetin; 3,6-dimethyl-3-octanol; 2R - Acetoxymethyl-1,3,3-trimethtyl - 4t - (3-methyl-2-buten-1-yl) - 1c - cyclohexanol and Stigmastan - 3,5-diene in DCM fraction. These compounds were docked with the active sites of cyclooxygenase-2 (COX-2). Triacetin, 3,6-dimethyl-3-Octanol, and 2R-Acetoxymethyl-1,3,3-trimethtyl-4t-(3-methyl-2-buten-1-yl)-1c-cyclohexanol docked comfortably with COX-2 with good scoring function (-CDocker energy) indicating their inhibitory potency against COX-2. 3,6-dimethyl-3-Octanol, displayed the lowest predicted free energy of binding (-21.4kcalmol -1 ) suggesting its stronger interaction with COX-2, this was followed by 2R - Acetoxymethyl-1, 3, 3-trimethtyl-4t-(3-methyl-2-buten-1-yl)-1c-cyclhexanol (BE=-20.5kcalmol -1 ), and triacetin (BE=-10.9kcalmol -1 ). Stigmastan - 3,5-diene failed to dock with COX-2. The observed suppressive effect of the DCM fraction of C. volubile flower methanolic extract on phagocytic oxidative burst indicates an immunomodulatory potential. This is further reflected in its free scavenging activities and synergetic modulation of COX-2 activities by its identified compounds in silico. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Target-Catalyzed DNA Four-Way Junctions for CRET Imaging of MicroRNA, Concatenated Logic Operations, and Self-Assembly of DNA Nanohydrogels for Targeted Drug Delivery.

PubMed

Bi, Sai; Xiu, Bao; Ye, Jiayan; Dong, Ying

2015-10-21

Here we report a target-catalyzed DNA four-way junction (DNA-4WJ) on the basis of toehold-mediated DNA strand displacement reaction (TM-SDR), which is readily applied in enzyme-free amplified chemiluminescence resonance energy transfer (CRET) imaging of microRNA. In this system, the introduction of target microRNA-let-7a (miR-let-7a) activates a cascade of assembly steps with four DNA hairpins, followed by a disassembly step in which the target microRNA is displaced and released from DNA-4WJ to catalyze the self-assembly of additional branched junctions. As a result, G-quadruplex subunit sequences and fluorophore fluorescein amidite (FAM) are encoded in DNA-4WJ in a close proximity, stimulating a CRET process in the presence of hemin/K(+) to form horseradish peroxidase (HRP)-mimicking DNAzyme that catalyzes the generation of luminol/H2O2 chemiluminescence (CL), which further transfers to FAM. The background signal is easily reduced using magnetic graphene oxide (MGO) to remove unreacted species through magnetic separation, which makes a great contribution to improve the detection sensitivity and achieves a detection limit as low as 6.9 fM microRNA-let-7a (miR-let-7a). In addition, four-input concatenated logic circuits with an automatic reset function have been successfully constructed relying on the architecture of the proposed DNA-4WJ. More importantly, DNA nanohydrogels are self-assembled using DNA-4WJs as building units after centrifugation, which are driven by liquid crystallization and dense packaging of building units. Moreover, the DNA nanohydrogels are readily functionalized by incorporating with aptamers, bioimaging agents, and drug loading sites, which thus are served as efficient nanocarriers for targeted drug delivery and cancer therapy with high loading capacity and excellent biocompatibility.

The oxidative burst reaction in mammalian cells depends on gravity

PubMed Central

2013-01-01

Gravity has been a constant force throughout the Earth’s evolutionary history. Thus, one of the fundamental biological questions is if and how complex cellular and molecular functions of life on Earth require gravity. In this study, we investigated the influence of gravity on the oxidative burst reaction in macrophages, one of the key elements in innate immune response and cellular signaling. An important step is the production of superoxide by the NADPH oxidase, which is rapidly converted to H2O2 by spontaneous and enzymatic dismutation. The phagozytosis-mediated oxidative burst under altered gravity conditions was studied in NR8383 rat alveolar macrophages by means of a luminol assay. Ground-based experiments in “functional weightlessness” were performed using a 2 D clinostat combined with a photomultiplier (PMT clinostat). The same technical set-up was used during the 13th DLR and 51st ESA parabolic flight campaign. Furthermore, hypergravity conditions were provided by using the Multi-Sample Incubation Centrifuge (MuSIC) and the Short Arm Human Centrifuge (SAHC). The results demonstrate that release of reactive oxygen species (ROS) during the oxidative burst reaction depends greatly on gravity conditions. ROS release is 1.) reduced in microgravity, 2.) enhanced in hypergravity and 3.) responds rapidly and reversible to altered gravity within seconds. We substantiated the effect of altered gravity on oxidative burst reaction in two independent experimental systems, parabolic flights and 2D clinostat / centrifuge experiments. Furthermore, the results obtained in simulated microgravity (2D clinorotation experiments) were proven by experiments in real microgravity as in both cases a pronounced reduction in ROS was observed. Our experiments indicate that gravity-sensitive steps are located both in the initial activation pathways and in the final oxidative burst reaction itself, which could be explained by the role of cytoskeletal dynamics in the assembly and function of the NADPH oxidase complex. PMID:24359439

Variation of iron redox kinetics and its relation with molecular composition of standard humic substances at circumneutral pH.

PubMed

Lee, Ying Ping; Fujii, Manabu; Kikuchi, Tetsuro; Terao, Koumei; Yoshimura, Chihiro

2017-01-01

Oxidation and reduction kinetics of iron (Fe) and proportion of steady-state Fe(II) concentration relative to total dissolved Fe (steady-state Fe(II) fraction) were investigated in the presence of various types of standard humic substances (HS) with particular emphasis on the photochemical and thermal reduction of Fe(III) and oxidation of Fe(II) by dissolved oxygen (O2) and hydrogen peroxide (H2O2) at circumneutral pH (pH 7-8). Rates of Fe(III) reduction were spectrophotometrically determined by a ferrozine method under the simulated sunlight and dark conditions, whereas rates of Fe(II) oxidation were examined in air-saturated solution using luminol chemiluminescence technique. The reduction and oxidation rate constants were determined to substantially vary depending on the type of HS. For example, the first-order rate constants varied by up to 10-fold for photochemical reduction and 7-fold for thermal reduction. The degree of variation in Fe(II) oxidation was larger for the H2O2-mediated reaction compared to the O2-mediated reaction (e.g., 15- and 3-fold changes for the former and latter reactions, respectively, at pH 8). The steady-state Fe(II) fraction under the simulated sunlight indicated that the Fe(II) fraction varies by up to 12-fold. The correlation analysis indicated that variation of Fe(II) oxidation is significantly associated with aliphatic content of HS, suggesting that Fe(II) complexation by aliphatic components accelerates Fe(II) oxidation. The reduction rate constant and steady-state Fe(II) fractions in the presence of sunlight had relatively strong positive relations with free radical content of HS, possibly due to the reductive property of radical semiquinone in HS. Overall, the findings in this study indicated that the Fe reduction and oxidation kinetics and resultant Fe(II) formation are substantially influenced by chemical properties of HS.

Isolation and characterization of a pigmentless-conidium mutant of Aspergillus fumigatus with altered conidial surface and reduced virulence.

PubMed Central

Jahn, B; Koch, A; Schmidt, A; Wanner, G; Gehringer, H; Bhakdi, S; Brakhage, A A

1997-01-01

Aspergillus fumigatus is an important pathogen of immunocompromised hosts, causing pneumonia and invasive disseminated disease with high mortality. The factors contributing to the predominance of A. fumigatus as an opportunistic pathogen are largely unknown. Since the survival of conidia in the host is a prerequisite for establishing disease, we have been attempting to identify factors which are associated with conidia and, simultaneously, important for infection. Therefore, an A. fumigatus mutant strain (white [W]) lacking conidial pigmentation was isolated. Scanning electron microscopy revealed that conidia of the W mutant also differed in their surface morphology from those of the wild type (WT). Mutant (W) and WT conidia were compared with respect to their capacities to stimulate an oxidative response in human phagocytes, their intracellular survival in human monocytes, and virulence in a murine animal model. Luminol-dependent chemiluminescence was 10-fold higher when human neutrophils or monocytes were challenged with W conidia compared with WT conidia. Furthermore, mutant conidia were more susceptible to killing by oxidants in vitro and were more efficiently damaged by human monocytes in vitro than WT conidia. In a murine animal model, the W mutant strain showed reduced virulence compared with the WT. A reversion analysis of the W mutant demonstrated that all phenotypes associated with the W mutant, i.e., altered conidial surface, amount of reactive oxygen species release, susceptibility to hydrogen peroxide, and reduced virulence in an murine animal model, coreverted in revertants which had regained the ability to produce green spores. This finding strongly suggests that the A. fumigatus mutant described here carries a single mutation which caused all of the observed phenotypes. Our results suggest that the conidium pigment or a structural feature related to it contributes to fungal resistance against host defense mechanisms in A. fumigatus infections. PMID:9393803

The oxidative burst reaction in mammalian cells depends on gravity.

PubMed

Adrian, Astrid; Schoppmann, Kathrin; Sromicki, Juri; Brungs, Sonja; von der Wiesche, Melanie; Hock, Bertold; Kolanus, Waldemar; Hemmersbach, Ruth; Ullrich, Oliver

2013-12-20

Gravity has been a constant force throughout the Earth's evolutionary history. Thus, one of the fundamental biological questions is if and how complex cellular and molecular functions of life on Earth require gravity. In this study, we investigated the influence of gravity on the oxidative burst reaction in macrophages, one of the key elements in innate immune response and cellular signaling. An important step is the production of superoxide by the NADPH oxidase, which is rapidly converted to H2O2 by spontaneous and enzymatic dismutation. The phagozytosis-mediated oxidative burst under altered gravity conditions was studied in NR8383 rat alveolar macrophages by means of a luminol assay. Ground-based experiments in "functional weightlessness" were performed using a 2 D clinostat combined with a photomultiplier (PMT clinostat). The same technical set-up was used during the 13th DLR and 51st ESA parabolic flight campaign. Furthermore, hypergravity conditions were provided by using the Multi-Sample Incubation Centrifuge (MuSIC) and the Short Arm Human Centrifuge (SAHC). The results demonstrate that release of reactive oxygen species (ROS) during the oxidative burst reaction depends greatly on gravity conditions. ROS release is 1.) reduced in microgravity, 2.) enhanced in hypergravity and 3.) responds rapidly and reversible to altered gravity within seconds. We substantiated the effect of altered gravity on oxidative burst reaction in two independent experimental systems, parabolic flights and 2D clinostat / centrifuge experiments. Furthermore, the results obtained in simulated microgravity (2D clinorotation experiments) were proven by experiments in real microgravity as in both cases a pronounced reduction in ROS was observed. Our experiments indicate that gravity-sensitive steps are located both in the initial activation pathways and in the final oxidative burst reaction itself, which could be explained by the role of cytoskeletal dynamics in the assembly and function of the NADPH oxidase complex.

Pathogenicity of Peptostreptococcus micros morphotypes and Prevotella species in pure and mixed culture.

PubMed

van Dalen, P J; van Deutekom-Mulder, E C; de Graaff, J; van Steenbergen, T J

1998-02-01

Recently, an atypical rough colony morphotype of Peptostreptococcus micros, a species which is found in ulcerating infections, including periodontitis, was isolated. The virulence of morphotypes alone and in combination with Prevotella intermedia and P. nigrescens was investigated both in vivo and in vitro. All strains tested induced abscesses containing fluid pus in a mouse skin model, and lesions caused by monocultures of the rough morphotype strains of P. micros were statistically significantly larger than those induced by the smooth morphotype strains. Inocula containing both morphotypes produced similar sized abscesses compared to mono-inocula containing the same bacterial load. Both Prevotella species induced small abscesses when inoculated alone, and when Pr. nigrescens was inoculated with one of the other strains, the abscesses were not significantly different from the abscesses induced by the mono-infections of this strain. Synergy, in terms of higher numbers of colony forming units (cfu) in the mixed inocula, was found for all combinations of the rough morphotypes of P. micros and both Prevotella spp. Pus from abscesses caused by combinations of Peptostreptococcus and Prevotella spp. transmitted the infection to other mice, but no abscesses were formed in mice inoculated with pus induced by mono-inocula. These results demonstrated synergic activity between both rough and smooth P. micros strains and oral Prevotella strains. The in-vitro co-culture experiments produced no evidence of growth stimulation. The effect of P. micros strains on the immune system was investigated by testing their ability to initiate luminol-dependent chemiluminescence of polymorphonuclear leucocytes in the presence and absence of human serum. In the latter, the rough morphotype strains initiated higher counts than the smooth morphotype strains. Further work is needed to elucidate the difference in virulence between the smooth and the rough morphotype cells of P. micros and the nature of the interaction with the Prevotella spp.

Hyperactivity and reactivity of peripheral blood neutrophils in chronic periodontitis

PubMed Central

Matthews, J B; Wright, H J; Roberts, A; Cooper, P R; Chapple, I L C

2007-01-01

Some evidence exists that peripheral neutrophils from patients with chronic periodontitis generate higher levels of reactive oxygen species (ROS) after Fcγ-receptor stimulation than those from healthy controls. We hypothesized that peripheral neutrophils in periodontitis also show both hyper-reactivity to plaque organisms and hyperactivity in terms of baseline, unstimulated generation and release of ROS. Peripheral neutrophils from chronic periodontitis patients and age/sex/smoking-matched healthy controls (18 pairs) were assayed for total ROS generation and extracellular ROS release, with and without stimulation (Fcγ-receptor and Fusobacterium nucleatum), using luminol and isoluminol chemiluminescence. Assays were performed with and without priming with Escherichia coli lipopolysaccharide (LPS) and granulocyte–macrophage colony-stimulating factor (GM-CSF). Phox gene expression (p22, p47, p67, gp91) was investigated using reverse transcription–polymerase chain reaction (RT–PCR). Neutrophils from patients produced higher mean levels of ROS in all assays. Total generation and extracellular release of ROS by patients' cells were significantly greater than those from controls after FcγR-stimulation, with (P = 0·023) and without (P ≤ 0·023) priming with GM-CSF. Differences in unstimulated total ROS generation were not significant. By contrast, patients' cells demonstrated greater baseline, extracellular ROS release than those from controls (P = 0·004). This difference was maintained after priming with LPS (P = 0·028) but not GM-CSF (P = 0·217). Phox gene expression was similar in patient and control cells at baseline and stimulation with F. nucleatum (3 h) consistently reduced gp91PHOX transcripts. Our data demonstrate that peripheral neutrophils from periodontitis patients exhibit hyper-reactivity following stimulation (Fcγ-receptor and F. nucleatum) and hyperactivity in terms of excess ROS release in the absence of exogenous stimulation. This hyperactive/-reactive neutrophil phenotype is not associated with elevated phox gene expression. PMID:17223966

Modelling cortical cataractogenesis 22: is in vitro reduction of damage in model diabetic rat cataract by taurine due to its antioxidant activity?

PubMed

Kilic, F; Bhardwaj, R; Caulfeild, J; Trevithick, J R

1999-09-01

The protective effect of taurine in model in vitro diabetic cataract and the mechanism of this effect were investigated in isolated rat lenses. Isolated rat lenses were incubated in medium 199 in elevated glucose (55.6 m m) with taurine (5 m m). Taurine concentrations in the lenses were determined by amino acid analysis. Accumulative leakage of the intracellular enzyme lactate dehydrogenase (LDH) was used to estimate damage to the lens, as previously reported. In the clear lenses, prior to vacuole formation, after 1 or 2 days of incubation, the taurine and amino acids in lenses decreased progressively in concentration. In lenses incubated with 5 m m taurine, the level of taurine was increased towards that of control lenses. In taurine-treated lenses LDH leakage was significantly decreased, and lens clarity was maintained, similarly to that found previously for vitamin C and lipoic acid. To test whether taurine has similar antioxidant activity, we tested its ability to decrease luminol luminescence generated by (1) superoxide from hypoxanthine/xanthine oxidase and (2) peroxide from diluted glucose/glucose oxidase. For either superoxide or peroxide, the luminescence was decreased to zero, as a function of increasing taurine concentration, at 30 m m, approximately the physiological concentration of taurine in the lens. Spin trapping confirmed that taurine scavenged superoxide. This is consistent with a role for taurine as an important antioxidant protecting the lens against oxidative insults. Amino acids also had antioxidant activity in this assay, and as a group, when all activities were summed, their loss also contributed significantly to the antioxidant loss. Taken in conjunction with Wolff and Crabbe's observation of increased free radical generation by glucose auto-oxidation in diabetes, this suggests a push-pull mechanism for increased oxidative stress in diabetic cataract, involving both increased free radicals and decreased radical scavenging antioxidants. Copyright 1999 Academic Press.

An ultrasensitive chemiluminescence aptasensor for thrombin detection based on iron porphyrin catalyzing luminescence desorbed from chitosan modified magnetic oxide graphene composite.

PubMed

Sun, Yuanling; Wang, Yanhui; Li, Jianbo; Ding, Chaofan; Lin, Yanna; Sun, Weiyan; Luo, Chuannan

2017-11-01

In this work, an ultrasensitive chemiluminescence (CL) aptasensor was prepared for thrombin detection based on iron porphyrin catalyzing luminol - hydrogen peroxide luminescence under alkaline conditions, and iron porphyrin was desorbed from chitosan modified magnetic oxide graphene composite (CS@Fe 3 O 4 @GO). Firstly, CS@Fe 3 O 4 @GO was prepared. CS@Fe 3 O 4 @GO has advantages of the good biocompatibility and positively charged on its surface of CS, the large specific surface area of GO and the easy separation characteristics of Fe 3 O 4 . GO, Fe 3 O 4 and CS@Fe 3 O 4 @GO were confirmed by transmission electron microscopy (TEM), scanning electron microscope (SEM), fourier transform infrared (FTIR) and X-ray powder diffraction (XRD). Then, thrombin aptamer (T-Apt) and hemin (HM, an iron porphyrin) were sequentially modified on the surface of CS@Fe 3 O 4 @GO to form CS@Fe 3 O 4 @GO@T-Apt@HM. The immobilization properties of CS@Fe 3 O 4 @GO to T-Apt and adsorption properties of CS@Fe 3 O 4 @GO@T-Apt to HM were sequentially researched through the curves of kinetics and the curves of thermodynamics. When thrombin existed in solutions, HM was desorbed from the surface of CS@Fe 3 O 4 @GO@T-Apt@HM owing to the strong specific recognition ability between thrombin and T-Apt, causing the changes of CL signal. Under optimized CL conditions, thrombin could be measured with the linear concentration range of 5.0×10 -15 -2.5×10 -10 mol/L. The detection limit was 1.5×10 -15 mol/L (3δ) while the relative standard deviation (RSD) was 3.2%. Finally, the CS@Fe 3 O 4 @GO@T-Apt@HM-CL aptasensor was used for the determination of thrombin in practical serum samples and recoveries ranged from 95% to 103%. Those satisfactory results revealed potential application of the CS@Fe 3 O 4 @GO@T-Apt@HM-CL aptasensor for thrombin detection in monitoring and diagnosis of human blood diseases. Copyright © 2017 Elsevier B.V. All rights reserved.

A Permeable Cuticle Is Associated with the Release of Reactive Oxygen Species and Induction of Innate Immunity

PubMed Central

L'Haridon, Floriane; Besson-Bard, Angélique; Binda, Matteo; Serrano, Mario; Abou-Mansour, Eliane; Balet, Francine; Schoonbeek, Henk-Jan; Hess, Stephane; Mir, Ricardo; Léon, José; Lamotte, Olivier; Métraux, Jean-Pierre

2011-01-01

Wounded leaves of Arabidopsis thaliana show transient immunity to Botrytis cinerea, the causal agent of grey mould. Using a fluorescent probe, histological staining and a luminol assay, we now show that reactive oxygen species (ROS), including H2O2 and O2 −, are produced within minutes after wounding. ROS are formed in the absence of the enzymes Atrboh D and F and can be prevented by diphenylene iodonium (DPI) or catalase. H2O2 was shown to protect plants upon exogenous application. ROS accumulation and resistance to B. cinerea were abolished when wounded leaves were incubated under dry conditions, an effect that was found to depend on abscisic acid (ABA). Accordingly, ABA biosynthesis mutants (aba2 and aba3) were still fully resistant under dry conditions even without wounding. Under dry conditions, wounded plants contained higher ABA levels and displayed enhanced expression of ABA-dependent and ABA-reporter genes. Mutants impaired in cutin synthesis such as bdg and lacs2.3 are already known to display a high level of resistance to B. cinerea and were found to produce ROS even when leaves were not wounded. An increased permeability of the cuticle and enhanced ROS production were detected in aba2 and aba3 mutants as described for bdg and lacs2.3. Moreover, leaf surfaces treated with cutinase produced ROS and became more protected to B. cinerea. Thus, increased permeability of the cuticle is strongly linked with ROS formation and resistance to B. cinerea. The amount of oxalic acid, an inhibitor of ROS secreted by B. cinerea could be reduced using plants over expressing a fungal oxalate decarboxylase of Trametes versicolor. Infection of such plants resulted in a faster ROS accumulation and resistance to B. cinerea than that observed in untransformed controls, demonstrating the importance of fungal suppression of ROS formation by oxalic acid. Thus, changes in the diffusive properties of the cuticle are linked with the induction ROS and attending innate defenses. PMID:21829351

Amiodarone causes acute oxidant lung injury in ventilated and perfused rabbit lungs.

PubMed

Kennedy, T P; Gordon, G B; Paky, A; McShane, A; Adkinson, N F; Peters, S P; Friday, K; Jackman, W; Sciuto, A M; Gurtner, G H

1988-07-01

Amiodarone (ADR), a new antiarrhythmic drug for life-threatening cardiac arrhythmias, causes pneumonitis or lung fibrosis in a sizeable minority of patients. The cause of lung damage is not known. We have shown that infusion of 10 mg amiodarone into the inflow circuit of ventilated and perfused rabbit lungs causes immediate increase in pulmonary artery pressure (mean +/- SEM) (from 13.6 +/- 1.2 to 40.6 +/- 9.5 mm Hg, p less than 0.01) and pulmonary edema with marked increase in the pulmonary generation of thromboxane and leukotrienes C4 and/or D4. Albumin (2 g%) in the perfusate prevents any increase in lung perfusion pressure or edema formation. When lung perfusion pressure increase is blocked with the combined cyclooxygenase and lipoxygenase inhibitor enolicam sodium (CG5391B, 35 microM in perfusate), significant lung edema still occurs after amiodarone, indicating that amiodarone causes increased alveolar-capillary membrane permeability. Addition of catalase (100 U/ml) or superoxide dismutase and catalase (100 U/ml each) to perfusate fails to protect from amiodarone lung injury. Immediate infusion of amiodarone (10 mg) into lungs ventilated with room air (ADR + RA) causes an increase in lung weight gain from baseline (delta W) of 5.7 +/- 1.5 g/min. Compared with ADR + RA, ventilation of lungs with 4% O2 (delta W = 0.7 +/- 0.3 g/min, p less than 0.05), pretreatment of rabbits for 3 days with butylated hydroxyanisole (BHA, 100 mg/kg/day i.p., delta W = 0.05 +/- 0.02 g/min, p less than 0.01), pretreatment of rabbits for 3 days with vitamin E (Vit E, 300 U/day orally, delta W = 0.6 +/- 0.2 g/min, p less than 0.05), or addition of N-acetylcysteine to the lung perfusate (NAC, 5 mM, delta W = 0.1 +/- 0.08 g/min, p less than 0.01) all protect from lung edema formation after amiodarone. Amiodarone (100 mg) also caused a marked increase in luminol-enhanced lung chemiluminescence, lung production of superoxide anion (O2-), and tissue levels of lung glutathione disulfide. These results suggest that amiodarone causes lung injury by an oxidant mechanism.

Role of oxidative stress in multiparity-induced endothelial dysfunction.

PubMed

Tawfik, Huda E; Cena, Jonathan; Schulz, Richard; Kaufman, Susan

2008-10-01

Multiparity is associated with increased risk of cardiovascular disease. We tested whether multiparity induces oxidative stress in rat vascular tissue. Coronary arteries and thoracic aorta were isolated from multiparous and age-matched virgin rats. Relaxation to ACh and sodium nitroprusside (SNP) was measured by wire myography. We also tested the effect of the superoxide dismutase mimetic MnTE2PyP (30 microM), the NADPH oxidase inhibitor apocynin (10 microM), and the peroxynitrite scavenger FeTPPs (10 microM) on ACh-mediated relaxation in coronary arteries. Vascular superoxide anion was measured using the luminol derivative L-012 and nitric oxide (NO) generation by the Griess reaction. Multiparity reduced maximal response and sensitivity to ACh in coronary arteries [maximal relaxation (E(max)): multiparous 49+/-3% vs. virgins 95%+/-3%; EC(50): multiparous 135+/-1 nM vs. virgins 60+/-1 nM], and in aortic rings (E(max): multiparous 38+/-3% vs. virgins 79+/-4%; EC(50): multiparous 160+/-2 nM vs. virgins 90+/-3 nM). Coronary arteries from the two groups relaxed similarly to SNP. Superoxide anions formation was significantly higher in both coronary arteries (2.8-fold increase) and aorta (4.1-fold increase) from multiparous rats compared with virgins. In multiparous rats, incubation with MnTE2PyP, apocynin, and FeTPPs improved maximal relaxation to ACh (MnTE2PyP: 74+/-5%; vehicle: 41+/-5%; apocynin: 73+/-3% vs. vehicle: 41+/-3%; FeTPPs: 72+/-3% vs. vehicle: 46+/-3%) and increased sensitivity (EC(50): MnTE2PyP: 61+/-0.5 nM vs. vehicle: 91+/-1 nM; apocynin: 45+/-3 nM vs. vehicle: 91+/-6 nM; FeTPP: 131 +/- 2 nM vs. vehicle: 185+/-1 nM). Multiparity also reduced total nitrate/nitrite levels (multiparous: 2.5+/-2 micromol/mg protein vs. virgins: 7+/-1 micromol/mg protein) and endothelial nitric oxide synthase protein levels (multiparous: 0.53+/-0.1 protein/actin vs. virgins: 1.0+/-0.14 protein/actin). These data suggest that multiparity induces endothelial dysfunction through decreased NO bioavailability and increased reactive oxygen species formation.

The Effects of Plantago major on the Activation of the Neutrophil Respiratory Burst

PubMed Central

Reina, Elaine; Al-Shibani, Nouf; Allam, Eman; Gregson, Karen S.; Kowolik, Michael; Windsor, L. Jack

2013-01-01

Plantago major is a common plant that grows worldwide in temperate zones and is found in fields, lawns, and on the roadsides. Its leaves and seeds have been used in almost all parts of the world for centuries as a wound healer, analgesic, antioxidant, and antibiotic, as well as an immune system modulator, antiviral, antifungal, and anti-inflammatory agent. Baicalein and aucubin are the two most biologically active components of P. major, and both have been shown to have antioxidant, anti-inflammatory, and anticancer properties. Neutrophils have a pivotal role in wound healing and inflammation. Their principal mechanism of host defense is the killing of pathogens via the production of reactive oxygen species (ROS). The aim of the present study was to determine the in vitro effects of P. major extract, baicalein, and aucubin on human neutrophil respiratory burst activity. The cytotoxicity of the agents was assessed by lactate dehydrogenase (LDH) assays. A standard luminol-dependent chemiluminescence (CL) assay was utilized to monitor the respiratory burst of the neutrophils after exposure to P. major extract and its two active ingredients, baicalein and aucubin. Three replicates per group were included in each of the three runs of the experiments and analysis of variance (ANOVA) was used for statistical analysis. P. major and baicalein were not toxic to the cells at any of the concentrations examined. Aucubin was toxic to the cells only at the highest concentration tested (P = 0.0081). However, genistein was toxic to the cells at all of the concentrations examined except for the lowest concentration of 16.9 μg/ml (P = 0.985). P. major (−0.10 ± 0.11), aucubin (0.06 ± 0.16), baicalein (−0.10 ± 0.11), and genistein (−0.18 ± 0.07) all significantly (P < 0.0001) inhibited ROS production from the neutrophils. P. major extract inhibited neutrophil ROS production, as did aucubin and baicalein. Therefore, these components should be investigated further with relation to the regulation of destructive ROS production in conditions such as periodontal disease. PMID:24716188

The Effects of Plantago major on the Activation of the Neutrophil Respiratory Burst.

PubMed

Reina, Elaine; Al-Shibani, Nouf; Allam, Eman; Gregson, Karen S; Kowolik, Michael; Windsor, L Jack

2013-10-01

Plantago major is a common plant that grows worldwide in temperate zones and is found in fields, lawns, and on the roadsides. Its leaves and seeds have been used in almost all parts of the world for centuries as a wound healer, analgesic, antioxidant, and antibiotic, as well as an immune system modulator, antiviral, antifungal, and anti-inflammatory agent. Baicalein and aucubin are the two most biologically active components of P. major, and both have been shown to have antioxidant, anti-inflammatory, and anticancer properties. Neutrophils have a pivotal role in wound healing and inflammation. Their principal mechanism of host defense is the killing of pathogens via the production of reactive oxygen species (ROS). The aim of the present study was to determine the in vitro effects of P. major extract, baicalein, and aucubin on human neutrophil respiratory burst activity. The cytotoxicity of the agents was assessed by lactate dehydrogenase (LDH) assays. A standard luminol-dependent chemiluminescence (CL) assay was utilized to monitor the respiratory burst of the neutrophils after exposure to P. major extract and its two active ingredients, baicalein and aucubin. Three replicates per group were included in each of the three runs of the experiments and analysis of variance (ANOVA) was used for statistical analysis. P. major and baicalein were not toxic to the cells at any of the concentrations examined. Aucubin was toxic to the cells only at the highest concentration tested (P = 0.0081). However, genistein was toxic to the cells at all of the concentrations examined except for the lowest concentration of 16.9 μg/ml (P = 0.985). P. major (-0.10 ± 0.11), aucubin (0.06 ± 0.16), baicalein (-0.10 ± 0.11), and genistein (-0.18 ± 0.07) all significantly (P < 0.0001) inhibited ROS production from the neutrophils. P. major extract inhibited neutrophil ROS production, as did aucubin and baicalein. Therefore, these components should be investigated further with relation to the regulation of destructive ROS production in conditions such as periodontal disease.

Mitochondrial DNA maintenance is regulated in human hepatoma cells by glycogen synthase kinase 3β and p53 in response to tumor necrosis factor α.

PubMed

Vadrot, Nathalie; Ghanem, Sarita; Braut, Françoise; Gavrilescu, Laura; Pilard, Nathalie; Mansouri, Abdellah; Moreau, Richard; Reyl-Desmars, Florence

2012-01-01

During chronic liver inflammation, up-regulated Tumor Necrosis Factor alpha (TNF-α) targets hepatocytes and induces abnormal reactive oxygen species (ROS) production responsible for mitochondrial DNA (mtDNA) alterations. The serine/threonine Glycogen Synthase Kinase 3 beta (GSK3β) plays a pivotal role during inflammation but its involvement in the maintenance of mtDNA remains unknown. The aim of this study was to investigate its involvement in TNF-α induced mtDNA depletion and its interrelationship with p53 a protein known to maintain mtDNA copy numbers. Using quantitative polymerase chain reaction (qPCR) we found that at 30 min in human hepatoma HepG2 cells TNF-α induced 0.55±0.10 mtDNA lesions per 10 Kb and a 52.4±2.8% decrease in mtDNA content dependent on TNF-R1 receptor and ROS production. Both lesions and depletion returned to baseline from 1 to 6 h after TNF-α exposure. Luminol-amplified chemiluminescence (LAC) was used to measure the rapid (10 min) and transient TNF-α induced increase in ROS production (168±15%). A transient 8-oxo-dG level of 1.4±0.3 ng/mg DNA and repair of abasic sites were also measured by ELISA assays. Translocation of p53 to mitochondria was observed by Western Blot and co-immunoprecipitations showed that TNF-α induced p53 binding to GSK3β and mitochondrial transcription factor A (TFAM). In addition, mitochondrial D-loop immunoprecipitation (mtDIP) revealed that TNF-α induced p53 binding to the regulatory D-loop region of mtDNA. The knockdown of p53 by siRNAs, inhibition by the phosphoSer(15)p53 antibody or transfection of human mutant active GSK3βS9A pcDNA3 plasmid inhibited recovery of mtDNA content while blockade of GSK3β activity by SB216763 inhibitor or knockdown by siRNAs suppressed mtDNA depletion. This study is the first to report the involvement of GSK3β in TNF-α induced mtDNA depletion. We suggest that p53 binding to GSK3β, TFAM and D-loop could induce recovery of mtDNA content through mtDNA repair.

The effect of altered gravity on immune cells (Ground studies: TRIPLE LUX-A BIOLAB experiment)

NASA Astrophysics Data System (ADS)

Horn, Astrid; Huber, Kathrin; Kuebler, Ulrich; Briganti, Luca; Baerwalde, Sven; Zander, Vanja; Ullrich, Oliver; Hemmersbach, Ruth

The experiment TRIPLE LUX A, whose performance on Biolab is foreseen for 2010, aims to increase the information about the functioning of immune cells during space flight. Thus, we investigate the impact of altered gravity -microgravity and hypergravity conditions -on the immune response of mammalian macrophages. Previous studies had already demonstrated that phagocytosis in macrophages, an essential step in the innate immune response, is decreased on a fast rotating clinostat. Now, the production of ROS (reactive oxygen species) within the oxidative burst reaction, was measured by means of a luminol assay (luminescence + photo-multiplier technique) comparable to the set up which will be used in the TRIPLE LUX flight hardware. The kinetics of the ROS production was investigated a) under 1 g conditions, b) on a clinostat (with one rotation axis) under varied rotational speed c) in short-term real micro-gravity on a parabolic flight and d) in hypergravity (1.8 g) on the Short Arm Human Centrifuge (SAHC) at DLR Cologne. By means of a photomultiplier clinostat online kinetic luminescent measurements during clinorotation were possible. Permanent fast clinorotation (60 rpm) leads to a dramatic reduction of the oxidative burst signal by up to 60% compared to the signal at 1 g. Slower rotation (30 rpm to 2 rpm) reduces the signal strength even more by up to 90% of the original strength. 60 rpm clinorotation as well as short-term real microgravity (22 s) during parabolic flight likewise decreases the signal of the oxidative burst to a comparable amount, thus the term "simulated weightlessness" is valid for the chosen experimental condi-tion. In contrast, hypergravity leads to a significant signal increase. The results demonstrate a clear effect of altered gravity on the immune response of the macrophages. In the upcoming ISS experiment the established test system (oxidative burst of macrophages) will be tested in continues microgravity within the Biolab hardware, designed by EADS Astrium. The core of the TRIPLELUX experiment hardware onboard the International Space Station consists of two specifically developed Biolab Advanced Experiment Containers (AECs) that, exploiting Biolab automatic features such as the robotic arm Handling Mechanism, allow for fully-automated life support of sample cells as well as investigations of their behaviour in microgravity through the measurement of luminescence.

Anticonvulsive and free radical scavenging actions of two herbs, Uncaria rhynchophylla (MIQ) Jack and Gastrodia elata Bl., in kainic acid-treated rats.

PubMed

Hsieh, C L; Tang, N Y; Chiang, S Y; Hsieh, C T; Lin, J G

1999-01-01

Uncaria rhynchophylla (Miq.) Jack (UR) and Gastrodia elata BI. (GE) are traditional Chinese herbs that are usually used in combination to treat convulsive disorders, such as epilepsy, in China. The aim of this study was to compare the anticonvulsive and free radical scavenging activities of UR alone and UR in combination with GE in rats. For the in vitro studies, brain tissues from 6 male Sprague-Dawley (SD) rats were treated with 120 microg/ml kainic acid (KA), with or without varied concentrations of UR or UR plus GE. For the in vivo studies, male SD rats (6 per group) received intraperitoneal (i.p.) injection of KA 12 mg/kg to induce epileptic seizures and generation of free radicals, with or without oral administration of UR 1 g/kg alone or UR 1 g/kg plus GE 1 g/kg. Epileptic seizures were verified by behavioral observations, and electroencephalography (EEG) and electromyography (EMG) recordings. These results showed that UR alone decreased KA-induced lipid peroxide levels in vitro, whereas UR plus GE did not produce a greater effect than UR alone. UR significantly reduced counts of wet dog shakes (WDS), paw tremor (PT) and facial myoclonia (FM) in KA-treated rats and significantly delayed the onset time of WDS, from 27 min in the control group to 40 min in the UR group. UR plus GE did not inhibit seizures more effectively than UR alone, but did further prolong the onset time of WDS to 63 min (P < 0.05 vs. UR alone). UR alone reduced the levels of free radicals in vivo, as measured by lipid peroxidation in the brain and luminol-chemiluminescence (CL) counts and lucigenin-CL counts in the peripheral whole blood, but the combination of GE and UR did not reduce free radical levels more markedly than UR alone. In conclusion, our results indicate that UR has anticonvulsive and free radical scavenging activities, and UR combined with GE exhibit greater inhibition on the onset time of WDS than UR alone. These findings suggest that the anticonvulsive effects of UR and GE may be synergistic. However, the mechanism of interaction between UR and GE remains unknown.

Highly selective and sensitive chemiluminescence biosensor for adenosine detection based on carbon quantum dots catalyzing luminescence released from aptamers functionalized graphene@magnetic β-cyclodextrin polymers.

PubMed

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

2018-08-15

In this work, a highly selective and sensitive chemiluminescence (CL) biosensor was prepared for adenosine (AD) detection based on carbon quantum dots (CQDs) catalyzing the CL system of luminol-H 2 O 2 under alkaline environment and CQDs was released from the surface of AD aptamers functionalized graphene @ magnetic β-cyclodextrin polymers (GO@Fe 3 O 4 @β-CD@A-Apt). Firstly, GO@Fe 3 O 4 @β-CD and CQDs were prepared and characterized by transmission electron microscopy (TEM), scanning electron microscope (SEM), UV-Vis absorption spectra (UV), fluorescence spectra (FL), fourier transform infrared (FTIR) and X-ray powder diffraction (XRD). For GO@Fe 3 O 4 @β-CD, Fe 3 O 4 was easy to separate, GO had good biocompatibility and large specific surface area, and β-CD further increased the specific surface area of the adenosine polymers (A-Apt) to provided larger binding sites to A-Apt. Then, A-Apt was modified on the surface of GO@Fe 3 O 4 @β-CD while CQDs was modified by ssDNA (a single stranded DNA partially complementary to A-Apt). The immobilization property (GO@Fe 3 O 4 @β-CD to A-Apt) and the adsorption property (GO@Fe 3 O 4 @β-CD@A-Apt to CQDs-ssDNA) were sequentially researched. The base-supported chain-like polymers - GO@Fe 3 O 4 @β-CD@A-Apt/CQDs-ssDNA was successfully obtained. When AD existed, CQDs-ssDNA was released from the surface of GO@Fe 3 O 4 @β-CD@A-Apt and catalyzed CL. After that, under optimized CL conditions, AD could be measured with the linear concentration range of 5.0 × 10 -13 -5.0 × 10 -9 mol/L and the detection limit of 2.1 × 10 -13 mol/L (3δ) while the relative standard deviation (RSD) was 1.4%. Finally, the GO@Fe 3 O 4 @β-CD@A-Apt/CQDs-ssDNA-CL biosensor was used for the determination of AD in urine samples and recoveries ranged from 98.6% to 101.0%. Those satisfactory results illustrated the proposed CL biosensor could achieve highly selective, sensitive and reliable detection of AD and revealed potential application for AD detection in monitoring and diagnosis of human cancers. Copyright © 2018 Elsevier B.V. All rights reserved.

Redox speciation of dissolved iron in the northeastern atlantic ocean.

NASA Astrophysics Data System (ADS)

Ussher, S. J.; Achterberg, E. P.; Worsfold, P. J.

2003-04-01

Dissolved iron (<0.2 micron) and iron(II) (<0.2 micron) distributions were determined during the Iron from Below and Iron from Above research cruises in the North Eastern Atlantic Ocean. The cruises were part of the EU Ironages project. Iron(II) was measured on-board ship using an iron(II) specific, automated flow injection analyser with luminol chemiluminescence detection [1]. Total dissolved iron (DFe) was determined in a land-based laboratory, using the same FI technique but with prior reduction of iron(III) to iron(II) [2]. The limits of detection for the methods were 5 -15 pM and 35 pM respectively, the analysis time was 8 - 10 minutes per sample (minimum of 3 replicates). The Iron from Below expedition took place over the European Continental Shelf, 200 km South West of Brittany (France) in March 2002. A transect between 47.61°N, 4.24°W and 46.00°N, 8.01°W was completed. Over the transect, the depth increased from 100 m to 5000 m. Iron(II) concentrations ranged between 10 and 100 pM and DFe between 0.2 and 1 nM, with the higher concentrations (Fe(II) ca. > 50 pM and DFe ca. > 0.8 nM) generally found in the shallow shelf waters. These observations imply that benthic inputs and sediment resuspension may form important inputs of dissolved iron and iron(II) in the shelf waters. Iron speciation measurements were also made for underway surface and shallow cast samples during the Iron from Above cruise October 2002. Fe(II) and DFe concentrations were typically 5 to 50 pM and 0.2 to 0.6 nM, respectively. Sampling was carried out within a grid in the Canary Basin around 5 degrees W of the Canary Islands, an area assumed to be strongly influenced by the Saharan dust plume. Observed Fe(II) concentrations are compared and ratioed to the DFe concentrations, and indicate that iron(II) forms an important fraction (between 5 and 15%) of the total dissolved iron concentration in the study areas. Data plots for surface samples are presented with the corresponding physical oceanographic and solar irradiance data. The concentrations of Fe(II) observed during our studies exceed the values predicted from thermodynamic equilibrium modelling. This indicates that there is a steady supply of Fe(II) (possibly from photoreduction and/or biological origins) and/or Fe(II) is prevented from oxidation through stabilisation mechanisms (possibly by organic ligands). [1] A. R. Bowie, E. P. Achterberg, P. N. Sedwick, S. Ussher, P. J. Worsfold, Environ. Sci. Technol., 36, (2002) 4600. [2] A. R. Bowie, E. P. Achterberg, R. F. C. Mantoura, P. J. Worsfold, Anal. Chim. Acta, 377, (1998) 113.

Peroxy radical measurements with NCAR's chemical amplifier

NASA Technical Reports Server (NTRS)

Cantrell, Christopher; Shetter, Richard; Calvert, Jack G.

1994-01-01

The present NCAR instrument for HO2/RO2 measurements has been described previously. It is based on the reactions involving HO2, RO2, and HO radicals with CO and NO. Since (HO2) + (RO2) + (HO) is much greater than (HO) for most atmospheres, it is useful as a peroxy radical detector. Operation of the instrument depends on the creation of a chemical chain reaction which is initiated as HO2 and RO2 radicals in ambient air encounter added NO gas; this forms an NO2 molecule and an HO or RO radical: HO2(RO2) + NO yields HO(RO) + NO2. RO radicals react relatively efficiently with O2 to form an HO2 radical, and subsequently an HO-radical, by reaction with NO. CO gas added to the reaction chamber during part of the operating cycle, recycles the HO to HO2; HO + CO (+O2) yields HO2 + CO2. The reaction sequence may form several hundred NO2 molecules per HO2 (RO2) originally present, before chain termination occurs. The added CO is replaced by N2 addition periodically so that the chain reaction is suppressed, and a 'blank' signal resulting from NO2, O3 and possibly other NO2-forming species (non-chain processes) in ambient air is recorded. The difference between the signal with and without CO is proportional to the peroxy radical concentration. The NO2 produced is monitored using a sensitive luminol chemiluminescence detector system. In the NCAR instrument the length of the amplification chain is determined using a stable source of HO2 radicals (H2O2 thermal decomposition); the ratio of the signal seen with CO present to that with N2 present gives the sensitivity of the instrument to HO2 (molecules of NO2 formed/peroxy radical). The instrument is automated to carry out in hourly repeated cycles: (1) chain length determination; (2) NO2 calibration; and (3) linearity check on the response of signals. One minute averages of signals are normally recorded. The sensitivity of the instrument to detect peroxy radicals is in the pptv range. The present instrument has operated continuously (24 hr/day) in the field studies which extended over a period of several weeks. The major advantages of this instrument are as follows: (1) its relative simplicity; (2) low power requirements; and (3) its rapid response to all types of peroxy radicals--HO2, CH3O2 and the higher alkyl and acyl peroxy radicals; however not all RO2 species generate HO2 radicals with perfect efficiency and hence have somewhat lower response/molecule than HO2 radicals.

Large-scale identification of wheat genes resistant to cereal cyst nematode Heterodera avenae using comparative transcriptomic analysis.

PubMed

Kong, Ling-An; Wu, Du-Qing; Huang, Wen-Kun; Peng, Huan; Wang, Gao-Feng; Cui, Jiang-Kuan; Liu, Shi-Ming; Li, Zhi-Gang; Yang, Jun; Peng, De-Liang

2015-10-16

Cereal cyst nematode Heterodera avenae, an important soil-borne pathogen in wheat, causes numerous annual yield losses worldwide, and use of resistant cultivars is the best strategy for control. However, target genes are not readily available for breeding resistant cultivars. Therefore, comparative transcriptomic analyses were performed to identify more applicable resistance genes for cultivar breeding. The developing nematodes within roots were stained with acid fuchsin solution. Transcriptome assemblies and redundancy filteration were obtained by Trinity, TGI Clustering Tool and BLASTN, respectively. Gene Ontology annotation was yielded by Blast2GO program, and metabolic pathways of transcripts were analyzed by Path_finder. The ROS levels were determined by luminol-chemiluminescence assay. The transcriptional gene expression profiles were obtained by quantitative RT-PCR. The RNA-sequencing was performed using an incompatible wheat cultivar VP1620 and a compatible control cultivar WEN19 infected with H. avenae at 24 h, 3 d and 8 d. Infection assays showed that VP1620 failed to block penetration of H. avenae but disturbed the transition of developmental stages, leading to a significant reduction in cyst formation. Two types of expression profiles were established to predict candidate resistance genes after developing a novel strategy to generate clean RNA-seq data by removing the transcripts of H. avenae within the raw data before assembly. Using the uncoordinated expression profiles with transcript abundance as a standard, 424 candidate resistance genes were identified, including 302 overlapping genes and 122 VP1620-specific genes. Genes with similar expression patterns were further classified according to the scales of changed transcript abundances, and 182 genes were rescued as supplementary candidate resistance genes. Functional characterizations revealed that diverse defense-related pathways were responsible for wheat resistance against H. avenae. Moreover, phospholipase was involved in many defense-related pathways and localized in the connection position. Furthermore, strong bursts of reactive oxygen species (ROS) within VP1620 roots infected with H. avenae were induced at 24 h and 3 d, and eight ROS-producing genes were significantly upregulated, including three class III peroxidase and five lipoxygenase genes. Large-scale identification of wheat resistance genes were processed by comparative transcriptomic analysis. Functional characterization showed that phospholipases associated with ROS production played vital roles in early defense responses to H. avenae via involvement in diverse defense-related pathways as a hub switch. This study is the first to investigate the early defense responses of wheat against H. avenae, not only provides applicable candidate resistance genes for breeding novel wheat cultivars, but also enables a better understanding of the defense mechanisms of wheat against H. avenae.

Ehrlichia chaffeensis and Its Invasin EtpE Block Reactive Oxygen Species Generation by Macrophages in a DNase X-Dependent Manner.

PubMed

Teymournejad, Omid; Lin, Mingqun; Rikihisa, Yasuko

2017-11-21

The obligatory intracellular pathogen Ehrlichia chaffeensis lacks most genes that confer resistance to oxidative stress but can block reactive oxygen species (ROS) generation by host monocytes-macrophages. Bacterial and host molecules responsible for this inhibition have not been identified. To infect host cells, Ehrlichia uses the C terminus of its surface invasin, entry-triggering protein of Ehrlichia (EtpE; EtpE-C), which directly binds the mammalian cell surface receptor glycosylphosphatidylinositol-anchored protein DNase X. We investigated whether EtpE-C binding to DNase X blocks ROS production by mouse bone marrow-derived macrophages (BMDMs). On the basis of a luminol-dependent chemiluminescence assay, E. chaffeensis inhibited phorbol myristate acetate (PMA)-induced ROS generation by BMDMs from wild-type, but not DNase X -/- , mice. EtpE-C is critical for inhibition, as recombinant EtpE-C (rEtpE-C)-coated latex beads, but not recombinant N-terminal EtpE-coated or uncoated beads, inhibited PMA-induced ROS generation by BMDMs from wild-type mice. DNase X is required for this inhibition, as none of these beads inhibited PMA-induced ROS generation by BMDMs from DNase X -/- mice. Previous studies showed that E. chaffeensis does not block ROS generation in neutrophils, a cell type that is a potent ROS generator but is not infected by E. chaffeensis Human and mouse peripheral blood neutrophils did not express DNase X. Our findings point to a unique survival mechanism of ROS-sensitive obligate intramonocytic bacteria that involves invasin EtpE binding to DNase X on the host cell surface. This is the first report of bacterial invasin having such a subversive activity on ROS generation. IMPORTANCE Ehrlichia chaffeensis preferentially infects monocytes-macrophages and causes a life-threatening emerging tick-transmitted infectious disease called human monocytic ehrlichiosis. Ehrlichial infection, and hence the disease, depends on the ability of this bacterium to avoid or overcome powerful microbicidal mechanisms of host monocytes-macrophages, one of which is the generation of ROS. Our findings reveal that an ehrlichial surface invasin, EtpE, not only triggers bacterial entry but also blocks ROS generation by host macrophages through its host cell receptor, DNase X. As ROS sensitivity is an Achilles' heel of this group of pathogens, understanding the mechanism by which E. chaffeensis rapidly blocks ROS generation suggests a new approach for developing effective anti-infective measures. The discovery of a ROS-blocking pathway is also important, as modulation of ROS generation is important in a variety of ailments and biological processes. Copyright © 2017 Teymournejad et al.

Anti-inflammatory and antioxidant effect of cerium dioxide nanoparticles immobilized on the surface of silica nanoparticles in rat experimental pneumonia.

PubMed

Serebrovska, Z; Swanson, R J; Portnichenko, V; Shysh, A; Pavlovich, S; Tumanovska, L; Dorovskych, A; Lysenko, V; Tertykh, V; Bolbukh, Y; Dosenko, V

2017-08-01

A massage with the potent counter-inflammatory material, cerium dioxide nanoparticles, is promising and the antioxidant properties of CeO 2 are considered the main, if not the only, mechanism of this action. Nevertheless, the elimination of ceria nano-particles from the organism is very slow and there is a strong concern for toxic effect of ceria due to its accumulation. To overcome this problem, we engineered a combined material in which cerium nanoparticles were immobilized on the surface of silica nanoparticles (CeO 2 NP), which is shown to be easily removed from an organism and could be used as carriers for nano-ceria. In our study particle size was 220±5nm, Zeta-potential -4.5mV (in water), surface charge density -17.22μC/cm 2 (at pH 7). Thirty-six male Wistar rats, 5 months old and 250-290g were divided into four groups: 1) control; 2) CeO 2 NP treatment; 3) experimental pneumonia (i/p LPS injection, 1mg/kg); and 4) experimental pneumonia treated with CeO 2 NP (4 times during the study in dosage of 0.6mg/kg with an orogastric catheter). Gas exchange and pulmonary ventilation were measured four times: 0, 1, 3 and 24h after LPS injection in both untreated and CeO 2 NP-treated animals. The mRNA of TNF-α, Il-6, and CxCL2 were determined by RT-PCR. ROS-generation in blood plasma and lung tissue homogenates were measured by means of lucigenin- and luminol-enhanced chemiluminescence. Endotoxemia in the acute phase was associated with: (1) pathological changes in lung morphology; (2) increase of ROS generation; (3) enhanced expression of CxCL2; and (4) a gradual decrease of VO 2 and V E . CeO2 NP treatment of intact animals did not make any changes in all studied parameters except for a significant augmentation of VO 2 and V E. CeO 2 NP treatment of rats with pneumonia created positive changes in diminishing lung tissue injury, decreasing ROS generation in blood and lung tissue and decreasing pro-inflammatory cytokine expression (TNF-α, Il-6 and CxCL2). Oxygen consumption in this group was increased compared to the LPS pneumonia group. In our study we have shown anti-inflammatory and antioxidant effects of CeO 2 NP. In addition, this paper is the first to report that CeO 2 NP stimulates oxygen consumption in both healthy rats, and rats with pneumonia. We propose the key in understanding the mechanisms behind the phenomena lies in the property of CeO 2 NP to scavenge ROS and the influence of this potent antioxidant on mitochondrial function. The study of biodistribution and elimination of СеО 2 NP is the purpose of our ongoing study. Copyright © 2017 Elsevier Masson SAS. All rights reserved.