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1

Flow injection chemiluminescence determination of 2-methoxyestradiol based on inhibition of luminol-potassium ferricyanide reaction.  

PubMed

A novel flow-injection chemiluminescence (FI-CL) method is described for the determination of 2-methoxyestradiol (2-ME). The method is based on the inhibitory effect of 2-ME on the CL reaction of luminol and potassium ferricyanide in alkaline solution. Under optimal conditions, net CL intensity was proportional to 2-ME concentration in synthetic and mouse plasma samples. Corresponding linear regression equations were 8.0 x 10(-9) -1.0 x 10(-7) g/mL for synthetic samples and 2.0 x 10(-9) -1.0 x 10(-7) g/mL for plasma samples. Detection limit for synthetic samples and limits for quantification of plasma samples were 8.4 x 10(-10) g/mL (3?) for synthetic samples and 4.0 x 10(-9) g/mL for mouse samples. A complete analysis was performed for 60 s, including washing and sampling, resulting in a throughput of ? 60/h. The proposed method was applied for the determination of 2-ME in synthetic and mouse plasma samples. Percentage recoveries were 101.0-102.8% and 98.0-105.0%, respectively. A possible mechanism responsible for CL reaction is proposed. PMID:22522659

Jin, Jianwen; Yao, Hanchun; Chen, Zheng; Pang, Li; Du, Bin

2013-01-01

2

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

PubMed

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. PMID:24254330

Iranifam, Mortaza; Kharameh, Merhnaz Khabbaz

2014-09-01

3

Determination of cysteine and glutathione based on the inhibition of the dinuclear Cu(II)-catalyzed luminol-H2O2 chemiluminescence reaction  

NASA Astrophysics Data System (ADS)

The catalyzed luminol chemiluminescent reaction has received a great amount of attention because of its high sensitivity and low background signal which make the reaction an attractive analytical chemistry tool. The present study, introduces the beneficial catalytic effects of dinuclear Cu(II) complex [Cu2L2(TAE)]X2, where TAE = tetraacetylethane; L = N,N'-dibenzylethylenediamine and X = ClO4 on the luminol chemiluminescent reaction as a novel probe for the determination of glutathione (GSH) and L-cysteine (CySH) in human serum and urine. The [Cu2L2(TAE)]X2 has exhibited highly efficient catalytic activity of luminol CL as an artificial peroxidase model at pH as low as 7.5 in water in the presence of H2O2?GSH and CySH can induce a sharp decrease in CL intensity from the [Cu2L2(TAE)]X2-catalyzed luminol system. Under the selected experimental conditions, a linear relationship was obtained between the CL intensity and the concentrations of GSH and CySH in the range of 1.0 × 10-7-1.0 × 10-4 M, with detection limits (S/N = 3) of 2.7 × 10-8 and 6.8 × 10-8 M and RSD < 4.2% (n = 7) for GSH and CySH, respectively.

Chaichi, Mohammad Javad; Ehsani, Mahjoobeh; Khajvand, Tahereh; Golchoubian, Hamid; Rezaee, Ehsan

2014-03-01

4

In vitro monitoring sub-nanogram amounts analgin in human urine by its inhibitory of the luminol-periodate chemiluminescence reaction using reagent immobilization release technique.  

PubMed

A selective and sensitive as well as rapid chemiluminescence (CL) flow sensor for the determination of analgin is described. The analytical reagents involved in chemiluminescence reaction, luminol and periodate, were both immobilized on an anion-exchange column. The CL signals produced by the reaction between luminol and periodate, which were eluted from the column through water injection, were decreased in the presence of analgin. Analgin was sensed by measuring the decrement of CL intensity, and which was observed linear over the logarithm of analgin concentration range of 0.1 to 50.0 ng mL(-1), and the limit of detection was 0.04 ng mL(-1) (3ó). At a flow rate of 2.0 mL min(-1), including sampling and washing, the detection could be performed in 0.5 min with a relative standard deviation of less than 3.0%. The proposed procedure was applied successfully in the monitoring of analgin in human urine samples without any pre-treatment process. It was found that the analgin concentration reached its maximum after being orally administrated for 4 h, and the analgin metabolism ratio in 10 h was 9.28% in the body of volunteers. The flow sensor offered reagentless procedures and remarkable stability in determination of analgin, and could be easily reused over 80 h. PMID:11983504

Song, Zhenghua; Zhang, Ni

2002-07-01

5

Study of the catalytic effect of PAR on the luminol-potassium ferricyanide reaction using a flow-injection chemiluminescence method.  

PubMed

We discovered that 4-(2-pyridylazo) resorcinol (PAR) has a strong catalytic effect on luminol-potassium ferricyanide chemiluminescence (CL). Results indicated that the chemiluminescence intensities at maximum light emission were linearly corrected with the concentration of PAR over the range 1.0 x 10(-5)-1.0 x 10(-7) mol/L. A detection limit of 5.7 x 10(-8) mol/L for PAR was achieved. It was found that some metal ions strongly affected this catalytic reaction. Based on this finding, the luminol-potassium ferricyanide-PAR reaction was developed for the determination of metal ions. The detection limits (S/N = 3) for Ni2+, Cr3+, Zn2+, Co2+ and Mn2+ were determined to be 1.0 x 10(-9) mol/L, 5.0 x 10(-9) mol/L, 5.0 x 10(-8) mol/L, 1.0 x 10(-9) mol/L and 1.0 x 10(-8) mol/L, respectively. In addition, the relative standard deviation values for these metal ion assays were in the range 0.82-2.72% (n = 6). PMID:15685655

Hu, Yonggang; Pang, Zhitao; Yang, Zeyu; Wei, Wei; Wu, Yuping

2005-01-01

6

Post-chemiluminescence behaviour of Ni2+, Mg2+, Cd2+ and Zn2+ in the potassium ferricyanide-luminol reaction.  

PubMed

A new chemiluminescence (CL) reaction was observed when Ni2+, Mg2+, Cd2+ or Zn2+ was injected into the reaction mixture after the finish of the CL reaction of alkaline luminol and potassium ferricyanide. This reaction is described as a post-chemiluminescence (PCL) reaction. The possible mechanism for the PCL was proposed based on studies of the CL kinetic characteristic and the CL spectra. The experimental conditions of the CL reactions were optimized and the feasibility of using the reaction to analyse these metal ions was evaluated. The PCL reaction method operates in the ranges: 1 x 10(-7)-8 x 10(-6) g/L Ni2+; 3 x 10(-6)-2 x 10(-4) g/L Mg2+; 8 x 10(-7)-1 x 10(-4) g/L Cd2+; and 2 x 10(-4)-2 x 10(-3) g/L Zn2+, with detection limits of 4 x 10(-8) g/mL, 1 x 10(-6) g/mL, 3 x 10(-7) g/mL, 8 x 10(-5) g/mL, respectively. PMID:16134227

Feng, Na; Lu, Jiuru; He, Yunhua; Du, Jianxiu

2005-01-01

7

Towards chemiluminescence detection in micro-sequential injection lab-on-valve format: A proof of concept based on the reaction between Fe(II) and luminol in seawater.  

PubMed

Micro-sequential injection lab-on-valve (µSI-LOV) is a well-established analytical platform for absorbance and fluorescence based assays but its applicability to chemiluminescence detection remains largely unexplored. In this work, we describe a novel fluidic protocol and two distinct strategies for photon collection that enable chemiluminescence detection using µSI-LOV for the first time. To illustrate this proof of concept, we selected the reaction between Fe(II) and luminol and developed a preliminary protocol for Fe(II) determinations in acidified seawater. The optimized fluidic strategy consists of holding 100µL of the luminol reagent in a confined zone of the LOV and then displacing it with 50µL of sample while monitoring the chemiluminescent product. Detection is achieved using two strategies: one based on a bifurcated optical fiber and the other based on a customized detection window created by mounting a photomultiplier tube atop of the LOV device. We show that detection is possible using both strategies but that the window strategy yields significantly enhanced sensitivity (355×) due to the larger detection area. In our final experimental conditions and using window detection, it was possible to achieve a limit of detection (LOD) of 1nmolL(-1) and to quantify Fe(II) in acidified seawater samples up to 20.00nmolL(-1) with high precision (RSD<6%). These analytical features combined with the long-term stability of luminol solution and the full automation and low reagent consumption make this approach a promising analytical tool for shipboard analysis of Fe(II). The intrinsic capacity of the LOV to operate at a low microliter level and to handle solid phases also opens up a new avenue for chemiluminescence applications. Moreover, this contribution shows that LOV can be a universal platform for optical detection, capable of absorbance, fluorescence and luminescence measurements in a single instrument setup. PMID:25435235

Oliveira, Hugo M; Grand, Maxime M; Ruzicka, Jaromir; Measures, Christopher I

2015-02-01

8

Effects of neopterin-derivatives on H2O2-induced luminol chemiluminescence: mechanistic aspects.  

PubMed

Neopterin, 6-D-erythro-1',2',3'-trihydroxypropyl-pterin, and its dihydroform, 7,8-dihydro-neopterin, are synthesized by human monocytes/macrophages upon stimulation by interferon-gamma. In the presence of iron chelator complexes neopterin enhances hydrogen peroxide-induced luminol chemiluminescence at neutral or slightly alkaline pH (7.5). In contrast, 7,8-dihydroneopterin scavenges chemiluminescence independently from the pH value and iron. In this study, we explored in more detail the mechanism possibly involved: analysis of the reaction products shows that 7,8-dihydroneopterin is oxidized and degraded to 7,8-dihydroxanthopterin and xanthopterin, whereas the neopterin molecule is not chemically altered during the chemiluminescence reaction. Investigations of the neopterin-induced effect show that mannitol, a scavenger of hydroxyl radicals, does not alter the enhancing effect of neopterin. L-histidine, which scavenges singlet oxygen almost as effective as hydroxyl radicals, reduces the enhancing effect of neopterin. However, singlet oxygen was not detectable during the reaction by measuring monomol light emission (1270 nm). When replacing hydrogen peroxide by 3-morpholinosydnonimine, a generator of hydroxyl radicals, or naphthalene-endoperoxide, a generator of singlet oxygen, in the luminol chemiluminescence assay, neopterin shows no enhancing effect irrespective of the presence of iron-(III)-EDTA. The data suggest that neopterin enhances hydrogen peroxide-induced luminol chemiluminescence in the presence of iron-(III)-EDTA by formation of a catalytic complex that seems to favor the formation of oxygen intermediates which derive from hydrogen peroxide and react with luminol. PMID:8886794

Murr, C; Baier-Bitterlich, G; Fuchs, D; Werner, E R; Esterbauer, H; Pfleiderer, W; Wachter, H

1996-01-01

9

Luminol-enhanced chemiluminescence of rabbit polymorphonuclear leukocytes: The nature of oxidants that directly cause luminol oxidation  

Microsoft Academic Search

In this study, we investigated the pathways (including the formation of hydroxyl radicals and chloramines) leading to luminol\\u000a chemiluminescence induced by hypochlorite generated in a suspension of stimulated rabbit polymorphonuclear leukocytes. Chemiluminescence\\u000a of leukocytes stimulated by phorbol myristate acetate, which was enhanced by luminol (0.02 mM), did not change in the presence\\u000a of dimethyl sulfoxide at moderate concentrations (0.02–2.6 mM),

D. I. Roshchupkin; N. S. Belakina; M. A. Murina

2006-01-01

10

Luminol-silver nitrate chemiluminescence enhancement induced by cobalt ferrite nanoparticles.  

PubMed

CoFe(2)O(4) nanoparticles (NPs) could stimulate the weak chemiluminescence (CL) system of luminol and AgNO(3), resulting in a strong CL emission. The UV-visible spectra, X-ray photoelectron spectra and TEM images of the investigated system revealed that AgNO(3) was reduced by luminol to Ag in the presence of CoFe(2)O(4) NPs and the formed Ag covered the surface of CoFe(2)O(4) NPs, resulting in CoFe(2)O(4)-Ag core-shell nanoparticles. Investigation of the CL reaction kinetics demonstrated that the reaction among luminol, AgNO(3) and CoFe(2)O(4) NPs was fast at the beginning and slowed down later. The CL spectra of the luminol - AgNO(3) - CoFe(2)O(4) NPs system indicated that the luminophor was still an electronically excited 3-aminophthalate anion. A CL mechanism has been postulated. When the CoFe(2)O(4) NPs were injected into the mixture of luminol and AgNO(3), they catalyzed the reduction of AgNO(3) by luminol to produce luminol radicals and Ag, which immediately covered the CoFe(2)O(4) NPs to form CoFe(2)O(4)-Ag core-shell nanoparticles, and the luminol radicals reacted with the dissolved oxygen, leading to a strong CL emission. With the continuous deposition of Ag on the surface of CoFe(2)O(4) NPs, the catalytic activity of the core-shell nanoparticles was inhibited and a decrease in CL intensity was observed and also a slow growth of shell on the nanoparticles. PMID:21400653

Shi, Wenbing; Wang, Hui; Huang, Yuming

2011-01-01

11

[Luminol oxidation by hydrogen peroxide with chemiluminescent signal formation catalyzed by peroxygenase from the fungus Agrocybe aegerita V.Brig].  

PubMed

Conditions of luminol oxidation by hydrogen peroxide in the presence of peroxygenase from the mushroom Agrocybe aegerita V.Brig have been optimized. The pH value (8.8) at which fungal peroxygenase produces a maximum chemiluminescent signal has been shown to be similar to the pH optimum value of horseradish peroxidase. Luminescence intensity changed when the concentration of Tris buffer was varied; maximum intensity of chemiluminescence was observed in 40 mM solution. It has been shown that enhancer (p-iodophenol) addition to the substrate mixture containing A. aegerita peroxygenase exerted almost no influence on the intensity of the chemiluminescent signal, similarly to soybean, palm, and sweet potato peroxidases. Enzyme detection limit in the reaction of luminol oxidation by hydrogen peroxide was 0.8 pM. High stability combined with high sensitivity make this enzyme a promising analytical reagent. PMID:20198921

Vdovenko, M M; Ulrich, R; Hofrichter, M; Sakharov, I Iu

2010-01-01

12

Photodegradation and flow-injection determination of simetryn herbicide by luminol chemiluminescence detection.  

PubMed

A novel and simple flow injection chemiluminescence method is reported for the determination of simetryn, a common herbicide. The method is based on the direct oxidation of luminol by the photoproducts of the simetryn in alkaline medium in the absence of catalyst/oxidant. The linear concentration range was 0.01 - 2 microg mL(-1) simetryn with a correlation coefficient (r(2)) of 0.9997 and relative standard deviations (RSD; n = 4) in the range of 0.9 - 2.3%. The limit of detection (S/N = 3) was 7.5 ng mL(-1) with a sample throughput of 100 h(-1). The proposed method has been applied to determine simetryn in natural waters using Sep-Pak C(18) cartridges for solid phase extraction (SPE) procedure. The recoveries were in the range of 97 +/- 1 to 104 +/- 2%. The mechanism of chemiluminescence reaction has also been discussed briefly. PMID:18689937

Waseem, Amir; Yaqoob, Mohammad; Nabi, Abdul

2008-08-01

13

Pharmacokinetic of Pseudoephedrine in Rat Serum with Luminol-Pepsin Chemiluminescence System by Flow Injection Analysis.  

PubMed

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) (3?). 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. PMID:25427591

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

2014-11-27

14

Natural cyclodextrins as efficient boosters of the chemiluminescence of luminol and isoluminol: exploration of potential applications.  

PubMed

The chemiluminescent oxidation of luminol (LUM) and isoluminol (ISOL) is notably enhanced, both in intensity and duration, in the presence of natural cyclodextrins (alpha-, beta-, gamma-CD). The experiments have considered some of the most widespread applications of these compounds: the determination of metal cations and the revealing of bloodstains by oxidation with hydrogen peroxide in alkaline solution in the presence of Co(II), Fe(III), human hemoglobin, and blood, in order to explore potential applications. The largest enhancement in the emitted intensity occurs for the reaction of LUM with Co(II) in the presence of beta-CD. The use of the more soluble gamma-CD permits to expand the range of concentration and obtain more intense emission, although soluble derivatives of the beta-CD (methyl, hydroxypropyl-beta-CD, and a soluble cross-linked epichlorhydrin polymer) do not improve the chemiluminescence (CL) yield. In the case of hemoglobin and diluted human blood, the CDs aid in producing more light but only at high concentration of CDs, with a more lasting luminescence, up to three times longer. The changes in CL when glucose is used instead, much lower than with any of the CDs, imply that the cyclic structure of these oligosaccharides plays a key factor in the boosting of the emission. The results are explained in terms of the binding between the luminescent intermediate of the reaction, 3-aminophthalate (3-AP) and the CD, rather than to the luminescent reactant itself. The association constants obtained by steady-state fluorescence by assuming 1:1 stoichiometries reveal that the most stable association occurs between beta-CD and the intermediate, in accordance with the trend in the chemiluminescence. The topology of the complex deduced via ROESY experiments confirms a shallow inclusion of the double-charged intermediate by the primary rim of the CD, which accounts for the low stability of the complexes. PMID:20131859

Maeztu, Raquel; Tardajos, Gloria; González-Gaitano, Gustavo

2010-03-01

15

Luminol-labeled gold nanoparticles for ultrasensitive chemiluminescence-based chemical analyses.  

PubMed

We report a study on chemiluminescence-based chemical analyses using luminol molecules covalently attached to 10 nm diameter gold nanoparticles (GNPs). Chemiluminescence (CL) has been systematically studied under two schemes by varying the concentrations of luminol-labeled GNPs and [Fe(CN)6](3-) catalyst, respectively. The CL signal of luminol-labeled GNPs is enhanced by 5 to 10 times compared to the bulk luminol solutions of the same concentration. The log-log plot of the CL signal versus the number of luminol-labeled GNPs suspended in a standard 96-well plate shows two characteristic linear curves with distinct slopes across eight orders of magnitude variation in the GNP quantity (from 1.82 × 10(2) to 1.82 × 10(10) GNPs per well). The detection limit represented by the cross-point of these two curves can reach down to ~6.1 × 10(5) GNPs per well (corresponding to 1.0 × 10(-14) M GNP and 2.4 × 10(-11) M equivalent luminol concentration). The attachment of luminol molecules to GNP nano-carriers allows a large amount of luminol to be placed in a greatly reduced volume (or area) toward developing miniaturized CL sensors. We have demonstrated this by preloading dried luminol-labeled GNPs in homemade microwell arrays (with a volume of ~12 ?L per well). A linear log-log curve can be obtained across the full range from 1 × 10(3) to 1 × 10(10) GNPs per microwell. The CL signal was detectable with as few as ~1000 GNPs. We have further applied this microwell method to the detection of highly diluted blood samples, in both intact and lysed forms, which releases Fe(3+)-containing hemoglobin to catalyze luminol CL. The lysed blood sample can be detected even after a 10(8) fold dilution (corresponding to ~0.18 cells per well). This ultrasensitive CL detection method may be readily adapted for developing various miniaturized multiplex biosensors for rapid chemical/biochemical analyses. PMID:23851397

Syed, Lateef U; Swisher, Luxi Zhang; Huff, Hannah; Rochford, Caitlin; Wang, Fengli; Liu, Jianwei; Wu, Judy; Richter, Mark; Balivada, Sivasai; Troyer, Deryl; Li, Jun

2013-10-01

16

Determination of cortisol in human blood sera by a new Ag(III) complex-luminol chemiluminescent system.  

PubMed

A new chemiluminescence (CL) system based on the reaction of Ag(III) complex with luminol is, for the first time, reported in this work. Incorporated with a flow injection analyses (FIA), the new CL system has been applied for the determination of free cortisol in human sera. The system is based on the CL reaction of luminol with Ag(III) in alkaline solutions, while cortisol can dramatically enhance CL intensities. Under optimum conditions, CL intensities are proportional to concentration of cortisol in the range of 0.05-7.5 nM. The limit of detection is 2.0x10(-11) M (3sigma), with a relative standard deviation (n=11) of 1.9% for 3.5x10(-9) M cortisol. Eight human blood serum samples were all handled by solid-phase extraction (SPE) clean-up and enrichment before detection. This detection system is highly sensitive and convenient and may find wide applications. Based on the chemiluminescent spectra, a possible reaction mechanism is also suggested. PMID:19454253

Shi, Hongmei; Xu, Xiangdong; Ding, Yuexin; Liu, Shipeng; Li, Liqing; Kang, Weijun

2009-04-15

17

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

NASA Astrophysics Data System (ADS)

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-1and the relative standard deviation (RSD) ?5%. 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.

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

2013-12-01

18

Flow Injection Photosensitized Chemiluminescence of Luminol with Cu(II)-Rose Bengal: Mechanistic Approach and Vitamin A and C Determination  

PubMed Central

Rose Bengal photosensitized flow injection chemiluminescence method is reported using luminol-Cu(II) for the determination of vitamins A and C in pharmaceutical formulations. The reaction is based on the enhancement effect of analyte in the production of anion radicals of Rose Bengal (RB•?) which rapidly interact with dissolved oxygen and generate superoxide anions radicals (O2•?) and hydrogen peroxide (H2O2). Highly reactive hydroxyl radicals (•OH) were produced via dismutation of H2O2 by catalyst (Cu2+). The generated superoxide anions radicals and hydroxyl radicals thus oxidize luminol in alkaline medium to generate strong chemiluminescence. The limit of detection (3s of the blank, n = 6) of vitamins A and C and RB was found to be 0.008, 0.005, and 0.05??g?mL?1, respectively. The sample throughput of 70?h?1 for vitamins A and C and 30?h?1 for RB was found. Calibration curve was linear in the range of 0.05–15, 0.01–20, and 0.1–50??g?mL?1 for vitamins A and C and RB, respectively, with relative standard deviations (RSDs; n = 3) in the range 1.6–3.6%. The method was successfully applied to pharmaceutical formulations and the results obtained were in good agreement with the labeled values. PMID:25614739

Asgher, Muhammad; Yaqoob, Mohammad; Nabi, Abdul; Siddiqi, Abdul Rauf

2014-01-01

19

Effects of pH and Surfactant on the Ultrasound-Induced Chemiluminescence of Luminol  

NASA Astrophysics Data System (ADS)

The pH dependence of the sonochemi-luminescence (SCL) of luminol at 141 kHz was investigated and compared to the effect of pH on its fluorescence emission intensity. From the fluorescence intensity, the pKa1* and the pKa2* values were determined to be 6.4 and 10.5 respectively, which was consistent with changes observed in the SCL intensity of luminol when the pH was varied. An inverse relationship was found to exist between the SCL and the fluorescence intensities against pH, i.e., the luminol SCL spectrum at pH=10.8 (mono-anionic form) had the same shape as the fluorescence emission spectra in acidic pH solutions, where luminol exists in either the mono-cationic or neutral form. The addition of an anionic surfactant, sodium dodecyl sulfate (SDS), significantly decreased the luminol SCL intensity at high pH@. It is proposed that the generation of a negative electric potential at the surface of cavitation bubbles effectively prevented the negatively charged form of luminol from approaching the bubbles, thereby inhibiting the reaction of luminol with OH radicals.

Miyoshi, Norio; Hatanaka, Shin-ichi; Yasui, Kyuichi; Mitome, Hideto; Fukuda, Masaru

2001-06-01

20

Determination of 2-methoxyestradiol by chemiluminescence based on luminol-KMnO4-CdTe quantum dots system  

NASA Astrophysics Data System (ADS)

In this study, water-soluble CdTe quantum-dots (QDs) capped with glutathione (GSH) was synthesized. It was found that CdTe QDs could greatly enhance the chemiluminescence (CL) emission from the luminol-KMnO4 system in alkaline medium, and 4 nm CdTe QDs was used as catalysts to enhance the reaction sensitivity. The CL intensity of CdTe QDs-luminol-KMnO4 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. Based on this inhibition, a novel CL method with a lower detection limit and wider linear range was developed for the determination of 2-ME. The detection limit of plasma samples was 3.07 × 10-10 g mL-1 with a relative standard deviation of 0.24% for 8.0 × 10-9 g mL-1 2-ME. The method was successfully applied for determination of 2-ME in plasma samples. The possible CL reaction mechanism was also discussed briefly.

Du, Bin; Wang, Tiantian; Han, Shuping; Cao, Xiaohui; Qu, Tiantian; Zhao, Feifei; Guo, Xinhong; Yao, Hanchun

2015-02-01

21

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

PubMed

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. PMID:24850667

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

2015-02-01

22

Effect of aggregated silver nanoparticles on luminol chemiluminescence system and its analytical application  

NASA Astrophysics Data System (ADS)

We found that after silver nanoparticles (AgNPs) aggregated, its catalytic activity on luminol CL reaction obviously changed, and the change characteristic was closely related to the sizes of AgNPs. UV-visible spectra, X-ray photoelectron spectra, zeta potential and transmission electron microscopy studies were carried out to investigate the CL effect mechanism. The different CL responses of aggregated AgNPs with different size were suggested to be due to the two effects of quantum size and electron density in nanoparticle's conduction bands, and which one played a major role. The poisonous organic contaminants such as anilines, could induce the aggregation of AgNPs, were observed to affect effectively the luminol-H2O2-7 nm and 15 nm AgNPs CL systems and were detectable by use of a flow injection method with the enhanced or inhibited CL detection.

Qi, Yingying; Li, Baoxin; Xiu, Furong

2014-07-01

23

Aluminum salts stimulate luminol-enhanced chemiluminescence production by human neutrophils.  

PubMed

Aluminum intoxication is currently thought to play a major role in the development of Alzheimer's disease and in certain pathologic manifestations seen during long-term hemodialysis and aging. The hypothesis that aluminum toxicity is mediated via an increased free radical production was tested by studying the effects of two aluminum and five other metallic compounds on the production of luminol-enhanced chemiluminescence (LECL) by human neutrophils. AlCl3, Al2(SO4)3 and FeCl3 were found to stimulate LECL production by human neutrophils whereas FeCl2, CuCl, CuCl2, AuCl3 were inactive. Metal chelators such as Desferal, EDTA and DETAPA suppressed aluminum-induced stimulation and depressed cell-dependent LECL below basal levels. Sodium azide and Cytochalasin B greatly depressed both basal and aluminum-induced stimulation of LECL production, suggesting that, in this system, most of this stimulation was due to myeloperoxidase. These results suggest that high tissue aluminum concentrations may induce cell-tissue lesions by stimulating local production or release of mediators of tissue damage. PMID:1902435

Stankovic, A; Mitrovic, D R

1991-01-01

24

Simultaneous quantification of catecholamines in rat brain by high-performance liquid chromatography with on-line gold nanoparticle-catalyzed luminol chemiluminescence detection.  

PubMed

A new method based on high-performance liquid chromatography (HPLC) coupled with on-line gold nanoparticle-catalyzed luminol chemiluminescence (CL) detection was developed for the simultaneous quantitation of catecholamines in rat brain. In the present CL system, gold nanoparticles were produced by the on-line reaction of H2 O2 , NaHCO3 -Na2 CO3 (buffer solution of luminol) and HAuCl4. Norepinephrine (NE), epinephrine (EP) and dopamine (DA) could strongly enhance the CL signal of the on-line gold nanoparticle-catalyzed luminol system. The UV-visible absorption spectra and transmission electron microscopy studies were carried out, and the CL enhancement mechanism was proposed. Catecholamines promoted the on-line formation of more gold nanoparticles, which better catalyzed the luminol-H2 O2 CL reaction. The good separation of NE, EP and DA was achieved with isocratic elution using a mixture of methanol and 0.2% aqueous phosphoric acid (5:95, v/v) within 8.5?min. Under the optimized conditions, the detection limits, defined as a signal-to-noise ratio of 3, were in the range of 1.32-1.90?ng/mL, corresponding to 26.4-38.0?pg for 20??L sample injection. The recoveries of catecholamines added to rat brain sample were >94.6%, with the precisions <5.5%. The validated HPLC-CL method was successfully applied to determine NE and DA in rat brain without prior sample purification. Copyright © 2014 John Wiley & Sons, Ltd. PMID:24890328

Mu, Chunlei; Zhang, Qi; Wu, Dong; Zhang, Yunjing; Zhang, Qunlin

2014-06-01

25

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)

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 ?g for colorimetric detection and from 10 ng to 1.0 ?g 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.

He, Yi; Peng, Rufang

2014-11-01

26

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

PubMed

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 HAuCl? 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 ?g for colorimetric detection and from 10 ng to 1.0 ?g 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. PMID:25327146

He, Yi; Peng, Rufang

2014-11-14

27

Comparative study on thiol drugs' effect on tert-butyl hydroperoxide induced luminol chemiluminescence in human erythrocyte lysate and hemoglobin oxidation.  

PubMed

The current studies have investigated the effect of heterocyclic drugs with the single thiol group (thiamazole, mercaptopurine) and dithiol aliphatic drugs (dimercaptosuccinic acid, dithiothreitol) under oxidative stress conditions, using tert-butyl hydroperoxide (t-BuOOH), in human erythrocyte lysate with the luminol-enhanced chemiluminescence technique. Knowing that oxidative processes induced by t-BuOOH are triggered by (oxy)hemoglobin (Hb), the effect of different thiol drugs (RSH) on isolated human Hb oxidation to methemoglobin (MHb) and hemichromes (HChr) was further considered. Three types of chemiluminescence curves, fitting to logistic-exponential model, have been revealed under influence of RSH. Structure of the data (MHb and HChr production, and free radical activity of RSH) in Principal Component Analysis visualization and kinetic profiles of chemiluminescence integrate information in terms of the diversity of RSH reaction mechanisms depending on the specific molecular context of the given thiol: aliphatic or aromatic nature as well as the number and position of the -SH groups in the molecule. The study conducted in presented in vitro systems indicates the potential role of thiol drugs mediated toxicity in an oxidative stress dependent mechanism. PMID:25308193

Sajewicz, Waldemar; Zalewska, Marta; Milnerowicz, Halina

2015-02-01

28

Chemiluminescent Reactions Catalyzed by Nanoparticles of Gold, Silver, and Gold/Silver Alloys  

NASA Astrophysics Data System (ADS)

Chemiluminescence (CL) reactions are catalyzed by metals nanoparticles, which display unique catalytic properties due to an increased surface area. The present study describes the catalytic effects of nanoparticles (NP) of silver, gold, and alloys of Au/Ag nanoparticles on the chemiluminescent reaction taking place between luminol and potassium ferricyanide. It was found that silver nanoparticles and alloy nanoparticles enhance the CL process when their sizes remained in the range of 30 nm to 50 nm. The data show that the intensity and rate of chemiluminescence were influenced by the mole fraction of gold and silver in the alloy. Data to this chemiluminescence reaction are modeled by a double exponential curve, which indicates that two competing processes are occurring.

Abideen, Saqib Ul

29

Luminol Test  

NSDL National Science Digital Library

Learners mix a solution containing luminol and copper with a fake blood solution. A chemical reaction between the luminol solution and fake blood (hydrogen peroxide) show learners a blue glow. Forensic scientists spray luminol onto surfaces at crime scenes to detect invisible blood stains. Luminol solution reacts with blood, changing the structure of the molecule and temporarily adding energy. This energy causes the luminol to glow. This activity is used in the Crime Science Chemistry unit in OMSI's Chemistry Lab. Supply estimates are for 100 learners. For safety reasons, this activity should be conducted as a demonstration for younger audiences.

Oregon Museum of Science and Industry

1997-01-01

30

Sensitive assay of hexythiazox residue in citrus fruits using gold nanoparticles-catalysed luminol-H2O2 chemiluminescence.  

PubMed

A new sensitive chemiluminescence (CL) procedure for the detection of hexythiazox (HXTZ) is presented, based on the quenching effect of the HXTZ in the luminol-H2O2 system using gold nanoparticles (GNPs) as a catalyst. The Box-Behnken design matrix and response surface methodology (RSM) have been applied in designing the experiments for studying the interactive effects of the three most important variables pH, luminol, and H2O2 concentrations on the CL intensity of luminol catalysed by GNPs. Under the optimal conditions, the CL intensity was linear with HXTZ concentration in the range of 0.017-0.42?gmL(-1), and the limit of detection (LoD) was 0.011?gmL(-1). The procedure has been successfully applied to the detection of HXTZ residues in citrus fruits and water samples at trace levels. Mean recoveries obtained were between 84.0% and 95.3%, with a repeatability precision of <6%. Meanwhile, the possible mechanism of the inhibited CL intensity was discussed. PMID:25466053

Khajvand, Tahereh; Chaichi, Mohammad Javad; Colagar, Abasalt Hosseinzadeh

2015-04-15

31

Glucose determination in samples taken by microdialysis by peroxidase-catalyzed luminol chemiluminescence.  

PubMed

An automatic, luminometric assay of glucose in samples of the extracellular water space obtained by microdialysis is described. The assay involves oxidation by glucose oxidase (EC 1.1.3.4) and mutarotation of glucose by aldose mutarotase (EC 5.1.3.3.). The H2O2 formed is subsequently determined in a reaction catalyzed by horseradish peroxidase (EC 1.11.1.7) using luminol as electron donor. The assay is linear between 0.01 and 1 nmol in the cuvette. The detection limit, defined as 3 standard deviations of the reagent blank, was 0.008 mumol/liter in the cuvette. A complete oxidation of glucose is obtained within 4 min and 25 samples are automatically assayed within 75 min. Addition of microdialysate sample obtained from human adipose tissue in vivo did not interfere with the standard curves. Glucose added to microdialysate resulted in a complete recovery compared to a H2O2 standard. Analytical interference from different factors was investigated. No interference was observed up to the following concentrations: 5 mumol/liter epinephrine, 1 mumol/liter norepinephrine, 100 mumol/liter insulin, 500 mumol/liter pyruvate, 50 mmol/liter lactate, and 1 mumol/liter ascorbate. The glucose values with the present method correlated strongly (r = 0.984) with values obtained using a routine method involving glucose oxidase and peroxidase. PMID:2048727

Näslund, B; Arner, P; Bolinder, J; Hallander, L; Lundin, A

1991-01-01

32

Enhancement of hydrogen peroxide-induced luminol-dependent chemiluminescence by neopterin depends on the presence of iron chelator complexes.  

PubMed

We have previously shown that neopterin, 6-D-erythro-trihydroxypropyl-pteridine, synthesized by human monocytes/macrophages upon stimulation by interferon-gamma, enhances toxicity of reactive oxygen at neutral or slightly alkaline pH (7.5), but not at acidic pH (below 6.5). In the present study, we explored in more detail the necessary requirements for neopterin to modulate the effects of hydrogen peroxide in a luminol-dependent chemiluminescence assay. We demonstrate that neopterin enhances hydrogen peroxide effects only in the presence of iron chelator complexes like iron-(III)- or iron-(II)-EDTA or iron-(III)-DTPA. Thus, iron chelator complexes together with neopterin may play an important role in macrophage-mediated effector mechanisms. PMID:8307184

Murr, C; Fuchs, D; Gössler, W; Hausen, A; Reibnegger, G; Werner, E R; Werner-Felmayer, G; Esterbauer, H; Wachter, H

1994-01-31

33

[Determining the postmortem interval of bone samples: a comparison of luminol chemiluminescence, Hexagon OBTI test, and Combur test].  

PubMed

In the experiment, 16 human bones with known postmortem interval (PMI) that had been buried in soil (0.2 to about 2000 years) were tested in a blind setup with two established methods for determining the PMI (UV fluorescence of the surface of a fresh cut and the luminol chemiluminescence) and with two methods applied for this purpose for the first time (Hexagon OBTI test and Combur test). The results underline the importance of the UV fluorescence and luminol tests in determining the PMI, especially with regard to the question whether the PMI is forensically relevant or not. The results for both new methods, the Combur test strips and the Hexagon OBTI test, which were originally developed for the detection of hemoglobin, were negative for all samples. It remains to be seen if the negative results for these two methods may be due to an inability of hemoglobin or its metabolites to dissolve in the Tris buffer solution used in the experiment. PMID:20806675

Ebach, Sarah C; Ramsthaler, Frank; Birngruber, Christoph G; Verhoff, Marcel A

2010-01-01

34

Research and development of a luminol-carbon monoxide flow system  

NASA Technical Reports Server (NTRS)

Adaption of the luminol-carbon monoxide injection system to a flowing type system is reported. Analysis of actual wastewater samples was carried out and revealed that bacteria can be associated with particles greater than 10 microns in size in samples such as mixed liquor. Research into the luminol reactive oxidation state indicates that oxidized iron porphyrins, cytochrome-c in particular, produce more luminol chemiluminescence than the reduced form. Correlation exists between the extent of porphyrin oxidation and relative chemiluminescence. In addition, the porphyrin nucleus is apparently destroyed under the current chemiluminescent reaction conditions.

Thomas, R. R.

1977-01-01

35

The use of the magnetic field effect for studying a chemiluminescent chemical reaction in aqueous solution. Reaction rate constants and lifetimes of intermediate molecules  

NASA Astrophysics Data System (ADS)

The phase shift magnetic field effect technique is applied for investigation of the chemiluminescent (ChL) reaction of luminol oxidation by potassium ferricyanide in aqueous alkali solution. The external modulated magnetic field changed the rate constant of recombination of luminol radicals. Rate constants of intermediate stages of the reaction are obtained: 10 8 M -1 s -1 for diazaquinone reaction with hydrogen peroxide, 2 X 10 6 M -1 s -1 for diazaquinone hydrolysis and 2 X 10 5 s -1 for the decomposition of hydroperoxide, which is a precursor of the light emitter.

Triebel, Michael M.; Totrov, Maxim M.; Zorinyants, George E.; Frankevich, Eugene L.

1993-11-01

36

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

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

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

2014-01-01

37

Study on the reaction mechanism and the static injection chemiluminescence method for detection of acetaminophen.  

PubMed

Acetaminophen, also called paracetamol, is found in Tylenol, Excedrin and other products as over-the-counter medicines. In this study, acetaminophen as a luminol signal enhancer was used in the chemiluminescence (CL) substrate solution of horseradish peroxidase (HRP) for the first time. The use of acetaminophen in the luminol-HRP-H2O2 system affected not only the intensity of the obtained signal, but also its kinetics. It was shown that acetaminophen was to be a potent enhancer of the luminol-HRP-H2O2 system. A putative enhancement mechanism for the luminol-H2O2-HRP-acetaminophen system is presented. The resonance of the nucleophilic amide group and the benzene ring of acetaminophen structure have a great effect on O-H bond dissociation energy of the phenol group and therefore on phenoxyl radical stabilization. These radicals act as mediators between HRP and luminol in an electron transfer reaction that generates luminol radicals and subsequently light emission, in which the intensity of CL is enhanced in the presence of acetaminophen. In addition, a simple method was developed to detect acetaminophen by static injection CL based on the enhanced CL system of luminol-H2O2-HRP by acetaminophen. Experimental conditions, such as pH and concentrations of substrates, have been examined and optimized. The proposed method exhibited good performance, the linear range was from 0.30 to 7.5 mM, the relative standard deviation was 1.86% (n = 10), limit of detection was 0.16 mM and recovery was 99 ± 4%. PMID:23408702

Wu, Yongjun; Zhang, Huili; Yu, Songcheng; Yu, Fei; Li, Yanqiang; Zhang, Hongquan; Qu, Lingbo; Harrington, Peter de B

2013-01-01

38

CoFe2O4 nanoparticles as oxidase mimic-mediated chemiluminescence of aqueous luminol for sulfite in white wines.  

PubMed

Recently, the intrinsic enzyme-like activity of nanoparticles (NPs) has become a growing area of interest. However, the analytical applications of the NP-based enzyme mimetic are mainly concentrated on their peroxidase-like activity; no attempts have been made to investigate the analytical applications based on the oxidase mimic activities of NPs. For the first time, we report that CoFe(2)O(4) NPs were found to possess intrinsic oxidase-like activity and could catalyze luminol oxidation by dissolved oxygen to produce intensified chemiluminescence (CL). The effect of sulfite on CoFe(2)O(4) NP oxidase mimic-mediated CL of aqueous luminol was investigated. It is very interesting that when adding sulfite to the luminol-CoFe(2)O(4) system, the role of sulfite in the luminol-CoFe(2)O(4) NP-sulfite system depends on its concentration. At a relatively low concentration level, sulfite presents an inhibition effect on the luminol-CoFe(2)O(4) NP system. However, it does have an enhancement effect at a higher concentration level. Investigations on the effect of the solution pH and luminol and CoFe(2)O(4) NP concentrations on the kinetic characteristics of the studied CL system in the presence of trace sulfite suggested that the enhancement and inhibition of the luminol-CoFe(2)O(4) NP-sulfite CL system also depended on the solution pH. It seems that the concentrations of luminol and CoFe(2)O(4) NPs did not influence the CL pathway. The possible mechanism of the luminol-CoFe(2)O(4) NP-sulfite CL system was also discussed. On this basis, a flow injection chemiluminescence method was established for the determination of trace sulfite in this study. Under the optimal conditions, the proposed system could respond down to 2.0 × 10(-8) M sulfite. The method has been applied to the determination of trace sulfite in white wine samples with satisfactory results. The results given by the proposed method are in good agreement with those given by the standard titration method. PMID:23289402

Zhang, Xiaodan; He, Shaohui; Chen, Zhaohui; Huang, Yuming

2013-01-30

39

Influence of polyclonal immunoglobulins on the polymorphonuclear leukocyte response to lipopolysaccharide of Salmonella enteritidis as measured with luminol-enhanced chemiluminescence.  

PubMed Central

In gram-negative sepsis, the activation of polymorphonuclear leukocytes (PMN) by lipopolysaccharide (LPS) and the resulting production of superoxide and other oxygen radicals may be an important cause of tissue damage. A suppression of the PMN response to LPS stimulation would be therapeutically beneficial. The aim of this study was to determine whether different polyclonal immunoglobulins (Igs; 5S-Ig, 7S-Ig, and 19S-Ig) influence the PMN response to LPS of Salmonella enteritidis in vitro. The respiratory burst activity of PMN was measured with luminol-enhanced chemiluminescence. After addition of a 5S-Ig solution containing F(ab')2 fragments of IgG and a 19S-Ig solution containing 12% polyclonal IgM, luminol-enhanced chemiluminescence was reduced by 27% (P < 0.05) and 46% (P < 0.005), respectively. However, after addition of a 7S-Ig solution containing polyclonal IgG, luminol-enhanced chemiluminescence was increased fourfold (P < 0.05). The results suggest that the influence of polyclonal Igs on PMN response to LPS stimulation is dependent on the Ig class, F(ab')2 fragments of IgG and IgM leading to LPS neutralization and IgG leading to the production of potentially toxic oxygen radicals. PMID:7927690

Wagner, D R; Heinrich, D

1994-01-01

40

Flow-injection chemiluminescence determination of cloxacillin in water samples and pharmaceutical preparation by using CuO nanosheets-enhanced luminol-hydrogen peroxide system  

NASA Astrophysics Data System (ADS)

In this paper, a rapid and sensitive flow-injection chemiluminescence (flow-CL) system was developed for the determination of cloxacillin sodium in environmental water samples and pharmaceutical preparations. The method was based on the enhancement effect of cloxacillin sodium on the CL reaction of luminal-H2O2-CuO nanosheets (NSs) in alkaline medium. The CuO nanosheets were synthesized using a green sonochemical method. The physical properties of the synthesized CuO nanosheets were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses. The influences of various experimental factors such as H2O2, NaOH, luminol and CuO nanosheets concentrations were investigated. Under the optimum conditions, the enhanced CL intensity was linearly related to the concentration of cloxacillin sodium in the range of the 0.05-30.00 mg L-1 with a correlation coefficient of 0.995. The corresponding detection limit (3?) was calculated to be 0.026 mg L-1. The relative standard deviation (RSD) of the developed method was 2.21% with 11 repeated measurements of 4.00 mg L-1 cloxacillin sodium. Also, a total analysis time per sample was 30 s which confirmed the rapidity of the proposed method. The analytical applicability of the proposed CL system was assessed by determining cloxacillin sodium in spiked environmental water samples and pharmaceutical preparation. Furthermore, the possible mechanism of CL reaction was discussed.

Khataee, Alireza; Iranifam, Mortaza; Fathinia, Mehrangiz; Nikravesh, Mina

2015-01-01

41

Enhancement of electrogenerated chemiluminescence of luminol by ascorbic acid at gold nanoparticle/graphene modified glassy carbon electrode  

NASA Astrophysics Data System (ADS)

Gold nanoparticle/graphene (GNP/GR) nanocomposite was one-pot synthesized from water soluble graphene and HAuCl4 by hydrothermal method and characterized by TEM, Raman spectroscopy, XRD, XPS, UV-vis spectroscopy, and electrochemical impedance spectroscopy (EIS). Electrogenerated chemiluminescence (ECL) of luminol was investigated at the GNP/GR modified glassy carbon electrode (GNP/GR/GCE) and the GNP modified glassy carbon electrode (GNP/GCE) in aqueous solution respectively. The results revealed that one strong anodic ECL peak could be observed at ?0.8 V at two modified electrodes compared with that at the bare electrode. The intensity of the anodic ECL at the GNP/GR/GCE is weaker than that at the GNP/GCE, which should be due to the synergic effect of the enhancing effect of gold nanoparticles and the inhibiting effect of graphene on anodic luminol ECL. One strong cathodic ECL peak located at ?-0.8 V could be observed at the GNP/GR/GCE but not at the GNP/GCE, which should be result from the adsorbed oxygen at the graphene film. In the presence of ascorbic acid, the anodic ECL at the GNP/GR/GCE was enhanced more than 8-times, which is more apparent than that at the GNP/GCE. Whereas, the cathodic ECL peak was seriously inhibited at the GNP/GR/GCE. The enhanced ECL intensity at the GNP/GR/GCE varied linearly with the logarithm of ascorbic acid concentration in the range of 1.0 × 10-8 to 1.0 × 10-6 mol L-1 with a detection limit of 1.0 × 10-9 mol L-1. The possible ECL mechanism was also discussed.

Dong, Yongping; Gao, Tingting; Zhou, Ying; Chu, Xiangfeng; Wang, Chengming

2015-01-01

42

Enhancement of electrogenerated chemiluminescence of luminol by ascorbic acid at gold nanoparticle/graphene modified glassy carbon electrode.  

PubMed

Gold nanoparticle/graphene (GNP/GR) nanocomposite was one-pot synthesized from water soluble graphene and HAuCl? by hydrothermal method and characterized by TEM, Raman spectroscopy, XRD, XPS, UV-vis spectroscopy, and electrochemical impedance spectroscopy (EIS). Electrogenerated chemiluminescence (ECL) of luminol was investigated at the GNP/GR modified glassy carbon electrode (GNP/GR/GCE) and the GNP modified glassy carbon electrode (GNP/GCE) in aqueous solution respectively. The results revealed that one strong anodic ECL peak could be observed at ?0.8 V at two modified electrodes compared with that at the bare electrode. The intensity of the anodic ECL at the GNP/GR/GCE is weaker than that at the GNP/GCE, which should be due to the synergic effect of the enhancing effect of gold nanoparticles and the inhibiting effect of graphene on anodic luminol ECL. One strong cathodic ECL peak located at ?-0.8 V could be observed at the GNP/GR/GCE but not at the GNP/GCE, which should be result from the adsorbed oxygen at the graphene film. In the presence of ascorbic acid, the anodic ECL at the GNP/GR/GCE was enhanced more than 8-times, which is more apparent than that at the GNP/GCE. Whereas, the cathodic ECL peak was seriously inhibited at the GNP/GR/GCE. The enhanced ECL intensity at the GNP/GR/GCE varied linearly with the logarithm of ascorbic acid concentration in the range of 1.0 × 10(-8) to 1.0 × 10(-6)mol L(-1) with a detection limit of 1.0 × 10(-9) mol L(-1). The possible ECL mechanism was also discussed. PMID:25022493

Dong, Yongping; Gao, Tingting; Zhou, Ying; Chu, Xiangfeng; Wang, Chengming

2015-01-01

43

Studies of chemiluminescence in boron atom reactions  

SciTech Connect

Chemiluminescence has been observed in the single collision reactions of boron atoms with O/sub 2/, SO/sub 2/, N/sub 2/O, NO/sub 2/, and H/sub 2/O/sub 2/. The experiments were performed in a beam-gas apparatus using photon counting to detect the optical signals. The electronically excited A/sup 2/pi state of BO was observed in all the reactions. In addition the BO/sup -/ excited state, B/sup 2/..sigma../sup +/, was observed in the reaction of boron with N/sub 2/O. Excited BO/sub 2/ (A/sup 2/pi/sub u/) was observed in the reaction with SO/sub 2/ and excited OH (A/sup 2/..sigma../sup +/) was observed in the reaction with H/sub 2/O/sub 2/. Cross sections for the production of electronically excited molecules were determined. These cross sections for the reactions with O/sub 2/, SO/sub 2/, N/sub 2/O, NO/sub 2/, and H/sub 2/O/sub 2/ are, respectively, 0.048 A/sup 2/, 0.078 A/sup 2/, 0.011 A/sup 2/, 0.19 A/sup 2/, and 0.0058 A/sup 2/. In those reactions involving more than one chemiluminescent product channel, branching ratios were obtained for the observed products. The vibrational distributions in the electronically excited states of BO were determined for all the reactions and were analyzed using information theory. Some implications of the results are discussed.

DeHaven, J.J.

1982-01-01

44

An optimized, sensitive and stable reduced graphene oxide-gold nanoparticle-luminol-H2O2 chemiluminescence system and its potential analytical application  

NASA Astrophysics Data System (ADS)

The chemiluminescence (CL) performance of luminol is improved using reduced graphene oxide/gold nanoparticle (rGO-AuNP) nano-composites as catalyst. To prepare this catalyst, we propose a linker free, one-step method to in-situ synthesize rGO-AuNP nano-composites. Various measurements are utilized to characterize the resulting rGO-AuNP samples, and it is revealed that rGO could improve the stability and conductivity. Furthermore, we investigate the CL signals of luminal catalyzed by rGO-AuNP. Afterwards, the size effect of particle and the assisted enhancement effect of rGO are studied and discussed in detail. Based on the discussion, an optimal, sensitive and stable rGO-AuNP-luminon-H2O2 CL system is proposed. Finally, we utilize the system as a sensor to detect hydrogen peroxide and organic compounds containing amino, hydroxyl, or thiol groups. The CL system might provide a more attractive platform for various analytical devices with CL detection in the field of biosensors, bioassays, and immunosensors.

Wang, Wen-Shuo; He, Da-Wei; Wang, Ji-Hong; Duan, Jia-Hua; Peng, Hong-Shang; Wu, Hong-Peng; Fu, Ming; Wang, Yong-Sheng; Zhang, Xi-Qing

2014-04-01

45

Diclofenac-Choline Antioxidant Activity Investigated by means of Luminol Amplified Chemiluminescence of Human Neutrophil Bursts and Electron Paramagnetic Resonance Spectroscopy.  

PubMed

A new diclofenac salt called diclofenac-choline (DC) has recently been proposed for the symptomatic treatment of oropharyngeal inflammatory processes and pain because its greater water solubility allows the use of high concentrations, which are useful when the contact time between the drug and the oropharyngeal mucosa is brief, as in the case of mouthwashes or spray formulations. The antioxidant activity of DC has not yet been investigated, and so the aim was to use luminol-amplified-chemiluminescence (LACL) to verify whether various concentrations of DC (1.48, 0.74 and 0.37?mg/mL for incubation times of 2, 4 and 8?min) interfere with oxygen and nitrogen radicals during the course of human neutrophils respiratory bursts; electron paramagnetic resonance (EPR) spectroscopy was used to investigate its direct antiradical (scavenger) activity. The EPR findings showed that DC has concentration-dependent scavenging activity against the ABTS, the DPPH, and the hydroxyl radicals, but no activity on superoxide anion, as has been previously reported in the case of other NSAIDs. LACL revealed an inhibitory effect that was statistically significant after only 2?min of incubation, and similar after 4 and 8?min. The effects on the peroxynitrite radical paralleled those observed in the previous test. High concentrations and short incubation times showed that there is no interference on PMN viability, and so the inhibitory findings must be attributed to the effect of the drug. The anti-inflammatory effects of DC cannot be attributed solely to the inhibition of prostaglandin synthesis, but its effects on free radicals and neutrophil bursts suggest that they may contribute to its final therapeutic effect. PMID:24918344

Braga, P C; Lattuada, N; Greco, V; Sibilia, V; Falchi, M; Bianchi, T; Dal Sasso, M

2014-06-11

46

Red-shifted emission from 1,2-dioxetane-based chemiluminescent reactions.  

PubMed

Commercial chemiluminescent reagents emit across a broad portion of the electromagnetic spectrum (400-500?nm). A challenge to the use of chemiluminescence to monitor biological processes is the presence of interfering substances in the biological optical window. In the present study, longer wavelength emitting fluorophores (the organic dyes Alexa 568 and Alexa 647), and a semiconductor nanoparticle (QDOT800) were used to red-shift the emission from commercially available 1,2-dioxetane-based chemiluminescent substrate reactions. By adding non-conjugated fluorescent emitters into chemiluminescent reaction mixtures, an emission peak occurred at the predicted wavelength of the fluorescent emitter. The excitation and emission from QDOT800 was preserved in the presence of a 100?µm-thick glass barrier separating it from the chemiluminescent reaction components. The maximum tissue phantom penetration by QDOT800 emission was 8.5?mm; in comparison, the native chemiluminescent emission at 500?nm was unable to penetrate the thinnest tissue phantom of 2.5?mm. The described method for red-shifted emissions from chemiluminescent reactions does not require direct interaction between the chemiluminescent reaction and the fluorescent emitters. This suggests that the mechanism of chemiluminescent excitation of fluorophores and QDOT800 is not exclusive to chemiluminescence resonance energy transfer or sensitized chemiluminescence, but rather by broad energization from the native chemiluminescent emission. PMID:24760607

Park, Jason Y; Gunpat, Joshua; Liu, Li; Edwards, Brooks; Christie, Alana; Xie, Xian-Jin; Kricka, Larry J; Mason, Ralph P

2014-09-01

47

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

PubMed

A 2-dimensional imaging system was constructed and applied in measurements of gaseous ethanol emissions from the human palm. This imaging system measures gaseous ethanol concentrations as intensities of chemiluminescence by luminol reaction induced by alcohol oxidase and luminol-hydrogen peroxide-horseradish peroxidase system. Conversions of ethanol distributions and concentrations to 2-dimensional chemiluminescence were conducted on an enzyme-immobilized mesh substrate in a dark box, which contained a luminol solution. In order to visualize ethanol emissions from human palm skin, we developed highly sensitive and selective imaging system for transpired gaseous ethanol at sub ppm-levels. Thus, a mixture of a high-purity luminol solution of luminol sodium salt HG solution instead of standard luminol solution and an enhancer of eosin Y solution was adapted to refine the chemiluminescent intensity of the imaging system, and improved the detection limit to 3ppm gaseous ethanol. The highly sensitive imaging allows us to successfully visualize the emissions dynamics of transdermal gaseous ethanol. The intensity of each site on the palm shows the reflection of ethanol concentrations distributions corresponding to the amount of alcohol metabolized upon consumption. This imaging system is significant and useful for the assessment of ethanol measurement of the palmar skin. PMID:25445620

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

2015-05-15

48

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

PubMed

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. PMID:25461149

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

2014-10-17

49

Fast and sensitive chemiluminescence assay of aminophylline in human serum using luminol-diperiodatoargentate(III) system catalyzed by coated iron nanoparticles  

NASA Astrophysics Data System (ADS)

The CL intensity of luminol-diperiodatoargentate(III) (DPA) system is strongly enhanced by addition of iron nanoparticles (FeNPs) covered with C12E4. On injection of aminophylline into luminol-DPA-FeNPs system, the CL intensity is significantly increased. On this basis, a sensitive CL assay was developed for determination of AmP in human serum. FeNPs could catalyze the oxidation rate of luminol in the present of oxygen. Also, the CL intensity of luminol-DPA-FeNPs system is significantly increased in the presence of aminophylline (AmP). Based on this ruling, a sensitive CL assay was developed for determination of AmP in human serum. The influences of analytical variables on the CL signal were studied and optimized. Under the optimum conditions in the present of FeNPs, the CL intensity is linearly increased with AmP concentration in the range of 1.0 × 10-8-2.0 × 10-6 mol L-1. The detection limit was 9.8 × 10-9 mol L-1 AmP and the relative standard deviation for ten parallel measurements of 8.0 × 10-7 mol L-1 AmP was also 4.8%. The proposed system was successfully applied to determine AmP in human serum samples.

Rezaei, B.; Ensafi, Ali A.; Zarei, L.

2012-05-01

50

Simultaneous Determinations of Histamine and N ?-Methylhistamine by High-Performance Liquid Chromatography-Chemiluminescence Coupled with Immobilized Diamine Oxidase  

Microsoft Academic Search

A method for the simultaneous determinations of histamine and its metabolite N?-methylhistamine by HPLC-chemiluminescence coupled with immobilized diamine oxidase was developed. The method was based on the determination of chemiluminescence formed by the reaction of a luminol-ferricyanide mixture in alkaline medium with hydrogen peroxide which is one of the metabolic products of histamine and N?-methylhistamine formed by diamine oxidase. HPLC

M. K. Alam; M. Sasaki; T. Watanabe; K. Maeyama

1995-01-01

51

Detection of gamma irradiated pepper and papain by chemiluminescence  

NASA Astrophysics Data System (ADS)

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 ?m) 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 ?m, 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.

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

52

CoFe2O4 magnetic nanoparticles as a peroxidase mimic mediated chemiluminescence for hydrogen peroxide and glucose.  

PubMed

This communication presents a new peroxidase mimic of CoFe(2)O(4) nanoparticles evaluated by the luminol-based chemiluminescent (CL) reaction. This offers a new method for evaluation and screening of the nanoparticles-based enzyme mimetics. PMID:21892508

Shi, Wenbing; Zhang, Xiaodan; He, Shaohui; Huang, Yuming

2011-10-14

53

Determination of phenolic compounds and their antioxidant activity in Erigeron acris L. extracts and pharmaceutical formulation by flow injection analysis with inhibited chemiluminescent detection  

Microsoft Academic Search

It was found that the chemiluminescence (CL) produced from the reaction of luminol with iodine in the alkaline medium was strongly inhibited by plant phenolic compounds. Based on this finding, a new flow injection CL method was developed for the determination of caffeic acid and 6?-caffeoylerigeroside. The latter compound was isolated for the first time from Erigeron acris L. herb.

Edyta Nalewajko-Sieliwoniuk; Jolanta Nazaruk; Ewelina Antypiuk; Anatol Koj?o

2008-01-01

54

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

NASA Technical Reports Server (NTRS)

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

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

1971-01-01

55

Chemiluminescence flow sensor with immobilized reagents for the determination of iron(III)  

Microsoft Academic Search

A novel chemiluminescence (CL) flow sensor has been developed for the monitoring of iron(III). The analytical reagents involved in the CL reaction, including luminol and hexacyanoferrate(II) were both immobilized on an anion-exchange resin column. When sodium sulfate solution was passed through the column, these two reagents were eluted from the resins and then mixed with an iron(III) stream. By the

Wei Qin; Zhujun Zhang; Chengjie Zhang

1998-01-01

56

Investigation of a chemiluminescent system for the determination of ammonia by flow-injection analysis  

SciTech Connect

A novel system for the determination of ammonia based on the chemiluminescent reaction between hypochlorite and luminol is presented. The technique of flow injection analysis was employed to automate the system. Ammonia reacts with hypochlorite to form monochloramine in basic solution which decreases the observed chemiluminescence intensity. Several interferents are identified, and the reasons why they interfere are discussed. The effects of interferents are minimized through the use of a double-tube dialyzer where the ammonia is diffused across the dialyzer membrane into a recipient stream of hydrochloric acid.

Kraus, P.R.; Crouch, S.R.

1987-01-01

57

Short-Time-Response measurements of nitrogen dioxide and peroxyacetyl nitrate by fast capillary gas chromatography with luminol detection.  

SciTech Connect

The interaction of hydrocarbons and nitrogen oxides in sunlight to produce photochemical smog has been well studied over the years. In the past, the workhorse for the measurement of NO{sub 2}and NO was the chemiluminescent reaction with ozone. This method has detection limits of approximately 0.5 ppb in most commercial instruments, but it cannot detect NO{sub 2} directly; the instrument detects NO and uses hot catalytic surfaces to decompose all other nitrogen oxides (including NO{sub 2}) to NO for detection (l). The main problem with the method is the inherent difficulty in detecting excited NO{sub 2}, which emits over a broad region beginning at approximately 660 nm and has a maximum at 1270 nm, thus requiring a red-shifted photomultiplier for detection. The use of luminol for direct chemiluminescent detection of NO{sub 2} was demonstrated to have greater inherent sensitivity (detection limits of 5 ppt) than the indirect ozone chemiluminescence detection (2). In the luminol system, a gas-liquid reaction leads to light emission with a maximum at approximately 425 nm, at the maximum sensitivity for most photomultiplier tubes. This emission is responsible for the increased detection sensitivities. The biggest problem with this method for direct measurement of NO{sub 2} has been interference due to other soluble oxidants, particularly peroxyacyl nitrates (PANs).

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

2000-12-07

58

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

PubMed

A novel post-chemiluminescence (PCL) reaction was discovered when lercanidipine was injected into the CL reaction mixture of N-chlorosuccinimide with alkaline eosin Y in the presence of cetyltrimethylammonium bromide (CTAB), where eosin Y was used as the CL reagent and CTAB as the surfactant. Based on this observation, a simple and highly sensitive PCL method combined with a flow injection (FI) technique was developed for the assay of lercanidipine. Under optimum conditions, the CL signal was linearly related to the concentration of lercanidipine in the range 7.0 × 10(-10) to 3.0 × 10(-6) ?g/mL with a detection limit of 2.3 × 10(-10) g/mL (3?). The relative standard deviation (RSD) was 2.1% for 1.0 × 10(-8) g/mL lercanidipine (n = 13). The proposed method had been applied to the estimation of lercanidipine in tablets and human serum samples with satisfactory results. The possible CL mechanism is also discussed briefly. PMID:24615899

Wang, Guowei; Zhao, Fang; Gao, Ying

2014-12-01

59

Generation of chemiluminescence upon reaction of aliphatic amines with tris(2,2'-bipyridine)ruthenium(III)  

Microsoft Academic Search

Tris(2,2'-bipyridine)ruthenium(III) (Ru(bpy)â\\/sup 3 +\\/) will undergo an electron-transfer reaction with an appropriate reducing agent to form Ru(bpy)â\\/sup 2 +\\/, which upon achieving an excited state can result in chemiluminescence. Aliphatic amines with an increasing number of carbon atoms were tested between a pH of 4 and 6 and found to act as chemiluminescent reducing agents. In addition, some diamines and

James B. Noffsinger; Neil D. Danielson

1987-01-01

60

Three dimethoxy-substituted luminol derivatives: A comparative study using theoretical method  

NASA Astrophysics Data System (ADS)

In this research, geometrical optimisation, Mulliken charge, molecular electrostatic potential, and the frontier molecular orbitals of three dimethoxy-substituted luminol derivatives were investigated by ab initio, density functional, and Møller-Plesset perturbation theory with a 6-311G (d, p) basis set in gas phase, water, and dimethylsulphoxide solution. The UV-vis spectra were calculated by time dependent density functional theory method. The properties of derivatives were compared with luminol at a molecular level to investigate the change induced by the methoxy group. The three derivatives were also compared with the aim of predicting the order of chemiluminescent efficiency. The results showed that methoxy substitution significantly changed the electronic and spectral properties of luminol. Among three derivatives, structure 2 was suggested to have the highest chemiluminescent efficiency. The results may shed some light on the design and selection of chemiluminescent reagents.

Xue, Bingchun; Liu, Cuilan; Liu, Yanhong; Liu, Erbao

2015-02-01

61

Sulfide chemiluminescence detection  

DOEpatents

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

Spurlin, Stanford R. (Ames, IA); Yeung, Edward S. (Ames, IA)

1985-01-01

62

Sulfide chemiluminescence detection  

DOEpatents

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

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

1985-11-26

63

Chemiluminescence: An Illuminating Experiment  

ERIC Educational Resources Information Center

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

Gafney, Harry D.; Adamson, Arthur W.

1975-01-01

64

Flow-injection chemiluminescence method to detect a ?2 adrenergic agonist.  

PubMed

A new method for the detection of ?2 adrenergic agonists was developed based on the chemiluminescence (CL) reaction of ?2 adrenergic agonist with potassium ferricyanide-luminol CL. The effect of ?2 adrenergic agonists including isoprenaline hydrochloride, salbutamol sulfate, terbutaline sulfate and ractopamine on the CL intensity of potassium ferricyanide-luminol was discovered. Detection of the ?2 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 ?2 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-?2 adrenergic agonist was discussed from the UV/vis spectra. Copyright © 2014 John Wiley & Sons, Ltd. PMID:24830367

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

2014-05-16

65

Chemiluminescence detection of peroxynitrite with flow injection  

NASA Astrophysics Data System (ADS)

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.

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

2001-09-01

66

Method of generating chemiluminescent light  

DOEpatents

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

Spurlin, Stanford R. (Ames, IA); Yeung, Edward S. (Ames, IA)

1986-01-01

67

Comparison of Uric Acid Quantity with Different Food in Human Urine by Flow Injection Chemiluminescence Analysis  

PubMed Central

Based on the inhibitory effect of uric acid (UA) on luminol-Co2+ chemiluminescence (CL) system, a sensitive method for the determination of UA at nanomolar level by flow injection (FI) CL was proposed. The proposed method was successfully applied to real-time monitoring of UA excretion in human 24?h urine with different food intake, showing that meats, vegetables, and porridge intake caused differential UA excretions of 879, 798, and 742?mg, respectively. It was also found that UA concentrations in urine under the three kinds of food intake simultaneously reached maximum at 2?h after meals with the values of 417, 318, and 288??g?mL?1, respectively. The UA concentration in human serum was also determined by this approach, and the possible mechanism of luminol-Co2+-UA?CL reaction was discussed in detail. PMID:24251067

Wang, Jiajia; Tan, Xijuan; Song, Zhenghua

2013-01-01

68

Electrogenerated ferrate(VI) for CE-chemiluminescence detection to determine benzenediol isomers.  

PubMed

Based on the quenched chemiluminescence intensity of the luminol reaction sensitized by ferrate(VI) in alkaline medium, a novel CE with on-line inhibited method for the simultaneous analysis of benzenediol isomers was developed. The ferrate(VI) solution was freshly prepared by electrochemical technique before electrophoresis. The parameters influencing detection and separation were carefully investigated. Baseline separation of benzenediols including catechol, resorcinol, and hydroquinone was achieved in less than 8 min with 5.0 mmol/L sodium tetraborate and 2.0 mmol/L luminol at an applied voltage of 18 kV. The LODs (S/N=3) for catechol, resorcinol and hydroquinone were determined to be 8.5 x 10(-9), 8.0 x 10(-7) and 6.5 x 10(-9) mol/L, respectively. Finally, the proposed method was applied for phenolic compounds in hair dye. PMID:20127910

Li, Fang; Hu, Yonggang; Zhang, Huijing; Zhang, Jie

2010-03-01

69

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

PubMed

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. PMID:25435236

Koronkiewicz, Stanislawa; Kalinowski, Slawomir

2015-02-01

70

Method and apparatus for eliminating luminol interference material  

NASA Technical Reports Server (NTRS)

A method and apparatus for removing porphyrins from a fluid sample which are unrelated to the number of bacteria present in the sample and prior to combining the sample with luminol reagent to produce a light reaction is disclosed. The method involves a pre-incubation of the sample with a dilute concentration of hydrogen peroxide which inactivates the interfering soluble porphyrins. Further, by delaying taking a light measurement for a predetermined time period after combining the hydrogen peroxide-treated water sample with a luminol reagent, the luminescence produced by the reaction of the luminol reagent with ions present in the solution, being short lived, will have died out so that only porphyrins within the bacteria which have been released by rupturing the cells with the sodium hydroxide in the luminol reagent, will be measured. The measurement thus obtained can then be related to the concentration of live and dead bacteria in the fluid sample.

Jeffers, E. L.; Thomas, R. R. (inventors)

1979-01-01

71

Sensitive quantification of Escherichia coli O157:H7, Salmonella enterica , and Campylobacter jejuni by combining stopped polymerase chain reaction with chemiluminescence flow-through DNA microarray analysis.  

PubMed

Rapid analysis of pathogenic bacteria is essential for food and water control to preserve the public health. Therefore, we report on a chemiluminescence (CL) flow-through DNA microarray assay for the rapid and sensitive quantification of the pathogenic bacteria Escherichia coli O157:H7, Salmonella enterica , and Campylobacter jejuni in water. Using the stopped polymerase chain reaction (PCR) strategy, the amount of amplified target DNA was strongly dependent on the applied cell concentration. The amplification was stopped at the logarithmic phase of the PCR to quantify the DNA products on the DNA microarray chip. The generation of single-stranded DNA sequences is essential for DNA hybridization assays on microarrays. Therefore, the DNA strands of the PCR products were separated by streptavidin-conjugated magnetic nanoparticles. This was achieved by introducing a reverse primer labeled with biotin together with a digoxigenin labeled forward primer for CL microarray imaging. A conjugate of an antidigoxigenin antibody and horseradish peroxidase recognized the digoxigenin-labeled antistrands bound to the probes on the microarray surface and catalyzed the reaction of luminol and hydrogen peroxide. The generated light emission was recorded by a sensitive charge-coupled device (CCD) camera. The quantification was conducted by a flow-through CL microarray readout system. The DNA microarrays were based on an NHS-activated poly(ethylene glycol)-modified glass substrate. The DNA probes which have the same DNA sequence as the reverse primer were immobilized on this surface. The full assay was characterized by spiking experiments with heat-inactivated bacteria in water. The total assay time was 3.5 h, and the detection limits determined on CL microarrays were for E. coli O157:H7, S. enterica , and C. jejuni 136, 500, and 1 cell/mL, respectively. The results of the DNA microarray assay were comparable to the SYBR green-based assays analyzed with a real-time PCR device. The advantage of the new microarray analysis method is seen in the ability of a high multiplex degree on DNA microarrays, the high specificity of DNA hybridization on DNA microarrays, and the possibility to get quantitative results on an automated CL flow-through microarray analysis system. PMID:21417213

Donhauser, Simon Christian; Niessner, Reinhard; Seidel, Michael

2011-04-15

72

Highly sensitive chemiluminescent analysis of residual bovine serum albumin (BSA) based on a pair of specific monoclonal antibodies and peroxyoxalate-glyoxaline-PHPPA dimer chemiluminescent system in vaccines.  

PubMed

Enzyme-linked immunosorbent assay (ELISA), horseradish peroxidase (HRP)-catalyzed fluorescent reaction, and oxalate chemiluminescence analysis have been combined to develop a highly sensitive, simple, and rapid method for analysis of bovine serum albumin (BSA) based on a pair of specific monoclonal antibodies in vaccines. A typical "sandwich type" immunoassay was used. Reaction of 3-(4-hydroxyphenyl propionate) (PHPPA) with hydrogen peroxide-urea, catalyzed by HRP, produced fluorescence of 3-(4-hydroxyphenyl propionate) dimer, which was detected by chemiluminescence analysis with the bis(2,4,6-trichlorophenyl)oxalate (TCPO)-H(2)O(2)-glyoxaline-PHPPA dimer chemiluminescent system. This method exhibited high performance with a linear correlation between response and amount of bovine serum albumin (BSA) in the range 0.1 to 100.0 ng mL(-1) (r?=?0.9988), and the detection limit was 0.03 ng mL(-1) (S/N?=?3). Intra- and interassay coefficient variations were all lower than 9.0% at three concentrations (1.0, 20.0, and 80.0 ng mL(-1)). The proposed method has been used for successful analysis of the amount of residual BSA in vaccines. The results obtained compared well with those obtained by conventional colorimetric ELISA and luminol chemiluminescent ELISA. PMID:22328250

Xue, Pan; Zhang, Kui; Zhang, Zhujun; Li, Yun; Liu, Feng; Sun, Yuanjie; Zhang, Xiaoming; Song, Chaojun; Fu, Aihua; Jin, Boquan; Yang, Kun

2012-03-01

73

Postmortem interval of skeletal remains through the detection of intraosseal hemin traces. A comparison of UV-fluorescence, luminol, Hexagon-OBTI®, and Combur® tests.  

PubMed

With the goal of obtaining additional practically applicable methods for estimating the PMI of skeletal remains, 39 samples of human and 5 samples of domestic animal long bones with known PMI (PMI=1 to approximately 2000 years) were tested with two established methods (UV-fluorescence of a freshly sawn cross-section and the luminol test) and two screening tests (Hexagon-OBTI® test and Combur® test) that were being tried out in this context for the first time. The hypothesis underlying this experiment was the supposition that the PMI-related chemiluminescence of the luminol reaction for bone is based on the presence of persisting hemin from hemoglobin molecules in bone. Our results showed that lack of luminescence and reduced UV-fluorescence were more meaningful results for estimating PMI and excluding forensic relevance than a positive luminol reaction or strong UV-fluorescence, as both of the latter findings revealed the limitations of these methods in this particular context. Particularly for cases showing a positive luminol reaction, the use of additional absolute dating methods may be indicated. Against our expectations, both the Combur® test strips and the Hexagon-OBTI® test, which were both devised to demonstrate blood, delivered negative results for all samples. They are thus not suitable for estimating the PMI of skeletal remains. Future research will be necessary to elucidate whether the negative results obtained for these tests may be due to the poor solubility of potentially present hemoglobin or hemoglobin breakdown products in the Tris buffer used in this experiment. PMID:21237592

Ramsthaler, Frank; Ebach, Sarah C; Birngruber, Christoph G; Verhoff, Marcel A

2011-06-15

74

Gold nanolabels for new enhanced chemiluminescence immunoassay of alpha-fetoprotein based on magnetic beads.  

PubMed

Gold'n'beads: A chemiluminescence immunoassay for the sensitive and rapid determination of AFP has been developed, employing bromophenol blue as a novel chemiluminescence enhancer by taking advantages of easy separation by magnetic beads and signal amplification by gold nanoparticles based on a sandwich-type immunoreaction (see scheme).A novel and sensitive chemiluminescence immunoassay (CLIA) has been developed by employing a new chemiluminescence (CL) enhancer, bromophenol blue (BPB), for the determination of alpha-fetoprotein (AFP) based on magnetic beads (MBs) and colloidal gold nanoparticles (AuNPs) modified with HRP-labeled anti-AFP antibodies. BPB, as a chemical indicator, was found to act as a novel and highly signal enhancer of the peroxidase-catalyzed CL reaction of luminol with hydrogen peroxide. After optimizing the CL reaction conditions, this new luminol-H(2)O(2)-HRP-BPB CL system was applied to a sandwich-type CLIA based on the magnetic separation and the amplification feature of AuNPs as HRP labels. A linear range was obtained when the concentrations of AFP were from 0.1 to 5.0 ng mL(-1) (R=0.9997) with the detection limit of 0.01 ng mL(-1) (3sigma), which is one order of magnitude lower than that obtained without using AuNPs, and much lower than that typically achieved by ELISA. The present method was successfully applied to the determination of AFP in human serum samples. The results indicated that this proposed protocol could be quite promising for the application in immunoassays. PMID:19291715

Bi, Sai; Yan, Yameng; Yang, Xiaoyan; Zhang, Shusheng

2009-01-01

75

Application of optimized chemiluminescence assay for determination of the antioxidant capacity of herbal extracts.  

PubMed

A chemiluminescence (CL) assay for the determination of antioxidant capacity (AOC) has been optimized and applied to analyses of herbal extracts in the present study. The optimal concentrations of reagents (luminol, H2O2, horseradish peroxidase) have been determined, as well as the optimal reaction conditions (wavelength, pH, temperature, sample volume). All of the measurements were performed at the emission maximum of the oxidized form of luminol (425?nm). The optimal concentrations of the reagents were determined as follows: 1.6?mmol/L luminol, 7.5?mmol/L H2O2 and 0.14 U/mL horseradish peroxidase activity in the reaction mixture. Analyses were carried out in phosphate buffer, pH 7.4, at room temperature. With the optimized CL assay, the AOCs of various water and methanol herbal extracts were determined (dog rose hips, plantain leaves and coltsfoot and thyme flowers) and the results were compared to those obtained by other classical methods for the evaluation of antioxidants. Strong correlations (r?>?0.9) with the Folin-Ciocalteau assay and the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH)(?) assay are confirmed, although there is no correlation between AOC and the concentration of ascorbic acid in the samples analysed. This optimized CL assay is simple, rapid and reliable, and it represents a good alternative to classical methods (Folin-Ciocalteau, DPPH(?)) for the determination of AOC of herbal extracts and other food samples. PMID:22290787

Poga?nik, Lea; Ulrih, Nataša Poklar

2012-01-01

76

The forensic luminol test for blood: unwanted interference and the effect on subsequent analysis  

Microsoft Academic Search

When no bloodstains are found by visual inspection in crime scene investigations the chemilumine- scence (CL) produced in the luminol test for blood is a useful aid. The complex reactions that give rice to the blue- green CL are facilitated by the catalytical activity of the hemoglobin in blood. The luminol test has a high sensitivity compared to other forensic

Anders Nilsson

77

Method of generating chemiluminescent light  

DOEpatents

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

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

1986-03-11

78

The enhanced electrochemiluminescence of luminol on the nickel phthalocyanine modified electrode.  

PubMed

A glassy carbon electrode (GCE) modified with nickel(II) tetrasulfophthalocyanine (NiTSPc) and Nafion was used for the investigation of the catalytic oxidation of luminol. The modified electrode was found to much more effectively improve the emission of electrochemiluminescence(ECL) of luminol in a solution containing hydrogen peroxide. The enhanced ECL signal corresponded to the catalytic oxidation of both luminol and H(2)O(2) by NiTSPc. Attached Ni(II) on GCE was oxidised to Ni(III) and then used as the catalyst for the chemiluminescence of luminol. The enhanced stability of the ECL signal with Nafion would mainly result from the prevention of the dissolution of NiTSPc and the adsorption of the oxidation product of luminol on the electrode surface. The proposed method enables a detection limit for luminal of 6.0 x 10(-8) mol L(-1) to be achieved in the presence of H(2)O(2) in the neutral solution. The enhanced ECL intensity had a linear relationship with the concentration of luminol in the range of 1.0 x 10(-7)-8.0 x 10(-6) mol L(-1). PMID:15614356

Wang, Jian; Chen, Guonan; Huang, Jinling

2005-01-01

79

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

PubMed

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 (? 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). PMID:24481623

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

2014-09-01

80

Chemiluminescence of the NI(b 1? + ? X 3? -) transition in active nitrogen reactions with aliphatic iodine compounds  

NASA Astrophysics Data System (ADS)

The emission spectra from the reactions of C 2H 5I, C 4H 9I and CH 2I 2 with active nitrogen are observed in a flowing afterglow reactor. The experimental results show that these reactions exhibit identical chemiluminescence characteristics. Thirty-five spectral peaks in the 620-840 nm wavelength range are assigned to vibrational transitions of the NI(b 1? +, v' = 0 ˜ 6 ? X 3? -) band system. This is the first experimental evidence for the generation of excited state NI(b 1? +) via chemical reactions in the gas phase. The possible formation mechanism of the electronically excited NI(b 1? +) is proposed to be the reaction of N( 2P) in active nitrogen with C 2H 5I, C 4H 9I, and CH 2I 2.

Tang, Xiaoshuan; Wang, Hongmei; Chu, Yannan; Zhang, Weijun; Zhou, Shikang

2006-05-01

81

Determination of folic acid by capillary electrophoresis with chemiluminescence detection.  

PubMed

A rapid and simple method is presented for the determination of folic acid (FA) by capillary electrophoresis (CE) with chemiluminescence (CL) detection. This method was based on enhance effect of FA on the CL reaction between luminol and BrO(-) in alkaline aqueous solution. Optimal separation and determination was obtained with an electrophoretic buffer of 35 mM sodium borate (pH 9.4) containing 0.8 mM luminol, and an oxidizer solution of 1.6 mM NaBrO in 100 mM NaCO(3) buffer solution (pH 12.0). Under the optimal conditions, the determination of FA was achieved in less than 20 min, and the detection limit was 2.0 x 10(-8) M (S/N=3). The relative standard deviations (RSDs) on peak area and migration time were in the 1.5 and 1.1%, respectively. The present CE-CL method was applied to the determination of FA in commercial pharmaceutical tablets, apple juices and human urine. PMID:16413558

Zhao, Shulin; Yuan, Hongyan; Xie, Chao; Xiao, Dan

2006-02-24

82

An assay for inorganic mercury(II) based on its post-catalytic enhancement effect on the potassium permanganate-luminol system.  

PubMed

A strong chemiluminescence (CL) response is observed when potassium permanganate solution is injected into basic luminol solution. When the CL reaction terminates, subsequent injection of Hg2+ solution into the reaction mixture results in a new CL reaction. Based on the post-catalytic enhancement effect of Hg2+ on the potassium permanganate-luminol system in basic media, a fast and simple CL-coupled flow injection analysis for the determination of Hg2+ was developed. In optimum conditions, CL intensity is proportional to Hg2+ concentration over the range 1.0 x 10(-8)-1.0 x 10(-5) g/mL, with a detection limit of 2.0 x 10(-9) g/mL. The relative standard deviation (RSD) is 3.6% for 1.0 x 10(-7) g/mL Hg2+ (n = 11). After pretreatment with sulphydryl cotton fibre, environmental water samples were analysed by the proposed method for total mercury determination with satisfactory results. The results were in good agreement with those given by hydride generation-cold vapour atomic absorption spectrometry (HG-CVAAS). PMID:16791822

Hu, Shangwei; Liu, Weibing; Huang, Yuming; Shu, Weiqun; Cao, Jia

2006-01-01

83

Reprint of: Infrared chemiluminescence study of the reaction Cl + HI ? HCl + I at enhanced collision energies  

NASA Astrophysics Data System (ADS)

The detailed rate constant k(V?, R?, T?; T), where V?, R? and T? are product vibrational, rotational and translational energies, and T is the reagent translational energy (approximately 4.7-12 kcal mole-1), has been measured for Cl + HI ? HCl + I by the infrared chemiluminescence method. The main findings are (a) that T becomes principally T?, (b) that V? broadens in distribution and (c) a second peak appears in R? of v? = 4, at enhanced T.

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

2013-12-01

84

Chemiluminescent matrix reactions of atomic oxygen, sulfur, and O(3P)+H2S  

Microsoft Academic Search

Optical multichannel techniques have been used to analyzed the visible chemiluminescence generated by diffusion-controlled warmup (8?20 °K) of separate, uv-photolyzed inert gas matrices containing O3, H2S, H2S+O2, and O3+H2S molecules. Oxygen atoms were observed to diffuse and recombine in solid argon at ?17 °K to produce the intense Herzberg I band system of molecular O2 (A?X) which was also observed

Richard R. Smardzewski

1978-01-01

85

Sensitive chemiluminescent immunoassay of triclopyr by digital image analysis.  

PubMed

An image based detection of chemiluminescence enzyme-linked immunosorbent assay (CL-ELISA) for the quantification of triclopyr has been developed. The immunoassay was an indirect competitive immunoassay with an anti-rabbit secondary antibody conjugated to horseradish peroxidase (HRP). Chemiluminescence was produced by the luminol/H(2)O(2)/HRP reaction, detected by a monochrome video CCD camera and digitized with an Imagraph IC-PCI frame grabber using a custom program developed in C(++) (Microsoft Visual C(++) 6.0). Two main improvements are reported in the data processing software: the implementation of a circular mesh covering the perimeter of each well, eliminating diffuse light from the neighboring wells, and the use of volume (the integration of light intensity of all pixels that define a well) as an analytical signal instead of CL intensity or area (as usual in commercial plate readers) to improve precision for normalization of the total light output. The standard curve was produced for 0.01-10 ng/L triclopyr. The limit of detection was 0.8 ng/L and the variation coefficient was 3.07% (n=10, P=0.05). PMID:22841045

Díaz, Aurora N; Sánchez, Francisco G; Baro, Enrique N; Díaz, Ana F G; Aguilar, Alfonso; Algarra, Manuel

2012-08-15

86

Flow-injection chemiluminescence determination of olanzapine using N-chlorosuccinimide-calcein reaction sensitized by zinc (II).  

PubMed

A novel, rapid and sensitive chemiluminescence (CL) method combined with flow-injection (FI) has been established for the estimation of olanzapine. This method is based on the CL signal generated between N-chlorosuccinimide and olanzapine in an alkaline medium in the presence of calcein and Zn(II). Under optimum conditions, the CL signal was proportional to the olanzapine concentration ranging from 1.0 × 10(-10) to 3.0 × 10(-7) g/mL. The detection limit is 8.9 × 10(-11) g/mL olanzapine (3?) and the relative standard deviation for 3.0 × 10(-9) g/mL of olanzapine is 1.9% (n = 11). The current CL method was applied to determine olanzapine in pharmaceutical formulations and biological fluids with satisfactory results. The possible CL reaction mechanism is discussed briefly. PMID:23723137

Zhao, Fang; Fan, Qi; Cai, Huan

2014-05-01

87

Chemiluminescence of human neutrophils induced by soluble stimuli: effect of divalent cations.  

PubMed Central

The effect of three soluble stimuli, phorbol myristate acetate, concanavalin A, and the calcium ionophore A23187, on the luminol-enhanced chemiluminescence of human neutrophils was investigated. All three stimuli elicited a strong burst of chemiluminescence which was dose dependent. The effect of phorbol myristate acetate was independent of the presence of divalent cations in the medium and, in fact, was greater in the presence of ethylene glycol-bis(beta-aminoethyl ether)-N,N-tetraacetic acid. The effect of concanavalin A was greatly stimulated by the presence of calcium in the medium, although some reaction was observed in the absence of this cation. In contrast, chemiluminescence induced by A23187 was absolutely dependent upon the presence of extracellular calcium. These results suggest that the mobilization of calcium into the cell is a sufficient, but not necessary, stimulus for initiation of the respiratory burst. Compounds such as phorbol myristate acetate, which act independently of extracellular divalent cations, may function by altering the intracellular ratio of bound/free calcium. PMID:6797947

DeChatelet, L R; Shirley, P S

1982-01-01

88

Apparatus for use in sulfide chemiluminescence detection  

DOEpatents

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

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

1987-01-06

89

Apparatus for use in sulfide chemiluminescence detection  

DOEpatents

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

Spurlin, Stanford R. (Ames, IA); Yeung, Edward S. (Ames, IA)

1987-01-01

90

NO2 measurement by chemiluminescence  

NASA Technical Reports Server (NTRS)

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

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

1979-01-01

91

The Chemiluminescence Homepage  

NSDL National Science Digital Library

Dr. Thomas Chasteen at Sam Houston State University created this compilation of sites and texts related to chemiluminescence, a process where "energy in the form of light is released from matter because of a chemical reaction." The site contains Quick Time animations, descriptions of related phenomena, links to related sites, and two bibliographies, one targeting advanced readers and the other targeting K-12 readers.

92

A novel chemiluminescence assay of mitoxantrone based on diperiodatocuprate(III) oxidation  

NASA Astrophysics Data System (ADS)

A novel and strong chemiluminescence (CL) of luminol with diperiodatocuprate (K5[Cu(HIO6)2]) was observed in alkaline medium. After the addition of mitoxantrone (MTX) into this system, the CL intensity could be greatly inhibited by MTX. Based on the phenomenon, a sensitive CL method was established for analysis of MTX combining with flow injection technology. Under optimum experimental conditions, the CL intensity was linearly related to the logarithm concentration of MTX from 5.0 × 10-9-1.0 × 10-7 g/ml with the detection limit of 1.1 × 10-9 g/ml (S/N = 3). The relative standard deviation was 1.2% for 5.0 × 10-8 g/ml of MTX. The proposed method was successfully applied for determination of MTX in pharmaceutical preparations and biological fluids. The possible CL reaction mechanism was also discussed briefly.

Yao, Hanchun; Zhang, Min; Zeng, Wenyuan; Zeng, Xiaoying; Zhang, Zhenzhong

2014-01-01

93

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

NASA Astrophysics Data System (ADS)

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.

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

1995-01-01

94

Chemiluminescence of benzoic and cinnamic acids, and flavonoids in the presence of aldehyde and hydrogen peroxide or hydroxyl radical by fenton reaction  

Microsoft Academic Search

Light emission (chemiluminescence; CL) was observed by exciting phenolic compounds with hydrogen peroxide (H2O2) or hydroxyl radical (HO·), formed from H2 and FeCl2 by the Fenton reaction. The intensity of the CL of benzoic acid derivatives in the presence of (H2 was in the order of gallic acid > caffeic acid > 3,5-dimethoxy-4-hydroxycinnamic acid > isovanillic acid = syringic acid.

Yumiko Yoshiki; Kazuyoshi Okubo; Masamichi Onuma; Kiharu Igarashi

1995-01-01

95

Organo-modified layered double hydroxide-catalyzed Fenton-like ultra-weak chemiluminescence for specific sensing of vitamin B?? in egg yolks.  

PubMed

In general, the chemiluminescence (CL) sensing of vitamin B12 is achieved by determining Co(II) liberated from acidified vitamin B12 by a luminol system. However, the luminol system for sensing vitamin B12 has poor selectivity due to serious interference from other metal ions. In this study, as a novel CL amplifier of the Co(II)+H2O2+OH(-) ultra-weak CL reaction (Fenton-like system), dodecylbenzene sulfonate (DBS)-layered double hydroxides (LDHs) have been applied to the specific determination of vitamin B12 by liberating Co(II). The CL intensity increased with increasing the concentration of vitamin B12 in a wide range from 1.0 ng mL(-1) to 5 ?g mL(-1) with a detection limit of 0.57 ng mL(-1) (S/N=3). The proposed method has been successfully applied to determine vitamin B12 in egg yolk with simple procedures, shorter time and higher selectivity. Recoveries from spiked real samples were 96-103%. The results of the proposed method for sensing vitamin B12 in real samples were agreed with those obtained by the standard inductively coupled plasma mass spectrometry (ICP-MS) method. To the best of our knowledge, this is the first report on the CL sensing of vitamin B12 with high selectivity in the absence of luminol. PMID:25127574

Zhang, Lijuan; Rong, Wanqi; Lu, Chao; Zhao, Lixia

2014-11-01

96

Integrated microfluidic system with chemiluminescence detection for single cell analysis after intracellular labeling.  

PubMed

This work describes the first application of microchip electrophoresis with chemiluminescence detection (MCE-CL) in single cell analysis. Human red blood cells were assayed to determine intracellular content of glutathione (GSH). Intracellular GSH was first labeled by incubating cells with diazo-luminol, and then individual cells were injected, in-line lysed, and MCE separated. CL detection was based on the oxidation reaction of luminol-labeled GSH with NaBrO. The MCE-CL assay had a linear calibration curve over a range from 0.2-90 amol GSH injected with a correlation coefficient of 0.9991 and a detection limit of 50 zmol or 3.6 x 10(-9) M (S/N = 3). The average content of GSH in individual human red blood cells was found 64.9 amol (n = 17). Compared with the MCE methods with laser induced fluorescence detection (LIF) reported so far for single cell analysis, the present MCE-CL assay of GSH is simple and about 100 times more sensitive. PMID:19382810

Zhao, Shulin; Li, Xiangtang; Liu, Yi-Ming

2009-05-15

97

Determination of agmatine in biological samples by capillary electrophoresis with chemiluminescence detection.  

PubMed

A fast and simple method based on capillary electrophoresis (CE) with chemiluminescence (CL) detection has been developed for the determination of agmatine, a recently identified neurotransmitter/modulator. The CE run time was approximately 2 min for each sample injected. CL detection employed a lab-built reaction flow cell and a photon counter. The CL reagents used were luminol and NaBrO. The optimized conditions for the CL detection were 5 x 10(-4)M luminol added to the CE running buffer and 5.0 x 10(-4)M NaBrO in 100 mM NaCO3-NaOH buffer solution at pH 12.5 introduced post column. Detection limit for agmatine was 4.3 x 10(-6)M (S/N=3). The precision (R.S.D.) on peak height (at 1 x 10(-5)M agmatine) and migration time were 3.7 and 2.5%, respectively. The present CE-CL method was evaluated with the determination of agmatine in tissue samples taken from rat brain, and rat and monkey stomachs. Samples were directly injected into the CE-CL system after the removal of proteins. A higher level of agmatine was detected in the stomach samples. Agmatine concentrations in the tissue samples taken from rat and monkey stomachs were similar at approximately 1950 ng/g wet tissue. PMID:16427815

Zhao, Shulin; Xie, Chao; Lu, Xin; Liu, Yi-Ming

2006-02-17

98

An Integrated Microfluidic System with Chemiluminescence Detection for Single Cell Analysis after Intracellular Labeling  

PubMed Central

This work describes the first application of microchip electrophoresis with chemiluminescence detection (MCE-CL) in single cell analysis. Human red blood cells were assayed to determine intracellular content of glutathione (GSH). Intracellular GSH was first labeled by incubating cells with diazo-luminol, and then individual cells were injected, in-line lysed, and MCE separated. CL detection was based on the oxidation reaction of luminol - labeled GSH with NaBrO. The MCE-CL assay had a linear calibration curve over a range from 0.2~ 90 amol GSH injected with a correlation coefficient of 0.9991 and a detection limit of 50 zmol or 3.6× 10?9 M (S/N = 3). The average content of GSH in individual human red blood cells was found 64.9 amol (n= 17). Compared with the MCE methods with laser induced fluorescence detection (LIF) reported so far for single cell analysis, the present MCE-CL assay of GSH is simple and about 100 times more sensitive. PMID:19382810

Zhao, Shulin; Li, Xiangtang

2009-01-01

99

Evaluation of the total antioxidant capacity by using a multipumping flow system with chemiluminescent detection.  

PubMed

An automated flow-based procedure for assessment of total antioxidant capacity was developed. It involved a multipumping flow system, a recent approach to flow analysis, and exploited the ability of selected compounds to inhibit the chemiluminescence reactions of luminol or lucigenin with hydrogen peroxide. The system included several discretely actuated solenoid micropumps as the only active components of the flow manifold. This enabled the reproducible insertion and efficient mixing of very low volumes of sample and reagents as well as the transportation of the sample zone toward a flow-through luminometer, where the chemiluminometric response was monitored. With luminol as the chemiluminogenic reagent, linearity of the analytical curves was noted up to 3.2x10(-4), 1.1x10(-3), and 8.8x10(-8) molL-1 for Trolox, ascorbic acid, and resveratrol, respectively. With lucigenin, linear calibration plots up to 2x10(-5) molL-1 of Trolox and 5.7x10(-5)molL-1 of ascorbic acid were obtained. As favorable analytical figures of merit, the measurement precision (RSD typically between 0.2 and 2.0%, n=10), low operational costs, low reagent consumption, sampling rate (160 and 70 h-1), and versatility should be highlighted. The proposed system can be used in distinct analytical circumstances without requiring physical reconfiguration. PMID:16125130

Meneses, Silvia R P; Marques, Karine L; Pires, Cherrine K; Santos, João L M; Fernandes, Eduarda; Lima, José L F C; Zagatto, Elias A G

2005-10-01

100

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

PubMed

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. PMID:24658027

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

2014-08-15

101

Aptamer--nanoparticle-based chemiluminescence for p53 protein.  

PubMed

A simple colorimetric biosensing technique based on the interaction of gold nanoparticles (AuNPs) with the aptamer was developed for detection of p53, a tumor suppressor protein, in the current study. Aggregation of AuNPs was induced by desorption of the p53 binding RNA aptamer from the surface of AuNPs as a result of the aptamer target interaction leading to the color change of AuNPs from red to purple. The detection limit of p53 protein by the colorimetric approach was 0.1 ng/ml after successful optimization of the amount of aptamer, AuNPs, salts, and incubation time. Furthermore, the catalytic activity of the aggregated AuNPs was greatly enhanced by chemiluminescence (CL) reaction, where the detection limit was enhanced to 10 pg/ml with a regression coefficient of R2 = 0.9907. Here the sensitivity was increased by 10-fold compared with the AuNP-based colorimetric method. Hence, the sensitivity of detection was increased by employing CL, by using the catalytic activity of aggregated AuNPs, on the luminol-hydrogen peroxide reaction. Thus, the combination of colorimetric and CL-based aptasensor can be of great advantage in increasing the sensitivity of detection for any target analyte. PMID:23816877

Shwetha, N; Selvakumar, L S; Thakur, M S

2013-10-01

102

Ultrasensitive detection of transcription factors using transcription-mediated isothermally exponential amplification-induced chemiluminescence.  

PubMed

Transcription factors (TFs) are important cellular components that modulate gene expression, and the malregulation of transcription will lead to a variety of diseases such as cancer and developmental syndromes. However, the conventional methods for transcription factor assay are generally cumbersome and costly with low sensitivity. Here, we develop a label-free strategy for ultrasensitive detection of transcription factors using a cascade signal amplification of RNA transcription, dual isothermally exponential amplification reaction (EXPAR), and G-quadruplex DNAzyme-driven chemiluminescence. Briefly, the specific binding of TF with the detecting probe prevents the cleavage of the detecting probe by exonuclease and subsequently facilitates the conversion of TF signal to abundant RNA triggers in the presence of T7 RNA polymerase. The obtained RNA triggers can initiate the strand displacement amplification to yield abundant DNAzymes and DNA triggers, and the released DNA triggers can further initiate the next rounds of EXPAR reaction. The synergistic operation of dual EXPAR reaction can produce large amounts of DNAzymes, which subsequently catalyze the oxidation of luminol by H2O2 to yield an enhanced chemiluminescence signal with the assistance of cofactor hemin. Conversely, in the absence of target TF, the naked detecting probes will be completely digested by exonucleases, leading to neither the transcription-mediated EXPAR nor the DNAzyme-driven chemiluminescence signal. This method has a low detection limit of as low as 6.03 × 10(-15) M and a broad dynamic range from 10 fM to 1 nM and can even measure the NF-?B p50 of crude cell nuclear extracts. Moreover, this method can be used to measure a variety of DNA-binding proteins by simply substituting the target-specific binding sequence in the detecting probes. PMID:24865817

Ma, Fei; Yang, Yong; Zhang, Chun-Yang

2014-06-17

103

Vibrational population distributions of the product of the chemiluminescent charge transfer reaction: O + (2D)+HCl --> O+HCl + (A 2Sigma + )  

NASA Astrophysics Data System (ADS)

The chemiluminescent charge transfer reaction of O+ (2 D)ions with HCl has been studied in the energy range of 7 to 100 eVc.m. . The vibrational population distributions of the HCl+(A 2 ?+,v') product have been analyzed from the emission spectra of the A?X transition. At low collision energy the distribution has a peak at v'=3. The partial reaction cross section ?(3) for this level increases with decreasing collision energy. The features of the reaction are very similar to the F+ +CO? F+CO+ (A) reaction reported previously. The mechanism has been discussed on the basis of curve crossing between the initial and final states along the HCl vibrational coordinate in the asymptotic region of the [O-HCl]+ system. The projectile ions C+ and N+ have also been tested for the charge transfer reaction of HCl(X)?HCl+(A).

Shiraishi, Yasushi; Kusunoki, Isao

1987-12-01

104

Vacuum-Ultraviolet Chemiluminescence in the Reaction of Atomic Oxygen with Acetylene  

Microsoft Academic Search

Vacuum-ultraviolet emission from the reaction of atomic oxygen with acetylene was investigated spectrographically and with photoionization detectors. The spectrum was observed at wavelengths above 1400 Å and consisted entirely of bands belonging to the fourth positive system of CO. At short wavelengths, the intensity declines rapidly, but radiation was detected with photoionization detectors filled with xylene (1425–1475 Å), NO (1100–1340

F. F. Marmo; J. P. Padur; P. Warneck

1967-01-01

105

Near-resonant versus nonresonant chemiluminescent charge-transfer reactions of atomic ions with HCl  

NASA Astrophysics Data System (ADS)

Charge-transfer reactions of C+, O+, F+, Ar+ and some other atomic ions with hydrogen chloride were investigated at collision energies between <1 eV and 1 keV. The electronically excited products HCl+ (A 2?+) were detected by means of the A 2?+?X 2?i optical emission. In some cases the spectra showed, at low collision energies, an enhanced excitation of specific vibrational HCl+(A,v') levels: for C+, v'=1; for O+, v'=3 as well as v'=1; and for F+, v'=6. These levels are populated in near-resonant, slightly exothermic processes. Their rotational temperature was on the order of 600-700 K. For the other vibrational levels the excitation is off-resonance, mostly endothermic, and here the rotational temperature was 1000-4000 K. Corresponding data are also given for DCl. The selectivity for certain vibrational states is explained by crossings between the vibronic entrance and exit state energy surfaces, calculated from classical electrostatic multipole potentials. The cross sections for the near-resonant reactions decrease monotonically with increasing collision energy, while for the endothermic channels they rise steeply from threshold to a plateau. With argon ions the excitation function exhibits an unusual shape. Here the charge-transfer cross sections for all vibrational levels go through a maximum just above threshold, which is followed by a distinct minimum at about 10 eVc.m.. This may be due to formation of a long-lived collision complex (Ar-HCl)+.

Glenewinkel-Meyer, Th.; Ottinger, Ch.

1994-01-01

106

A secondary antibody format chemiluminescence immunoassay for the determination of estradiol in human serum.  

PubMed

A competitive immunoassay for estradiol (E2) based on secondary antibody format was established. The donkey anti-rabbit IgG was used as the secondary antibody to coat micro-plates, and the horseradish peroxidase (HRP)-luminol-H(2)O(2) chemiluminescent system with high sensitivity was chosen as the detection system. The addition of sodium trichloroacetate (CCl(3)COONa) in the enzyme buffer as a replaceable packing material can realize directly analysis of E2 in human serum without extraction, which improved reproducibility and resolution of the assay. Additionally, the method showed specific recognition of estrogen, without cross-reaction for the major steroids (estrone (E1), estriol (E3), dihydrotestosterone (DHT), androstenedione, testosterone (T)) commonly found in human serum. The chemiluminescence immunoassay with secondary antibody can be applied to detect E2 with good precision at concentrations as low as 1.48 pg mL(-1). The proposed method has been successfully applied to the determination of E2 in 97 human sera and showed a good correlation compared with the commercially radioimmunoassay (RIA) kit with a correlative coefficient of 0.9881. This method has exhibited great potential in the fabrication of diagnostic kit and can be used in the clinical analysis of E2 in human serum. PMID:20801358

Xin, Tian-Bing; Chen, Hui; Lin, Zhen; Liang, Shu-Xuan; Lin, Jin-Ming

2010-09-15

107

Study of catalytic reaction processes on the {gamma}-Al{sub 2}O{sub 3} chemiluminescence-based gas sensors  

SciTech Connect

The authors have investigated a new chemiluminescence (CL)-based gas sensor made of aluminum oxide ({gamma}-Al{sub 2}O{sub 3}) which emits CL during the catalytic oxidation of combustible vapors in air. The CL intensity is proportional to the concentration in the wide region from 1 to 1000 ppm of ethanol, butanol and acetone in air. However, it has a tendency to saturate in concentrations above 1000 ppm. For the detection of vapors in the environmental atmosphere, improvements of the sensitivity and the linear characteristics of the sensor are necessary. Catalytic reaction processes on the sensor were studied for this purpose.

Utsunomiya, K.; Nakagawa, M.; Nishiyama, K.; Takechi, S. [Okayama Univ. of Science (Japan)] [and others

1996-12-31

108

Intricacies of Redoxome Function Demonstrated with a Simple In vitro Chemiluminescence Method, with Special Reference to Vitamin B12 as Antioxidant  

PubMed Central

The homeostatic control of the redox system (the redoxome) in mammalian cells depends upon a large number of interacting molecules, which tend to buffer the electronegativity of cells against oxidants or reductants. Some of these components kill – at high concentration – microbes and by-stander normal cells, elaborated by professional phagocytes. We examined whether a simple, in vitro chemiluminescence set-up, utilizing redox components from human polymorphonuclear neutrophils (PMN) and red blood cells (RBC), could clarify some unexplained workings of the redoxome. PMN or purified myeloperoxidase (MPO) triggers formation of reactive oxygen species (ROS), quantified by light emission from oxidized luminol. Both PMN and RBC can generate abundant amounts of ROS, necessitating the presence of a high-capacity redoxome to keep the cellular electronegativity within physiological limits. We obtained proof-of-principle evidence that our assay could assess redox effects, but also demonstrated the intricacies of redox reactions. Simple dose–responses were found, as for the PMN proteins S100A9 (A9) and S100A8 (A8), and the system also revealed the reducing capacity of vitamin B12 (Cbl) and lutein. However, increased concentrations of oxidants in the assay mixture could decrease the chemiluminescence. Even more remarkable, A9 and NaOCl together stimulated the MPO response, but alone they inhibited MPO chemiluminescence. Biphasic responses were also recorded for some dose–response set-ups and are tentatively explained by a ‘balance hypothesis’ for the redoxome. PMID:25345916

Bøyum, A; Forstrøm, R J; Sefland, I; Sand, K L; Benestad, H B

2014-01-01

109

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

NASA Technical Reports Server (NTRS)

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.

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

1998-01-01

110

Flow injection determination of diclofenac sodium based on its sensitizing effect on the chemiluminescent reaction of acidic potassium permanganate-formaldehyde.  

PubMed

A sensitive and simple chemiluminescent (CL) method for the determination of diclofenac sodium has been developed by combining the flow injection technique and its sensitizing effect on the weak CL reaction between formaldehyde and acidic potassium permanganate. A calibration curve is constructed for diclofenac sodium under optimized experimental parameters over the range 0.040-5.0?µg/mL and the limit of detection is 0.020?µg/mL (3?). The inter-assay relative standard deviation for 0.040?µg/mL diclofenac sodium (n?=?11) is 2.0%. This method is rapid, sensitive, simple, and shows good selectivity and reproducibility. The proposed method has been successfully applied to the determination of the studied diclofenac sodium in pharmaceutical preparations with satisfactory results. Furthermore, the possible mechanism for the CL reaction has been discussed in detail on the basis of UV and CL spectra. Copyright © 2014 John Wiley & Sons, Ltd. PMID:24802238

Song, Jingjing; Sun, Pulv; Ji, Zhongling; Li, Jianguo

2015-02-01

111

Studies of chemiluminescence in boron atom reactions with O/sub 2/, SO/sub 2/, N/sub 2/O, NO/sub 2/ and H/sub 2/O/sub 2/  

SciTech Connect

Chemiluminescence has been observed in the single collision reactions of boron atoms with O2, SO2, N2O, NO2, and H2O2. Experiments were performed in a beam-gas apparatus using photon counting to detect the optical signals. The electronically excited ((A sup 2) Pi) state of BO was observed in all reactions. In addition, the BO2((A sup 2) Pi mu) state was observed in the reaction of boron with SO2. Cross sections for the production of electronically excited molecules were determined. In the reactions of boron with SO2, the branching ratio was obtained for the two observed chemiluminescent reaction channels. The vibrational distributions in the electronically excited state of BO were determined in the reactions where the spectra were adequately resolved. Some implications of the results are discussed.

DeHaven, J.; O'Connor, M.T.; Davidovits, P.

1980-01-01

112

Online detection of reactive oxygen species in ultraviolet (UV)-Irradiated nano-TiO2 suspensions by continuous flow chemiluminescence.  

PubMed

Reactive oxygen species (ROS) play very important roles in the photocatalytic reactions of semiconductors. Using a continuous flow chemiluminescence (CFCL) system, we developed three methods for the selective, sensitive, and online detection of O2(• -), •OH, and H2O2 generated during ultraviolet (UV) irradiation of nano-TiO2 suspensions. TiO2 nanoparticles were irradiated in a photoreactor and pumped continuously into a detection cell. To detect O2(• -), luminol was mixed with TiO2 before it entered the detection cell. For the detection of short-lived •OH, phthalhydrazide was added into the photoreactor to capture •OH, and then mixed with H2O2/K5Cu(HIO6)2 to produce chemiluminescence (CL). To detect H2O2, an irradiated TiO2 suspension was kept in darkness for 30 min, and then mixed with luminol/K3Fe(CN)6 to produce CL. The selectivity of each method for a particular ROS was verified by using specific ROS scavengers. For a given ROS, a comparison between CL and conventional method showed good agreement for a series of TiO2 concentrations. The sensitivity of CL method was approximately 3-, 1200-, and 5-fold higher than the conventional method for O2(• -), •OH, and H2O2, respectively. To demonstrate the utility of the methods, ROS in three different types of TiO2 suspensions was detected by CFCL. It was found that photodegradation efficiency of Rhodamine B correlated the best (R(2) > 0.95) with the amount of photogenerated •OH, implying that •OH was the major oxidant in Rhodamine B photodegradation reaction. CFCL may provide a convenient tool for the studies on the reaction kinetics of ROS-participated decomposition of environmental contaminants. PMID:25275618

Wang, Dabin; Zhao, Lixia; Guo, Liang-Hong; Zhang, Hui

2014-11-01

113

A Facile and Effective Chemiluminescence Demonstration Experiment  

ERIC Educational Resources Information Center

Describes a chemiluminescence system which can be used to demonstrate the effects of certain factors which affect the rate of reaction (temperature, concentration, catalysis, solvent, etc.), and to perform experiments relevant to the mechanism of the system. (SLH)

Mohan, Arthur G.; Turro, Nicholas J.

1974-01-01

114

Steady-state chemiluminescence of Eu-doped yttrium oxide crystal phosphors in the catalytic reaction of hydrogen oxidation  

NASA Astrophysics Data System (ADS)

We report on the luminescence of Eu 3+-doped yttrium oxide phosphors brought in contact with oxyhydrogen gas mixtures at temperatures much below the gas-phase ignition point. Chemical energy released in the catalytic hydrogen oxidation is passed directly to the electron subsystem of the powder and subsequently converted into the visible luminescence radiation at 2 × 10 -6 quantum yield per H 2O molecule produced. Luminescence kinetics at various conditions are investigated to reveal the constituent stages of the catalytic energy conversion process. This observation could have far-reaching consequences including possibilities for the development of original chemiluminescent light sources, and novel electrochemical energy converters.

Nedrigaylov, Ievgen I.; Karpov, Eduard G.; Styrov, Vladislav V.

2008-11-01

115

Controllable copper deficiency in Cu2-xSe nanocrystals with tunable localized surface plasmon resonance and enhanced chemiluminescence  

NASA Astrophysics Data System (ADS)

Copper chalcogenide nanocrystals (CuCNCs) as a type of semiconductor that can also act as efficient catalysts are rarely reported. Herein, we study water-soluble size-controlled Cu2-xSe nanocrystals (NCs), which are copper deficient and could be prepared by a redox reaction with the assistance of surfactants. We found them to have strong near-infrared localized surface plasmon resonance (LSPR) properties originating from the holes in the valence band, and also catalytic activity of more than a 500-fold enhancement of chemiluminescence (CL) in a luminol-H2O2 system. Investigations into the mechanisms behind these results showed that the high concentration of free carriers in Cu2-xSe NCs, which are derived from their high copper deficiencies that make Cu2-xSe NCs both good electron donors and acceptors with high ionic mobility, could greatly enhance the catalytic ability of Cu2-xSe NCs to facilitate electron-transfer processes and the decomposition of H2O2 into OH&z.rad; and O2&z.rad;-, which are the commonly accepted key intermediates in luminol CL enhancement. Thus, it can be concluded that controllable copper deficiencies that are correlated with their near-infrared LSPR are critically responsible for the effective catalysis of Cu2-xSe NCs in the enhanced CL.Copper chalcogenide nanocrystals (CuCNCs) as a type of semiconductor that can also act as efficient catalysts are rarely reported. Herein, we study water-soluble size-controlled Cu2-xSe nanocrystals (NCs), which are copper deficient and could be prepared by a redox reaction with the assistance of surfactants. We found them to have strong near-infrared localized surface plasmon resonance (LSPR) properties originating from the holes in the valence band, and also catalytic activity of more than a 500-fold enhancement of chemiluminescence (CL) in a luminol-H2O2 system. Investigations into the mechanisms behind these results showed that the high concentration of free carriers in Cu2-xSe NCs, which are derived from their high copper deficiencies that make Cu2-xSe NCs both good electron donors and acceptors with high ionic mobility, could greatly enhance the catalytic ability of Cu2-xSe NCs to facilitate electron-transfer processes and the decomposition of H2O2 into OH&z.rad; and O2&z.rad;-, which are the commonly accepted key intermediates in luminol CL enhancement. Thus, it can be concluded that controllable copper deficiencies that are correlated with their near-infrared LSPR are critically responsible for the effective catalysis of Cu2-xSe NCs in the enhanced CL. Electronic supplementary information (ESI) available: Experimental section and additional figures for XRD, XPS, UV absorption, chemiluminescent spectra, SEM and TEM images. See DOI: 10.1039/c4nr02294g

Lie, Shao Qing; Wang, Dong Mei; Gao, Ming Xuan; Huang, Cheng Zhi

2014-08-01

116

A facile and sensitive chemiluminescence detection of amino acids in biological samples after capillary electrophoretic separation.  

PubMed

It was found that native amino acids enhanced the chemiluminescence (CL) reaction between luminol and BrO(-) in an alkaline aqueous solution. This has led to the development of a facile and highly sensitive CL detection scheme for the determination of amino acids in biological samples after capillary electrophoretic (CE) separation. The CE-CL conditions were optimized. An electrophoretic buffer of 2.5 x 10(-2) M sodium borate (pH 9.4) containing 1 x 10(-4) M luminol was used. The oxidizer solution of 8 x 10(-4) M NaBrO in 0.1 M sodium carbonate buffer solution (pH 12.5) was introduced post-column. Under the optimal conditions, the detection limits were 1.0 x 10(-7) M for glutamic acid (Glu) and 1.3 x 10(-7) M (S/N = 3) for aspartic acid (Asp). The relative standard deviations (RSDs) of peak area and migration time were in the ranges of 3.8-4.3% and 1.4-1.6%, respectively. The present method was applied to the determination of excitatory amino acids (i.e., Asp and Glu) in rat brain tissue and monkey plasma. The levels of these major excitatory amino acids in monkey plasma were quantified for the first time and found to be 1.17 +/- 0.17 x 10(-5) M (mean +/- SD, n = 6) for Glu and 1.64 +/- 0.19 x 10(-6) M for Asp, which were comparable with the levels in human plasma. PMID:15812841

Zhao, Shulin; Xie, Chao; Lu, Xin; Song, Yaru; Liu, Yi-Ming

2005-05-01

117

Direct determination of amino acids by pressurized capillary electrochromatography with chemiluminescence detection.  

PubMed

A pressurized CEC (pCEC) coupled with on-column chemiluminescence (CL) detection was developed for direct determination of amino acids, which was based on the principle of an enhanced effect of Cu(II)-amino acid complexes on the CL reaction between luminol and hydrogen peroxide in alkaline solution. The effects of some important factors on pCEC separation and CL intensity were systemically investigated. Baseline separation of amino acids including L-histidine (L-His), L-threonine (L-Thr), and L-tyrosine (L-Tyr) was achieved by using a monolithic column with a mobile phase of 5.0x10(-3) mol/L phosphate buffer at pH 8.0 that contained 25% v/v methanol and 5.0x10(-4) mol/L luminol and 1.0x10(-5) mol/L Cu(II) at an applied voltage of -5 kV. The calibration curves of the analytes by plotting the peak height against corresponding concentration were linear over the range of 3.2x10(-6)-3.2x10(-4) mol/L for L-His, 4.1x10(-6)-4.1x10(-4) mol/L for L-Thr, and 6.0x10(-7)-3.0x10(-4) mol/L for L-Tyr. The LODs for L-His, L-Thr, and L-Tyr were 6.4x10(-7), 8.4x10(-7), and 3.0x10(-7) mol/L (S/N = 2), respectively. The proposed method was applied to the analysis of amino acid injection sample with satisfactory results. Mean recoveries for three amino acids were from 84.3 to 89.6%. PMID:18666187

Lin, Zian; Xie, Zenghong

2008-08-01

118

Advent of innovative chemiluminescent enzyme immunoassay.  

PubMed

Using 1,1'-oxalyldiimidazole (ODI) chemiluminescence detection, a new chemiluminescent enzyme immunoassay (CLEIA) was developed to quantify prostate specific antigen (PSA) in human serum. The results observed in ODI CLEIA were compared with those obtained in commercially available enzyme linked immunosorbent assay (ELISA), fluorescence enzyme immunoassay (FEIA), and luminol CLEIA. PSA complex-conjugated horseradish peroxidase (HRP) was formed from one-step sandwich immunoreaction of PSA, PSA primary antibody and PSA secondary antibody-conjugated HRP for 15 min in a strip-well at 36.5°C. CL substrate solution (Amplex Red and H2O2 in PBS buffer, pH 7.4) was added in the washed strip-well and incubated for 10 min at room temperature. When resorufin formed in this process was mixed with 1,1'-oxalyldi-4-methylimidazole and H2O2 in a testing tube, rapid and bright CL was observed. Detection limit (0.035 ng/ml) of PSA in ODI CLEIA was much lower than those (0.50 and 0.25 ng/ml) in commercially available ELISA and luminol CLEIA even though total incubation time of the former (25 min) was shorter than those of the latter (45 and 35 min). Also, the dynamic range (0-100 ng/ml, R2=0.9996) of ODI CLEIA was wider than those of other EIAs. In conclusion, the excellent correlation (r=0.9767) between ODI CLEIA and Advia Centaur XP Immunoassay System indicates that the accurate, precise, and rapid ODI CLEIA can be applied as a novel CLEIA capable of diagnosing and monitoring various diseases. PMID:20739174

Lee, Ji Hoon; Rho, Jee-Eun R; Rho, Tae-Ho D; Newby, John G

2010-10-15

119

In SituDetection of Diamine Oxidase Activity Using Enhanced Chemiluminescence  

Microsoft Academic Search

In need of a simple and sensitive method for detection of diamine oxidase (EC 1.4.3.6) activity in connection with diamine oxidase purification from human placenta, we have developed an enhanced chemiluminescence method using putrescine as substrate and horseradish peroxidase and luminol for the detection of the H2O2produced by diamine oxidase. The method allows direct detection of small amounts of diamine

L. Bruun; G. Houen

1996-01-01

120

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

PubMed

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. PMID:25263118

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

2014-10-27

121

Increased monocyte chemiluminescence in cystic fibrosis patients and in their parents.  

PubMed

We examined the chemiluminescence response of peripheral blood monocytes from patients with cystic fibrosis (CF) and their asymptomatic parental carriers of the CF gene to three different types of stimulation. We found that monocytes from both patients and carriers have increased luminol-dependent chemiluminescence in the first 25 min after stimulation by adherence to glass. These results are consistent with the hypothesis that monocytes from both CF heterozygotes and homozygotes respond to adhesion with increased oxygen radical formation. The increased adherence-induced monocyte chemiluminescence of the parental carriers did not vary with age or length of exposure of the parents to a child with CF. Also, repeated exposure to medications and respiratory secretions of CF patients was not associated with an increase in adherence-induced monocyte chemiluminescence of their nonbiologically related caretakers. Thus, this observed increase in chemiluminescence is not simply secondary to the medications or respiratory dysfunction seen in the patients with CF. Patients with other types of obstructive lung disease did not show increased adherence-induced monocyte chemiluminescence. We conclude that increased early phase adherence-induced monocyte chemiluminescence occurs in patients with cystic fibrosis and the obligate carriers of the CF gene independent of environmental influences. PMID:3725459

Regelmann, W E; Lunde, N M; Porter, P T; Quie, P G

1986-07-01

122

Study on the proteins-luminol binding by use of luminol as a fluorescence probe  

NASA Astrophysics Data System (ADS)

In this paper, a new mathematical equation of lg(F0 - F)/F = 1/nlg[P] + 1/nlgKa, which was used to obtain interaction parameters (the binding constant Ka and the number of binding sites n) between the protein and the small molecule ligand by using the ligand as a fluorescence (FL) probe, was constructed for the first time. The interaction parameters between myoglobin, catalase, lysozyme, bovine serum albumin (BSA) and luminol were obtained by this equation with luminol used as a FL probe, showing that the binding constants Ka were 8.78 × 105, 4.47 × 105, 4.21 × 104 and 3.95 × 104 respectively, and the number of binding sites n approximately equaled to 1.0 for myoglobin, catalase, and 2.0 for lysozyme, BSA. The interactions of ferritin, ovalbumin, aldolase, chymotrypsinogen and ribonuclease with luminol were also studied by this method. The binding constants Ka were at 104-105 level, and the number of binding sites n mostly approximately equaled to 2.0. The binding ability of luminol to the studied proteins followed the pattern: myoglobin > aldolase > ferritin > ovalbumin > catalase > ribonuclease > lysozyme > BSA > chymotrypsinoge.

He, Xili; Song, Zhenghua

2013-10-01

123

Study on the proteins-luminol binding by use of luminol as a fluorescence probe.  

PubMed

In this paper, a new mathematical equation of lg(F0-F)/F=1/nlg[P]+1/nlgKa, which was used to obtain interaction parameters (the binding constant Ka and the number of binding sites n) between the protein and the small molecule ligand by using the ligand as a fluorescence (FL) probe, was constructed for the first time. The interaction parameters between myoglobin, catalase, lysozyme, bovine serum albumin (BSA) and luminol were obtained by this equation with luminol used as a FL probe, showing that the binding constants Ka were 8.78×10(5), 4.47×10(5), 4.21×10(4) and 3.95×10(4) respectively, and the number of binding sites n approximately equaled to 1.0 for myoglobin, catalase, and 2.0 for lysozyme, BSA. The interactions of ferritin, ovalbumin, aldolase, chymotrypsinogen and ribonuclease with luminol were also studied by this method. The binding constants Ka were at 10(4)-10(5) level, and the number of binding sites n mostly approximately equaled to 2.0. The binding ability of luminol to the studied proteins followed the pattern: myoglobin>aldolase>ferritin>ovalbumin>catalase>ribonuclease>lysozyme>BSA>chymotrypsinoge. PMID:23770511

He, Xili; Song, Zhenghua

2013-10-01

124

Metal-nanoparticle-involved chemiluminescence and its applications in bioassays.  

PubMed

Chemiluminescence-based bioassays have become increasingly important in clinical, pharmaceutical, environmental, and food safety fields owing to their high sensitivity, wide linear range, and simple instrumentation. During the past decade, it has been found that metal nanoparticles can initiate various liquid-phase chemiluminescence reactions as catalysts, reductants, energy acceptors, and nanosized reaction platforms owing to their unique optical, catalytic, and surface properties and chemical reactivity, which are very important for chemiluminescence bioassays based on metal nanoparticles as nanoprobes or a nanointerface. In this article, we summarize recent progress in metal-nanoparticle-initiated liquid-phase chemiluminescence, including reaction systems, mechanisms, and their applications in chemiluminescence-based bioassays, especially for immunoassays, DNA assays, aptamer-based assays, high-performance liquid chromatography or capillary electrophoresis analysis, and flow injection analysis. PMID:24908408

Li, Na; Liu, Danqing; Cui, Hua

2014-09-01

125

MOBILE SOURCE NOX MONITOR, HYDROGEN-ATOM DIRECT CHEMILUMINESCENCE METHOD  

EPA Science Inventory

An analyzer was developed for measuring motor vehicle NOx (NO and NO2) emissions based on the chemiluminescence reaction of NO and NO2 with hydrogen atoms. This eliminated the need for an NO2 to NO converter as required with ozone chemiluminescence for NOx analysis. The hydrogen-...

126

Simple simultaneous determination of butylated hydroquinone (TBHQ) and butylated hydroxyanisole (BHA) antioxidants in oil using high-performance liquid chromatography with chemiluminescence detection.  

PubMed

A highly sensitive and convenient high-performance liquid chromatography technique coupled with chemiluminescence detection for the simultaneous determination butylated hydroquinone (TBHQ) and butylated hydroxyanisole (BHA) in oil is established. The detection is based on the inhibitory effect on the CL reaction between luminol and potassium ferricyanide in an alkaline medium. Samples were separated through a reverse-phase C18 column using a mobile phase of methanol and water (80: 20, v/v) at a flow rate of 0.5 mL/min. The effects of various parameters including mobile phase, flow rate and chemiluminescence regent were studied. Under optimum conditions, both TBHQ and BHA showed good linear relationships in the range 1 × 10(-7) -1 × 10(-5) g/mL with detection limits of 24 and 33 ng/mL, respectively. The proposed method is simple and sensitive, with low costs. The method was successfully applied for the quantification of TBHQ and BHA in sesame oil. The possible inhibition mechanism is also discussed briefly. Copyright © 2014 John Wiley & Sons, Ltd. PMID:24723449

Xu, Shuangjiao; Chen, Funan; Deng, Mao; Sui, Yanyan

2014-12-01

127

Chemiluminescent detection of induced reactive oxygen metabolite production of human polymorphonuclear leucocytes by anthophyllite asbestos.  

PubMed

Incidences of lung cancer and pleural plaque have been reported in relation to exposure to anthophyllite asbestos. To investigate the pathogenic mechanisms of anthophyllite, chemiluminescence (CL) detection of reactive oxygen metabolite (ROM) generation of human polymorphonuclear leucocytes (PMN) stimulated by anthophyllite asbestos was determined and compared with that of other asbestos and mineral fiber samples. When anthophyllite fiber sample was mixed with the luminol-primed PMN, high levels of CL which exhibited a specific time course characterized by two separate peaks were induced. The CL induced by anthophyllite sample was greater than that induced by chrysotile, crocidolite, and amosite asbestos. We further investigated the two peaks of CL using specific inhibitors of signal transduction mechanisms. The two peaks of CL by anthophyllite sample were different in sensitivity to cytochalasin B and genistein; the former relates to the cytoskeleton-dependent mechanism and the latter has been shown to inhibit tyrosine kinase, which resides in the pathway to cause PMN activation. The strong ROM reaction of PMN by anthophyllite suggests that the surface characteristics of the fiber may participate in the pathogenic mechanisms of anthophyllite asbestos. PMID:11896666

Iwata, Toyoto; Kohyama, Norihiko; Yano, Eiji

2002-01-01

128

Sensitive determination of positional isomers of benzenediols in human urine by boronate affinity capillary electrophoresis with chemiluminescence detection.  

PubMed

A boronate ACE coupled with chemiluminescence (CL) detection was developed for sensitive determination of three isomeric benzenediols, which was based on the principle of an inhibited effect of borate complexation on the CL reaction between luminol and potassium hexacyanoferrate (K3 Fe(CN)6 ) in alkaline solution. The effects of some important factors on CE separation and CL intensity were systemically investigated. Baseline separation of isomeric benzenediols including o-benzenediol, m-benzenediol, and p-benzenediol was achieved by using a mobile phase of 40 mmol/L glycine-NaOH buffer at pH 9.4 containing 0.8 mmol/L luminol and 0.4 mol/L 4-iodophenylboronic acid. The calibration curves of the analytes by plotting the peak height against corresponding concentration were linear over the range of 4.5 × 10(-8) ? 4.5 × 10(-5) mol/L for p-benzenediol, 6.8 × 10(-8) ? 2.7 × 10(-5) mol/L for m-benzenediol, and 9.0 × 10(-8) ? 4.5 × 10(-5) mol/L for o-benzenediol. The corresponding detection limits for p-, m-, and o-benzenediols were 2.8 × 10(-8) mol/L (68 amol), 3.2 × 10(-8) mol/L (108.4 amol), and 3.7 × 10(-8) mol/L (125.8 amol; S/N = 3), respectively. The proposed method has been successfully applied to the analysis of trace benzenediols in spiked human urine sample and the recoveries were >97.2%. Our primary result demonstrated the proposed CE-CL method has great potential for biomarker determination in clinical diagnosis. PMID:24115126

Lin, Zian; Sun, Xiaobo; Hu, Wenli; Yin, Yuqing; Chen, Guonan

2014-04-01

129

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

PubMed

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 (3?) 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. PMID:21830295

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

2012-01-01

130

Aqueous chemiluminescent systems  

NASA Technical Reports Server (NTRS)

This invention relates to novel water-soluble esters of oxalic acid, and to compositions that are useful for generating chemiluminescent emission by reacting said esters of oxalic acid with hydrogen peroxide in the presence of water and a fluorescent compound, and to a process for generating chemiluminescent emission by using said compositions.

Mohan, Arthur Gaudens (Inventor)

1977-01-01

131

The effect of low levels of dietary cobalt on the chemiluminescence response of polymorphonuclear leukocytes of goats  

Microsoft Academic Search

Twenty ten-week-old newly weaned male Batinah goats were randomly assigned to a control (n=10) and a treated (n=10) group and were fed a diet containing 0.1mg\\/kg DM cobalt (Co). Goats in the treated group received bi-monthly subcutaneous injections of 2000?g of hydroxycobalamin. The phagocytic function of the polymorphonuclear leukocytes (PMN) were tested using a luminol-dependent chemiluminescence assay with opsonized zymosan

Eugene H. Johnson; Khalid Al-Habsi; Rashid Al-Busaidy; Samera Kasim Khalaf

2010-01-01

132

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

Microsoft Academic Search

The methanol extracts of 20 selected medicinal plants were investigated for their effects on the respiratory burst of human\\u000a whole blood, isolated human polymorphonuclear leukocytes (PMNs) and isolated mice macrophages using a luminol\\/lucigenin-based\\u000a chemiluminescence assay. We also tested the effect of the extracts on chemotactic migration of PMNs using the Boyden chamber\\u000a technique. The extracts of Curcuma domestica L., Phyllanthus

Ibrahim JantanNurul; Nurul Hikmah Harun; Abdi Wira Septama; Shahnaz Murad; M. A. Mesaik

2011-01-01

133

Chemiluminescent reactions of electronically excited alkaline earth atoms. II. Energy dependence in Ba*+O2 --> BaO*+O  

NASA Astrophysics Data System (ADS)

The reaction of Ba(6s 6p1P1) with O2 has been investigated in a crossed beam experiment as a function of the collision energy. The electronically excited product BaO is not statistically populated and the difference from statistics increases with the collision energy. Such a result is markedly in contrast with what was observed in the reactions of Ba(6s21S0) and Ba(6s5d1D2) with O2 where the existence of a long-lived complex results in a statistical distribution of internal energy of the BaO product. The present result is interpreted as due to the collisional system following a different channel involving excited electronic states of the intermediate, BaO2 above the ionization limit, instead of the strongly bound states of barium peroxide which are involved in reactions of less excited Ba states.

Visticot, J. P.; Alcaraz, C.; Berlande, J.; Cuvellier, J.; Gustavsson, T.; Mestdagh, J. M.; Meynadier, P.; de Pujo, P.; Sublemontier, O.

1991-04-01

134

A novel HPLC-UV/nano-TiO2-chemiluminescence system for the determination of selenocystine and selenomethionine.  

PubMed

Active oxygen species from the photocatalytic reaction in aqueous solution react with luminol to emit strong chemiluminescence (CL), and this can be inhibited by the UV decomposed-products of selenocystine (SeCys) or selenomethionine (SeMet). Based on this phenomenon, a novel hyphenated technique, HPLC-UV/nano-TiO(2)-CL, was established for the determination of SeCys and SeMet. The effects of pH, the UV irradiation time, the TiO(2) coated on the inner surface of the reaction tubing, and the Co(2+) catalyst concentration on the CL intensity and/or chromatographic resolution were systematically investigated. Under these optimized conditions, the inhibited CL intensity has a good linear relationship with the concentration of SeCys in the range of 0.04-10.6 microg mL(-1) or SeMet in the range of 0.05-12.4 microg mL(-1), with a limit of detection (S/N=3) of 6.4 microg L(-1) for SeCys or 12 microg L(-1) for SeMet. As an example, the method was preliminarily applied to the determination of the selenoamino acids in garlic and rabbit serum, with a recovery of 88-104%. PMID:18585988

Su, Yingying; Chen, He; Gao, Ying; Li, Xiaohong; Hou, Xiandeng; Lv, Yi

2008-07-15

135

Tested Demonstrations. A Chemiluminescence Demonstration - Oxalyl Chloride Oxidation.  

ERIC Educational Resources Information Center

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

Gilber, George L., Ed.

1979-01-01

136

Remarkable increase in luminol electrochemiluminescence by sequential electroreduction and electrooxidation.  

PubMed

Luminol electrochemiluminescence is dramatically increased by about five hundred times by taking full advantage of both electrochemical reduction and electrochemical oxidation using simple linear sweep voltammetry, leading to sensitive detection. PMID:25314948

Liu, Xiaoyun; Qi, Wenjing; Gao, Wenyue; Liu, Zhongyuan; Zhang, Wei; Gao, Ying; Xu, Guobao

2014-12-01

137

A Chemiluminescence Detector for Ozone Measurement.  

ERIC Educational Resources Information Center

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

Carroll, H.; And Others

138

Biological water quality monitoring using chemiluminescent and bioluminescent techniques  

NASA Technical Reports Server (NTRS)

Automated chemiluminescence and bioluminescence sensors were developed for the continuous monitoring of microbial levels in water supplies. The optimal chemical procedures were determined for the chemiluminescence system to achieve maximum sensitivity. By using hydrogen peroxide, reaction rate differentiation, ethylene diamine tetraacetic acid (EDTA), and carbon monoxide pretreatments, factors which cause interference were eliminated and specificity of the reaction for living and dead bacteria was greatly increased. By employing existing technology with some modifications, a sensitive and specific bioluminescent system was developed.

Thomas, R. R.

1978-01-01

139

Product state distributions for the C + (4P)+H2(D2) reaction from chemiluminescence spectra  

NASA Astrophysics Data System (ADS)

Optical emission resulting from low-energy (1-3 eVc.m.) impact of metastable C+(4P) ions on H2 and D2 molecules has been studied spectroscopically in the 2700-3900 Å range. The b 3?--a 3? transition of CH+ (CD+) was resolved into numerous bands. From a spectrum simulation by computer, rotational-vibrational population distributions of the excited triplet state were obtained. In contrast to previous related studies, the vibrational excitation decreases with increasing collision energy. One-parameter surprisal fits of the vibrational (and, to a lesser extent, the rotational) population distributions are found to be unsatisfactory. The reaction is discussed in terms of changes of molecular orbital occupancy, which suggest a direct interaction mechanism. This is consistent with the observed population distributions.

Kusunoki, I.; Ottinger, Ch.

1982-02-01

140

Chemi-luminescence measurements of hyperthermal Xe{sup +}/Xe{sup 2+}+ NH{sub 3} reactions  

SciTech Connect

Luminescence spectra are recorded for the reactions of Xe{sup +}+ NH{sub 3} and Xe{sup 2+}+ NH{sub 3} at energies ranging from 11.5 to 206 eV in the center-of-mass (E{sub cm}) frame. Intense features of the luminescence spectra are attributed to the NH (A {sup 3}{Pi}{sub i}-X {sup 3}{Sigma}{sup -}), hydrogen Balmer series, and Xe I emission observable for both primary ions. Evidence for charge transfer products is only found through Xe I emission for both primary ions and NH{sup +} emission for Xe{sup 2+} primary ions. For both primary ions, the absolute NH (A-X) cross section increases with collision energy before leveling off at a constant value, approximately 9 x 10{sup -18} cm{sup 2}, at about 50 eV while H-{alpha} emission increases linearly with collision energy. The nascent NH (A) populations derived from the spectral analysis are found to be independent of collision energy and have a constant rotational temperature of 4200 K.

Prince, Benjamin D.; Steiner, Colby P. [Air Force Research Laboratory, Space Vehicles Directorate, Kirtland AFB, New Mexico 87117 (United States); Chiu, Yu-Hui [Busek Co. Inc, Natick, Massachusetts 01760 (United States)

2012-04-14

141

A High-Performance Liquid Chromatography:Chemiluminescence Method for Potential Determination of Vardenafil in Dietary Supplement  

PubMed Central

A flow method of high-performance liquid chromatography (HPLC) seperation and chemiluminescence (CL) detection for sensitive vardenafil analysis in dietary supplements was developed. The vardenafil separation was achieved on a C18 column at 30°C using ethanol-H3PO4 and ethylenediaminetetraacetic acid disodium salt (Na2EDTA) aqueous solution (25?:?75, v/v%) as mobile phase. The followed continuous CL detection was conducted based on the strong CL enhancement by the presence of vardenafil to luminol-K3Fe(CN)6 reaction in alkaline medium. At the flow rate of 0.8?mL/min, the vardenafil retention time (tR) was 6.4 min. Factors that affected the HPLC resolution and CL detection were studied and optimized. The calibration curve obtained for vardenafil standard was linear in concentration range of 8.0 × 10?7 ~ 1.0 × 10?4?mol/L. The relative standard deviations (RSD) of intraday and interday precision were less than 3.5%. The proposed method was applied to the vardenafil determination in oral liquid, wine, and capsule samples. PMID:21331172

Di, Youjun; Zhao, Min; Nie, Yingchun; Wang, Fei; Lv, Jiagen

2011-01-01

142

Chemiluminescents Light Up the Night.  

ERIC Educational Resources Information Center

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

Dashiell, Judy

1997-01-01

143

On the structure of luminol sodium salts  

NASA Astrophysics Data System (ADS)

The structures of Tamerit® ( A) and Galavit® ( B) pharmaceutical preparations have been solved by X-Ray single crystal and powder diffraction. These are luminol sodium salts possessing immunomodulatory and anti-inflammatory properties. It is shown that Tamerit® ( A) is a hydrated salt, while Galavit® ( B) is a mixture of two polymorphic modifications ( B1 and B2) of anhydrous salt. Compound A is crystallized in a monoclinic system: a = 8.3429(4) Å, b = 22.0562(11) Å, c = 5.2825(2) Å, ? = 99.893(3)°, V = 957.59(8) Å3, and Z = 4; sp. gr. P21/ c. Compound B1 is crystallized in a monoclinic system: a = 14.7157(18), b = 3.7029(19), c = 16.0233(15) Å, ? = 116.682(13)°, V = 780.1(4) Å3, and Z = 4; sp. gr. P21/ c. Compound B2 is crystallized in an orthorhombic system: a = 27.7765(15) Å, b = 3.3980(19) Å, c = 8.1692(19) Å, V = 771.0(5) Å3, and Z = 4; sp. gr. Pna21. The absence of phase transitions between the B1 and B2 polymorphs has been established by differential scanning calorimetry.

Rybakov, V. B.; Chernyshev, V. V.; Paseshnichenko, K. A.; Sheludyakov, V. D.; Belyakov, N. G.; Boziev, R. S.; Mochalov, V. N.; Storozhenko, P. A.

2014-05-01

144

A homogeneous chemiluminescent immunoassay method.  

PubMed

A new homogeneous chemiluminescent immunoassay method featuring the use of specific binding members separately labeled with an acridan-based chemiluminescent compound and a peroxidase is reported. Formation of an immunocomplex brings the chemiluminescent compound and the peroxidase into close proximity. Without any separation steps, a chemiluminescent signal is generated upon addition of a trigger solution, and the intensity is directly correlated to the quantity of the analyte. PMID:23477541

Akhavan-Tafti, Hashem; Binger, Dean G; Blackwood, John J; Chen, Ying; Creager, Richard S; de Silva, Renuka; Eickholt, Robert A; Gaibor, Jose E; Handley, Richard S; Kapsner, Kenneth P; Lopac, Senja K; Mazelis, Michael E; McLernon, Terri L; Mendoza, James D; Odegaard, Bruce H; Reddy, Sarada G; Salvati, Michael; Schoenfelner, Barry A; Shapir, Nir; Shelly, Katherine R; Todtleben, Jeff C; Wang, Guoping; Xie, Wenhua

2013-03-20

145

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

PubMed

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. PMID:25644330

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

2015-02-12

146

Chemiluminescence resonance energy transfer-based detection for microchip electrophoresis.  

PubMed

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 approximately 10(-9) M for biogenic amines including dopamine and epinephrine and approximately 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 10-1000 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

Zhao, Shulin; Huang, Yong; Shi, Ming; Liu, Rongjun; Liu, Yi-Ming

2010-03-01

147

Chemiluminescence Resonance Energy Transfer-based Detection for Microchip Electrophoresis  

PubMed Central

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

Huang, Yong; Shi, Ming; Liu, Rongjun

2010-01-01

148

Determination of photoirradiated tetracyclines in water by high-performance liquid chromatography with chemiluminescence detection based reaction of rhodamine B with cerium (IV).  

PubMed

A simple, selective and sensitive method has been developed for the simultaneous determination of tetracycline, oxytetracycline, chlorotetracycline, demeclocycline, doxycycline and meclocycline based on reversed-phase high-performance liquid chromatography with chemiluminescence detection. The procedure was based on the chemiluminescent enhancement by photoirradiated tetracyclines of the cerium (IV)-rhodamine B system in sulphuric acid medium. The six tetracyclines were separated on an Aquasil-C18 column with a gradient elution using a mixture of acetonitrile and 0.1 mol L(-1) phosphate buffer as mobile phase, photoderivatized using a photoreactor consisting of a tube reactor coil of PFA and a 8W Xenon lamp. Under the optimized conditions, the method was validated with respect to linearity, precision, limits of detection and quantification and accuracy. The relative standard deviation (RSD) on intra-day precision was below 10% and detection limits ranged between 0.12 and 0.34 microg L(-1). The proposed method has been successfully applied to the determination of tetracyclines in surface water samples. A possible mechanism of the chemiluminescence in the system is discussed. PMID:17765910

Santiago Valverde, R; Sánchez Pérez, I; Franceschelli, F; Martínez Galera, M; Gil García, M D

2007-10-01

149

Application of horse-radish peroxidase linked chemiluminescence to determine the production mechanism of Shiga-like toxins by E. coli O157:H7  

Microsoft Academic Search

A sandwiched immunoassay consisting of toxin capture by immunomagnetic beads (IMB) and toxin detection by horseradish peroxidase (HRP) linked chemiluminescence was used to follow the production of Shiga-like toxins (SLT) by E. coli O157:H7. The intensity of luminescence generated by the oxidation of luminol-liked compounds was used to represent the concentration of toxins produced. The time-course of SLT production by

Shu-I. Tu; Joseph Uknalis; Andrew Gehring; Yiping He

2007-01-01

150

Ultrasensitive opto-microfluidic immunosensor integrating gold nanoparticle-enhanced chemiluminescence and highly stable organic photodetector.  

PubMed

The expensive fabrication of current opto-microfluidic sensors is a barrier to the successful adoption of these devices in point-of-care testing. This work reports a simple inexpensive opto-microfluidic device incorporating a poly(dimethylsiloxane)-glass hybrid microfluidic chip modified with gold nanoparticles and a high-detectivity, high-stability organic photodetector. The enhancing effect of the gold nanoparticles on horseradish peroxidase-luminol-H2O2 chemiluminescence was exploited in rapid single-analyte immunoassays. The limit of detection for 17-? estradiol was 2.5??pg/ml, which is ?200 times more sensitive than previously reported chemiluminescent immunosensors employing other organic photodetectors. Detection was also demonstrated in complex media, including natural water and blood serum. PMID:24615640

Pires, Nuno Miguel Matos; Dong, Tao

2014-03-01

151

Sensitive competitive flow injection chemiluminescence immunoassay for IgG using gold nanoparticle as label.  

PubMed

A sensitive competitive flow injection chemiluminescence (CL-FIA) immunoassay for immunoglobulin G (IgG) was developed using gold nanoparticle as CL label. In the configuration, anti-IgG antibody was immobilized on a glass capillary column surface by 3-(aminopropyl)-triethoxysilane and glutaraldehyde to form immunoaffinity column. Analyte IgG and gold nanoparticle labeled IgG were passed through the immunoaffinity column mounted in a flow system and competed for the surface-confined anti-IgG antibody. CL emission was generated from the reaction between luminol and hydrogen peroxide in the presence of Au (III), generated from chemically oxidative dissolution of gold nanoparticle by an injection of 0.10 mol L(-1) HCl-0.10 mol L(-1) NaCl solution containing 0.10 mmol L(-1) Br(2). The concentration of analyte IgG was inversely related to the amount of bound gold nanoparticle labeled IgG and the CL intensity was linear with the concentration of analyte IgG from 1.0 ng mL(-1) to 40 ng mL(-1) with a detection limit of 5.2×10(-10) gm L(-1). The whole assay time including the injections and washing steps was only 30 min for one sample, which was competitive with CL immunoassays based on a gold nanoparticle label and magnetic separation. This work demonstrates that the CL immunoassay incorporation of nanoparticle label and flow injection is promising for clinical assay with sensitivity and high-speed. PMID:21862396

Qi, Honglan; Shangguan, Li; Liang, Lin; Ling, Chen; Gao, Qiang; Zhang, Chengxiao

2011-11-01

152

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

PubMed

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. PMID:19345084

Bi, Sai; Zhou, Hong; Zhang, Shusheng

2009-06-15

153

Determination of residual enrofloxacin in food samples by a sensitive method of chemiluminescence enzyme immunoassay.  

PubMed

A chemiluminescence enzyme immunoassay (CLEIA) based on the HRP-luminol-H?O? chemiluminescence system for highly sensitive detection of enrofloxacin (ENR) was proposed in this study. Key factors that affect the precision and accuracy for the determination of ENR residues were optimised. Under the optimal conditions, the proposed method showed an excellent performance. The linearity range for method developed for determination of ENR was 0.35-1.0 ng/mL with a correlation coefficient greater than 0.994. The limit of detection was 0.03 ng/mL and the relative standard deviations (RSDs) were less than 9.4% and 13.0% for intra-day and inter-day assays. The proposed method was satisfactorily applied to determine ENR in milk, eggs, and honey samples at three spiked levels (0.4, 0.7, and 1.0 ng/mL) and the recoveries ranged from 92.4% to 104.2% for milk, 93.8% to 103.2% for eggs and 94.1% to 105.0% for honey, respectively. Compared the results of CLEIA with those of ELISA and HPLC, the advantages of the CLEIA were further confirmed. Moreover, one 96-well microtiter plate coated with anti-ENR can be used to detect multiple samples at the same time, which indicated that the CLEIA using HRP-luminol-H?O? system was a sensitive, high throughput and real-time method for ENR residues analysis. PMID:24295678

Yu, Fei; Yu, Songcheng; Yu, Lanlan; Li, Yanqiang; Wu, Yongjun; Zhang, Hongquan; Qu, Lingbo; Harrington, Peter de B

2014-04-15

154

Simultaneous quantification of 5-hydroxyindoleacetic acid and 5-hydroxytryptamine by capillary electrophoresis with quantum dot and horseradish peroxidase enhanced chemiluminescence detection.  

PubMed

A capillary electrophoresis (CE) with chemiluminescence (CL) detection method was developed for the simultaneous quantification of 5-hydroxyindoleacetic acid (5-HIAA) and 5-hydroxytryptamine (5-HT). In this method, CdTe quantum dot (QD) and horseradish peroxidase (HRP) were used as enhancing reagents to co-catalyze the post-column CL reaction between luminol and hydrogen peroxide, achieving highly efficient CL emission. 5-HIAA and 5-HT inhibit the CL emission resulting to the formation of negative peaks in electropherogram. The degree of CL suppression is proportional to the concentration of 5-HT and 5-HIAA. The linear ranges for the determination of 5-HIAA and 5-HT were 2.5×10(-8)-2.5×10(-6) M and 2.5×10(-8)-5.0×10(-6) M with detection limits (signal/noise=3) of 7.0×10(-9) M and 6.0×10(-9) M, respectively. Intraday precision do not exceed 5.0%. The accuracy was confirmed by the recoveries ranged from 98% to 104%. The present method was successfully applied for the quantification of 5-HIAA and 5-HT in human urine. The concentrations of 5-HT and 5-HIAA in human urine were found to be in the range of 0.78-1.2 ?M and 3.2-5.1 ?M, respectively. PMID:25125395

Zhang, Liangliang; Zhao, Yunsha; Huang, Junming; Zhao, Shulin

2014-09-15

155

Determination of naphazoline hydrochloride in biological and pharmaceutical samples by a quantum dot-assisted chemiluminescence system using response-surface methodology.  

PubMed

A simple and highly sensitive chemiluminescence (CL) method is reported for the determination of naphazoline hydrochloride (NH). It was found that the weak CL from the reaction of luminol and KIO4 in an alkaline medium could be highly amplified by cysteine-capped cadmium telluride quantum dots (QDs) and the enhanced CL was effectively quenched by NH and this finding was utilized as a basis for the determination of NH. The QDs were synthesized in aqueous medium and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and UV-vis and photoluminescence spectroscopy. A possible mechanism was proposed for the CL system based on radical identification experiments, along with CL spectrum of the system. The experimental parameters were optimized by the reliable response surface methodology (RSM). Under the optimized experimental conditions, the proposed method allowed the determination of NH over the range of 5.0?×?10(-10) -2.0?×?10(-7) ?mol/L (r(2) ?=?0.9993, n?=?10). The precision (RSD%) of the method, obtained from five replicate determinations of 2.0 and 150?nmol/L NH, was found to be 1.0% and 1.3%, respectively. The method was successfully applied to the determination of NH in pharmaceutical formulations and human urine and serum samples with results corroborated with the aid of those obtained from a standard method. Copyright © 2014 John Wiley & Sons, Ltd. PMID:24733642

Imani-Nabiyyi, Amin; Sorouraddin, Mohammad H

2014-12-01

156

Determination of phenolic compounds and their antioxidant activity in Erigeron acris L. extracts and pharmaceutical formulation by flow injection analysis with inhibited chemiluminescent detection.  

PubMed

It was found that the chemiluminescence (CL) produced from the reaction of luminol with iodine in the alkaline medium was strongly inhibited by plant phenolic compounds. Based on this finding, a new flow injection CL method was developed for the determination of caffeic acid and 6'-caffeoylerigeroside. The latter compound was isolated for the first time from Erigeron acris L. herb. The method was simple, rapid and sensitive with a detection limit of 4 x 10(-3) ng mL(-1) (caffeic acid) and 0.18 ng mL(-1) (6'-caffeoylerigeroside), linear range of 0.1-1.5 ng mL(-1) (caffeic acid) and 1-200 ng mL(-1) (6'-caffeoylerigeroside), relative standard deviation of 3.3% for 10 measurements of 0.45 ng mL(-1) caffeic acid and 2.9% for 40 ng mL(-1) 6'-caffeoylerigeroside. This method was successfully applied to determine the content of phenolic compounds/antioxidant activity of E. acris L. extracts and phenolic acids content in pharmaceutical formulation. A possible mechanism of the inhibition of the proposed CL system was discussed. PMID:18597966

Nalewajko-Sieliwoniuk, Edyta; Nazaruk, Jolanta; Antypiuk, Ewelina; Koj?o, Anatol

2008-11-01

157

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

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. PMID:23832716

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

2014-06-01

158

Modulatory effect of visible light on chemiluminescence of stimulated and nonstimulated blood leukocytes of carp (Cyprinus carpio, L)  

NASA Astrophysics Data System (ADS)

Irradiation of carp blood leukocytes with a non-laser visible light resulted in a significant inhibition of the spontaneous luminol-dependent chemiluminescence in the cells of a part of the fish. Those leukocytes that were sensitive to the visible light, showed a shorter time-to-peak than the non sensitive, following their stimulation with Ca ionophore. Because a shorter time-to-peak correlates with inflammation, it could be suggested that the visible light susceptible leukocyte reflect a pre-inflammatory state of their donors.

Belotsky, Sandro; Avtalion, Ramy R.; Friedmann, Harry; Lubart, Rachel

1998-12-01

159

"Signal on" electrochemiluminescence pentachlorophenol sensor based on luminol-MWCNTs@graphene oxide nanoribbons system.  

PubMed

A "signal on" electrochemiluminescence (ECL) sensor for pentachlorophenol (PCP) detection was constructed based on the amplified ECL of luminol at a multiwalled carbon nanotubes@graphene oxide nanoribbons (MWCNTs@GONRs) modified electrode. Due to the good electrocatalytic activity of MWCNTs@GONRs toward luminol system, the oxidation peak current of luminol at the MWCNTs@GONRs modified electrode was enhanced for ~6-fold than that of the bare electrode; and the ECL intensity of luminol was amplified for ~5.3-fold correspondingly. Furthermore, the amplified ECL signal of luminol was linear with the concentration of PCP in the range between 2pgmL(-1) and 10ngmL(-1) with a detection limit of 0.7pgmL(-1) (S/N=3). With the merits of good reproducibility, acceptable stability, wide linear range, low detection limit and simplicity, the proposed luminol ECL sensor showed great potential in the field of analytical applications. PMID:25618692

Liu, Qian; Huan, Juan; Fei, Airong; Mao, Hanping; Wang, Kun

2015-03-01

160

Fast determination of thiacloprid by photoinduced chemiluminescence.  

PubMed

A new and sensitive application of chemiluminescence detection has been developed for the determination of the pesticide thiacloprid in water. It was based on the on-line photoreaction of thiacloprid in a basic medium, with quinine acting as the sensitizer of the chemiluminescent response; cerium (IV) in sulfuric acid medium was used as the oxidant. High degrees of automation and reproducibility were achieved using a flow-injection analysis (FIA) manifold. The validation of the method was performed in terms of selectivity, linearity, limit of detection (LOD), precision, and accuracy. Liquid chromatography with ultraviolet (UV) detection was used as reference for mineral, tap, ground, and spring water samples. The proposed method is fast (with a throughput of 130 h(-1)), sensitive (LOD of 0.8 ng mL(-1) without preconcentration steps and of 0.08 ng mL(-1) with solid-phase extraction [SPE]), low cost, and possible to couple with separation methods for the simultaneous determination of other pesticides. The enhanced chemiluminescence intensity was linear with the thiacloprid concentration above the 2-80 and 80-800 ng mL(-1) ranges. A possible reaction mechanism is also discussed. PMID:25014719

Catalá-Icardo, Mónica; López-Paz, José Luis; Pérez-Plancha, Laura María

2014-01-01

161

Structure sensitivity in the kinetics and the dynamics of CO oxidation over stepped Pd(335) studied by the molecular beam infrared chemiluminescence technique: Determination of working sites during the steady-state reaction  

SciTech Connect

Kinetics and dynamics of CO oxidation have been studied on a stepped Pd(335) surface at a steady-state condition and compared with those on flat Pd(111). The infrared (IR) chemiluminescence technique was applied to determine where the active catalytic sites are on the Pd(335) surface. Since the vibrational energy state of the product CO{sub 2} is sensitive to the structures of the reaction sites on Pd surfaces, information about the working reaction sites during the steady-state CO oxidation can be obtained from the IR emission spectra of the product CO{sub 2}. The production rate of CO{sub 2} was higher on Pd(335) than on Pd(111), indicating that the steps on the surface enhance the catalytic activity for Co oxidation under the steady-state condition. However, the rate data do not necessarily show the real active sites for the CO + O recombination reaction. At a surface temperature of 850 K, the vibrational Boltzmann temperature (T{sub v}) of the product CO{sub 2} on Pd(335) was quite different from (much lower than) that on Pd(111), although the Pd(335) surface has four-atom wide (111) terraces. The lower T{sub v} value on Pd(335) was similar to that on Pd(110)(1 x 1), indicating that a relatively linear activated CO{sub 2} complex was formed. Therefore, during the steady-state CO oxidation on Pd(335), the reaction does not take place on the (111) terrace sites, but mostly on the step sites at 850 K. On the contrary, as the CO coverage increased at a lower surface temperature and at a high CO/O{sub 2} ratio, the T{sub v} values on Pd(335) tend to approach those on Pd(111), indicating that the contribution of the active sites on the steps is decreased and the working reaction sites shift to the (111) terrace sites.

Uetsuka, H.; Watanabe, K.; Kimpara, H.; Kunimori, K.

1999-08-31

162

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

SciTech Connect

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. 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.

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

1981-06-01

163

Determination of catecholamines by flow-injection analysis and high-performance liquid chromatography with chemiluminescence detection.  

PubMed

A chemiluminescence (CL) detection of catecholamines [norepinephrine (NE), epinephrine (E), dopamine (DA) and L-dopa (LD)] is described for the flow-injection (FI) and high-performance liquid chromatographic (HPLC) determination of these compounds. The detection method is based on the inhibition effect of catecholamines (CAs) on the CL reaction of luminol with iodine in the alkaline medium. The proposed FI method allows the determination of CAs in pharmaceutical preparations for the purpose of drug quality control. The calibration curves show good linearity in the concentration range of: 1.1-20.0 microg l(-1) (NE), 0.5-5.0 microg l(-1) (E), 0.6-9.0 microg l(-1) (DA) and 0.6-10.0 microg l(-1) (LD). The limits of detection (defined as a signal-to-noise ratio of 3) are: 0.34 microg l(-1) (NE), 0.15 microg l(-1) (E) and 0.18 microg l(-1) (DA, LD). The HPLC procedure was successfully applied for the determination of catecholamines (NE, E, DA) in human urine after solid-phase extraction (SPE). In a simple run time CAs can be determined in 20 min. The chromatographic linear ranges are: 5.0-72.0 microg l(-1) (NE), 5.0-48.0 microg l(-1) (E) and 5.0-96.0 microg l(-1) (DA). The limits of detection for three urinary CAs are: 0.71 microg l(-1) (NE), 0.26 microg l(-1) (E) and 0.73 microg l(-1) (DA). PMID:17289328

Nalewajko, Edyta; Wiszowata, Aneta; Koj?o, Anatol

2007-04-11

164

CHEMILUMINESCENCE MEASUREMENT OF REACTIVITY WEIGHTED ETHYLENE-EQUIVALENT HYDROCARBONS  

EPA Science Inventory

A reactive hydrocarbon analyzer (RHA), based on the chemiluminescent reaction of hydrocarbons with oxygen atoms, is used to provide a rapid indication of reactivity weighted hydrocarbon mass in automobile exhaust. Samples are reported by their ethylene-equivalent concentration--t...

165

Chemiluminescence characteristics of furan derivatives as blue fluorescers in peroxyoxalate-hydrogen peroxide system.  

PubMed

Furan derivatives (synthesized and purified in organic laboratories) are a great interest as fluorescent emitters for peroxyoxalate chemiluminescence. Reaction of peroxyoxalates such as bis-(2,4,6-trichloro-phenyl) oxalate with H(2)O(2) can transfer energy to fluorophore via formation of dioxetanedione intermediate. Furan derivatives used as a novel fluorescer in this study which produces a blue light in the chemiluminescence systems. The relationship between the chemiluminescence intensity and concentrations of TCPO, sodium salicylate, hydrogen peroxide and the fluorescer has been investigated. The linear ranges for Furan derivatives were 0.25-5 × 10(-4) M and 0.1-5 × 10(-4) M (A and B compounds, respectively). Kinetic parameters for the peroxyoxalate-chemiluminescence were also calculated from the computer fitting of the corresponding chemiluminescence intensity/time profiles. PMID:22684823

Chaichi, M J; Azizi, S N; Heidarpour, M; Aalijanpour, O; Qandalee, M

2012-09-01

166

Ultrasensitive chemiluminescent immunoassay of Salmonella with silver enhancement of nanogold labels.  

PubMed

In this paper, silver enhancement of nanogold labels coupled with chemiluminescence detection was developed for ultrasensitive immunoassay of Salmonella based upon antigen-antibody immunoreaction. Polyclonal rabbit anti-Salmonella sp. antibodies (pAb) were employed to establish the analytical protocol. The pAb coated onto ELISA microwell plates and Au nanoparticles (Au NPs) conjugated pAb capture target Salmonella to form a sandwich-type complex. Silver then was in situ deposited around the Au NPs core and resulted in the signal amplification. In consequence, silver was dissolved to form Ag(+) and a sensitive chemiluminescence based on the Ag(+)-K2S2O8-Mn(2+)-luminol system was coupled for further signal amplification. Under the optimized conditions, the chemiluminescent intensity is proportional to target Salmonella over the range of 5-1038?cfu?mL(-1) with a detection limit of 5?cfu?mL(-1). The relative standard deviation for 11 measurements of about 50-100?cfu/mL target Salmonella is 4.7%. The proposed method was successfully applied to measure Salmonella in food samples and the results are identical to those of the offical standard method of China. These offer us a more powerful tool for ultrasensitive assay of foodborne pathogens. PMID:21491565

Wang, Zhouping; Duan, Nuo; Li, Jingquan; Ye, Jing; Ma, Shufeng; Le, Guowei

2011-01-01

167

Chemiluminescence from UVA-exposed skin: separating photo-induced chemiluminescence from photophysical light emission.  

PubMed

Several previous studies have reported luminescence emission from skin following exposure to UVA radiation in air. We show that UVA irradiation of biomaterials and polymers in oxygen, including bovine stratum corneum, followed by photon counting results in a complex emission due to a combination of photophysical processes together with photo-induced chemiluminescence (PICL). The photophysical processes include fluorescence, phosphorescence and charge-recombination luminescence. By irradiating materials in an inert atmosphere such as nitrogen and allowing photophysical light emission to fully decay before admitting oxygen, the weak photo-induced chemiluminescence generated via free radical reactions with oxygen can be separated and analysed. PICL emission from bovine stratum corneum is weaker than for wool keratin and bovine skin collagen, probably due to its higher water content, and the presence of the natural antioxidants ascorbate and tocopherol. PMID:22727928

Millington, Keith R; Jones, Leslie N; Sinclair, Rodney D

2012-09-01

168

Highly sensitive analysis of four hemeproteins by dynamically-coated capillary electrophoresis with chemiluminescence detector using an off-column coaxial flow interface.  

PubMed

Dynamic coating of the surface in capillary electrophoresis with chemiluminescence detection (CE-CL) using an off-column coaxial flow interface for the determination of four hemeproteins was developed. This method is based on the luminol-hydrogen peroxide reaction catalyzed by metalloproteins in alkaline medium. The experimental setup of the CE-CL system with the proposed off-column coaxial interface was evaluated by separation and detection of dopamine and catechol based on inhibition of the luminol-potassium ferricyanide reaction. Highly efficient separation of the two model compounds with symmetrical peak shape and satisfactory reproducibility was achieved by using this interface. In addition, in order to obtain a good resolution for hemeproteins, polyvinylpyrrolidone (PVP) combined with sodium dodecyl sulfate (SDS) were introduced as dynamic modifiers to reduce the unwanted adsorption of non-specific protein. Several parameters affecting the CE separation and CL detection were investigated in detail. Under the optimized conditions, a mixture of the four hemeproteins (horseradish peroxidase (HRP), catalase (Cat), myoglobin (Mb) and cytochrome C (Cyt C)) could be well separated within 20 min. The linear ranges of the four proteins were 5.7 × 10(-8) to 1.1 × 10(-6) mol L(-1) for HRP, 4.0 × 10(-8) to 2.0 × 10(-6) mol L(-1) for Cat, 1.1 × 10(-10) to 5.6 × 10(-8) mol L(-1) for Mb, and 3.8 × 10(-7) to 7.7 × 10(-6) mol L(-1) for Cyt C. The limits of detection (LODs) (S/N = 3) for HRP, Cat, Mb and Cyt C were 2.2 × 10(-8) mol L(-1) (104.5 amol), 1.6 × 10(-8) mol L(-1) (74 amol), 5.6 × 10(-11) mol L(-1) (0.26 amol), and 1.95 × 10(-7) mol L(-1) (0.89 fmol), respectively. The proposed method has been successfully applied to the analysis of low-level Mb in a spiked human urine sample and the recoveries were above 97%. Our primary result demonstrated that the proposed CE-CL method has great potential for Mb determination in clinical diagnosis. PMID:23443524

Lin, Zian; Sun, Xiaobo; Lin, Yao; Chen, Guonan

2013-04-21

169

Chemiluminescent prediction of service life  

NASA Technical Reports Server (NTRS)

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

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

1976-01-01

170

Electrogenerated chemiluminescence from Au nanoclusters.  

PubMed

Electrogenerated chemiluminescence (ECL) of Au clusters is observed for the first time using triethyamine (TEA) as the coreactant. The potential application of ECL Au clusters in analytical chemistry is also demonstrated using Pb(2+) as an example. PMID:21165495

Fang, Yi-Min; Song, Jing; Li, Juan; Wang, Yi-Wei; Yang, Huang-Hao; Sun, Jian-Jun; Chen, Guo-Nan

2011-02-28

171

Chemiluminescence and bioluminescence microbe detection  

NASA Technical Reports Server (NTRS)

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

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

1978-01-01

172

Online phototransformation-flow injection chemiluminescence determination of triclosan.  

PubMed

A highly selective and sensitive chemiluminescence method for the determination of triclosan is proposed. The method is based on the phototransformation of triclosan to a light-emitting precursor in the presence of fluorescein in alkaline medium and the chemiluminescence reaction is then triggered by strong base or oxidants such as N-bromosuccinimide. Based on this reaction an online phototransformation-flow injection manifold was developed, in which the photoreactor comprises a 150-cm-long x 0.8-mm-i.d. piece of PTFE tubing coiled around a 25-W fluorescent lamp, and the phototransformed products were then injected into a carrier stream of borate buffer. After mixing with the oxidant stream the produced light was detected by a photomultiplier. A wide calibration range from 8.0 x 10(-8) to 1.0 x 10(-4) mol L(-1) was obtained under the optimized conditions, and the detection limit was as low as 5.0 x 10(-8) mol L(-1). The whole process of analysis, including the online phototransformation and subsequent chemiluminescence detection, could be completed in 6 min. Most of the foreign substances tested showed high tolerance levels, and the proposed method was directly applied to the determination of triclosan in toothpaste samples without any pre-separation procedure. Figure Schematic representation of the phototransformation of triclosan and subsequent chemiluminescence reaction. PMID:17294174

Song, Shujuan; Song, Qi Jun; Chen, Zhongliang

2007-04-01

173

Stimulus specific effect of ibuprofen on chemiluminescence of sheep neutrophils  

SciTech Connect

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 ZAP 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.

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

1986-03-05

174

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

PubMed Central

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.

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

2008-01-01

175

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

NASA Astrophysics Data System (ADS)

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 ?-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.

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

2006-01-01

176

A paper-based chemiluminescence device for the determination of ofloxacin.  

PubMed

Paper-based devices are biodegradable and have been used in diagnosis and environmental analysis field. In this work, a wax-printed paper-based analytical device combined with silver nanoparticles (AgNPs) catalyzed luminol chemiluminescence (CL) system for the determination of ofloxacin (OFLX) was presented. It was based on the enhancement of CL intensity of luminol-H2O2-OFLX system by AgNPs. Wax-printing fabrication technique was used to make the simple circle shaped paper device and large scale chips can be fabricated at the same time. Under the selected experimental conditions, a linear relationship was obtained between the CL intensity and the concentration of OFLX in the range from 1.0×10(-9) g/mL to 1.0×10(-6) g/mL with a detection limit of 3.0×10(-10) g/mL. This method has been successfully applied to the determination of OFLX in eyedrop samples. PMID:25306129

Liu, Wei; Guo, Yumei; Li, Huifang; Zhao, Mei; Lai, Zesheng; Li, Baoxin

2015-02-25

177

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

PubMed

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. PMID:22473830

Chen, Xiaolan; Tan, Xinmei; Wang, Jianxiu

2013-01-01

178

Flow-injection chemiluminescence determination of gentamicin: optimization by central composite design.  

PubMed

A simple and sensitive flow-injection chemiluminescence (CL) method has been developed for the determination of gentamicin sulfate. The method is based on the inhibitory effect of gentamicin on the CL emission accompanying oxidation of luminol by H2 O2 in an alkaline medium in the presence of Cu(II) as a catalyst. Inhibition was caused by the formation of a strong complex between analyte and the catalyst. Experimental variables, including the concentrations of luminol (µmol/L), H2 O2 (mol/L), Cu(II) (mol/L) and NaOH (mol/L), were optimized using a central composite design. Under optimum conditions, the plot of CL intensity versus gentamicin concentration was found to have two linear ranges. One range was at low concentrations from 1.0 to 10.0?mg/L and the other was from 10.0 to 30.0?mg/L. Precision was calculated by analyzing samples containing 5.0?mg/L gentamicin (n?=?11) and the relative standard deviation (RSD) was 1.7%. Also, a high injection throughput of 120 samples/h was achieved. This method was successfully applied to the determination of gentamicin sulfate in pharmaceutical formulations and water samples. PMID:23744581

Iranifam, M; Hasanzadeh, A; Fathinia, M; Khataee, A R; Mousavi, S A

2014-05-01

179

A paper-based chemiluminescence device for the determination of ofloxacin  

NASA Astrophysics Data System (ADS)

Paper-based devices are biodegradable and have been used in diagnosis and environmental analysis field. In this work, a wax-printed paper-based analytical device combined with silver nanoparticles (AgNPs) catalyzed luminol chemiluminescence (CL) system for the determination of ofloxacin (OFLX) was presented. It was based on the enhancement of CL intensity of luminol-H2O2-OFLX system by AgNPs. Wax-printing fabrication technique was used to make the simple circle shaped paper device and large scale chips can be fabricated at the same time. Under the selected experimental conditions, a linear relationship was obtained between the CL intensity and the concentration of OFLX in the range from 1.0 × 10-9 g/mL to 1.0 × 10-6 g/mL with a detection limit of 3.0 × 10-10 g/mL. This method has been successfully applied to the determination of OFLX in eyedrop samples.

Liu, Wei; Guo, Yumei; Li, Huifang; Zhao, Mei; Lai, Zesheng; Li, Baoxin

2015-02-01

180

Flow injection-chemiluminescence determination of paraben preservative in food safety  

Microsoft Academic Search

The determination of a group of parabens including methylparaben, ethylparaben, propylparaben, and butylparaben using flow injection analysis technique with chemiluminescence detection has been carried out. The method is based on the enhancement by parabens of cerium(IV)-rhodamine 6G chemiluminescence reaction in sulfuric acid medium. Under the optimized conditions, the linear range of 4.5 × 10?10 to 1.5 × 10?7, 3.0 ×

Aung Myint; Qunlin Zhang; Lijuan Liu; Hua Cui

2004-01-01

181

Luminescent Oxygen Channeling Immunoassay: Measurement of Particle Binding Kinetics by Chemiluminescence  

Microsoft Academic Search

A method for monitoring formation of latex particle pairs by chemiluminescence is described. Molecular oxygen is excited by a photosensitizer and an antenna dye that are dissolved in one of the particles. ^1Delta_gO_2 diffuses to the second particle and initiates a high quantum yield chemiluminescent reaction of an olefin that is dissolved in it. The efficiency of ^1Delta_gO_2 transfer between

Edwin F. Ullman; Hrair Kirakossian; Sharat Singh; Z. Ping Wu; Benjamin R. Irvin; John S. Pease; Arthur C. Switchenko; Jennifer D. Irvine; Alan Dafforn; Carl N. Skold; Daniel B. Wagner

1994-01-01

182

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

PubMed

We have combined the principles of microwave circuitry and antenna design and our recent work in microwave-triggered metal-enhanced chemiluminescence to now "trigger" chemically and enzyme-catalyzed chemiluminescent reactions with spatial and temporal control. With this technology platform, we achieve spatial and temporal control of enzyme and chemically catalyzed chemiluminescence reactions to achieve more than 500-fold increases in "on-demand" photon flux from chemically catalyzed chemiluminescent reactions. We also report a 6-fold increase in photon flux from HRP-catalyzed assays on disposable coverslips functionalized with HRP and placed proximal to the substrates modified with thin-film aluminum triangle disjointed "bow-tie" structures. In addition, we demonstrate the applicability of this technology to develop multiplexed or high-throughput chemiluminescent assays. We also demonstrate the clinical and biological relevance of this technology platform by affixing aluminum structures in proximity to HRP protein immobilized on nitrocellulose to improve the sensitivity for this model Western blot scheme by 50-fold. We believe analytical applications that rely on enzyme-catalyzed chemiluminescence, such as immunoassays, may greatly benefit from this new platform technology. PMID:17696497

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

2007-09-15

183

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

PubMed

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. PMID:22938618

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

2012-10-01

184

Automated chemiluminescence immunoassay for a nonionic surfactant using a recycled spinning-pausing controlled washing procedure on a compact disc-type microfluidic platform.  

PubMed

A fully automated and integrated chemiluminescence immunoassay, carried out on a compact disc (CD)-type microfluidic platform, for the detection of alkylphenol polyethoxylates (APnEOs) is described. The pattern of the CD-type microchip was designed so as to permit the sequential solution delivery of the sample solution, the washing solution and the luminol solution, which are required in the chemiluminescence immunoassay process, along with a designed rotation program for spinning the CD-type microchip. The procedure for flowing the washing solution, the volume of which was limited on the CD-type microchip, was optimized by using a recycled spinning-pausing rotation program to overcome the non-specific adsorption of the horseradish peroxidase labeled APnEOs at the detection area. The detection limit of the immunoassay is about 10 ppb. PMID:25435234

Guo, Shuai; Ishimatsu, Ryoichi; Nakano, Koji; Imato, Toshihiko

2015-02-01

185

Chemiluminescence Study on Thermal Degradation of Aircraft Tire Elastomers  

NASA Technical Reports Server (NTRS)

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

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

1976-01-01

186

Simplified ozone detection by chemiluminescence  

NASA Technical Reports Server (NTRS)

Ozone is detected by film coated with solid, such as rubrene, that reacts with ozone to degree proportional to concentration in sample gas. Gas flow is stopped, and film is heated to produce light (chemiluminescence) in proportion to amount of reacted material on sensor.

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

1977-01-01

187

CHEMILUMINESCENT MONITOR FOR VINYL CHLORIDE  

EPA Science Inventory

A monitor for vinyl chloride monomer (VCM) in ambient air was constructed using commercially available components of a gas chromatograph (GC) coupled with a chemiluminescence ozone analyzer slightly modified to make it suitable for use as a GC detector. The specificity for VCM is...

188

Disposable luminol copolymer-based biosensor for uric acid in urine  

Microsoft Academic Search

A new electrochemiluminescent (ECL) disposable biosensor for uric acid was manufactured by immobilization in a double-layer design of luminol as a copolymer with 3,3?,5,5?-tetramethylbenzidine (TMB) and the enzyme uricase in chitosan on gold screen-printed cells. The good mechanical and improved electroluminescent characteristics of the new copolymer poly(luminol–TMB) make it possible to determine uric acid by measuring the growing ECL emission

J. Ballesta-Claver; I. F. Díaz Ortega; M. C. Valencia-Mirón; L. F. Capitán-Vallvey

2011-01-01

189

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

E-print Network

We demonstrate an in-fiber gas phase chemical detection architecture in which a chemiluminescent (CL) reaction is spatially and spectrally matched to the core modes of hollow photonic bandgap (PBG) fibers in order to enhance ...

Stolyarov, Alexander Mark

190

Are the bio- and chemiluminescence states of the firefly oxyluciferin the same as the fluorescence state?  

PubMed

A usual strategy in both experimental and theoretical studies on bio- and chemiluminescence is to analyze the fluorescent properties of the bio- and chemiluminescence reaction product. Recent findings in a coelenteramide and Cypridina oxyluciferin model raise a concern on the validity of this procedure, showing that the light emitters in each of these luminescent processes might differ. Here, the thermal decomposition path of the firefly dioxetanone and the light emission states of the Firefly oxyluciferin responsible for the bio-, chemiluminescence, and fluorescence of the molecule are characterized using ab initio quantum chemistry and hybrid quantum chemistry/molecular mechanics methods to determine if the scenario found in the coelenteramide and Cypridina oxyluciferin study does also apply to the Firefly bioluminescent systems. The results point out to a unique emission state in the bio-, chemiluminescence, and fluorescence phenomena of the Firefly oxyluciferin and, therefore, using fluorescence properties of this system is reasonable. PMID:23057607

Navizet, Isabelle; Roca-Sanjuán, Daniel; Yue, Ling; Liu, Ya-Jun; Ferré, Nicolas; Lindh, Roland

2013-01-01

191

Unprecedented chemiluminescence behaviour during peroxyoxalate chemiluminescence of oxalates with fluorescent or electron-donating aryloxy groups.  

PubMed

A series of diaryl and bis(4-styrylphenyl) oxalates with electron-donating substituents or fluorescent moieties were subjected to the peroxyoxalate chemiluminescence (PO-CL) reaction, some of which were found to behave in a unprecedented manner. The reaction of bis(p-methyoxyphenyl) oxalate, as a representative example, emits light due not only to the emission from the externally added excited fluorophore, but also from the presumable excimer of p-methoxyphenol. Also, during the reaction of the bis(4-styrylphenyl) oxalates, the emission based on the fluorescence as well as the excimer of the eliminating group were observed. These experimental results suggest that such emitting species would be formed by an intra- and intermolecular electronic interaction with a high-energy intermediate, such as a dioxetanone. PMID:16502395

Koike, Ryu; Kato, Yuji; Motoyoshiya, Jiro; Nishii, Yoshinori; Aoyama, Hiromu

2006-01-01

192

Ozone chemiluminescent detection of olefins: Potential applications for real-time measurements of natural hydrocarbon emissions  

SciTech Connect

A chemiluminescence analyzer has been constructed that takes advantage of the temperature dependence of the ozone-hydrocarbon reaction. When operated at a temperature of 170 C, the analyzer functions as a total nonmethane hydrocarbon analyzer with sensitivities 10--1,000 times better than a conventional FID. However, with operation at varying temperatures, the chemiluminescent signal reflects the differences in rates of reaction of the hydrocarbons with ozone. Preliminary studies at room temperature indicated that the relative rates of reaction of isoprene, {alpha}-pinene, {beta}-pinene, and limonene with ozone correlated with the observed chemiluminescence signal. When hydrocarbons are grouped in classes of similar structure, their rates of reaction with electrophilic atmospheric oxidants (e.g., OH, O{sub 3}, NO{sub 3}) can be correlated with each other. By varying the temperature of the reaction chamber, the chemiluminescence analyzer can be tuned to more reactive classes of hydrocarbons. Therefore, the chemiluminescence analyzer has the ability to determine atmospheric hydrocarbon concentrations as a function of class and will also provide a measure of the atmospheric reactivity of the hydrocarbons.

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

1997-10-01

193

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

PubMed

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 (79-104?g/kg) was significantly higher than that in mandarins (1.66-2.82?g/kg). PMID:23790860

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

2013-11-15

194

Using a large area CMOS APS for direct chemiluminescence detection in Western blotting electrophoresis  

NASA Astrophysics Data System (ADS)

Western blotting electrophoretic sequencing is an analytical technique widely used in Functional Proteomics to detect, recognize and quantify specific labelled proteins in biological samples. A commonly used label for western blotting is Enhanced ChemiLuminescence (ECL) reagents based on fluorescent light emission of Luminol at 425nm. Film emulsion is the conventional detection medium, but is characterized by non-linear response and limited dynamic range. Several western blotting digital imaging systems have being developed, mainly based on the use of cooled Charge Coupled Devices (CCDs) and single avalanche diodes that address these issues. Even so these systems present key drawbacks, such as a low frame rate and require operation at low temperature. Direct optical detection using Complementary Metal Oxide Semiconductor (CMOS) Active Pixel Sensors (APS)could represent a suitable digital alternative for this application. In this paper the authors demonstrate the viability of direct chemiluminescent light detection in western blotting electrophoresis using a CMOS APS at room temperature. Furthermore, in recent years, improvements in fabrication techniques have made available reliable processes for very large imagers, which can be now scaled up to wafer size, allowing direct contact imaging of full size western blotting samples. We propose using a novel wafer scale APS (12.8 cm×13.2 cm), with an array architecture using two different pixel geometries that can deliver an inherently low noise and high dynamic range image at the same time representing a dramatic improvement with respect to the current western blotting imaging systems.

Esposito, Michela; Newcombe, Jane; Anaxagoras, Thalis; Allinson, Nigel M.; Wells, Kevin

2012-03-01

195

Flow-injection chemiluminescence and electrogenerated chemiluminescence determination of escitalopram oxalate in tablet form.  

PubMed

Rapid, simple and highly sensitive flow-injection (FI) chemiluminescence (CL) and flow-injection electrogenerated chemiluminescence (ECL) methods were developed for the determination of escitalopram oxalate (ESC), a selective serotonin reuptake inhibitor used as an antidepressant drug. The CL method was based on the CL reaction of ESC with acidic cerium(IV) and tris(2,2'-bipyridyl)ruthenium(II) (Ru(bipy)(3)(2)+). Various experimental parameters affecting CL intensity were carefully studied and optimised. The method enabled the determination of 0.001-50 µg/mL of ESC in bulk form with a correlation coefficient r = 0.9999. The limit of detection (LOD) was 0.01 ng/mL (S/N = 3). The ECL method was based on the ECL reaction of Ru(bipy)(3)(2)+ with the drug in an acidic medium, permitting the determination of ESC in the range of 0.00001-70 µg/mL with r = 0.9999 and LOD of 1 x 10(-4) ng/mL. The proposed methods were applied to the determination of ESC in commercial tablets. The results were compared statistically with those obtained from a published method using t- and F-tests. PMID:22555899

Alarfaj, Nawal A; Aly, Fatma A; Al-Qahtany, Abeer A

2013-01-01

196

Effects of 4-hydroxynonenal on isolated hepatocytes. Studies on chemiluminescence response, alkane production and glutathione status.  

PubMed Central

The effect of 4-hydroxy-2,3-trans-nonenal, a diffusible product of lipid peroxidation, on isolated hepatocytes was evaluated with two non-invasive techniques measuring low-level chemiluminescence and alkane evolution. Oxygen-induced low-level chemiluminescence and ethane and n-pentane formation by hepatocytes is enhanced over 7-fold in the presence of 4-hydroxynonenal (2 mM). Glutathione-depleted hepatocytes show a higher increase than controls in both low-level chemiluminescence and alkane formation upon supplementation with 4-hydroxynonenal. The effects on both parameters are diminished by vitamin E pretreatment of rats and are absent under anaerobiosis. At variance with chemiluminescence and alkane formation, 4-hydroxynonenal does not elicit a concomitant increase in malonaldehyde or diene-conjugate formation. Addition of 4-hydroxynonenal to a suspension of hepatocytes causes a rapid loss of cellular glutathione in the form of a glutathione conjugate with the alkenal as observed with high-pressure liquid-chromatographic analysis. The reaction between glutathione and 4-hydroxynonenal proceeds also spontaneously in vitro at 1:1 stoichiometry. The cellular effects of 4-hydroxynonenal evaluated by low-level chemiluminescence and alkane formation are independent of the formation of a glutathione conjugate and seem to rely on the remaining not-bound 4-hydroxynonenal. The sensitivity of 4-hydroxynonenal-enhanced chemiluminescence and alkane formation to free-radical quenchers suggests the participation of a free-radical propagation process. PMID:6688523

Cadenas, E; Müller, A; Brigelius, R; Esterbauer, H; Sies, H

1983-01-01

197

Solution mixing and the emission of light in flow-cells for chemiluminescence detection.  

PubMed

Constructing flow-through reactors for chemiluminescence detection by machining channels into polymer disks has enabled the exploration of new configurations and materials that can improve signal intensity beyond that attainable with the traditional coiled-tubing design. Several approaches to merge reactant solutions were examined: an intersection, chamber or deeper well in the centre of a serpentine configuration flow-cell (directly in front of a photomultiplier tube), or a confluence point outside the detection zone. For several analytically useful, rapid chemiluminescence reactions, the single-inlet flow-cell with external Y-piece was most suitable, but for others (such as KMnO(4)/Mn(II) with morphine, and [Ir(f-ppy)(2)BPS](-) with fluoroquinolones) the dual-inlet configuration provided greater signals. The introduction of central mixing zones with larger widths than the channel reduced the chemiluminescence response. The reversing turns of a serpentine channel promote efficient mixing and greater chemiluminescence intensities than a spiral channel, but increasing the sharpness of the turns created areas of poor solution flow and decreased the chemiluminescence response. Teflon disks impregnated with glass microspheres increased the chemiluminescence signals by 13%-17%, due to the greater reflection of stray light towards the photodetector. PMID:21127794

Terry, Jessica M; Zammit, Elizabeth M; Slezak, Teo; Barnett, Neil W; Olson, Don C; Wolcott, Duane K; Edwards, Donna L; Francis, Paul S

2011-03-01

198

Role of background observed in aptasensor with chemiluminescence detection.  

PubMed

One-step chemiluminescent aptasensor was developed using chemically initiated electron exchange luminescence (CIEEL) between high-energy intermediate formed from 1,1'-oxalyldiimidazole chemiluminescence (ODI-CL) reaction and G-quadruplex (ochratoxin A (OTA)-bound aptamer conjugated with TEX615) generated. The sensitivity of chemiluminescent aptasensor, optimized with various variables (e.g., property of microfibers fabricated with 3,4,9,10-perylenetetracarboxylic dimide, determination of fluorescent dye labeled with aptamer, physical properties of buffer solution), was dependent on the background (concentration of high-energy intermediate) generated in ODI-CL reaction. The limit of detection (LOD=background+3×standard deviation, 0.5 nM) of ODI-CL aptasensor with lower background was lower than that (3.7 nM) with 20 times higher background. Also, the ratio of signal to background (S/B) of ODI-CL aptasensor with low background was about 5-fold higher than that with high background. The sensitivities of ODI-CL aptasensors, with low as well as high background, capable of accurately and precisely quantifying OTA within 10 min, were better than those of fluorescent aptasensors and as good as those of highly sensitive but time-consuming competitive enzyme-linked immune-sorbent assays (ELISAs) using expensive antibody produced with the sacrifice of small animals. PMID:24148468

Park, Lucienne; Kim, Julie; Lee, Ji Hoon

2013-11-15

199

Lophine derivatives as activators in peroxyoxalate chemiluminescence.  

PubMed

Lophine and four of its derivatives were used as activators (ACTs) of the chemiluminescent peroxyoxalate (PO) reaction of bis(2,4,6-trichlorophenyl)oxalate with H2O2, catalysed by imidazole. Kinetic emission assays have shown that with the tested compounds the reaction mechanism, regarding the formation of the high energy intermediate (HEI) of the PO reaction, occurs as previously seen for commonly used ACTs. A bimolecular interaction of the compounds with the HEI leads to chemiexcitation through the chemically initiated electron exchange luminescence (CIEEL) mechanism, as confirmed by a linear free-energy correlation between the relative catalytic rate constants and the oxidation potentials of the compounds. The yields of excited state formation and light emission, in the range of 10(-2)-10(-3) E mol(-1), are comparable to the ones seen with commonly used ACTs. A Hammett plot with ? = -0.90 indicates the buildup of a partial positive charge on the transition step of the catalytic process, consistent with the formation of a radical cation of the ACT, being an additional validation of the CIEEL mechanism in this system. PMID:25373732

Alves, J; Boaro, A; da Silva, J S; Ferreira, T L; Keslarek, V B; Cabral, C A; Orfão, R B; Ciscato, L F M L; Bartoloni, F H

2015-02-01

200

[Influence of nonsteroidal anti-inflammatory drugs on chemiluminescence of polymorphonuclear leukocytes in patients with intolerance of these drugs].  

PubMed

We have studied the intensity of barium sulfate stimulated luminol- and lucigenin-dependent chemiluminescence (SLCHL and SLCCHL) in polymorphonuclear leukocytes (PML) after pre-incubation of PML suspension with sodium salicylate, sodium metamizole, or sodium diclofenac at various concentrations in healthy donors and patients with intolerance to aspirin, and/or sodium metamizole, and/or sodium diclofenac. No significant differences of SLCHL and SLCCHL indicators in PML isolated from healthy donors and patients with intolerance to these drugs have been found, which indirectly indicates the absence of any specific features in the oxidative metabolism of PML enzymes under the influence of indicated NSAIDs in patients intolerant of these drugs as compared to donors. PMID:25033569

2014-01-01

201

Light Stick Chemistry: Bioluminescence and Chemiluminescence (title provided or enhanced by cataloger)  

NSDL National Science Digital Library

This activity will offer students an introduction to chemiluminescence and bioluminescence, an opportunity to observe the effect of temperature on reaction, and an activity that integrates art and science. Students explore how the temperature of the chemicals that combine affects a chemiluminescent reaction. They will also learn that since solar radiation does not reach the ocean depths, the bottom of the deep ocean remains largely in complete darkness. However, certain animals in this extreme environment can generate bioluminescent light to communicate with each other and even to lure prey.

Dispezio, Michael

202

Firefly chemiluminescence and bioluminescence: efficient generation of excited states.  

PubMed

Firefly luciferase catalyzes a light-emitting reaction in which an excited-state product is formed. Both experimental and theoretical methodologies are used to study this system, and the reactions catalyzed by luciferase are relatively well characterized. However, the mechanism by which an excited-state product is formed is still unknown. This Minireview deals with the current understanding of firefly bioluminescence and chemiluminescence. Thermal decomposition of simple 1,2-dioxetanes is also discussed, due to their role in formation of the excited-state bioluminophore. PMID:22532490

Pinto da Silva, Luís; Esteves da Silva, Joaquim C G

2012-06-18

203

Speciation of As(III)/As(V) in water samples by a magnetic solid phase extraction based on Fe?O?/Mg-Al layered double hydroxide nano-hybrid followed by chemiluminescence detection.  

PubMed

A novel magnetic solid phase extraction method was developed for the speciation of As(III)/As(V) in aqueous solutions utilizing Fe3O4-doped Mg-Al layered double hydroxide (LDH) as a nano-sorbent. The method is based on the separation and pre-concentration of As(V) by Fe3O4/Mg-Al LDH nano-hybrid prior to determination by a chemiluminescence (CL) technique. The CL route involves the oxidation of luminol by vanadomolybdoarsenate heteropoly acid in a basic media. Since the existing cations cannot be adsorbed by positively charged layers of the LDH and other potentially interferent anions had no considerable effect on the CL reaction, it provides a very selective and sensitive determination approach for As(V). The determination of total arsenic and hence indirectly As(III) involve the pre-oxidation of As(III) to As(V) by a mixture of hydrogen peroxide and potassium hydroxide. Several factors affecting the extraction and determination of the analyte were investigated and optimized. Under optimum conditions, the calibration graph was linear in the range of 5.0-5000 ng L(-1). The limit of detection and enrichment factor was 2.0 ng L(-1) and 80, respectively. The method was validated by the analysis of a standard reference material (NIST SRM 1643e), and successfully applied to the speciation of arsenic in several water samples with recoveries in the range of 93.3-106.7% for the spiked samples. PMID:25059142

Abdolmohammad-Zadeh, Hossein; Talleb, Zeynab

2014-10-01

204

Flame Chemiluminescence Rate Constants for Quantitative Microgravity Combustion Diagnostics  

NASA Technical Reports Server (NTRS)

Absolute excited state concentrations of OH(A), CH(A), and C2(d) were determined in three low pressure premixed methane-air flames. Two dimensional images of chemiluminescence from these states were recorded by a filtered CCD camera, processed by Abel inversion, and calibrated against Rayleigh scattering, Using a previously validated 1-D flame model with known chemistry and excited state quenching rate constants, rate constants are extracted for the reactions CH + O2 (goes to) OH(A) + CO and C2H + O (goes to) CH(A) + CO at flame temperatures. Variations of flame emission intensities with stoichiometry agree well with model predictions.

Luque, Jorge; Smith, Gregory P.; Jeffries, Jay B.; Crosley, David R.; Weiland, Karen (Technical Monitor)

2001-01-01

205

Storable, thermally activated, near-infrared chemiluminescent dyes and dye-stained microparticles for optical imaging  

PubMed Central

Optical molecular imaging employs relatively harmless, low-energy light and technically straightforward instrumentation. Self-illuminating, chemiluminescent systems are especially attractive since they have inherently high signal contrast due to the lack of background emission. Currently, chemiluminescence imaging involves short-lived molecular species that are not stored but instead generated in situ, and they typically emit visible light, which does not penetrate far through heterogeneous biological media. Here, we describe a new paradigm for optical molecular imaging using squaraine rotaxane endoperoxides (SREPs), interlocked fluorescent and chemiluminescent dye molecules that have a squaraine chromophore encapsulated inside a macrocycle endoperoxide. SREPs can be stored indefinitely at temperatures below ?20 °C, but upon warming to body temperature they undergo a unimolecular chemical reaction and emit near infrared light that can pass through a living mouse. Dye-stained microparticles are easily prepared for in vivo near-infrared optical imaging using commercial imaging stations. PMID:21107365

Baumes, Jeffrey M.; Gassensmith, Jeremiah J.; Giblin, Jay; Lee, Jung-Jae; White, Alexander G.; Culligan, William J.; Leevy, W. Matthew; Kuno, Masaru; Smith, Bradley D.

2011-01-01

206

Sorption of platinum on immobilized microorganisms for its on-line preconcentration and chemiluminescent determination in water samples.  

PubMed

Fungi of the type Aspergillus sp. were immobilized on a cellulosic resin and used as a biosorbent for the on-line preconcentration and separation of Pt(IV) ions prior to their chemiluminescent determination via flow injection analysis. Biosorption and elution conditions were optimized, and the results compared to biosorbents based on the use of Chlorella vulgaris algae and Saccharomyces cerevisiae yeast in terms of preconcentration and selective retention of Pt(IV). The immobilized fungi presented here have a high potential for use in platinum biosorption. The procedure exhibits the currently lowest limit of detection (0.02 ng mL(-1) of Pt) and very high selectivity. The procedure was applied to the determination of Pt(IV) in river water, road run-off, and wastewater samples.FigureSchematic diagram of flow injection manifold for on-line preconcentration/separation of Pt(IV) on immobilized fungi followed by its luminol-based chemiluminescent determination. The CL-FIA manifold was applied to the determination of platinum in river water, road run-off, and wastewater samples. PMID:22347728

Malejko, Julita; Szyga?owicz, Marzena; Godlewska-?y?kiewicz, Beata; Koj?o, Anatol

2012-02-01

207

Applications of Nanomaterials in Electrogenerated Chemiluminescence Biosensors  

PubMed Central

Electrogenerated chemiluminescence (also called electrochemiluminescence and abbreviated ECL) involves the generation of species at electrode surfaces that then undergo electron-transfer reactions to form excited states that emit light. ECL biosensor, combining advantages offered by the selectivity of the biological recognition elements and the sensitivity of ECL technique, is a powerful device for ultrasensitive biomolecule detection and quantification. Nanomaterials are of considerable interest in the biosensor field owing to their unique physical and chemical properties, which have led to novel biosensors that have exhibited high sensitivity and stability. Nanomaterials including nanoparticles and nanotubes, prepared from metals, semiconductor, carbon or polymeric species, have been widely investigated for their ability to enhance the efficiencies of ECL biosensors, such as taking as modification electrode materials, or as carrier of ECL labels and ECL-emitting species. Particularly useful application of nanomaterials in ECL biosensors with emphasis on the years 2004-2008 is reviewed. Remarks on application of nanomaterials in ECL biosensors are also surveyed. PMID:22389624

Qi, Honglan; Peng, Yage; Gao, Qiang; Zhang, Chengxiao

2009-01-01

208

Reactivity of chemiluminescence reagents toward oxidants  

SciTech Connect

Hydroperoxyl radical (HO{sub 2}) and its conjugate base, superoxide radical (O{sub 2}{sup -}) are important chemical intermediates. O{sub 2}{sup -} is ubiquitous in aerobic cells and has been implicated in arthritis, cancer, and aging, among other biological processes. HO{sub 2} plays a central role in atmospheric photochemistry. Because of their short lifetime, there are few reliable analytical methods for the detection of HO{sub 2}/O{sub 2}{sup -}. In a number of recent publications, the chemiluminescence reagent CLA has been exploited as a specific marker for these species. Using UV/visible spectroscopy, we have investigated the stability of CLA and several of its analogs in the presence of oxidants, including O{sub 2}, H{sub 2}O{sub 2}, OH and HO{sub 2}/O{sub 2}{sup -}. The spectral changes observed suggest that the reaction with HO{sub 2}/O{sub 2}{sup -} is rather nonspecific.

Khevelev, M.; Weinstein-Loyd, J.B. [State Univ. of New York, Old Westbury, NY (United States)

1996-10-01

209

HALOCARBON INTERFERENCES IN CHEMILUMINESCENT MEASUREMENTS OF NOX  

EPA Science Inventory

Anomalous NOx responses were observed when halocarbons were irradiated in the presence of oxides of nitrogen. Interferences to chemiluminescent NOx monitor using heated carbon converter were studied for phosgene, tri-chloroacetyl chloride, chloroform, chlorine, and hydrochloric a...

210

Long-lived chemiluminescence in cigarette smoke  

Microsoft Academic Search

Cigarette smoke contains high concentrations of unstable molecules that react with oxygen to produce chemiluminescence. The chemiluminescent activity concentrated in the aerosol phase that can be absorbed on glass-fiber filters and extracted into organic solvents. Cigarette smoke in N,N-dimethylformamide produces a long-lasting luminescence visible to the dark-adapted eye. We have demonstrated the oxygen dependence and have measured the kinetics, activation

H. H. Seliger; W. H. Biggley; J. P. Hamman

1974-01-01

211

Human saliva-based quantitative monitoring of clarithromycin by flow injection chemiluminescence analysis: a pharmacokinetic study.  

PubMed

Human saliva quantitative monitoring of clarithromycin (CLA) by chemiluminescence (CL) with flow injection analysis was proposed for the first time, which was based on the quenching effect of CLA on luminol-bovine serum albumin (BSA) CL system with a linear range from 7.5 × 10(-4) to 2.0 ng/ml. This proposed approach, offering a maximum sample throughput of 100 h(-1), was successfully applied to the quantitative monitoring of CLA levels in human saliva during 24 h after a single oral dose of 250 mg intake, with recoveries of 95.2 ? 109.0% and relative standard deviations lower than 6.5 % (N = 7). Results showed that CLA reached maximum concentration of 2.28 ± 0.02 ?g/ml at approximately 3 h, and the total elimination ratio was 99.6 % in 24 h. The pharmacokinetic parameters including absorption rate constant (0.058 ± 0.006 h(-1)), elimination rate constant (0.149 ± 0.009 h(-1)) and elimination half-life time (4.66 ± 0.08 h) were obtained. A comparison of human saliva and urine monitoring was also given. The mechanism study of BSA-CLA interaction revealed the binding of CLA to BSA is an entropy driven and spontaneous process through hydrophobic interaction, with binding constant K BSA-CLA of 4.78 × 10(6) l/mol and the number of binding sites n of 0.82 by flow injection-chemiluminescence model. Molecular docking analysis further showed CLA might be in subdomain IIA of BSA, with K BSA-CLA of 6.82 × 10(5) l/mol and ?G of -33.28 kJ/mol. PMID:24166104

Tan, Xijuan; Song, Zhenghua

2014-02-01

212

Application of chemiluminescence with FCLA in photodynamic therapy  

NASA Astrophysics Data System (ADS)

In photodynamic therapy (PDT), a target tissue with pre-administered photosensitizer is exposed to laser light. The photochemical process produces reaction oxygen species (ROS), such as singlet oxygen and superoxide, and leads to ultimate cell death. A direct monitoring of ROS production during PDT, thus, may provide important information in both basic science and clinical practice. A cypridina luciferin analogue (FCLA) is a chemiluminescence (CL) probe that selectively detects singlet oxygen and superoxide. In this study, FCLA was used as an optical reporter of ROS produced by photosensitization reaction of Photofrin in Hanks solution and the CL was measured by a photomultiplier system operated at single photon counting mode. By varying the amount of PDT dosage (photosensitizer dose, light irradiation fluence rate) and the amount of FCLA, the intensity of CL were investigated. The results showed the FCLA concentration affects the ratio of the signal to background CL. The decay time of the photosensitized CL was approximately 10 sec., after the excitation source was turned off. In addition, the intensity of the CL-FCLA increased with increasing concentration of Photofrin and fluence rate. The work supported the potential application of FCLA-chemiluminescence probe as a dosimetric tool for PDT.

Qin, Yanfang; Xing, Da; Zhong, Xueyun; Zhou, Jing; Luo, Shiming; Chen, Qun

2005-01-01

213

Mechanistic insight into the chemiluminescent decomposition of firefly dioxetanone.  

PubMed

The peroxide decomposition that generates the excited-state carbonyl compound is the key step in most organic chemiluminescence, and chemically initiated electron exchange luminescence (CIEEL) has been widely accepted for decades as the general mechanism for this decomposition. The firefly dioxetanone, which is a peroxide, is the intermediate in firefly bioluminescence, and its decomposition is the most important step leading to the emission of visible light by a firefly. However, the firefly dioxetanone decomposition mechanism has never been explored at a reliable theoretical level, because the decomposition process includes biradical, charge-transfer (CT) and several nearly degenerate states. Herein, we have investigated the thermolysis of firefly dioxetanone in its neutral (FDOH) and anionic (FDO(-)) forms using second-order multiconfigurational perturbation theories in combination with the ground-state intrinsic reaction coordinate calculated via the combined hybrid functional with Coulomb attenuated exchange-correlation, and considered the solvent effect on the ground-state reaction path using the combined hybrid functional with Coulomb attenuated exchange-correlation. The calculated results indicate that the chemiluminescent decomposition of FDOH or FDO(-) does not take place via the CIEEL mechanism. An entropic trap was found to lead to an excited-state carbonyl compound for FDOH, and a gradually reversible CT initiated luminescence (GRCTIL) was proposed as a new mechanism for the decomposition of FDO(-). PMID:22720977

Yue, Ling; Liu, Ya-Jun; Fang, Wei-Hai

2012-07-18

214

Selective Detection of Neurotransmitters by Fluorescence and Chemiluminescence Imaging  

SciTech Connect

In recent years, luminescence imaging has been widely employed in neurochemical analysis. It has a number of advantages for the study of neuronal and other biological cells: (1) a particular molecular species or cellular constituent can be selectively visualized in the presence of a large excess of other species in a heterogeneous environment; (2) low concentration detection limits can be achieved because of the inherent sensitivity associated with fluorescence and chemiluminescence; (3) low excitation intensities can be used so that long-term observation can be realized while the viability of the specimen is preserved; and (4) excellent spatial resolution can be obtained with the light microscope so subcellular compartments can be identified. With good sensitivity, temporal and spatial resolution, the flux of ions and molecules and the distribution and dynamics of intracellular species can be measured in real time with specific luminescence probes, substrates, or with native fluorescence. A noninvasive detection scheme based on glutamate dehydrogenase (GDH) enzymatic assay combined with microscopy was developed to measure the glutamate release in cultured cells from the central nervous system (CNS). The enzyme reaction is very specific and sensitive. The detection limit with CCD imaging is down to {micro}M levels of glutamate with reasonable response time. They also found that chemiluminescence associated with the ATP-dependent reaction between luciferase and luciferin can be used to image ATP at levels down to 10 nM in the millisecond time scale. Similar imaging experiments should be feasible in a broad spectrum of biological systems.

Ziqiang Wang; Edward S. Yeung

2001-08-06

215

STUDY OF INTERFERENCES IN OZONE UV AND CHEMILUMINESCENCE MONITORS  

EPA Science Inventory

A study was conducted to examine interferences and other measurement anomalies in chemiluminescence and ultraviolet ozone monitors. revious results had shown that there was a positive deviation in the chemiluminescence monitors and no direct interference with ultraviolet monitors...

216

Quantitative assessment of human neutrophil chemiluminescence induced by opsonized Escherichia coli K-12.  

PubMed

The interaction of opsonized E. coli K-12 bacteria and polymorphonuclear leukocytes (PMN) was quantified, using luminol-enhanced chemiluminescence (CL) as a parameter of PMN stimulation. On a double-logarithmic scale light emission depended on the opsonin concentration used during pre-opsonisation. The most potent CL-inducing agent was fresh human serum, and its stimulatory activity depended on an intact complement (C) system. Both inactivation of C by heating or blocking the classical C pathway with EGTD decreased the CL-inducing potency by a factor of 8 to 16. Hypogammaglobulinemic heated serum mediated little CL. IgG for intravenous use mediated CL generation, but reduction/alkylation and sulphitolysis reduced the stimulatory power. Evidence is presented that the anti-K-12 antibodies within commercial IgG and IgM used for substitution do not improve the stimulatory power of IgG-deficient, IgM- and C-sufficient serum, unless very high Ig concentrations are substituted. PMID:2648712

Jungi, T W; Schmid, A; Morell, A; Spaeth, P J; Peterhans, E

1989-01-01

217

Chemiluminescence response induced by mesenteric ischaemia/reperfusion: effect of antioxidative compounds ex vivo  

PubMed Central

Ischaemia and reperfusion (I/R) play an important role in human pathophysiology as they occur in many clinical conditions and are associated with high morbidity and mortality. Interruption of blood supply rapidly damages metabolically active tissues. Restoration of blood flow after a period of ischaemia may further worsen cell injury due to an increased formation of free radicals. The aim of our work was to assess macroscopically the extent of intestinal pathological changes caused by mesenteric I/R, and to study free radical production by luminol enhanced chemiluminescence (CL) of ileal samples. In further experiments, the antioxidative activity of the drugs tested was evaluated spectrophotometrically by the use of the DPPH radical. We studied the potential protective ex vivo effect of the plant origin compound arbutin as well as of the pyridoindole stobadine and its derivative SMe1EC2. I/R induced pronounced haemorrhagic intestinal injury accompanied by increase of myeloperoxidase (MPO) and N-acetyl-?-D-glucosaminidase (NAGA) activity. Compared to sham operated (control) rats, there was only a slight increase of CL response after I/R, probably in association with neutrophil increase, indicated by enhanced MPO activity. All compounds significantly reduced the peak values of CL responses of the ileal samples ex vivo, thus reducing the I/R induced increase of free radical production. The antioxidants studied showed a similar inhibitory effect on the CL response influenced by mesenteric I/R. If proved in vivo, these compounds would represent potentially useful therapeutic antioxidants. PMID:21217883

Nosál'ová, Viera; Sotníková, Ružena; Drábiková, Katarína; Fialová, Silvia; Koš?álová, Daniela; Banášová, Silvia; Navarová, Jana

2010-01-01

218

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

NASA Technical Reports Server (NTRS)

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)).

Bairai, Solomon T.; Stedman, Donald H.

1992-01-01

219

CuO nanosheets-enhanced flow-injection chemiluminescence system for determination of vancomycin in water, pharmaceutical and human serum  

NASA Astrophysics Data System (ADS)

A novel, rapid and sensitive CuO nanosheets (NSs) amplified flow-injection chemiluminescence (CL) system, luminol-H2O2-CuO nanosheets, was developed for determination of the vancomycin hydrochloride for the first time. It was found that vancomycin could efficiently inhibit the CL intensity of luminol-H2O2-CuO nanosheets system in alkaline medium. Under the optimum conditions, the inhibited CL intensity was linearly proportional to the concentration of vancomycin over the ranges of 0.5-18.0 and 18.0-40.0 mg L-1, with a detection limit (3?) of 0.1 mg L-1. The precision was calculated by analyzing samples containing 5.0 mg L-1 vancomycin (n = 11) and the relative standard deviation (RSD) was 2.8%. Also, a high injection throughput of 120 sample h-1 was obtained. The CuO nanosheets were synthesized by a sonochemical method. Also, X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses were employed to characterize the CuO nanosheets. The method was successfully employed to determine vancomycin hydrochloride in environmental water samples, pharmaceutical formulation and spiked human serum.

Khataee, A. R.; Hasanzadeh, A.; Iranifam, M.; Fathinia, M.; Hanifehpour, Y.; Joo, S. W.

2014-03-01

220

Highly sensitive flow-injection chemiluminescence determination of pyrogallol compounds  

NASA Astrophysics Data System (ADS)

A highly sensitive flow-injection chemiluminescent method for the direct determination of pyrogallol compounds has been developed. Proposed method is based on the enhanced effect of pyrogallol compounds on the chemiluminescence signals of KMnO 4-H 2O 2 system in slightly alkaline medium. Three important pyrogallol compounds, pyrogallic acid, gallic acid and tannic acid, have been detected by this method, and the possible mechanism of the CL reaction is also discussed. The proposed method is simple, convenient, rapid (60 samples h -1), and sensitive, has a linear range of 8 × 10 -10 mol L -1 to 1 × 10 -5 mol L -1, for pyrogallic acid, with a detection limit of 6 × 10 -11 mol L -1, 4 × 10 -8 mol L -1 to 5 × 10 -3 mol L -1 for gallic acid with a detection limit of 9 × 10 -10 mol L -1, and 8 × 10 -8 mol L -1 to 5 × 10 -2 mol L -1 for tannic acid, with a detection limit of 2 × 10 -9 mol L -1, respectively. The relative standard deviation (RSD, n = 15) was 0.8, 1.1 and 1.3% for 5 × 10 -6 mol L -1 pyrogallic acid, gallic acid and tannic acid, respectively. The proposed method was successfully applied to the determination of pyrogallol compounds in tea and coffee samples.

Kanwal, Shamsa; Fu, Xiaohong; Su, Xingguang

2009-12-01

221

Chemiluminescence assay for the detection of biological warfare agents  

SciTech Connect

A chemiluminescent homogeneous immunoassay and a hand-size multiassay reader are described that could be used for detecting biological materials. The special feature of the assay is that it employs two different antibodies that each bind to a unique epitope on the same antigen. Each group of epitope-specific antibodies has linked to it an enzyme of a proximal-enzyme pair. One enzyme of the pair utilizes a substrate in high concentration to produce a second substrate required by the second enzyme. This new substrate enables the second enzyme to function. The reaction of the second enzyme is configured to produce light. This chemiluminescence is detected with a charge-coupled device (CCD) camera. The proximal pair enzymes must be in close proximity to one another to allow the second enzyme to react with the product of the first enzyme. This only occurs when the enzyme-linked antibodies are attached to the antigen, whether antigen is a single protein with multiple epitopes or the surface of a cell with a variety of different antigens. As a result of their juxtaposition, the enzymes produce light only in the presence of the biological material. A brief description is given as to how this assay could be utilized in a personal bio-agent detector system.

Langry, K; Horn, J

1999-11-05

222

Chemiluminescence Study of the Autoxidation of cis-1,4-Polyisoprene  

NASA Technical Reports Server (NTRS)

The free-radical mechanism for the autoxidation of cis-1,4-polyisoprene (natural rubber or its synthetic counterpart) has been investigated extensively. An important feature of this mechanism, and indeed also of the autoxidation of hydrocarbons generally, is that it is a chain process propagated by alkyl and peroxy radicals and terminated through bimolecular reactions involving these same radicals. In the usual oxidation situation, that is, at all oxygen pressures greater than a few torr, the alkyl radicals are rapidly converted to peroxy radicals, and the termination step proceeds almost exclusively through the latter radicals. The bimolecular decay of the peroxy radicals is accompanied by a weak emission of light or chemiluminescence. Kinetic evidence is consistent with an electronically excited ketone produced in the termination reaction as the source of the emission. The first observation of chemiluminescence from the oxidative degradation of polymers was reported by Ashby, who dealt mainly with polypropylene but made passing mention of several other polymers. Subsequently, a number of papers have appeared dealing with oxidative chemiluminescence from a variety of polymers. In this paper we report the first detailed study of the chemiluminescence emitted in the autoxidation of cis-1,4-polyisoprene. The chemiluminescence technique is extremely sensitive and can follow rates of oxidation that are too slow to be measured conveniently by other means. This work thus offered the potential of throwing new light on the autoxidation of cis-1,4-polyisoprene, especially in the very early stages or under ambient conditions where conventional spectroscopic procedures are rather insensitive.

Mendenhall, G. David; Nathan, Richard A.; Golub, Morton A.

1978-01-01

223

Experimental and numerical study of chemiluminescent species in low-pressure flames  

NASA Astrophysics Data System (ADS)

Chemiluminescence has been observed since the beginning of spectroscopy, nevertheless, important facts still remain unknown. Especially, reaction pathways leading to chemiluminescent species such as OH?, CH?, C2^{*}, and CO2^{*} are still under debate and cannot be modeled with standard codes for flame simulation. In several cases, even the source species of spectral features observed in flames are unknown. In recent years, there has been renewed interest in chemiluminescence, since it has been shown that this radiation can be used to determine flame parameters such as stoichiometry and heat release under some conditions. In this work, we present a reaction mechanism which predicts the OH?, CH? (in A- and B-state), and C2^{*} emission strength in lean to fuel-rich stoichiometries. Measurements have been performed in a set of low-pressure flames which have already been well characterized by other methods. The flame front is resolved in these measurements, which allows a comparison of shape and position of the observed chemiluminescence with the respective simulated concentrations. To study the effects of varying fuels, methane flame diluted in hydrogen are measured as well. The 14 investigated premixed methane-oxygen-argon and methane-hydrogen-oxygen-argon flames span a wide parameter field of fuel stoichiometry ( ?=0.5 to 1.6) and hydrogen content (H2 vol%=0 to 50). The relative comparison of measured and simulated excited species concentrations shows good agreement. The detailed and reliable modeling for several chemiluminescent species permits correlating heat release with all of these emissions under a large set of flame conditions. It appears from the present study that the normally used product of formaldehyde and OH concentration may be less well suited for such a prediction in the flames under investigation.

Kathrotia, T.; Riedel, U.; Seipel, A.; Moshammer, K.; Brockhinke, A.

2012-06-01

224

OPTIMIZED CHEMILUMINESCENCE SYSTEM FOR MEASURING ATMOSPHERIC AMMONIA  

EPA Science Inventory

The optimization and testing of a continuous measurement system for analyzing atmospheric ammonia concentrations (0 to 10 ppb) is described. The measurement system combines an ultra-sensitive chemiluminescence nitric oxide detector, with a thermal converter for NH3 to nitric oxid...

225

Illustrating Chemiluminescence with Siloxene Indicator.  

ERIC Educational Resources Information Center

Discusses the nature of light-producing reactions and provides a procedure for demonstrating chemical luminescence using siloxene indicator. Indicates source of this chemical and safety precautions. (SK)

Hoff, Ray

1981-01-01

226

Chemiluminescence determination of folic acid by a flow injection analysis assembly.  

PubMed

A flow injection (FI) method is reported for the determination of folic acid by chemiluminescence method. This method is based on the reaction of folic acid with Ru(bipy)(3)(2+) and Ce(IV) to produce chemiluminescence. The calibration curve was linear over the range of 2.5×10(-5)-3.1×10(-7) mol/L with a detection limit of 2.3×10(-8) mol/L (S/N=3). The relative standard deviation of 1.0×10(-6) mol/L folic acid was found 3.5% (n=11). The influences of potential interfering substances were studied. The recovery was higher than 95.3%. The method was accurate, sensitive, and effective for assay of folic acid. This CL method was successfully applied to the determination of folic acid in pharmaceutical preparations. The mechanism of CL reaction was also studied. PMID:23334502

Wabaidur, Saikh Mohammad; Alam, Seikh Mafiz; Lee, Sang Hak; Alothman, Zeid Abdullah; Eldesoky, Gaber E

2013-03-15

227

Egg-Citing! Isolation of Protoporphyrin IX from Brown Eggshells and Its Detection by Optical Spectroscopy and Chemiluminescence  

ERIC Educational Resources Information Center

A simple and cost-effective laboratory experiment is described that extracts protoporphyrin IX from brown eggshells. The porphyrin is characterized by UV-vis and fluorescence spectroscopy. A chemiluminescence reaction (peroxyoxalate ester fragmentation) is performed that emits light in the UV region. When the porphyrin extract is added as a fluor…

Dean, Michelle L.; Miller, Tyson A.; Bruckner, Christian

2011-01-01

228

Analytical applications of tris(2,2?-bipyridyl)ruthenium(III) as a chemiluminescent reagent  

Microsoft Academic Search

This paper reviews the analytical applications of the chemiluminescence reactions involving tris(2,2?-bipyridyl)ruthenium(III), from the earliest paper in 1978 to mid 1998. After an introduction which briefly describes historical perspectives, spectroscopic and mechanistic considerations, the review is divided into two major sections. The first section discusses the methods of generation of tris(2,2?-bipyridyl)ruthenium(III) reagent, including chemical\\/photochemical, electrochemical and in situ electrochemiluminescence methods.

Richard D. Gerardi; Neil W. Barnett; Simon W. Lewis

1999-01-01

229

A study on the selection of chemiluminescence system for the flow injection determination of the total polyphenol index of plant-derived foods.  

PubMed

Different chemiluminescence systems based on luminol, permanganate, manganese(IV) and cerium(IV) reagents were compared regarding their sensitivity and selectivity to determine plant polyphenols. Among the seventeen systems tested, Mn(IV)-formaldehyde-hexametaphosphate was considered to be the most suitable for polyphenols detection. The developed flow injection method (FI-CL) based on enhancing effect of polyphenols on Mn(IV) chemiluminescence is characterised by low detection limit of gallic acid (0.02?gL(-1)) and high precision (RSD=1.7%). The calibration graph was linear from 0.1 to 100?gL(-1). The selectivity studies revealed that the FI-CL method ensures accurate determination of the total polyphenols content in food samples. The method was successfully applied to analysis of a variety of plant-derived foods (wine, tea, cereal coffee, fruit and vegetable juices, herbs and spices). The proposed method is superior to conventional spectrophotometric assays due to its higher sample throughput (195samplesh(-1)), simplicity, sensitivity and, above all, higher selectivity. PMID:25624221

Nalewajko-Sieliwoniuk, Edyta; Malejko, Julita; ?wi?czkowska, Marta; Kowalewska, Agata

2015-06-01

230

Internal detection of surface plasmon coupled chemiluminescence during chlorination of potassium thin films  

NASA Astrophysics Data System (ADS)

The interaction of chlorine with potassium surfaces is a prototype reaction with a strong non-adiabatic energy transfer leading to exoemission and chemiluminescence. Thin film K/Ag/p-Si(111) Schottky diodes with 8 nm potassium on a 5-200 nm thick Ag layer are used as 2?-photodetectors for the chemiluminescence during chlorination of the K film at 110 K. The observed photocurrent shows a sharp maximum for small exposures and decreases gradually with the increasing chloride layer. The time dependence can be explained by the reaction kinetics, which is governed initially by second-order adsorption processes followed by an electric field-assisted diffusion. The detector current corresponds to a yield of a few percent of elementary charge per reacting chlorine molecule and is orders of magnitude larger than for external detection. The photoyield can be enhanced by increasing the Ag film thickness. For Ag films of 30 and 50 nm, the yield exhibits a maximum indicating surface plasmon coupled chemiluminescence. Surface plasmon polaritons in the Ag layer are excited by the reaction and decay radiatively into Si leading to the observed currents. A model calculation for the reverse process in attenuated total reflection is applied to explain the observed current yield maxima.

Becker, Felix; Krix, David; Hagemann, Ulrich; Nienhaus, Hermann

2013-01-01

231

Chemiluminescent Determination of Menadione Sodium Bisulfite  

Microsoft Academic Search

A chemiluminescence (CL) system for menadione sodium bisulfite (MSB) combined with a flow-injection system is presented in this paper. It is based on CL produced by the oxidation of bisulfite liberated from MSB by Ce(IV). The system responds linearly to MSB concentration in the range of 0.01 ? 10 ?g\\/mL with the detection limit (3?f) of 2 x 10 ?g\\/mL.

Yuming Huang; Zhiqiong Chen; Zhujun Zhang

1999-01-01

232

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

PubMed Central

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

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

2010-01-01

233

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

PubMed Central

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

2013-01-01

234

Disposable luminol copolymer-based biosensor for uric acid in urine.  

PubMed

A new electrochemiluminescent (ECL) disposable biosensor for uric acid was manufactured by immobilization in a double-layer design of luminol as a copolymer with 3,3',5,5'-tetramethylbenzidine (TMB) and the enzyme uricase in chitosan on gold screen-printed cells. The good mechanical and improved electroluminescent characteristics of the new copolymer poly(luminol-TMB) make it possible to determine uric acid by measuring the growing ECL emission with the analyte concentration. The combination of enzymatic selectivity with ECL sensitivity results in a disposable analytical device with a linear range for uric acid from 1.5×10(-6) to 1.0×10(-4) M, a limit of detection of 4.4×10(-7) M and a precision of 13.1% (1.0×10(-5) M, n=10) as relative standard deviation. Satisfactory results were obtained for uric acid determination in 24h-urine samples compared to a reference procedure. This uric acid biosensor can be used as a low-cost alternative to conventional methods. PMID:21839206

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

2011-09-30

235

Potassium permanganate-acridine yellow chemiluminescence system for the determination of fluvoxamine, isoniazid and ceftriaxone.  

PubMed

Based on the oxidation of acridine yellow by permanganate in basic medium, a new chemiluminescence system was developed for the sensitive determination of some important drugs. The remarkable inhibiting effect of fluvoxamine, ceftriaxone and isoniazid on this reaction was applied to their detection. A possible mechanism was proposed for this system based on chemiluminescence emission wavelengths and experimental observations. Under optimum conditions, calibration graphs were obtained for 1?×?10(-9) to 1?×?10(-6) ?mol/L of fluvoxamine; 2?×?10(-8) to 8?×?10(-6) ?mol/L of ceftriaxone and 5?×?10(-8) to 4?×?10(-5) ?mol/L of isoniazid. This proposed method was satisfactorily used in the determination of these drugs in pharmaceutical samples and human urine and serum. Copyright © 2014 John Wiley & Sons, Ltd. PMID:24753178

Abolhasani, Jafar; Hassanzadeh, Javad

2014-12-01

236

Luminescent oxygen channeling immunoassay: measurement of particle binding kinetics by chemiluminescence.  

PubMed

A method for monitoring formation of latex particle pairs by chemiluminescence is described. Molecular oxygen is excited by a photosensitizer and an antenna dye that are dissolved in one of the particles. 1 delta gO2 diffuses to the second particle and initiates a high quantum yield chemiluminescent reaction of an olefin that is dissolved in it. The efficiency of 1 delta gO2 transfer between particles is approximately 3.5%. The technique permits real-time measurement of particle binding kinetics. Second-order rate constants increase with the number of receptor binding sites on the particles and approach diffusion control. By using antibody-coated particles, a homogeneous immunoassay capable of detecting approximately 4 amol of thyroid-stimulating hormone in 12 min was demonstrated. Single molecules of analyte produce particle heterodimers that are detected even when no larger aggregates are formed. PMID:8202502

Ullman, E F; Kirakossian, H; Singh, S; Wu, Z P; Irvin, B R; Pease, J S; Switchenko, A C; Irvine, J D; Dafforn, A; Skold, C N

1994-06-01

237

Luminescent oxygen channeling immunoassay: measurement of particle binding kinetics by chemiluminescence.  

PubMed Central

A method for monitoring formation of latex particle pairs by chemiluminescence is described. Molecular oxygen is excited by a photosensitizer and an antenna dye that are dissolved in one of the particles. 1 delta gO2 diffuses to the second particle and initiates a high quantum yield chemiluminescent reaction of an olefin that is dissolved in it. The efficiency of 1 delta gO2 transfer between particles is approximately 3.5%. The technique permits real-time measurement of particle binding kinetics. Second-order rate constants increase with the number of receptor binding sites on the particles and approach diffusion control. By using antibody-coated particles, a homogeneous immunoassay capable of detecting approximately 4 amol of thyroid-stimulating hormone in 12 min was demonstrated. Single molecules of analyte produce particle heterodimers that are detected even when no larger aggregates are formed. PMID:8202502

Ullman, E F; Kirakossian, H; Singh, S; Wu, Z P; Irvin, B R; Pease, J S; Switchenko, A C; Irvine, J D; Dafforn, A; Skold, C N

1994-01-01

238

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

PubMed

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. PMID:24427941

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

2013-11-01

239

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

PubMed

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 ? -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

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

240

Ultrasensitive determination of diphacinone by flow injection chemiluminescence: application to quantification in biofluids and photodegradation monitoring in water samples.  

PubMed

An ultrasensitive, quick, and simple approach for the determination of pg levels of diphacinone (DPN) by flow injection chemiluminescence (CL) analysis is proposed for the first time. It is based on the quenching effect of DPN on the CL intensity from a luminol-bovine serum albumin (BSA) CL system, for which the CL intensity decrease was linearly proportional to the logarithm of DPN concentration in the range of 5.0 to 5000 pg/mL. The LOD for DPN determination was as low as 2.0 pg/mL (3? a), and the RSD values were less than 5.0%. One determination cycle that included sampling and washing could be performed in 0.5 min with a sample throughput of 120/h under the optimum experimental conditions. This proposed method was successfully applied to determining DPN in human gastric juice and serum samples with recoveries from 91.8 to 114.3%, and to continuous monitoring of the degradation of DPN in water samples exposed to sunlight during 43 h with a variation ratio of 99.99%. The possible interaction behavior of BSA-DPN is briefly discussed. PMID:25632450

Tan, Xijuan; Song, Zhenghua; Chen, Donghua; Lv, Airu

2014-01-01

241

The effect of low levels of dietary cobalt on the chemiluminescence response of polymorphonuclear leukocytes of goats.  

PubMed

Twenty ten-week-old newly weaned male Batinah goats were randomly assigned to a control (n=10) and a treated (n=10) group and were fed a diet containing 0.1mg/kg DM cobalt (Co). Goats in the treated group received bi-monthly subcutaneous injections of 2000 microg of hydroxycobalamin. The phagocytic function of the polymorphonuclear leukocytes (PMN) were tested using a luminol-dependent chemiluminescence assay with opsonized zymosan as the phagocytic target. One month after the onset of the experiment PMN from the control group exhibited a significantly (p<0.05) lower CL response, which continued for the second month. The results of the present study demonstrated that low levels of dietary cobalt leads to an early impairment of phagocytic function. This may at least in part, be an explanation as to why at the field level in Oman young goats fed diets containing low levels of Co appear to be more susceptible to infections. PMID:19679325

Johnson, Eugene H; Al-Habsi, Khalid; Al-Busaidy, Rashid; Khalaf, Samera Kasim

2010-02-01

242

Silver nanoparticle enhanced chemiluminescence method for the determination of nitrazepam.  

PubMed

We report on a simple and sensitive chemiluminescence (CL) method to determine nitrazepam. This method is based on the fact that rhodamine 6G (Rh6G) enhanced the weak CL emission of the reaction of hexacyanoferrate with nitrazepam, and that it was further enhanced by silver nanoparticles (AgNPs). The effects of the concentrations of K3Fe(CN)6, Rh6G, AgNPs and NaOH on the CL reaction were investigated. Under the optimum conditions, the CL intensity was proportional to the concentration of nitrazepam in the range from 1.0 nM to 10.0 ?M. The detection limit (3?) was at 0.1 nM. The relative standard deviation was 2.1% (at a 0.1 ?M concentration and for n = 11). The method was successfully applied to the determination of nitrazepam in Coca-Cola beverage, urine and plasma, and the recovery was 98 - 103%. We also considered the possible CL reaction mechanism. PMID:24717660

Han, Suqin; Li, Xia; Wei, Bei

2014-01-01

243

Differential effects of luminol, nickel, and arsenite on the rejoining of ultraviolet light and alkylation-induced DNA breaks  

SciTech Connect

When Chinese hamster ovary cells were treated with ultraviolet (UV) light or methyl methane-sulfonate (MMS), a large number of DNA strand breaks could be detected by alkaline elution. These strand breaks gradually disappeared if the treated cells were allowed to recover in a drug-free medium. The presence of nickel or arsenite during the recovery incubation retarded the disappearance of UV-induced strand breaks, whereas the disappearance of MMS-induced strand breaks was retarded by the presence of arsenite or of luminol, a new inhibit for poly(ADP-ribose) synthetase. Luminol, however, had no apparent effect on the repair of UV-induced DNA strand breaks, and nickel had no effect on the repair of MMS-induced DNA strand breaks. When UV- or MMS-treated cells were incubated in cytosine arabinofuranoside (AraC) plus hydroxyurea (HU), a large amount of low molecular weight DNA was detected by alkaline sucrose sedimentation. The molecular weight of these DNAs increased if the cells were further incubated in a drug-free medium. This rejoining of breaks in cells pretreated with UV plus AraC and HU was inhibited by nickel and by arsenite, but not by luminol. The rejoining of breaks in cells pretreated with MMS plus AraC and HU was inhibited by luminol and by arsenite, but not by nickel. These results suggest that different enzymes may be used in DNA resynthesis and/or ligation during the repairing of UV- and MMS-induced DNA strand breaks, and that nickel, luminol, and arsenite may have differential inhibitory effects on these enzymes. 29 refs., 4 figs., 1 tab.

Lee-Chen, S.F.; Yu, C.T.; Wu, D.R. [Institute of Zoology, Taipei (Taiwan, Province of China)] [and others

1994-12-31

244

[Detection of MRSA with antimicrobial susceptibility by using chemiluminescent assay].  

PubMed

Chemiluminescent assay can give the result of the detection of MRSA about 13 hours more rapidly than conventional broth microdilution method. In order to apply chemiluminescent assay to detection of MRSA, we compared MIC and antimicrobial susceptibility to MPIPC in using chemiluminescent assay with these in using broth microdilution method. In MSSA, rate of concordance of MIC and antimicrobial susceptibility to MPIPC obtained by both methods was 87%, but all MICs come to be agreed by modifying the concentration of bacterial liquid. In MRSA, all MICs and susceptibility to MPIPC are agreed in both methods. Although we have used chemiluminescent assay to detect MRSA for one year, no trouble has been reported by clinical side. The chemiluminescent assay is evaluated to be good in detecting MRSA. PMID:14574840

Takakura, Rumie; Arita, Ken-ichi; Kohara, Tadahiro; Nishino, Ryohei

2003-09-01

245

Real-time chemiluminescence imaging using nano-lantern probes.  

PubMed

Chemiluminescence imaging can be performed without excitation light sources at various spatial levels ranging from a single cell to the whole body. Thus far, chemiluminescence imaging has been primarily performed with long exposure times because of weak signals, resulting in low temporal resolution. Recently, the brightest-known chemiluminescent proteins--Nano-lantern and Nano-lantern-based functional indicators--have been developed. Nano-lantern probes break the limitation of temporal resolution and enable chemiluminescence imaging of living samples such as cells, plants, and small animals at video rates. This unit describes one protocol for observation of a freely moving unshaved mouse transplanted with Nano-lantern-expressing tumor cells, and another for compatible use of optogenetic tools and a Nano-lantern calcium indicator. Both protocols utilize the synchronization of illumination and camera acquisition sessions, thereby enabling real-time chemiluminescence imaging. PMID:25445178

Arai, Yoshiyuki; Nagai, Takeharu

2014-01-01

246

Integrated thin-film polymer/fullerene photodetectors for on-chip microfluidic chemiluminescence detection.  

PubMed

We report the use of solution-processed thin-film organic photodiodes for microscale chemiluminescence. The active layer of the photodiodes comprised a 1 : 1 blend by weight of the conjugated polymer poly(3-hexylthiophene) [P3HT] and [6,6]-phenyl-C(61)-butyric acid-methylester [PCBM]--a soluble derivative of C(60). The devices had an active area of 1 mm x 1 mm, and a broad-band response from 350 to 700 nm, with an external quantum efficiency of more than 50% between 450 and 550 nm. The photodiodes have a simple layered structure that permits facile integration with planar chip-based systems. To evaluate the suitability of the organic devices as integrated detectors for microscale chemiluminescence, a peroxyoxalate based chemiluminescence reaction (PO-CL) was monitored within a poly(dimethyl-siloxane) (PDMS) microfluidic device. Quantitation of hydrogen peroxide indicated excellent linearity and yielded a detection limit of 10 microM, comparable with previously reported results using micromachined silicon microfluidic chips with integrated silicon photodiodes. The combination of organic photodiodes with PDMS microfluidic chips offers a means of creating compact, sensitive and potentially low-cost microscale CL devices with wide-ranging applications in chemical and biological analysis and clinical diagnostics. PMID:17180205

Wang, Xuhua; Hofmann, Oliver; Das, Rupa; Barrett, Edward M; deMello, Andrew J; deMello, John C; Bradley, Donal D C

2007-01-01

247

Real-time monitoring of singlet oxygen in photodynamic therapy with chemiluminescence  

NASA Astrophysics Data System (ADS)

Photodynamic therapy (PDT) is a cancer therapy most of which using light excites sensitizer mainly to produce singlet oxygen (1O2) to kill tumor cells by oxidation reaction. Monitoring the singlet oxygen production is an important task for getting more useful dosage information in photodynamic therapy to enhance the effect. In order to monitor singlet oxygen in PDT, the Chemiluminescence (CL) probe, which could react with singlet oxygen and emit photons, was selected and employed on mice to produce CL. The CL was collected and recorded by a single photon detection system in real time. The results showed that the signal intensity was high and indicated that the chemiluminescence could measure singlet oxygen in vivo sensitively. And during photodynamic therapy the CL signal dropped gradually. Different therapy dosages had different decay life. Any of the decay had two different parts: the rapid component and the slow component. During PDT, reactive oxygen would oxidize biomolecules of tissue, and oxygen was consumed. It would cause a rapid component; by combining with chemiluminescence and fluorescence detection technique, the first-order elimination coefficient of tissue was proved to be degressive during PDT. We deduced that the damaged vascular in PDT would provide littler oxygen and tissue hypoxia was more severely. It may quicken CL decay and caused the slow component. In conclusion, the results proved that monitoring 1O2 by CL could give useful information not only to evaluate the effect of PDT but also to judge the tissue oxygen depletion.

Wei, Yan chun; Yang, Li yong; Song, Jia xing

2008-12-01

248

Molecular Fluorescence, Phosphorescence, and Chemiluminescence Spectrometry  

SciTech Connect

This review covers the 2 year period since our last review (1) from January 2008 through December 2009. A computer search of Chemical Abstracts provided most of the references for this review. A search for documents written in English containing the terms fluorescence or phosphorescence or chemiluminescence published in 2008-2009 resulted in more than 100 000 hits. An initial screening reduced this number to approximately 23 000 publications that were considered for inclusion in this review. Key word searches of this subset provided subtopics of manageable size. Other citations were found through individual searches by the various authors who wrote a particular section of this review.

Powe, Aleeta [University of Louisville, Louisville; Das, Susmita [Louisiana State University; Lowry, Mark [Lousianna State University; El-Zahab, Bilal [Lousianna State University; Fakayode, Sayo [Winston-Salem State University; Geng, Maxwell [University of Iowa; Baker, Gary A [ORNL; Wang, Lin [Southern Illinois University; McCarroll, Matthew [Southern Illinois University; Patonay, Gabor [Georgia State University, Atlanta; Li, Min [Lousianna State University; Aljarrah, Mohannad [Louisiana State University; Neal, Sharon [University of Delaware; Warner, Isiah M [ORNL

2010-01-01

249

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

PubMed

Cost-effective and sensitive aptasensor with guanine chemiluminescence detection capable of simply quantifying thrombin in human serum was developed using thrombin aptamer (TBA), one of the G-quadruplex DNA aptamers, without expensive nanoparticles and complicated procedures. Guanines of G-quadruplex TBA-conjugated carboxyfluorescein (6-FAM) bound with thrombin do not react with 3,4,5-trimethoxylphenylglyoxal (TMPG) in the presence of tetra-n-propylammonium hydroxide (TPA), whereas guanines of free TBA- and TBA-conjugated 6-FAM immobilized on the surface of graphene oxide rapidly react with TMPG to emit light. Thus, guanine chemiluminescence in 5% human serum with thrombin was lower than that without thrombin when TBA-conjugated 6-FAM was added in two samples and incubated for 20 min. In other words, the brightness of guanine chemiluminescence was quenched due to the formation of G-quadruplex TBA-conjugated 6-FAM bound with thrombin in a sample. High-energy intermediate, capable of emitting dim light by itself, formed from the reaction between guanines of TBA and TMPG in the presence of TPA, transfers energy to 6-FAM to emit bright light based on the principle of chemiluminescence energy transfer (CRET). G-quadruplex TBA aptasensor devised using the rapid interaction between TBA-conjugated 6-FAM and thrombin quantified trace levels of thrombin without complicated procedures. The limit of detection (LOD = background + 3 × standard deviation) of G-quadruplex TBA aptasensor with good linear calibration curve, accuracy, precision, and recovery was as low as 12.3 nM in 5% human serum. Using the technology reported in this research, we expect that various types of G-quadruplex DNA aptasensors capable of specifically sensing a target molecule such as ATP, HIV, ochratoxin, potassium ions, and thrombin can be developed. PMID:24080210

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

2014-02-15

250

Imaging of DNA sequences with chemiluminescence.  

PubMed Central

We have coupled a chemiluminescent detection method that uses an alkaline phosphatase label to the genomic DNA sequencing protocol of Church and Gilbert [Church, G. M. & Gilbert, W. (1984) Proc. Natl. Acad. Sci. USA 81, 1991-1995]. Images of sequence ladders are obtained on x-ray film with exposure times of less than 30 min, as compared to 40 h required for a similar exposure with a 32P-labeled oligomer. Chemically cleaved DNA from a sequencing gel is transferred to a nylon membrane, and specific sequence ladders are selected by hybridization to DNA oligonucleotides labeled with alkaline phosphatase or with biotin, leading directly or indirectly to deposition of enzyme. If a biotinylated probe is used, an incubation with avidin-alkaline phosphatase conjugate follows. The membrane is soaked in the chemiluminescent substrate (AMPPD) and is exposed to film. Dephosphorylation of AMPPD leads in a two-step pathway to a highly localized emission of visible light. The demonstrated shorter exposure times may improve the efficiency of a serial reprobing strategy such as the multiplex sequencing approach of Church and Kieffer-Higgins [Church, G. M. & Kieffer-Higgins, S. (1988) Science 240, 185-188]. Images PMID:2191292

Tizard, R; Cate, R L; Ramachandran, K L; Wysk, M; Voyta, J C; Murphy, O J; Bronstein, I

1990-01-01

251

Electrogenerated chemiluminescence 73: acid–base properties, electrochemistry, and electrogenerated chemiluminescence of neutral red in acetonitrile  

Microsoft Academic Search

We characterized the acid–base properties, electrochemistry, and electrogenerated chemiluminescence (ECL) of neutral red in acetonitrile (MeCN). To determine the acid–base properties, the basic form (NR) of neutral red was prepared and titrated with anhydrous HClO4, yielding pKa=6.5 in MeCN. NR showed three irreversible electrochemical oxidations and a one-electron reversible reduction. However, the acid form (NRH+) was reduced at more positive

Jai-Pil Choi; Allen J. Bard

2004-01-01

252

A Novel Captopril Chemiluminescence System for Determination of Copper(II) in Human Hair and Cereal Flours  

Microsoft Academic Search

A novel chemiluminescence (CL) reaction, captopril–H2O2, for determination of Cu(II) at nanogram per milliliter level in batch-type system has been described. The method relies\\u000a on the catalytic effect of Cu(II) on the oxidation of captopril with hydrogen peroxide in alkaline medium. The optimization\\u000a step was performed using univariate methodology and the factors studied were: pH and concentrations of the utilized

M. H. Sorouraddin; M. Iranifam; A. Imani-Nabiyyi

2009-01-01

253

Introducing confinement effects into ultraweak chemiluminescence for an improved sensitivity.  

PubMed

So-called confinement effects at the interface of nanomaterials could spring up unique properties in catalytical activities and optical amplifiers. There is apparently no good reason to disregard confinement effect-amplified chemiluminescence (CL). In this work, confinement effects were first introduced into CL field using cetyltrimethylammonium bromide (CTAB) bilayer aggregates confined at the interface of the CTAB-carbon dots, which were prepared by one-step microwave irradiation using glycerol as carbon source in the presence of CTAB. Interestingly, it was found that the CTAB bilayer confined at the interface of carbon dots can amplify H2O2 induced ultraweak CL emissions, such as the Co(II)-triggered Fenton-like reaction, the peroxynitrous acid (ONOOH) system, and the peroxymonocarbonate (HCO4(-)) system. The study of fluorescent properties of the as-prepared CTAB-carbon dots and the comparison with the CL efficiency of their analogues indicated that the CTAB bilayer confined in carbon dots could act as a special micelle microenvironment, helping the access of reactive intermediates to the central carbon core. Our findings opened up new possibilities in confinement-enhanced CL emissions. PMID:25010336

Dong, Shichao; Zhong, Jinpan; Lu, Chao

2014-08-01

254

Flow-based analysis using microfluidics-chemiluminescence systems.  

PubMed

This review will discuss various approaches and techniques in which analysis using microfluidics-chemiluminescence systems (MF-CL) has been reported. A variety of applications is examined, including environmental, pharmaceutical, biological, food and herbal analysis. Reported uses of CL reagents, sample introduction techniques, sample pretreatment methods, CL signal enhancement and detection systems are discussed. A hydrodynamic pumping system is predominately used for these applications. However, several reports are available in which electro-osmotic (EO) pumping has been implemented. Various sample pretreatment methods have been used, including liquid-liquid extraction, solid-phase extraction and molecularly imprinted polymers. A wide range of innovative techniques has been reported for CL signal enhancement. Most of these techniques are based on enhancement of the mixing process in the microfluidics channels, which leads to enhancement of the CL signal. However, other techniques are also reported, such as mirror reaction, liquid core waveguide, on-line pre-derivatization and the use of an opaque white chip with a thin transparent seal. Photodetectors are the most commonly used detectors; however, other detection systems have also been used, including integrated electrochemiluminescence (ECL) and organic photodiodes (OPDs). PMID:22941964

Al Lawati, Haider A J

2013-01-01

255

Flow injection-photoinduced-chemiluminescence determination of ziram and zineb.  

PubMed

A simple, sensitive and rapid method for the determination of the pesticides ziram and zineb was described. This new method was based on the coupling of FIA methodology and direct chemiluminescent detection; this approach had not been used up to now with these pesticides. The additional use of an 'on line' photochemical reaction, which was performed by using a photoreactor consisting of a long piece of PTFE helically coiled around a 15W low-pressure lamp, increased by a factor >20 the chemiluminometric response of the pesticides. An additional 3-fold improvement in the analytical signal was also achieved by using quinine as sensitizer. The obtained throughputs were very high (121 and 101 h(-1) for ziram and zineb, respectively); this feature together with its low limit of detection (1 ng mL(-1)) makes this method particularly well suited to routine analyses of environmental samples. On the other hand, its applicability to two members of the dithiocarbamate family of pesticides, makes it promising for the determination of the rest of the members of this family. The method was demonstrated by application to spiked water samples from different origins (ground, river and irrigation). PMID:18724991

López Paz, J L; Catalá-Icardo, M

2008-09-12

256

Water-binding phospholipid nanodomains and phase-separated diacylglycerol nanodomains regulate enzyme reactions in lipid monolayers.  

PubMed

Phospholipid 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) nanodomains covered with bound water as well as diacylglycerol 1-palmitoyl-2-oleoyl-sn-glycerol (POG) nanodomains separated from a lipid membrane were studied, using monolayer surfaces of POPC hydrolyzed by phospholipase C (PLC). The investigation was based on the analysis of compression isotherms and on atomic force microscope (AFM) observations of Langmuir-Blodgett (LB) films and Langmuir-Schaefer (LS) films. The results included reaction rate constants obtained by kinetic analysis of phosphocholine at surface pressures from 0.1 to 31 mN/m and determined by a luminol-enhanced chemiluminescence method. Monolayer elastic modulus values and fluorescence microscopic images confirmed that hydrolysis by PLC progressed in the intermediate monolayer between a liquid-expanded (L1) film and a liquid-condensed (L2) film at 2-17 mN/m. Furthermore, the intermediate film was confirmed to consist of L1 film and the POPC nanodomains in the L2 state are covered with bound water, conclusions based on the following AFM results: (1) nanodomains in POPC LS films were catalyzed by PLC, (2) POG nanodomains extended out from LB films of mixed POPC/POG 9/1 (mol/mol) monolayers, and (3) POPC LS films were covered with bound water, as indicated by cross-sectional analysis. At the optimal surface pressure of 10 mN/m, when POPC nanodomains (L2), with internal diameters of ?75 nm, were hydrolyzed by PLC, they shrank down into pockets of the same size as those that appeared with POG. The resulting pocket sizes on LS films were in agreement with POG nanodomain sizes on LB films. This study demonstrated that PLC reacted with POPC nanodomains (L2) dispersed in L1/L2 mixed phase monolayers selectively and that POG nanodomains were phase-separated from the monolayer as hydrolysis proceeded. PMID:25565217

Nagashima, Teruyoshi; Uematsu, Shogo

2015-02-01

257

Enzyme-linked immunosorbent assay by enhanced chemiluminescence detection for the standardization of estrogenic miroestrol in Pueraria candollei Graham ex Benth.  

PubMed

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. PMID:25363375

Yusakul, Gorawit; Udomsin, Orapin; Tanaka, Hiroyuki; Morimoto, Satoshi; Juengwatanatrakul, Thaweesak; Putalun, Waraporn

2014-11-01

258

Chemiluminescent ion-molecule reactions B + +H2  

NASA Astrophysics Data System (ADS)

Emission spectra resulting from impact of low-energy (1-10 eVc.m.) B+ ions in a beam on an H2 target were measured. Numerous new bands of the BH+(A 2?-X 2?+) transition were observed besides the previously known (0,0) and (1,1) bands. Also, at higher energy a new band system was discovered which is ascribed to the BH+(B' 2?+-X 2?+) transition. It was identified by analogy with BeH and MgH. The results are discussed in terms of electronic state and molecular orbital correlation diagrams.

Ottinger, Ch.; Reichmuth, J.

1981-01-01

259

Lab-on-valve system integrating a chemiluminescent entity and in situ generation of nascent bromine as oxidant for chemiluminescent determination of tetracycline.  

PubMed

A novel configuration of a lab-on-valve (LOV) system was fabricated and applied for chemiluminescence (CL) detection by integrating a demountable Z-type flow cell onto the LOV unit. A bismuthate immobilized microcolumn was incorporated in one port of the LOV for in situ oxidation of KBr and generation of bromine as oxidant for the bromine-hydrogen peroxide-tetracycline (TC) chemiluminescent reaction. The nascent bromine reacts with hydrogen peroxide and produces a weak CL signal, the intensity of which was significantly enhanced in the presence of TC following an energy-transfer mechanism. A novel procedure for tetracycline quantification was therefore developed based on the present system. When compared with the reported flow injection-CL methods for TC, this procedure not only provided an improved detection limit of 2.0 microg L(-)(1) but also minimized sample and reagent consumption. A linear range of 6.0-10 000 microg L(-)(1) was derived along with RSD values of 5.9 (at the concentration level of quantification limit) and 2.2% (at 50 microg L(-)(1)), and a sampling frequency of 120 h(-)(1) was achieved. The system was validated with a National Standard Procedure (GB/T 18932.4-2002, HPLC with UV detection) by measuring TC contents in commercial milk samples. PMID:16906738

Yang, Mei; Xu, Ying; Wang, Jian-Hua

2006-08-15

260

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

PubMed

The intensity of emitted light from CdSe quantum dots (QDs)-H2O2 is described as a novel chemiluminescence (CL) reaction for determination of dysprosium. This reaction is based on the catalytic effect of Dy(3+) ions, causing a significant increase in the light emission, as a result of the reaction of quantum dots (QDs) with hydrogen peroxide. In the optimum conditions, this method was satisfactorily described by linear calibration curve in the range of 8.3×10(-7)-5.0×10(-6)M, the detection limit of 6.0×10(-8)M, and the relative standard deviation for five determinations of 2.5×10(-6)M Dy(3+) 3.2%. The main experimental advantage of the proposed method is its selective to Dy(3+) ions compared with common coexisting cations, therefore, it was successfully applied for the determination of dysprosium ions in water samples. PMID:24231747

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

2014-01-01

261

Prospects for the commercialization of chemiluminescence-based point-of-care and on-site testing devices.  

PubMed

Chemiluminescent reactions have found application in a number of commercial point-of-care and on-site testing devices. Notable examples include allergy tests (e.g., MASTpette, OPTIGEN® systems), flu tests (e.g., ZstatFlu®-II), cartridge-based immunoassay systems (FastPack® IP System, PATHFAST®), forensic tests for bloodstains, portable analyzers for biochip array assays (Evidence MultiStat), water quality tests (Eclox), air pollutants (e.g., oxides of nitrogen), and handheld devices for detecting explosives (e.g., E3500 Chemilux®). Many other point-of-care or on-site testing devices with a chemiluminescent end point have been devised on the basis of a variety of formats (e.g., cuvette, cassette, dipstick, test strip, microchip), but most have not progressed beyond a proof-of-principle or prototype stage. PMID:24658468

Park, Jason Y; Kricka, Larry J

2014-09-01

262

Evaluation of pyrimido[5,4-d]pyrimidine derivatives as peroxyoxalate chemiluminescence reagents using a flow injection system.  

PubMed

Eighteen kinds of pyrimido[5,4-d]pyrimidines together with several commercially available fluorescent compounds such as perylene, Rhodamine B, etc., were evaluated as the reagents for a peroxyoxalate chemiluminescence (CL) detection system by using a flow injection method. The peroxyoxalate CL reaction employed consists of bis(2,4,6-trichlorophenyl)oxalate, hydrogen peroxide, triethylamine, and a fluorophore. Under the conditions used, 2,6-bis[di-(2-hydroxyethyl)amino]-4,8- dipiperidinopyrimido[5,4-d]pyrimidine (Dipyridamole) and 2,4,6,8-tetrathiomorpholinopyrimido[5,4-d]pyrimidine (1i) gave very intense chemiluminescence intensities which were larger than those of any other commercially available fluorescent compounds tested (e.g., 10 times larger than that of perylene). PMID:2383690

Nakashima, K; Maki, K; Akiyama, S; Imai, K

1990-05-01

263

Determination of thiram in natural waters using flow-injection with cerium(IV)-quinine chemiluminescence system.  

PubMed

A simple and rapid flow-injection chemiluminescence method has been developed for the determination of dithiocarbamate fungicide thiram based on the chemiluminescence reaction of thiram with ceric sulfate and quinine in aqueous sulfuric acid. The present method allowed the determination of thiram in the concentration range of 7.5-2500 ng/mL and the detection limit (signal-to-noise ratio = 3) was 7.5 ng/mL with sample throughput of 120/h. The relative standard deviation was 2.5% for 10 replicate analyses of 500 ng/mL thiram. The effects of foreign species including various anions and cations present in water at environmentally relevant concentrations and some pesticides were also investigated. The proposed method was applied to determine thiram in spiked natural waters using octadecyl bonded phase silica (C(18)) cartridges for solid-phase extraction. The recoveries were in the range 99 +/- 1 to 104 +/- 1%. PMID:19630089

Waseem, Amir; Yaqoob, Mohammad; Nabi, Abdul

2010-01-01

264

Urea Monitor Based on Chemiluminescence and Electrolysis as a Marker for Dialysis Efficiency  

NASA Astrophysics Data System (ADS)

We have developed a practical urea monitor based on a chemiluminescent (CL) reaction of urea and hypobromous acid produced by electrolysis of sodium bromide (NaBr) for measuring urea concentration in spent dialysate at set intervals. A reagent containing 4×10-2 M hypobromous acid is produced by electrolysis of an electrolyte containing 5.9 M NaBr and 0.2 M sodium hydroxide (NaOH). Chemiluminescence is emitted by injection of spent hemodialysis fluid (0.11 ml) into the reagent, and the CL-intensity is measured by a photomultiplier tube using the photon counting technique. The CL-intensity is proportional to the 0.9th power of the urea concentration between 7×10-4 and 2×10-2 M. The urea monitor can determine the urea concentration in spent dialysate samples collected from the waste line of a dialyzer, and the time for the intermittent measurements including the cleaning cycle of the reaction chamber is 3 min. The urea concentrations measured by the monitor are in close agreement with those measured by the conventional enzyme colorimetric method using urease for the spent dialysate collected during a hemodialysis treatment, and the correlation coefficient is 0.93.

Ozaki, Masahiro; Okabayashi, Tohru; Ishimaru, Teppei; Hayashi, Kunihito; Hori, Jun'ya; Yamamoto, Isao; Nakagawa, Masuo

265

Determination of puerarin in biological samples and its application to a pharmacokinetic study by flow-injection chemiluminescence.  

PubMed

A simple and sensitive flow injection-chemiluminescence (FI-CL) method has been developed for the determination of puerarin, based on the fact that puerarin can greatly inhibit CL of the luminol-H?O?-haemoglobin system. The inhibition of CL intensity was linear to the logarithm of the concentration of puerarin in the range 0.08-10.0??g/mL (r² ?=?0.9912). The limit of detection was 0.05??g/mL (3?) and the relative standard deviation (RSD) for 1.0??g/mL (n?=?11) of puerarin solution was 1.4%. Coupled with solid-phase extraction (SPE) as the sample pretreatment, the determination of puerarin in biological samples and a preliminary pharmocokinetic study of puerarin in rats were performed. The recoveries for plasma and urine at three different concentrations were 89.2-110.0% and 91.4-104.8%, respectively. The pharmacokinetics of puerarin in plasma of rat coincides with the two-compartment open model. The T(½?) , T(½?) , CL/F, V(Z/F), AUC(??t), MRT???, T(max) and C(max) were 0.77?±?0.21?h, 7.55?±?2.64?h, 2.43?±?1.02?L/kg/h, 11.40?±?3.45?L/kg, 56.67?±?10.65?mg/h/L, 5.04?±?2.78?h, 1.00?±?0.35?h and 19.70?±?4.67??g/mL, respectively. PMID:21547999

Yang, Ran; Wang, Qingwen; Zeng, Huajin; Qin, Zao; Li, Jianjun; Qu, Lingbo

2011-01-01

266

Antioxidant activity of hyaluronic acid investigated by means of chemiluminescence of equine neutrophil bursts and electron paramagnetic resonance spectroscopy.  

PubMed

Activated neutrophils (PMNs), the ROS/RNS released by PMNs and the derived inflammatory processes are involved in the pathogenesis and progression of human inflammatory airway diseases. Similar diseases are also present in horses which suffer from recurrent airway obstruction (RAO), exercise-induced pulmonary haemorrhage (EIPH) and inflammatory airway diseases (IAD). Hyaluronic acid (HA) plays numerous roles in modulating inflammatory processes. The aim of this study was to examine whether a preparation of HA (MW 900 000 Da) interferes with ROS/RNS during the course of equine PMN respiratory bursts, and to establish the lowest concentration at which it still has antioxidant activity by means of luminol-amplified chemiluminescence (LACL). Electron paramagnetic resonance (EPR) spectroscopy was also used to investigate the direct antiradical activity of HA. The hydroxyl radical was significantly scavenged in a concentration-dependent manner at HA concentrations ranging from 2.5 to 0.16 mg/mL. Superoxide anion, Tempol radical and the ABTS(•+) were significantly inhibited at concentrations ranging from 2.5 to 0.62 mg/mL. The LACL of stimulated equine neutrophils showed that HA induced a statistically significant concentration-effect reduction from 5 mg/mL to 1.25 mg/mL. These findings were confirmed also when l-Arg was added to investigate the inhibition of the resulting peroxynitrite anion. Our findings indicate that, in addition to the human use, HA can also be used to antagonize the oxidative stress generated by free radicals in horses peripheral blood mononuclear cells (PBMCs). In order to achieve therapeutic concentrations, a direct aerosol administration to horses with horse respiratory diseases can be considered, as this route of application is also recommended in human medicine. PMID:25066541

Braga, P C; Dal Sasso, M; Lattuada, N; Greco, V; Sibilia, V; Zucca, E; Stucchi, L; Ferro, E; Ferrucci, F

2015-02-01

267

Chemiluminescent responses of alveolar macrophages from normal and Mycobacterium bovis BCG-vaccinated rabbits as a function of age.  

PubMed Central

Luminol-dependent chemiluminescence (CL) responses of alveolar macrophages (AM) from normal and Mycobacterium bovis BCG-vaccinated infant and adult rabbits were compared. AM from 1-, 7-, and 14-day-old normal rabbits exhibited much lower peak CL responses than did AM from 28- and 42-day-old normal animals as well as rabbits 2 to 3 or 5 to 6 months and 1 to 2 years of age. The most striking differences among AM from infant and adult rabbits were noted when AM were obtained from 28-day-old and 5- to 6-month old rabbits 21 days after the rabbits were immunized with 200 micrograms of BCG intravenously. In this case, AM from 5- to 6-month-old animals gave peak counts per minute of 400,000 to 500,000 whereas AM from 28-day-old rabbits vaccinated with BCG (harvested at 49 days of age) gave peak counts per minute of only 40,715 +/- 2,688. These data reveal that AM from neonatal animals are grossly deficient as responders to phorbol myristate acetate-induced CL. This deficiency, which improved with age, is still apparent in AM from 28-day-old animals. The data also reveal that BCG vaccination of 28-day-old animals yields AM that are poor responders to phorbol myristate acetate compared with AM from BCG-vaccinated animals 2 to 3 and 5 to 6 months of age. AM from animals vaccinated with BCG at 28 days of age contained fewer and smaller electron-dense lysosomelike structures than did AM from adult rabbits similarly vaccinated. These findings provide an explanation for the difficulties infants have in developing effective cell-mediated immune responses against intracellular parasites. Images PMID:3553004

Chida, K; Myrvik, Q N; Leake, E S; Gordon, M R; Wood, P H; Ricardo, M J

1987-01-01

268

Determination of beta-lactam antibiotics in milk using micro-flow chemiluminescence system with on-line solid phase extraction.  

PubMed

In this paper, a chemiluminescence (CL) micro-flow system combined with on-line solid phase extraction (SPE) is presented for determination of beta-lactam antibiotics (penicillin, cefradine, cefadroxil, cefalexin) in milk. It is based on the enhancement effect of beta-lactam antibiotics on the luminol-K3Fe(CN)6 CL system. The micro-flow system was fabricated from two polymethyl methacrylate (PMMA) plates (50 mm x 40 mm x 5 mm) with the microchannels of 200 microm wide and 150 microm deep. C18-modified silica gel was packed into the microchannel (length: 10 mm; width: 1 mm; depth: 500 microm) to serve as SPE device. Extraction and preconcentration of the analytes were carried out using on-line SPE micro-flow system and the selectivity of CL detection was improved. The detection limits were 0.5 microg mL(-1) of penicillin, 0.04 microg mL(-1) of cefradine, 0.08 microg mL(-1) of cefadroxil and 0.1 microg mL(-1) of cefalexin. The proposed method was also applied to analyze the beta-lactam antibiotics in milk. Experimental results were in good agreement with those obtained by high performance liquid chromatography (HPLC) method with UV detection. PMID:17512825

Liu, Wei; Zhang, Zhujun; Liu, Zuoqin

2007-06-01

269

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

PubMed

A highly sensitive chemiluminescence (CL) immunoassay was incorporated into a low-cost microfluidic paper-based analytical device (?-PAD) to fabricate a facile paper-based CL immunodevice (denoted as ?-PCLI). This ?-PCLI was constructed by covalently immobilizing capture antibody on a chitosan membrane modified ?-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 ?-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 ?-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 ?-PCLI could be very useful to realize highly sensitive, qualitative point-of-care testing in developing or developed countries. PMID:23355319

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

2013-01-01

270

Application of horse-radish peroxidase linked chemiluminescence to determine the production mechanism of Shiga-like toxins by E. coli O157:H7  

NASA Astrophysics Data System (ADS)

A sandwiched immunoassay consisting of toxin capture by immunomagnetic beads (IMB) and toxin detection by horseradish peroxidase (HRP) linked chemiluminescence was used to follow the production of Shiga-like toxins (SLT) by E. coli O157:H7. The intensity of luminescence generated by the oxidation of luminol-liked compounds was used to represent the concentration of toxins produced. The time-course of SLT production by E. coli O157:H7 under different conditions was investigated. In pure culture, optimal generation of SLT showed a significant delay than the steady state of cell growth. In mixed cultures of SLT producing E. coli O157:H7 and non-SLT producing E. coli K-12 strain, the production of toxins was substantially decreased. However, the growth of E. coli O157:H7 was not affected by the presence of K-12 strain. This decrease in SLT production was also observed in radiation-sterile ground beef. In regular ground beef that might contain numerous other bacteria, the growth of E. coli O157:H7 in EC media was not significantly affected but the lowered production of SLT was observed. The results showed that mechanism of inducing SLT production was complex with both the growth time and growth environment could influence SLT production. The addition of homo-serine lactone to the growth media enhanced the production of SLT. Thus, possibly cell-cell communication may have a role in SLT production by E. coli O157:H7.

Tu, Shu-I.; Uknalis, Joseph; Gehring, Andrew; He, Yiping

2007-09-01

271

Ultratrace determination of silver, gold, and iron oxide nanoparticles by micelle mediated preconcentration/selective back-extraction coupled with flow injection chemiluminescence detection.  

PubMed

A new method has been developed for the ultrasensitive determination of silver, gold, and iron oxide nanoparticles in environmental samples. Cloud point extraction was optimized and used as a means to extract and preconcentrate all nanoparticle species simultaneously from the same sample. The extracted nanoparticles were sequentially isolated from the surfactant-rich phase by a new selective back-extraction procedure and dissociated into their precursor metal ions. Each ion solution was injected in a flow injection analysis (FIA) manifold, accommodating the chemiluminogenic oxidation of luminol, in order to amplify chemiluminescence (CL) emission in a manner proportional to its concentration. Under the optimum experimental conditions, the detection limits were brought down to the picomolar and femtomolar concentration levels with satisfactory analytical features in terms of precision (2.0-13.0%), selectivity against dissolved ions, and recoveries (74-114%). The method was successfully applied to the determination of iron oxide, silver, and gold nanoparticles in environmental samples of different complexity, ranging from unpolluted river water to raw sewage. The developed method could also serve as a basis for future deployment of molecular spectrometry detectors for the selective determination and speciation analysis of nanoparticles in environmental applications. PMID:24576255

Tsogas, George Z; Giokas, Dimosthenis L; Vlessidis, Athanasios G

2014-04-01

272

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

PubMed

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 ?M to 231 ?M 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. PMID:22832507

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

2012-09-21

273

Development of time-resolved chemiluminescence for the determination of antu in river water, wheat, barley, and oat grain samples.  

PubMed

A novel chemiluminescence method for the determination of antu has been developed based on the reaction between potassium permanganate in acid medium with this rat-poison in the presence of formaldehyde as an emission enhancer. The main feature of the system used is that the recording of the whole chemiluminescence intensity-vs-time profiles can be obtained, using the stopped-flow technique in a continuous-flow system. This enables the use of three quantitative parameters adjustable via software settings, one of them a typically kinetic parameter, such as rate of the light-decay reaction, and the others conventional parameters, such as maximum emission intensity and total emission area, which are proportional to the analyte concentration. The optimum chemical conditions for the chemiluminescence emission were investigated. The effect of common emission enhancers, such as formic acid, formaldehyde, glutaraldehyde, acetaldehyde, quinine, fluorescein, rhodamine B, and rhodamine 6G, was studied. The parameters selected were sulfuric acid 4.0 mol L(-)(1), permanganate 0.1 mmol L(-)(1), and formaldehyde 1.0 mol L(-)(1). The calibration graphs obtained with each one of the measurement parameters were linear for the concentration range from 0.05 to 3.00 microg mL(-)(1). The detection limits ranged from 0.005 to 0.010 microg mL(-)(1), and RSD values (n = 10) of 0.99-1.79% at a 0.30 microg mL(-)(1) concentration level and 1.71-2.22% at a 1.0 microg mL(-)(1) concentration level were obtained. The present chemiluminescence procedures were applied to the determination of antu in different kinds of samples, such as river water, wheat, barley, and oat grain samples. Recovery values not significantly different from the spiked amount were found for these determinations. PMID:16104774

Murillo Pulgarín, José A; García Bermejo, Luisa F; Rubio Aranda, José A

2005-08-24

274

Chemiluminescence analysis of menadione sodium bisulfite and analgin in pharmaceutical preparations and biological fluids  

Microsoft Academic Search

A novel chemiluminescence (CL) flow system for two sulfite-containing drugs, namely, menadione sodium bisulfite (MSB) and analgin is described. It is based on the weak chemiluminescence induced by the oxidation of sulfite group in drugs with dissolved oxygen in the presence of acidic Rh6G. Tween 80 surfactant micelles showed a strong enhancement effect on this weak chemiluminescence. For MSB analysis,

Yuming Huang; Chao Zhang; Xinrong Zhang; Zhujun Zhang

1999-01-01

275

Effect of fuel type on equivalence ratio measurements using chemiluminescence in premixed flames  

Microsoft Academic Search

Local temporally-resolved measurements of chemiluminescent intensity from OH?, CH? and C?2 radicals were obtained in premixed counterflow flames operating with propane and prevaporised fuels (isooctane, ethanol and methanol), for different equivalence ratios and strain rates. The results quantified independently the effects of fuel type, strain rate and equivalence ratio on chemiluminescent emissions from flames. The ability of chemiluminescent intensity from

Mikaël Orain; Yannis Hardalupas

2010-01-01

276

Turn-off-on chemiluminescence determination of cyanide.  

PubMed

A flow injection chemiluminescence (FI-CL) method was developed for the determination of cyanide (CN(-) ) based on the recovered CL signal by Cu(2+) inhibiting a glutathione (GSH)-capped CdTe quantum dot (QD) and hydrogen peroxide system. In an alkaline medium, strong CL signals were observed from the reaction of CdTe QDs and H2 O2 , and addition of Cu(2+) could cause significant CL inhibition of the CdTe QDs-H2 O2 system. In the presence of CN(-) , Cu(2+) can be removed from the surface of CdTe QDs via the formation of particularly stable [Cu(CN)n ]((n-1)-) species, and the CL signal of the CdTe QDs-H2 O2 system was efficiently recovered. Thus, the CL signals of CdTe QDs-H2 O2 system were turned off and turned on by the addition of Cu(2+) and CN(-) , respectively. Further, the results showed that among the tested ions, only CN(-) could recover the CL signal, which suggested that the CdTe QDs-H2 O2 -Cu(2+) CL system had highly selectivity for CN(-) . Under optimum conditions, the CL intensity and the concentration of CN(-) show a good linear relationship in the range 0.0-650.0?ng/mL (R(2) ?=?0.9996). The limit of detection for CN(-) was 6.0?ng/mL (3?). This method has been applied to detect CN(-) in river water and industrial wastewater with satisfactory results. Copyright © 2014 John Wiley & Sons, Ltd. PMID:24804930

Han, Suqin; Wang, Jianbo; Jia, Shize

2015-02-01

277

Enhanced chemiluminescence CdSe quantum dots by histidine and tryptophan  

NASA Astrophysics Data System (ADS)

The enhancing effect of histidine and tryptophan on chemiluminescence (CL) of CdSe quantum dots (QDs)-H2O2 system was studied. This reaction is based on the catalytic effect of amino acids, causing a significant increase in the light emission, as a result of the reaction of quantum dots (QDs) with hydrogen peroxide. In the optimum conditions, this method was satisfactorily described by linear calibration curve in the range of 0.66-35.5 ?M and 0.83-35.1 ?M for histidine and tryptophan, respectively. The effect of various parameters such as concentration of CdSe QDs, concentration of H2O2 and concentration of imidazole on the intensity of CL system were studied. The main experimental advantage of the proposed method is it's selective to two amino acids compared with other amino acids.

Hosseini, Morteza; Ganjali, Mohammad Reza; Jarrahi, Afsaneh; Vaezi, Zahra; Mizani, Farhang; Faridbod, Farnoush

2014-11-01

278

Flow injection chemiluminescence determination of dihydralazine sulphate based on permanganate oxidation sensitized by rhodamine B.  

PubMed

A novel flow injection chemiluminescence (CL) method for the determination of dihydralazine sulphate (DHZS) is described. The method is based on the CL produced during the oxidation of DHZS by acidic permanganate solution in the presence of rhodamine B. Rhodamine B is suggested as a fluorescing compound for the energy-transferred excitation. The CL emission allows quantitation of DHZS concentration in the range 5-800 ng/mL, with a detection limit of 1.9 ng/mL (3sigma). The experimental conditions for the CL reaction are optimized and the possible reaction mechanism is discussed. The method has been applied to the determination of DHZS in pharmaceutical preparations and compares well with the high performance liquid chromatography (HPLC) method. PMID:15508136

Yang, Xiao-Feng; Wu, Dong-Bing; Li, Hua

2004-01-01

279

Enhanced chemiluminescence CdSe quantum dots by histidine and tryptophan.  

PubMed

The enhancing effect of histidine and tryptophan on chemiluminescence (CL) of CdSe quantum dots (QDs)-H2O2 system was studied. This reaction is based on the catalytic effect of amino acids, causing a significant increase in the light emission, as a result of the reaction of quantum dots (QDs) with hydrogen peroxide. In the optimum conditions, this method was satisfactorily described by linear calibration curve in the range of 0.66-35.5 ?M and 0.83-35.1 ?M for histidine and tryptophan, respectively. The effect of various parameters such as concentration of CdSe QDs, concentration of H2O2 and concentration of imidazole on the intensity of CL system were studied. The main experimental advantage of the proposed method is it's selective to two amino acids compared with other amino acids. PMID:24892543

Hosseini, Morteza; Ganjali, Mohammad Reza; Jarrahi, Afsaneh; Vaezi, Zahra; Mizani, Farhang; Faridbod, Farnoush

2014-11-11

280

Multiwell cartridge with integrated array of amorphous silicon photosensors for chemiluminescence detection: development, characterization and comparison with cooled-CCD luminograph.  

PubMed

We propose a disposable multiwell microcartridge with integrated amorphous silicon photosensors array for bio- and chemiluminescence-based bioassays, where the enzymatic reactions and the detection unit are coupled on the same glass substrate. Each well, made in a polydimethylsiloxane (PDMS) unit, hosts an enzymatic reaction that is monitored by one photosensor of the array. Photosensors were characterized in terms of their dark current background noise and response to different wavelengths of visible light in order to determine their suitability as detection devices for chemical luminescent phenomena. Calibration curves of the photosensors' response to different luminescent systems were then evaluated by using the chemiluminescent reactions catalyzed by alkaline phosphatase and horseradish peroxidase and the bioluminescent reaction catalyzed by firefly luciferase. Limits of detection in the order of attomoles for chemiluminescence enzymes and femtomoles for luciferase and sensitivities in the range between 0.007 and 0.1 pA pmol(-1) L were reached. We found that, without the need of cooling systems, the analytical performances of the proposed cartridge are comparable with those achievable with state-of-the-art thermoelectrically cooled charge-coupled device-based laboratory instrumentation. In addition, thanks to the small amount of generated output data, the proposed device allows the monitoring of long-lasting reactions with significant advantages in terms of data-storage needs, transmission bandwidth, ease of real-time signal processing and limited power consumption. Based on these results, the operation in model bioanalytical assays exploiting luminescent reactions was tested demonstrating that a-Si:H photosensors arrays, when integrated with PDMS microfluidic units, provide compact, sensitive and potentially low-cost microdevices for chemiluminescence and bioluminescence-based bioassays with a wide range of possible applications for in-field and point-of-care bio-analyses. PMID:24965161

Mirasoli, Mara; Nascetti, Augusto; Caputo, Domenico; Zangheri, Martina; Scipinotti, Riccardo; Cevenini, Luca; de Cesare, Giampiero; Roda, Aldo

2014-09-01

281

Analyzer for measurement of nitrogen oxide concentration by ozone content reduction in gas using solid state chemiluminescent sensor  

NASA Astrophysics Data System (ADS)

Role of nitrogen oxide in ambient air is described and analyzed. New method of nitrogen oxide concentration measurement in gas phase is suggested based on ozone concentration measurement with titration by nitrogen oxide. Research of chemiluminescent sensor composition is carried out on experimental stand. The sensor produced on the base of solid state non-activated chemiluminescent composition is applied as ozone sensor. Composition is put on the surface of polymer matrix with developed surface. Sensor compositions includes gallic acid with addition of rodamine-6G. Model of interaction process between sensor composition and ozone has been developed, main products appeared during reaction are identified. The product determining the speed of luminescense appearance is found. This product belongs to quinone class. Then new structure of chemiluminescent composition was suggested, with absence of activation period and with high stability of operation. Experimental model of gas analyzer was constructed and operation algorithm was developed. It was demonstrated that developed NO measuring instrument would be applied for monitoring purposes of ambient air. This work was partially financially supported by Government of Russian Federation, Grant 074-U01

Chelibanov, V. P.; Ishanin, G. G.; Isaev, L. N.

2014-05-01

282

Directional surface plasmon coupled chemiluminescence from nickel thin films: Fixed angle observation  

NASA Astrophysics Data System (ADS)

Directional surface plasmon coupled chemiluminescence (SPCC) from nickel thin films is demonstrated. Free-space and angular-dependent SPCC emission from blue, green and turquoise chemiluminescent solutions placed onto nickel thin films attached to a hemispherical prism were measured. SPCC emission was found to be highly directional and preferentially p-polarized, in contrast to the unpolarized and isotropic chemiluminescence emission. The largest SPCC emission for all chemiluminescence solutions was observed at a fixed observation angle of 60°, which was also predicted by theoretical Fresnel calculations. It was found that nickel thin films did not have a catalytic effect on chemiluminescence emission.

Weisenberg, Micah; Aslan, Kadir; Hortle, Elinor; Geddes, Chris D.

2009-04-01

283

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

NASA Astrophysics Data System (ADS)

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 ?M to 500 ?M. The detection limit of H2O2 was calculated to be about 0.7 ?M. 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 ?M to 500 ?M. The detection limit of H2O2 was calculated to be about 0.7 ?M. 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

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

2014-09-01

284

Determination of oxides of nitrogen (NO/sub x/) in cigarette smoke by chemiluminescent analysis  

SciTech Connect

The successful application of a commercial chemiluminescent No/sub x/ analyzer to the determination of oxides of nitrogen in cigarette smoke is reported. Individual puffs of the smoke vapor phase are rapidly diluted in an air stream before introduction into the analyzer. This acts to both reduce quenching of the chemiluminescent response by CO/sub 2/ and to prevent side reactions of the NO/sub x/ with vapor phase organic constituents. Sweeping the dilute smoke through a reduced silver-ion exchange resin bed removed a substantial positive interference from hydrogen cyanide. A range of deliveries of 3 to 47 ..mu..mol of NO/sub x/ per cigarette was observed for nine types of experimental cigarettes. Statistically significant differences between NO/sub x/ and NO levels (NO/sub x/ - NO = NO/sub 2/) in smoke were observed in only one type of cigarette, presumably due to large cigarette-to-cigarette variability in constituent deliveries. 2 figures, 3 tables.

Jenkins, R.A.; Gill, B.E.

1980-05-01

285

A comparison of chemiluminescent acridinium dimethylphenyl ester labels with different conjugation sites.  

PubMed

Chemiluminescent acridinium dimethylphenyl esters are highly sensitive labels that are used in automated assays for clinical diagnosis. Light emission from these labels and their conjugates is triggered by treatment with alkaline peroxide. Conjugation of acridinium ester labels is normally done at the phenol. During the chemiluminescent reaction of these acridinium esters, the phenolic ester is cleaved and the light emitting acridone moiety is liberated from its conjugate partner. In the current study, we report the synthesis of three new acridinium esters with conjugation sites at the acridinium nitrogen and compare their properties with that of a conventional acridinium ester with a conjugation site at the phenol. Our study is the first that provides a direct comparison of the emissive properties of acridinium dimethylphenyl esters (free labels and protein conjugates) with different conjugation sites, one where the light emitting acridone remains attached to its conjugate partner versus conventional labeling which results in cleavage of the acridone from the conjugate. Our results indicate that the conjugation at the acridinium nitrogen, which also alters how the acridinium ring and phenol are oriented with respect to the protein surface, has a minimal impact on emission kinetics and emission spectra. However, this mode of conjugation to three different proteins led to a significant increase in light yield which should be useful for improving the assay sensitivity. PMID:25581208

Natrajan, Anand; Wen, David

2015-02-18

286

Studies on water treeing and chemiluminescence on irradiated polyethylene  

SciTech Connect

The effect of {gamma}-radiations on the growth kinetics of water trees is examined using the CNRS laboratory model in LDPE samples of different origins. The effect of radiations on the material is studied from crosslinking degree measurements, IRTF spectroscopy and chemiluminescence. Correlations between the non-uniformity of the degradation and the growth of water trees are observed.

Notingher, P.V.; Ciuprina, F.; Radu, I. [Politehnica Univ. of Bucharest (Romania); Jipa, S.; Setnescu, T.; Setnescu, R. [ICPE, Bucharest (Romania); Filippini, J.C.; Gosse, B. [CNRS, Grenoble (France). Lab. d`Electrostatique et de Materiaux; Mihalcea, T. [Univ. of Bucharest (Romania)

1996-12-31

287

TECHNICAL ASSISTANCE DOCUMENT FOR THE CHEMILUMINESCENCE MEASUREMENT OF NITROGEN DIOXIDE  

EPA Science Inventory

Gas phase chemiluminescence has been designated as the reference measurement principle for the measurement of nitrogen dioxide (NO2) in the ambient atmosphere. Continuous analyzers based on this measurement principle may be calibrated with NO2 either from the gas phase titration ...

288

Determination of pentachlorophenol and 1-naphthol by peroxyoxalate chemiluminescence  

SciTech Connect

Peroxyoxalate chemiluminescence is used for the determination of pentachlorophenol and 1-naphthol in soil. 1-Naphthol is brominated to make it amenable to the procedure. Calibration curves are linear over concentration ranges spanning four orders of magnitude and limits of detection are at the micromolar level. The processes can be carried out in the soil without prior extraction of the analytes.

Chimeno, J.; von Wandruszka, R. (Univ. of Idaho, Moscow (United States))

1989-01-01

289

A new chemiluminescence method for determination of clonazepam and diazepam based on 1-Ethyl-3-Methylimidazolium Ethylsulfate/copper as catalyst  

NASA Astrophysics Data System (ADS)

A novel chemiluminescence (CL) reaction, Benzodiazepines-H2O2-1-Ethyl-3-Methylimidazolium Ethylsulfate/copper, for determination of clonazepam and diazepam at nanogram per milliliter level in batch-type system have been described. The method relies on the catalytic effect of 1-Ethyl-3-Methylimidazolium Ethylsulfate/copper on the chemiluminescence reaction of Benzodiazepines, the oxidation of Benzodiazepines with hydrogen peroxide in natural medium. The influences of various experimental parameters such as solution pH, the ratio of 1-Ethyl-3 Methylimidazolium ethylsulfate concentration to copper ion, the type of buffer and the concentration of CL reagents were investigated. Under the optimum condition, the proposed method was satisfactorily applied for the determination of these drugs in tablets and urine without the interference of their potential impurities.

Chaichi, M. J.; Alijanpour, S. O.

2014-01-01

290

Chemiluminescence lateral flow immunoassay based on Pt nanoparticle with peroxidase activity.  

PubMed

A lateral flow immunoassay (LF-immunoassay) with an enhanced sensitivity and thermostability was developed by using Pt nanoparticles with a peroxidase activity. The Pt nanoparticles were synthesized by citrate reduction method, and the peroxidase activity of Pt nanoparticles was optimized by adjusting reaction conditions. The peroxidase activity was estimated by using Michaelis-Menten kinetics model with TMB as a chromogenic substrate. The kinetics parameters of KM and Vmax were calculated and compared with horseradish peroxidase (HRP). The thermal stability of the Pt nanoparticles was compared with horseradish peroxidase (HRP) according to the storage temperature and long-term storage period. The feasibility of lateral flow immunoassay with a chemiluminescent signal band was demonstrated by the detection of human chorionic gonadotropin (hCG) as a model analyte, and the sensitivity was determined to be improved by as much as 1000-fold compared to the conventional rapid test based on colored gold-colloids. PMID:25467480

Park, Jong-Min; Jung, Ha-Wook; Chang, Young Wook; Kim, Hyung-Seok; Kang, Min-Jung; Pyun, Jae-Chul

2015-01-01

291

Chemiluminescent analysis of the antioxidant and immunomodulation effects of several psychotropic drugs on peritoneal macrophages.  

PubMed

The present study describes the application of several chemiluminescent (CL) methods for evaluation of antioxidant and immunomodulation effects of psychotropic drugs upon phagocytes: KO2-induced luminal-dependent CL for detection of superoxide anion radicals in a pure chemical system; PMA- and A23187-induced CL of peritoneal macrophages for detection of free radicals in cell suspension; and CL, produced by the luciferase-catalyzed luciferin + ATP reaction, for evaluation of cell viability before and after drug application. These methods provide also a way to investigate the location of drug action. It was found that the psychotropic drugs in fluence the 'oxidative burst' of macrophages through two mechanisms: by expression of drug antioxidant properties and/or by a direct immunomodulation effect. PMID:15558671

Hadjimitova, V; Traykov, T; Bakalova, R; Petrova, V; Lambev, I; Ohba, H; Ishikawa, M; Baba, Y

2004-01-01

292

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

PubMed

The oxidation reaction between cerium(IV) and Tween 85 in sulfuric acid medium produced weak chemiluminescence (CL). In this paper, it was found that citrate could strongly enhance the CL of cerium(IV)-Tween 85-polyphenol system. Based on studies of ultraviolet-visible spectra and CL spectra, the CL enhancement mechanism had been proposed. It was surmised that the light emission was from an excited oxygen molecular pair O2((1)?g)O2((1)?g(-)). The maximum emission wavelength was about 478 nm. The effects of 17 amino acids and 29 organic compounds on cerium(IV)-Tween 85-citrate CL were investigated by a flow injection procedure. This study showed the present system had a wide application for the determination of these compounds. PMID:23281191

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

2013-01-01

293

Simultaneous detection of single attoliter droplet collisions by electrochemical and electrogenerated chemiluminescent responses.  

PubMed

We provide evidence of single attoliter oil droplet collisions at the surface of an ultra-microelectrode (UME) by the observation of simultaneous electrochemical current transients (i-t curves) and electrogenerated chemiluminescent (ECL) transients in an oil/water emulsion. An emulsion system based on droplets of toluene and tri-n-propylamine (2:1 v/v) emulsified with an ionic liquid and suspended in an aqueous continuous phase was formed by ultrasonification. When an ECL luminophore, such as rubrene, is added to the emulsion droplet, stochastic events can be tracked by observing both the current blips from oxidation at the electrode surface and the ECL blips from the follow-up ECL reaction, which produces light. This report provides a means of studying fundamental aspects of electrochemistry using the attoliter oil droplet and offers complementary analytical techniques for analyzing discrete collision events, size distribution of emulsion systems, and individual droplet electroactivity. PMID:25213468

Dick, Jeffrey E; Renault, Christophe; Kim, Byung-Kwon; Bard, Allen J

2014-10-27

294

Tomographic reconstruction of 2D-OH?-chemiluminescence distributions in turbulent diffusion flames  

NASA Astrophysics Data System (ADS)

A recently developed fast tomographic reconstruction device (Anikin et al. in Appl. Phys. B 100:675, 2010) has been applied to detect 2-D chemiluminescence distributions of OH? in reaction zones of a near laminar and a turbulent diffusion flame. A series of single-shot experiments has been carried out in both flames offering cold gas flow velocities of 0.43 m/s and 4 m/s and flame diameters up to 60 mm, respectively. The emission of OH?-chemiluminescence originating from the reaction zones of the flame fronts was registered by ten Kepler-telescopes surrounding the object under investigation at different pre-defined angles. The signals emerging from each telescope are collected by a fiber cable consisting of 90 single fibers arranged side by side in a single row, respectively. The signals originating from the ten cables/10×90=900 fibers represent the corresponding Radon transforms. These signals are imaged by a relay-optics onto the photocathode of a single image intensified CCD-camera. The output data of the camera are used for the reconstructions of the 2D-distributions of OH?-emission using a numerical procedure solving the inverse problem of tomography (Anikin et al. in Appl. Phys. B 100:675, 2010, and references therein). From the experimental results it is shown that the reconstructions obtained at exposure times down to 200 ?s reproduce fine structures of the flames with a spatial resolution of ˜1 mm. Therefore, the method is a useful tool for the detailed investigation of turbulent combustion.

Anikin, N. B.; Suntz, R.; Bockhorn, H.

2012-06-01

295

Detection of lanthanides and actinides in solutions based on laser-induced luminescence and chemiluminescence  

NASA Astrophysics Data System (ADS)

This work is devoted to applications of the time-resolved laser- induced luminescence spectroscopy and time-resolved laser-induced chemiluminescence spectroscopy for detection of lanthanides and actinides. The limit of detection (LOD) of some lanthanides and actinides in solutions by the time-resolved laser luminescence spectroscopy is up to 10-13 mole/liter. Unfortunately, Pu, Np, and some U compounds do not produce luminescence in solutions, but when excited by laser radiation, they can induce chemiluminescence. The characteristics of chemiluminescence induced by excited lanthanide and actinide complexes in solutions are considered. A key problem of chemiluminescence application for lanthanide and actinide detection in solutions is the increase of the detection selectivity. This problem can be solved by using the multistep schemes of chemiluminescence excitation. It is shown that the time-resolved luminescence laser spectroscopy and chemiluminescence laser spectroscopy can be successfully used for detection of lanthanides and actinides in solutions.

Izosimov, I. N.; Firsin, N. G.; Gorshkov, N. G.; Nekhoroshkov, S. N.

2014-06-01

296

An overview on flow methods for the chemiluminescence determination of phosphorus.  

PubMed

A review on the flow analysis of phosphorus with chemiluminescence detection is presented. A brief discussion of the chemiluminescence principles and applications is given. Particular emphasis is devoted to coupling different flow techniques (flow injection, sequential injection, multicommutation, multisyringe flow injection, multi-pumping) to chemiluminescence detection. Enzymatic and non-enzymatic methods, mostly applied to environmental samples, are summarized and compared in terms of application range, detection limits, flow configuration, repeatability and sampling rate. PMID:18969997

Morais, Inês P A; Tóth, Ildikó V; Rangel, António O S S

2005-04-15

297

Crystallochemiluminescence of solutions  

NASA Astrophysics Data System (ADS)

It is shown that the chemiluminescence intensity from luminol solutions reaches a maximum when the latter are crystallized. This phenomenon is explained by the complex dynamics of the phase transition, chemical reactions, and degradation of electronic excitation energy. Luminescence of new type, called crystallochemiluminescence, is revealed.

Gus'kov, A. P.; Nekrasova, L. P.; Gornakova, A. S.; Shikunova, I. A.

2014-09-01

298

Chemiluminescent high-throughput microassay for evaluation of acetylcholinesterase inhibitors  

Microsoft Academic Search

Current drug therapies for Alzheimer's disease (AD) are mainly based on acetylcholinesterase (AChE) inhibitors. However, such inhibitors may possess non-optimal pharmacological properties or cause adverse effects, therefore research for the development of new drugs is still in progress. In this paper, a rapid and simple chemiluminescent (CL) assay for the in vitro evaluation of AChE inhibitors in which the activity

M. Guardigli; P. Pasini; M. Mirasoli; A. Leoni; A. Andreani; A. Roda

2005-01-01

299

Quantitation method of N,N '-disalicylidene-1,2-propanediamine by comprehensive two-dimensional gas chromatography coupled to a nitrogen chemiluminescence detector.  

PubMed

Metal deactivator additives (MDAs) have been used for over 60 years to prevent metal catalyzed reactions in petroleum products; a commonly used metal deactivator is N,N'-disalicylidene-1,2-propanediamine. The quantitation of low MDA concentrations in fuels is challenging due to the complexity of the sample matrix. In this work, this difficulty was overcome using GC × GC hyphenated with a nitrogen chemiluminescence detector. The high resolution power of GC × GC avoided co-elution between the MDA and other sample matrix compounds; while the enhanced sensitivity of GC × GC and the use of a nitrogen chemiluminescence detector supplied a high sensitivity and specificity for nitrogen compounds. For the analysis, the MDA additive was derivatized with the silylation agent N,O-bis (trimethylsilyl)trifluoroacetamide at room temperature and its quantitation was based on an external calibration curve; good linear response was obtained in the 1.4-8.6 ppm range. PMID:23494992

Lissitsyna, Kristina; Huertas, Sonia; Quintero, Luis Carlos; Polo, Luis Maria

2013-06-01

300

Determination of lipoic acid by flow-injection and high-performance liquid chromatography with chemiluminescence detection.  

PubMed

A new flow-injection (FI) and high performance liquid chromatography (HPLC) with chemiluminescence detection method has been proposed for the determination of ?-lipoic acid (LA). The assay is based on the measurement of chemiluminescence (CL) produced during the reaction of ?-lipoic acid with potassium permanganate in a sodium hexametaphosphate medium (pH 3). This reaction is accompanied by a weak CL, which is greatly increased in the presence of a formaldehyde solution. The proposed FI method allows the determination of LA over the range: 0.5-20?gmL(-1) with LOD 4×10(-3)?gmL(-1). An introduction of HPLC into the flow manifold improves selectivity of the method and allows the determination of LA in a complex sample. The chromatographic linear range is 2.5-30?gmL(-1) with LOD 1.774?gmL(-1). Chromatographic separation was achieved by isocratic elution (acetonitrile/potassium dihydrogen phosphate, pH 3, adjusted with phosphoric acid): 30/70 using a Cosmosil 5C(18)-MS-II (4.6mm×150mm I.D.) column at a flow rate of 1.0mLmin(-1). The presented methods were utilized to determine the ?-lipoic acid content in "Alfa-lipoic acid" capsules and in food products. PMID:22817954

Wo?yniec, E; Karpi?ska, J; Losiewska, S; Turkowicz, M; Klimczuk, J; Koj?o, A

2012-07-15

301

The effective peroxidase-like activity of chitosan-functionalized CoFe2O4 nanoparticles for chemiluminescence sensing of hydrogen peroxide and glucose.  

PubMed

Here, we report a highly simple and general protocol for functionalization of the CoFe(2)O(4) NPs with chitosan polymers in order to make CoFe(2)O(4) NPs disperse and stable in solution. The functionalized CoFe(2)O(4) NPs (denoted as CF-CoFe(2)O(4) NPs) were characterized by scanning electron microscope (SEM), thermogravimetric (TG), X-ray diffraction (XRD) and FT-IR spectra. It was found that the CoFe(2)O(4) NPs were successfully decorated and uniformly dispersed on the surface of chitosan without agglomeration. The CF-CoFe(2)O(4) NPs were found to increase greatly the radiation emitted during the CL oxidation of luminol by hydrogen peroxide. Results of ESR spin-trapping experiments demonstrated that the CF-CoFe(2)O(4) NPs showed catalytic ability to H(2)O(2) decomposition into ?OH radicals. On this basis, a highly sensitive and rapid chemiluminescent method was developed for hydrogen peroxide in water samples and glucose in blood samples. Under optimum conditions, the proposed method allowed the detection of H(2)O(2) in the range of 1.0 × 10(-9) to 4.0 × 10(-6) M and glucose in the range of 5.0 × 10(-8) to 1.0 × 10(-5) M with detectable H(2)O(2) as low as 500 pM and glucose as low as 10 nM, respectively. This proposed method has been successfully applied to detect H(2)O(2) in environmental water samples and glucose in serum samples with good accuracy and precision. PMID:22258160

Fan, Yingwei; Huang, Yuming

2012-03-01

302

A novel chemiluminescent ELISA for detecting furaltadone metabolite, 3-amino-5-morpholinomethyl-2-oxazolidone (AMOZ) in fish, egg, honey and shrimp samples.  

PubMed

In this study, an indirect competitive enzyme-linked immunosorbent assay with chemiluminescent (CLELISA) detection for 3-amino-5-morpholinomethyl-2-oxazolidone (AMOZ) was developed. A monoclonal antibody (MAb) against AMOZ was prepared through immunizing BALB/c mice with 4-carboxybenzaldehyle derivatized AMOZ (CPAMOZ), conjugated with bovine serum albumin (BSA) as antigen. The effects of the substrates luminol, p-iodophenol and urea peroxide on the performance of the assay were studied and optimized. In addition, the specificity of the MAb, estimated as the cross-reactivity values with 4-nitrobenzaldehyde derivatized AMOZ (NPAMOZ), CPAMOZ and AMOZ, was 100%, 27.45% and 0.18%, respectively. The sensitivity of the developed CLELISA was estimated as 50% inhibitory concentration (IC50) value (0.14?g/l) with a linear working range between 0.03 and 64?g/l, and a limit of detection of 0.01?g/l. The CLELISA described in this study was 5-fold more sensitive than the indirect competitive ELISA previously developed in our laboratory. Finally, this new CLELISA was compared with a commercial kit to detect NPAMOZ in spiked fish, shrimp, honey and egg samples. The recovery values from four spiked fish, shrimp, honey and egg samples with different concentrations of NPAMOZ in CLELISA were 92.1-107.7%. Thus, the immunoassay method described here has a broad detection range and high sensitivity and is a valid and cost-effective means for high throughput monitoring of residual AMOZ levels in fish, shrimps, honey and eggs with potential applications in other animal tissues. PMID:23810835

Liu, Ying-Chun; Jiang, Wei; Chen, Yong-Jun; Xiao, Yan; Shi, Jin-Lei; Qiao, Yuan-Biao; Zhang, Hua-Jing; Li, Tao; Wang, Quan

2013-09-30

303

Aggregation-induced emission: a simple strategy to improve chemiluminescence resonance energy transfer.  

PubMed

The emergence of aggregation-induced emission (AIE) has opened up a new avenue for scientists. There is a great demand for the development of a new generation chemiluminescence resonance energy transfer (CRET) acceptors with AIE characteristics due to the aggregation-caused chemiluminescence (CL) quenching effect commonly observed in the conventional fluorophore CL acceptors at high concentrations. However, the systematical studies involving in AIE-amplified CL are still scarce. Herein, it is the first report that the gold nanocluster aggregates (a type of well-defined AIE molecules) are used to study their influence on the bis(2,4,6-trichlorophenyl) oxalate (TCPO)-H2O2 CL reaction. Interestingly, the AIE molecules in the diluted solution are unable to boost the CL signal of the TCPO-H2O2 system, but their aggregates display a strongly enhanced CL emission compared to their counterparts of fluorophore molecules, thanks to the unique AIE effect of gold nanoclusters. In comparison to rhodamine B with the aid of an imidazole catalyst, the detection limit of the gold nanocluster aggregate-amplified CL probe for H2O2 (S/N = 3) is low in the absence of any catalyst. Finally, the other two typical AIE molecules, Au(I)-thiolate complexes and 9,10-bis[4-(3-sulfonatopropoxyl)-styryl]anthracene (BSPSA), are investigated to verify the generality of the AIE molecule-amplified CL emissions. These results demonstrate effective access to highly fluorescent AIE molecules with practical applications in avoiding the aggregation-induced CL quenching at high concentrations, which can be expected to provide a novel and sensitive platform for the CL amplified detection. PMID:25526522

Zhang, Lijuan; He, Nan; Lu, Chao

2015-01-20

304

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

SciTech Connect

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

Tripathi, Markandey M.; Krishnan, Sundar R.; Srinivasan, Kalyan K.; Yueh, Fang-Yu; Singh, Jagdish P.

2012-03-01

305

The molecular dynamics of atmospheric reaction  

NASA Technical Reports Server (NTRS)

Detailed information about the chemistry of the upper atmosphere took the form of quantitative data concerning the rate of reaction into specified states of product vibration, rotation and translation for exothermic reaction, as well as concerning the rate of reaction from specified states of reagent vibration, rotation and translation for endothermic reaction. The techniques used were variants on the infrared chemiluminescence method. Emphasis was placed on reactions that formed, and that removed, vibrationally-excited hydroxyl radicals. Fundamental studies were also performed on exothermic reactions involving hydrogen halides.

Polanyi, J. C.

1971-01-01

306

Simultaneous chemiluminescence determination of amoxicillin and clavulanic acid using least squares support vector regression  

Microsoft Academic Search

In this work, both the batch and flow injection chemiluminescence (CL) methods have been proposed for the simultaneous determination of two structurally similar ?-lactams including amoxicillin and clavulanic acid (CLAV). Chemiluminescence spectral overlap of these two structurally similar ?-lactams is the main limitation for the simultaneous analysis of the two compounds. Least squares support vector regression (LS-SVR) was applied to

F. Hasanpour; Ali A. Ensafi; T. Khayamian

2010-01-01

307

Chemiluminescence assay for catechin based on generation of hydrogen peroxide in basic solution  

Microsoft Academic Search

We have determined that the catechin group in basic solution efficiently produces hydrogen peroxide; moreover, a highly sensitive analysis methodology was developed to measure catechin employing a peroxalate chemiluminescence detection system. Identification of hydrogen peroxide generated by catechin was determined by ESR as well as peroxalate chemiluminescence using catalase and SOD. As a result, catechin-generated superoxide by electron reduction to

Hidetoshi Arakawa; Mahina Kanemitsu; Noriko Tajima; Masako Maeda

2002-01-01

308

Surface plasmon coupled chemiluminescence from iron thin films: Directional and approaching fixed angle observation  

NASA Astrophysics Data System (ADS)

We report the observation of surface plasmon coupled chemiluminescence (SPCC) from iron thin films. Theoretical Fresnel calculations were employed to determine the optimum thickness of iron thin films to be 15 nm, which is assessed by the value of minimum reflectivity curves for incident light upon the thin film. An overlayer 10 nm thick SiO2 was used to protect the iron thin films from oxidation by air or physical changes induced by chemiluminescent solutions. SPCC emission from blue, green, and chartreuse chemiluminescent solutions on iron films can be observed at a fixed angle of 60° for all the chemiluminescent solutions, while free-space emission was isotropic. Iron thin films do not have a catalytic effect on chemiluminescence emission.

Aslan, Kadir; Weisenberg, Micah; Hortle, Elinor; Geddes, Chris D.

2009-07-01

309

Investigation on the micelle-sensitized Ce(IV)-lornoxicam-Rh B chemiluminescence system and its application.  

PubMed

Based on the micelle synergism mechanism, a simple and sensitive flow injection chemiluminescence (FI-CL) method for the assay of lornoxicam was described. The CL signal generated from the reaction of Ce (IV) with lornoxicam in acidic solution was very weak, while the interfusion of sodium dodecyl benzene sulfonate (SDBS) resulted in a highly CL intensity. Under the optimum experimental conditions, the CL intensity was proportional to lornoxicam concentration over the range 1.0?×?10(-10)-7.3?×?10(-8) g/mL with a detection limit of 4.9?×?10(-11) g/mL (3?). The relative standard deviation for 11 replicate measurements of 3.0?×?10(-9) g/mL of lornoxicam was 1.9%. The proposed method was successfully applied for the assay of lornoxicam in pharmaceuticals, human serum and urine with excellent recovery. The possible mechanism of CL reaction was also discussed briefly. PMID:21968509

Zhao, Fang; Zhao, Wenhui

2012-01-01

310

Sensitive determination of phenolic compounds using high-performance liquid chromatography with cerium(IV)-rhodamine 6G-phenolic compound chemiluminescence detection.  

PubMed

A simple, selective and sensitive determination method of 20 phenolic compounds has been developed using high-performance liquid chromatography (HPLC) with chemiluminescence detection. The method is based on the chemiluminescent enhancement by phenolic compound of the cerium(IV)-rhodamine 6G system in sulfuric acid medium. Twenty phenolic compounds were separated on a XDB-C(8) column with a gradient elution using a mixture of methanol and 1.0% acetic acid as a mobile phase. Under the optimized conditions, a linear working range extends 2 orders of magnitude with the relative standard deviations of intra- and inter-day precision below 4.0%, and the detection limits (S/N = 3) were in the range of 1.5-82.1 ng/ml. The chemiluminescence reaction was compatible with the mobile phase of high-performance liquid chromatography. The proposed method has been successfully applied to the assay of phenolic compounds in red wine without any pretreatment. PMID:16275288

Zhang, Qunlin; Cui, Hua; Myint, Aung; Lian, Mei; Liu, Lijuan

2005-11-18

311

Simultaneous determination of quercetin, kaempferol, and isorhamnetin in phytopharmaceuticals of Hippophae rhamnoides L. by high-performance liquid chromatography with chemiluminescence detection.  

PubMed

A novel method based on reversed-phase high-performance liquid chromatography with chemiluminescence detection has been developed for the simultaneous determination of three flavonols including quercetin, kaempferol, and isorhamnetin. The procedure was based on the chemiluminescent enhancement by flavonols of the cerium(IV)-rhodamine 6G system in sulfuric acid medium. The effects of several parameters on the HPLC resolution and CL emission were studied systematically. Good separation was achieved with isocratic elution using a mixture of methanol and aqueous 1.0% acetic acid (37:63, v/v) within 25 min. Under optimized conditions, the linear working range covers 3 orders of magnitude with relative standard deviations below 4.5% for 11 replicate injected flavonol samples, and detection limits (S/N= 3) were 1.6 x 10(-8), 3.5 x 10(-9), and 6.5 x 10(-9) g mL(-1) for quercetin, kaempferol, and isorhamnetin, respectively. The chemiluminescence reaction was compatible with the mobile phase of high-performance liquid chromatography. The proposed method has been successfully applied to the determination of three active flavonols in phytopharmaceuticals of Hippophae rhamnoides L. After a simple extraction procedure, the repeatability and recovery were satisfactory. PMID:16116994

Zhang, Qunlin; Cui, Hua

2005-07-01

312

Electrogenerated chemiluminescence properties of bisalicylideneethylenediamino (salen) metal complexes  

Microsoft Academic Search

The spectroscopy, electrochemistry and electrogenerated chemiluminescence (ECL) of eight bisalicylideneethylenediamino (salen) metal complexes are reported. Two of the complexes contain an unsubstituted salen ligand and either cobalt(II) or nickel(II). The others have 1,2-cyclohexanediamonio-N,N?-bis(3,5-di-t-butylsalicylidene) as the ligand, and chromium(III), aluminum(III), cobalt(II), cobalt(III) or manganese(II) as the metal center. The complexes have lowest energy absorption maxima between 350 and 430nm. When excited

Megan Schnuriger; Eric Tague; Mark M. Richter

313

Determination of neurotransmitters and their metabolites using one- and two-dimensional liquid chromatography with acidic potassium permanganate chemiluminescence detection.  

PubMed

High-performance liquid chromatography with chemiluminescence detection based on the reaction with acidic potassium permanganate and formaldehyde was explored for the determination of neurotransmitters and their metabolites. The neurotransmitters norepinephrine and dopamine were quantified in the left and right hemispheres of rat hippocampus, nucleus accumbens and prefrontal cortex, and the metabolites vanillylmandelic acid, 3,4-dihydrophenylacetic acid, 5-hydroxyindole-3-acetic acid and homovanillic acid were identified in human urine. Under optimised chemiluminescence reagent conditions, the limits of detection for these analytes ranged from 2.5?×?10(-8) to 2.5?×?10(-7) M. For the determination of neurotransmitter metabolites in urine, a two-dimensional high-performance liquid chromatography (2D-HPLC) separation operated in heart-cutting mode was developed to overcome the peak capacity limitations of the one-dimensional separation. This approach provided the greater separation power of 2D-HPLC with analysis times comparable to conventional one-dimensional separations. PMID:24317518

Holland, Brendan J; Conlan, Xavier A; Stevenson, Paul G; Tye, Susannah; Reker, Ashlie; Barnett, Neil W; Adcock, Jacqui L; Francis, Paul S

2014-09-01

314

Evaluation of glycophenotype in prostatic neoplasm by chemiluminescent assay.  

PubMed

This work aimed to evaluate the glycophenotype in normal prostate, bening prostatic hyperplasia (BPH) and prostatic adenocarcinoma (PCa) tissues by a chemiluminescent method. Concanavalin A (Con A), Ulex europaeus agglutinin (UEA-I) and Peanut agglutinin (PNA) lectins were conjugated to acridinium ester (lectins-AE). These conjugates remained capable to recognize their specific carbohydrates. Tissue samples were incubated with lectins-AE. The chemiluminescence of the tissue-lectin-AE complex was expressed in relative light units (RLU). Transformed tissues (0.25 cm(2) by 8 µm of thickness) showed statistical significant lower ?-D-glucose/mannose (BPH: 226,931 ± 17,436; PCa: 239,520 ± 12,398) and Gal-?(1-3)-GalNAc (BPH: 28,754 ± 2,157; PCa: 16,728 ± 1,204) expression than normal tissues (367,566 ± 48,550 and 409,289 ± 22,336, respectively). However, higher ?-L-fucose expression was observed in PCa (251,118 ± 14,193) in relation to normal (200,979 ± 21,318) and BHP (169,758 ± 10,264) tissues. It was observed an expressive decreasing of the values of RLU by inhibition of the interaction between tissues and lectins-AE using their specific carbohydrates. The relationship between RLU and tissue area showed a linear correlation for all lectin-AE in both transformed tissues. These results indicated that the used method is an efficient tool for specific, sensitive and quantitative analyses of prostatic glycophenotype. PMID:25120756

da Silva, Lúcia Patrícia Bezerra Gomes; de Almeida, Sinara Mônica Vitalino; de Lima, Luiza Rayanna Amorim; Cavalcanti, Carmelita de Lima Bezerra; de Melo Lira, Mariana Montenegro; da Silva, Maria da Paz Carvalho; Beltrão, Eduardo Isidoro Carneiro; de Carvalho Júnior, Luiz Bezerra

2014-01-01

315

Evaluation of glycophenotype in prostatic neoplasm by chemiluminescent assay  

PubMed Central

This work aimed to evaluate the glycophenotype in normal prostate, bening prostatic hyperplasia (BPH) and prostatic adenocarcinoma (PCa) tissues by a chemiluminescent method. Concanavalin A (Con A), Ulex europaeus agglutinin (UEA-I) and Peanut agglutinin (PNA) lectins were conjugated to acridinium ester (lectins-AE). These conjugates remained capable to recognize their specific carbohydrates. Tissue samples were incubated with lectins-AE. The chemiluminescence of the tissue-lectin-AE complex was expressed in relative light units (RLU). Transformed tissues (0.25 cm2 by 8 µm of thickness) showed statistical significant lower ?-D-glucose/mannose (BPH: 226,931 ± 17,436; PCa: 239,520 ± 12,398) and Gal-?(1-3)-GalNAc (BPH: 28,754 ± 2,157; PCa: 16,728 ± 1,204) expression than normal tissues (367,566 ± 48,550 and 409,289 ± 22,336, respectively). However, higher ?-L-fucose expression was observed in PCa (251,118 ± 14,193) in relation to normal (200,979 ± 21,318) and BHP (169,758 ± 10,264) tissues. It was observed an expressive decreasing of the values of RLU by inhibition of the interaction between tissues and lectins-AE using their specific carbohydrates. The relationship between RLU and tissue area showed a linear correlation for all lectin-AE in both transformed tissues. These results indicated that the used method is an efficient tool for specific, sensitive and quantitative analyses of prostatic glycophenotype. PMID:25120756

da Silva, Lúcia Patrícia Bezerra Gomes; de Almeida, Sinara Mônica Vitalino; de Lima, Luiza Rayanna Amorim; Cavalcanti, Carmelita de Lima Bezerra; Lira, Mariana Montenegro de Melo; da Silva, Maria da Paz Carvalho; Beltrão, Eduardo Isidoro Carneiro; Júnior, Luiz Bezerra de Carvalho

2014-01-01

316

Fixed-angle observation of surface plasmon coupled chemiluminescence from palladium thin films  

NASA Astrophysics Data System (ADS)

In this letter, the fixed-angle observation of surface plasmon coupled chemiluminescence (SPCC) from palladium thin films is reported. Fresnel calculations predict that light 492-549 nm spectral range can efficiently induce surface plasmon modes in 15 nm palladium thin films. Free-space emission from blue, green, and chartreuse chemiluminescent solutions on palladium thin films was isotropic, while the SPCC emission was highly directional and predominantly p-polarized in accordance with the predictions of the Fresnel calculations. In addition, the decay rates of the SPCC and free-space emission were similar, which suggests that palladium thin films have no catalytic effect on chemiluminescence emission.

Aslan, Kadir; Weisenberg, Micah; Hortle, Elinor; Geddes, Chris D.

2009-09-01

317

Retrovirus-Induced Oxidative Stress with Neuroimmunodegeneration Is Suppressed by Antioxidant Treatment with a Refined Monosodium ?-Luminol (Galavit)  

PubMed Central

Oxidative stress is involved in many human neuroimmunodegenerative diseases, including human immunodeficiency virus disease/AIDS. The retrovirus ts1, a mutant of Moloney murine leukemia virus, causes oxidative stress and progressive neuro- and immunopathology in mice infected soon after birth. These pathological changes include spongiform neurodegeneration, astrogliosis, thymic atrophy, and T-cell depletion. Astrocytes and thymocytes are directly infected and killed by ts1. Neurons are not infected, but they also die, most likely as an indirect result of local glial infection. Cytopathic effects of ts1 infection in cultured astrocytes are associated with accumulation of the viral envelope precursor protein gPr80env in the endoplasmic reticulum (ER), which triggers ER stress and oxidative stress. We have reported (i) that activation of the Nrf2 transcription factor and upregulation of antioxidative defenses occurs in astrocytes infected with ts1 in vitro and (ii) that some ts1-infected astrocytes survive infection by mobilization of these pathways. Here, we show that treatment with a refined monosodium ?-luminol (Galavit; GVT) suppresses oxidative stress and Nrf2 activation in cultured ts1-infected astrocytes. GVT treatment also inhibits the development of spongiform encephalopathy and gliosis in the central nervous system (CNS) in ts1-infected mice, preserves normal cytoarchitecture in the thymus, and delays paralysis, thymic atrophy, wasting, and death. GVT treatment of infected mice reduces ts1-induced oxidative stress, cell death, and pathogenesis in both the CNS and thymus of treated animals. These studies suggest that oxidative stress mediates ts1-induced neurodegeneration and T-cell loss. PMID:16611916

Jiang, Yuhong; Scofield, Virginia L.; Yan, Mingshan; Qiang, Wenan; Liu, Na; Reid, Amy J.; Lynn, William S.; Wong, Paul K. Y.

2006-01-01

318

Neuroprotective effects of the drug GVT (monosodium luminol) is mediated by the stabilization of Nrf2 in astrocytes  

PubMed Central

Oxidative stress is implicated in various kinds of neurological disorders, including human immunodeficiency virus (HIV) associated dementia (HAD). Our laboratory has been studying the murine retrovirus ts1, a pathogenic mutant of the Moloney murine leukemia virus (MoMuLV), as a model for HAD. Like HIV in humans, ts1 induces oxidative stress and progressive neurodegeneration in mice. We have shown previously that an antioxidant and anti-inflammatory drug GVT or MSL (monosodium luminol) suppresses ts1-induced oxidative stress, attenuates the development of spoorm encephalopathy, and delays hind limb paralysis in infected mice. It is known that upregulation of the nuclear transcription factor NF-E2-related factor 2 (Nrf2) is involved in upregulating cellular antioxidant defenses. Since Nrf2 is associated with elevation of antioxidant defenses in general, and since GVT suppresses ts1-induced neurodegeneration, our aim in this study was to determine whether GVT neuroprotection is linked to Nrf2 upregulation in the brain. We report here that GVT upregulates the levels of Nrf2, both in primary astrocyte cultures and in brainstem of ts1-infected mice. Significant upregulation of Nrf2 expression by GVT occurs in both the cytosolic and nuclear fractions of cultured astrocytes and brainstem cells. Notably, although GVT treatment increases Nrf2 protein levels in cultured astrocytes and brainstem tissues, Nrf2 mRNA levels are not altered. This suggests that the neuroprotective effects of GVT may be mediated by the stabilization of the Nrf2 protein, allowing continuous upregulation of Nrf2 levels in the astrocytes. PMID:20211212

Reddy, Pichili Vijaya Bhaskar; Lungu, Gina; Kuang, Xianghong; Stoica, George; Wong, Paul KY

2014-01-01

319

Retrovirus-induced oxidative stress with neuroimmunodegeneration is suppressed by antioxidant treatment with a refined monosodium alpha-luminol (Galavit).  

PubMed

Oxidative stress is involved in many human neuroimmunodegenerative diseases, including human immunodeficiency virus disease/AIDS. The retrovirus ts1, a mutant of Moloney murine leukemia virus, causes oxidative stress and progressive neuro- and immunopathology in mice infected soon after birth. These pathological changes include spongiform neurodegeneration, astrogliosis, thymic atrophy, and T-cell depletion. Astrocytes and thymocytes are directly infected and killed by ts1. Neurons are not infected, but they also die, most likely as an indirect result of local glial infection. Cytopathic effects of ts1 infection in cultured astrocytes are associated with accumulation of the viral envelope precursor protein gPr80env in the endoplasmic reticulum (ER), which triggers ER stress and oxidative stress. We have reported (i) that activation of the Nrf2 transcription factor and upregulation of antioxidative defenses occurs in astrocytes infected with ts1 in vitro and (ii) that some ts1-infected astrocytes survive infection by mobilization of these pathways. Here, we show that treatment with a refined monosodium alpha-luminol (Galavit; GVT) suppresses oxidative stress and Nrf2 activation in cultured ts1-infected astrocytes. GVT treatment also inhibits the development of spongiform encephalopathy and gliosis in the central nervous system (CNS) in ts1-infected mice, preserves normal cytoarchitecture in the thymus, and delays paralysis, thymic atrophy, wasting, and death. GVT treatment of infected mice reduces ts1-induced oxidative stress, cell death, and pathogenesis in both the CNS and thymus of treated animals. These studies suggest that oxidative stress mediates ts1-induced neurodegeneration and T-cell loss. PMID:16611916

Jiang, Yuhong; Scofield, Virginia L; Yan, Mingshan; Qiang, Wenan; Liu, Na; Reid, Amy J; Lynn, William S; Wong, Paul K Y

2006-05-01

320

Energy distribution among reaction products. VII - H + F2.  

NASA Technical Reports Server (NTRS)

The 'arrested relaxation' variant of the IR chemiluminescence technique is used in a study of the distribution of vibrational, rotational and translational energies between the products of the reaction by which H + F2 yields HF + F. Diagrams are plotted and numerical values are obtained for the energy distribution rate constants.

Polanyi, J. C.; Sloan, J. J.

1972-01-01

321

The mechanism of electronic excitation in the bacterial bioluminescent reaction  

NASA Astrophysics Data System (ADS)

The current state of the problem of formation of the electron-excited product in the chemiluminescent reaction that underlies the bacterial luminescence is analysed. Various schemes of chemical transformations capable of producing a bacterial bioluminescence emitter are presented. The problem of excitation of secondary emitters is considered; two possible mechanisms of their excitation are analysed.

Nemtseva, E. V.; Kudryasheva, N. S.

2007-01-01

322

Method for detecting pollutants. [through chemical reactions and heat treatment  

NASA Technical Reports Server (NTRS)

A method is described for detecting and measuring trace amounts of pollutants of the group consisting of ozone, nitrogen dioxide, and carbon monoxide in a gaseous environment. A sample organic solid material that will undergo a chemical reaction with the test pollutant is exposed to the test environment and thereafter, when heated in the temperature range of 100-200 C., undergoes chemiluminescence that is measured and recorded as a function of concentration of the test pollutant. The chemiluminescence of the solid organic material is specific to the pollutant being tested.

Rogowski, R. S.; Richards, R. R.; Conway, E. J. (inventors)

1976-01-01

323

Application of a Chemiluminescence Detector for the Measurement of Total Oxides of Nitrogen and Ammonia in the Atmosphere  

NASA Technical Reports Server (NTRS)

By means of the thermal conversion of nitrogen dioxide to the nitric oxide, the chemiluminescent nitric oxide monitor, based on the nitric oxide plus ozone reaction, may be used for monitoring nitrogen dioxide plus nitric oxide (NO(x)). Under conditions previously described, ammonia is also converted to nitric oxide and therefore interferes. A metal surface, gold wool or stainless steel, operated at two different temperatures has been used to convert only nitrogen dioxide or nitrogen dioxide plus ammonia. Quantitative conversion of nitrogen dioxide to nitric oxide has been obtained at temperatures as low as 200 C. Conversion of ammonia is effected at temperatures of 300 C or higher. By the addition of a converter the basic nitric oxide monitor may be used for measuring NO(x) or NO(x) plus ammonia. As an alternate mode, for a fixed high temperature, a specific scrubber is described for removing NH3 without affecting NO2 concentrations.

Hodgeson, J. A.; Bell, J. P.; Rehme, K. A.; Krost, K. J.; Stevens, R. K.

1971-01-01

324

Automated, high performance, flow-through chemiluminescence microarray for the multiplexed detection of phycotoxins.  

PubMed

A novel multiplexed immunoassay for the analysis of phycotoxins in shellfish samples has been developed. Therefore, a regenerable chemiluminescence (CL) microarray was established which is able to analyze automatically three different phycotoxins (domoic acid (DA), okadaic acid (OA) and saxitoxin (STX)) in parallel on the analysis platform MCR3. As a test format an indirect competitive immunoassay format was applied. These phycotoxins were directly immobilized on an epoxy-activated PEG chip surface. The parallel analysis was enabled by the simultaneous addition of all analytes and specific antibodies on one microarray chip. After the competitive reaction, the CL signal was recorded by a CCD camera. Due to the ability to regenerate the toxin microarray, internal calibrations of phycotoxins in parallel were performed using the same microarray chip, which was suitable for 25 consecutive measurements. For the three target phycotoxins multi-analyte calibration curves were generated. In extracted shellfish matrix, the determined LODs for DA, OA and STX with values of 0.5±0.3 ?g L(-1), 1.0±0.6 ?g L(-1), and 0.4±0.2 ?g L(-1) were slightly lower than in PBS buffer. For determination of toxin recoveries, the observed signal loss in the regeneration was corrected. After applying mathematical corrections spiked shellfish samples were quantified with recoveries for DA, OA, and STX of 86.2%, 102.5%, and 61.6%, respectively, in 20 min. This is the first demonstration of an antibody based phycotoxin microarray. PMID:23830441

Szkola, Agathe; Campbell, Katrina; Elliott, Christopher T; Niessner, Reinhard; Seidel, Michael

2013-07-17

325

An Ultrasensitive Chemiluminescence Biosensor for Carcinoembryonic Antigen Based on Autocatalytic Enlargement of Immunogold Nanoprobes  

PubMed Central

A sensitive flow injection chemiluminescence assay for carcinoembryonic antigen (CEA) detection based on signal amplification with gold nanoparticles (NPs) is reported in the present work. The sandwich system of CEA/anti-CEA/goat-anti-mouse IgG functionalized Au nanoparticles was used as the sensing platform. In order to improve detection sensitivity, a further gold enlargement step was developed based on the autocatalytic Au deposition of gold nanoprobes via the reduction of AuCl4? to Au0 on their surface in the presence of NH2OH·HCl. AuCl4?, which is a soluble product of gold nanoprobes, served as an analyte in the CL reaction for the indirect measurement of CEA. Under optimized conditions, the CL intensity of the system was linearly related to the logarithm of CEA concentration in the range of 100 pg·mL?1 to 1,000 ng·mL?1, with a detection limit of 20 pg·mL?1. PMID:23443399

Hao, Minjia; Ma, Zhanfang

2012-01-01

326

An intramolecular charge/electron transfer chemiluminescence mechanism of oxidophenyl-substituted 1,2-dioxetane.  

PubMed

The chemiluminescence (CL) mechanism of oxidophenyl-substituted 1,2-dioxetane was investigated by performing TD-DFT calculations on biradicals of three model compounds. We propose a novel mechanism of CL in which excitation of a dissociative intermediate by infrared radiation (IRE) of the surrounding solvent is considered. The excitation energies and oscillator strengths (f-values) were estimated for intermediates along the reaction coordinate (Rx). The difference in efficiencies of CL between syn- and anti-isomers of m-oxidophenyl-dioxetane is explained using the difference in potential curves of the singlet excited states (S) and the IRE mechanism. At the point where the biradical of the anti-isomer decomposes into two fragments, the interaction between the S and triplet (T) states is induced by a significant back electron transfer (BET) from the dioxetane group to the oxido-phenyl group and the S(1) excited state is stabilized and CL efficiency is enhanced. In the syn-isomer, the barrier in the S(1) potential curve to reach the final CL state is higher than for the anti-isomer, which reduces the efficiency. The poor CL yield for the p-isomer is ascribed to a much higher barrier in the potential curve of the S(1) state. PMID:21829826

Tanaka, Chizuko; Tanaka, Jiro; Matsumoto, Masakatsu

2011-09-21

327

A microchip electrophoresis strategy with online labeling and chemiluminescence detection for simultaneous quantification of thiol drugs.  

PubMed

An integrated microfluidic device with online labeling and chemiluminescence (CL) detection was developed for the simultaneous quantification of thiol drugs. In this device, the online labeling, electrophoresis separation and CL detection were compactly integrated onto a glass/poly(dimethylsiloxane) (PDMS) hybrid microfluidic chip. CL detection was based on the oxidation reaction of N-(4-aminobutyl)-N-ethylisoluminol (ABEI) and o-phthalaldehyde (OPA) labeled thiol drugs with NaBrO. Four thiol drugs including 2-mercaptopropionylglycine (2-MPG), captopril (CP), 6-thioguanine (6-TG) and 6-mercaptopurine (6-MP) were employed as model compounds to examine the utility of the system. It was indicated that the separation and detection of four drugs can be completed within 90s. Detection limits (S/N=3) for the thiol drugs tested were in the range of 8.9×10(-9)-13.5×10(-9)M. The application of the present system was demonstrated by analyzing the thiol drugs in human plasma samples. PMID:21458189

Huang, Yong; Zhao, Shulin; Shi, Ming; Liang, Hong

2011-07-15

328

Simultaneous chemiluminescence determination of thebaine and noscapine using support vector machine regression  

NASA Astrophysics Data System (ADS)

In this work, a batch chemiluminescence (CL) method has been proposed for the simultaneous determination of two structurally similar alkaloids, noscapine and thebaine. The method is based on the kinetic distinction of the CL reactions of noscapine and thebaine with Ru(bipy) 32+ and Ce(IV) system in a sulfuric acid medium. The least squared support vector machine (LS-SVM) regression was applied for relating the concentrations of both compounds to their CL profiles. The parameters of the model consisting of ?2 and ? were optimized by constructing LS-SVM models with all possible combinations of these two parameters to select the model with the minimum root mean squared error of cross validation (RMSECV) as the best. The parameters of this model were then selected as optimized values. Under the optimized experimental conditions for both compounds, the detection limits obtained using the LS-SVM regression were 0.08 and 0.1 ?mol L -1 for noscapine and thebaine, respectively. The proposed method was utilized for the simultaneous determination of the compounds in pharmaceutical formulations and plasma samples with satisfactory results.

Ensafi, Ali A.; Hasanpour, F.; Khayamian, T.; Mokhtari, A.; Taei, M.

2010-02-01

329

Copy Number Variation Analysis by Ligation-Dependent PCR Based on Magnetic Nanoparticles and Chemiluminescence  

PubMed Central

A novel system for copy number variation (CNV) analysis was developed in the present study using a combination of magnetic separation and chemiluminescence (CL) detection technique. The amino-modified probes were firstly immobilized onto carboxylated magnetic nanoparticles (MNPs) and then hybridized with biotin-dUTP products, followed by amplification with ligation-dependent polymerase chain reaction (PCR). After streptavidin-modified alkaline phosphatase (STV-AP) bonding and magnetic separation, the CL signals were then detected. Results showed that the quantification of PCR products could be reflected by CL signal values. Under optimum conditions, the CL system was characterized for quantitative analysis and the CL intensity exhibited a linear correlation with logarithm of the target concentration. To validate the methodology, copy numbers of six genes from the human genome were detected. To compare the detection accuracy, multiplex ligation-dependent probe amplification (MLPA) and MNPs-CL detection were performed. Overall, there were two discrepancies by MLPA analysis, while only one by MNPs-CL detection. This research demonstrated that the novel MNPs-CL system is a useful analytical tool which shows simple, sensitive, and specific characters which are suitable for CNV analysis. Moreover, this system should be improved further and its application in the genome variation detection of various diseases is currently under further investigation. PMID:25553099

Liu, Ming; Hu, Ping; Zhang, Gen; Zeng, Yu; Yang, Haowen; Fan, Jing; Jin, Lian; Liu, Hongna; Deng, Yan; Li, Song; Zeng, Xin; Elingarami, Sauli; He, Nongyue

2015-01-01

330

Copy number variation analysis by ligation-dependent PCR based on magnetic nanoparticles and chemiluminescence.  

PubMed

A novel system for copy number variation (CNV) analysis was developed in the present study using a combination of magnetic separation and chemiluminescence (CL) detection technique. The amino-modified probes were firstly immobilized onto carboxylated magnetic nanoparticles (MNPs) and then hybridized with biotin-dUTP products, followed by amplification with ligation-dependent polymerase chain reaction (PCR). After streptavidin-modified alkaline phosphatase (STV-AP) bonding and magnetic separation, the CL signals were then detected. Results showed that the quantification of PCR products could be reflected by CL signal values. Under optimum conditions, the CL system was characterized for quantitative analysis and the CL intensity exhibited a linear correlation with logarithm of the target concentration. To validate the methodology, copy numbers of six genes from the human genome were detected. To compare the detection accuracy, multiplex ligation-dependent probe amplification (MLPA) and MNPs-CL detection were performed. Overall, there were two discrepancies by MLPA analysis, while only one by MNPs-CL detection. This research demonstrated that the novel MNPs-CL system is a useful analytical tool which shows simple, sensitive, and specific characters which are suitable for CNV analysis. Moreover, this system should be improved further and its application in the genome variation detection of various diseases is currently under further investigation. PMID:25553099

Liu, Ming; Hu, Ping; Zhang, Gen; Zeng, Yu; Yang, Haowen; Fan, Jing; Jin, Lian; Liu, Hongna; Deng, Yan; Li, Song; Zeng, Xin; Elingarami, Sauli; He, Nongyue

2015-01-01

331

Singlet oxygen generated from the decomposition of peroxymonocarbonate and its observation with chemiluminescence method  

NASA Astrophysics Data System (ADS)

The decomposition of peroxymonocarbonate (HCO 4-) has been investigated by flow-injection chemiluminescence (CL) method. An ultraweak CL was observed during mixing the bicarbonate and hydrogen peroxide solution in organic cosolvent. An appropriate amount of fluorescent organic compounds, such as dichlorofluorescein (DCF), was added to the HCO 4- solution, a strong CL was recorded. Based on studies of the spectrum of fluorescence, CL and UV-vis spectra, electron spin trapping (ESR) technique, mass spectra (MS) and comparison with H 2O 2/hypochlorite (ClO -) and H 2O 2/molybdate (MoO 4-) systems, the CL mechanism was proposed. The reaction is initiated by unimolecular homolysis of the peroxo O sbnd O bond in HO sbnd OCOO - molecule. It was suggested that the bond rearrangement within radicals yield superoxide ion (O 2rad -). The interaction of superoxide ion with perhydroxyl radical produces singlet oxygen ( 1O 2). The energy transfers from singlet oxygen to DCF forming an excited energy acceptor (DCF*). Luminescence ( ?max = 509 nm) was emitted during the relaxation of the energy acceptor to the ground state.

Lin, Jin-Ming; Liu, Meilin

2009-02-01

332

Synthesis of Chemiluminescent Esters: A Combinatorial Synthesis Experiment for Organic Chemistry Students  

ERIC Educational Resources Information Center

A group of techniques aimed at synthesizing a large number of structurally diverse compounds is called combinatorial synthesis. Synthesis of chemiluminescence esters using parallel combinatorial synthesis and mix-and-split combinatorial synthesis is experimented.

Duarte, Robert; Nielson, Janne T.; Dragojlovic, Veljko

2004-01-01

333

Ester oxidation on an aluminum surface using chemiluminescence  

NASA Technical Reports Server (NTRS)

The oxidation characteristics of a pure ester (trimethyolpropane triheptanoate) were studied by using a chemiluminescence technique. Tests were run in a thin film microoxidation apparatus with an aluminum alloy catalyst. Conditions included a pure oxygen atmosphere and a temperature range of 176 to 206 C. Results indicated that oxidation of the ester (containing .001 M diphenylanthracene as an intensifier) was accompanied by emission of light. The maximum intensity of light emission was a function of the amount of ester, the concentration of intensifier, and the test temperature. The induction period, or the time to reach one-half of maximum intensity was inversely proportional to test temperature. Decreases in light emission at the later stages of a test were caused by depletion of the intensifier.

Jones, William R., Jr.; Meador, Michael A.; Morales, Wilfredo

1986-01-01

334

Determination of diquat by flow injection-chemiluminescence.  

PubMed

A simple, economic, sensitive and rapid method for the determination of the pesticide diquat was described. This new method was based on the coupling of flow injection analysis methodology and direct chemiluminescent detection; to the authors' knowledge, this approach had not been used up to now with this pesticide. It was based on its oxidation with ferricyanide in alkaline medium; significant improvements in the analytical signal were achieved by using high temperatures and quinine as sensitiser. Its high throughput (144 h(-1)), together with its low limit of detection (2 ng mL(-1)), achieved without need of preconcentration steps, permitted the reliable quantification of diquat over the linear range of (0.01-0.6) microg mL(-1) in samples from different origins (river, tap, mineral and ground waters), even in the presence of a 40-fold concentration of paraquat, a pesticide commonly present in the commercial formulations of diquat. PMID:19172252

López-Paz, J L; Catalá-Icardo, M; Antón-Garrido, B

2009-06-01

335

Reaction of fluorine and chlorine atoms with formaldehyde and deutero-formaldehyde  

SciTech Connect

The following reactions were studied by using infrared multiple photon dissociation to produce fluorine atoms, and infrared chemiluminescence to monitor the rate of reaction: Cl + H/sub 2/O ..-->.. HCl + HCO; F + H/sub 2/CO ..-->.. HF + HCO; Cl + D/sub 2/CO ..-->.. DCl + DCO; and F + D/sub 2/CO ..-->.. DF + DCO.

Nogar, N.S.; Fasano, D.M.

1983-01-01

336

Optical tomography of fluorophores in dense scattering media based on ultrasound-enhanced chemiluminescence  

NASA Astrophysics Data System (ADS)

This letter proposes and demonstrates ultrasound-combined optical imaging in dense scattering media. A peroxyoxalate chemiluminescence system that includes fluorophores to chemically excite the pigment is stimulated by ultrasound irradiation with power of less than 0.14 W/cm2. Using focused ultrasound, the chemiluminescence is selectively spatially enhanced, which leads to imaging of the pigment when embedded in a light-scattering medium via scanning of the focal point. The ultrasonically enhanced intensity of the chemiluminescence depends on the base intensity of the chemiluminescence without the applied ultrasound irradiation, which thereby enables quantitative determination of the fluorophore concentration. The authors demonstrate the potential of this method to resolve chemiluminescent targets in a dense scattering medium that is comparable to biological tissue. An image was acquired of a chemiluminescent target that included indocyanine green as the fluorophore embedded at a depth of 20 mm in an Intralipid-10% 200 ml/l solution scattering medium (the reduced scattering coefficient was estimated to be approximately 1.3 mm-1), indicating the potential for expansion of this technique for use in biological applications.

Kobayashi, Masaki; Kikuchi, Naoto; Sato, Akihiro

2015-01-01

337

Development and optimization of an integrated capillary-based opto-microfluidic device for chemiluminescence quantitative detection  

NASA Astrophysics Data System (ADS)

A capillary-action driven device amenable for integration of organic photodiodes (OPDs) was developed for monitoring parallel chemiluminescence (CL) reactions. Device characterization was conducted using finite element method (FEM) simulations. Definition of the simulation setup, dimensional optimization of the reaction chamber and overall geometrical characterization of the microfluidic device were the main simulation results. Furthermore, a non-uniform filling process was observed during the final simulation of the capillary device. Validation of this result and the proposed capillary-driven filling process was later confirmed by experimental results. Experimental testing performed on a single chamber defined an optimal exposure time to the luminescent substrate of 5?min, indicating a quick analyte detection time. Further tests using one chamber presented a linear relation between the signal-to-noise ratio and increasing concentrations of the protein used. A measured limit of detection of 28?nM was obtained for streptavidin. Regarding the tests performed on the whole device, acceptable values of 39?s ± 5?s were obtained for the luminescent substrate total filling times. Also, the microfluidic device showed the capability to perform a quantitative detection of the occurring CL reactions. Weaker optical signals, due to the occurrence of CL reactions, were detected in the chambers with a later filling process, as predicted by simulation results. Notwithstanding these results, the capillary-based device is promising for quantitative detection of proteins in future point-of-care systems, presenting an unprompted filling process and parallel quantitative detection capability.

Honrado, Carlos; Dong, Tao

2014-12-01

338

Application of bis[4-nitro-2-(3,6,9-trioxadecyloxycarbonyl)-phenyl]oxalate to post-column chemiluminescence detection in high-performance liquid chromatography.  

PubMed

Bis[4-nitro-2-(3,6,9-trioxadecyloxycarbonyl)phenyl] oxalate (TDPO) was used to examine the peroxyoxalate chemiluminescence (CL) reaction for the detection of fluorescent compounds. Some fluorescent compounds (perylene, eosine, rhodamine, Rose Bengal, fluorescein and umbelliferone) gave higher CL intensities as the proportion of water in the reaction medium increased to ca. 40%, whereas dansylalanine, 8-anilinonaphthalene-1-sulphonic acid, 7-nitrobenzo-2-oxa-1,3-diazol-4-ylproline and dihydronicotinamide adenine dinucleotide gave opposite results. The effects of temperature and time on the post-column reaction in reversed-phase high-performance liquid chromatography (HPLC) were investigated. Under the optimal conditions, the detection limit for dansylamino acids was at the sub-femtomole level. The advantage of using TDPO in HPLC is its stability in the presence of hydrogen peroxide [ca. 10% loss of activity per 8 h vs. 60% per 8 h for bis(2,4,6-trichlorophenyl) oxalate]. PMID:3667744

Imai, K; Matsunaga, Y; Tsukamoto, Y; Nishitani, A

1987-07-29

339

Development of a multichannel Fourier-transform spectrometer to measure weak chemiluminescence: Application to the emission of singlet-oxygen dimol in the decomposition of hydrogen peroxide with gallic acid and K 3[Fe(CN) 6  

NASA Astrophysics Data System (ADS)

A Fourier-transform spectrometer equipped with a Savart-plate polarization interferometer was developed for observation of weak chemiluminescence and applied to a measurement of emission spectra in the decomposition of hydrogen peroxide with gallic acid and K 3[Fe(CN) 6]. The band appearing at ˜580 nm in the chemiluminescence spectrum was assigned to the emission of singlet-oxygen dimol, the peak wavelength being shifted from that observed in the reaction of hydrogen peroxide with sodium hypochlorite, ˜633 nm. The band intensity was increased with the increasing concentration of K 3[Fe(CN) 6] up to ˜100 mM, and thereafter the peak wavelength was shifted from 580 to 700 nm with a decrease in the intensity.

Tsukino, Kazuo; Satoh, Toshihiro; Ishii, Hiroshi; Nakata, Munetaka

2008-05-01

340

The Oxidant-Scavenging Abilities in the Oral Cavity May Be Regulated by a Collaboration among Antioxidants in Saliva, Microorganisms, Blood Cells and Polyphenols: A Chemiluminescence-Based Study  

PubMed Central

Saliva has become a central research issue in oral physiology and pathology. Over the evolution, the oral cavity has evolved the antioxidants uric acid, ascorbate reduced glutathione, plasma-derived albumin and antioxidants polyphenols from nutrients that are delivered to the oral cavity. However, blood cells extravasated from injured capillaries in gingival pathologies, or following tooth brushing and use of tooth picks, may attenuate the toxic activities of H2O2 generated by oral streptococci and by oxidants generated by activated phagocytes. Employing a highly sensitive luminol-dependent chemiluminescence, the DPPH radical and XTT assays to quantify oxidant-scavenging abilities (OSA), we show that saliva can strongly decompose both oxygen and nitrogen species. However, lipophilic antioxidant polyphenols in plants, which are poorly soluble in water and therefore not fully available as effective antioxidants, can nevertheless be solubilized either by small amounts of ethanol, whole saliva or also by salivary albumin and mucin. Plant-derived polyphenols can also act in collaboration with whole saliva, human red blood cells, platelets, and also with catalase-positive microorganisms to decompose reactive oxygen species (ROS). Furthermore, polyphenols from nutrient can avidly adhere to mucosal surfaces, are retained there for long periods and may function as a “slow- release devises” capable of affecting the redox status in the oral cavity. The OSA of saliva is due to the sum result of low molecular weight antioxidants, albumin, polyphenols from nutrients, blood elements and microbial antioxidants. Taken together, saliva and its antioxidants are considered regulators of the redox status in the oral cavity under physiological and pathological conditions. PMID:23658797

Ginsburg, Isaac; Kohen, Ron; Shalish, Miri; Varon, David; Shai, Ella; Koren, Erez

2013-01-01

341

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)

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.

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

2014-11-01

342

Direct chemiluminescence detection of nitric oxide in aqueous solutions using the natural nitric oxide target soluble guanylyl cyclase.  

PubMed

Nitric oxide (NO) is a free radical involved in many physiological processes including regulation of blood pressure, immune response, and neurotransmission. However, the measurement of extremely low, in some cases subnanomolar, physiological concentrations of nitric oxide presents an analytical challenge. The purpose of this methods article is to introduce a new highly sensitive chemiluminescence approach to direct NO detection in aqueous solutions using a natural nitric oxide target, soluble guanylyl cyclase (sGC), which catalyzes the conversion of guanosine triphosphate to guanosine 3',5'-cyclic monophosphate and inorganic pyrophosphate. The suggested enzymatic assay uses the fact that the rate of the reaction increases by about 200 times when NO binds with sGC and, in so doing, provides a sensor for nitric oxide. Luminescence detection of the above reaction is accomplished by converting inorganic pyrophosphate into ATP with the help of ATP sulfurylase followed by light emission from the ATP-dependent luciferin-luciferase reaction. Detailed protocols for NO quantification in aqueous samples are provided. The examples of applications include measurement of NO generated by a nitric oxide donor (PAPA-NONOate), nitric oxide synthase, and NO gas dissolved in buffer. The method allows for the measurement of NO concentrations in the nanomolar range and NO generation rates as low as 100 pM/min. PMID:19751819

Woldman, Yakov Y; Sun, Jian; Zweier, Jay L; Khramtsov, Valery V

2009-11-15

343

Antibacterial properties of breast milk: requirements for surface phagocytosis and chemiluminescence.  

PubMed

The opsonic components of breast milk responsible for phagocytosis of surface-adherent Staphylococcus aureus by human polymorphonuclear leukocytes were investigated. There was significantly greater phagocytosis of bacteria pre-opsonized with 100% breast milk than of unopsonized bacteria (p less than 0.001). Heat inactivation of breast milk had no effect on surface phagocytosis, indicating that phagocytosis is independent of complement. The predominant immunoglobulin in breast milk, secretory immunoglobulin A (IgA), did not promote phagocytosis. In contrast, IgG, which is present in very low amounts in breast milk (0.05 mg/ml), was as opsonic as 100% breast milk, suggesting that this is the major opsonin. An oxidative burst as measured by chemiluminescence was observed during phagocytosis of bacteria pre-opsonized with 100% breast milk. Heat inactivation of breast milk reduced the chemiluminescence response to the level of control. Neither secretory IgA nor IgG stimulated a polymorphonuclear leukocyte chemiluminescence response to surface-adherent bacteria. These experiments indicate that IgG is the principal component of breast milk responsible for surface phagocytosis but that complement is required for the generation of chemiluminescence and thus may be essential for intracellular killing of bacteria. Secretory IgA, despite its abundance in breast milk, has no effect on surface phagocytosis or neutrophil chemiluminescence. PMID:1802694

Avery, V M; Gordon, D L

1991-12-01

344

Development of a detector for liquid chromatography based on aerosol chemiluminescence on porous alumina.  

PubMed

This paper describes a novel aerosol chemiluminescence-based detector, which can be coupled to liquid chromatography for the determination of the chemicals with weak optical absorbance in the UV-visible region. This aerosol chemiluminescence (CL)-based detector, in which HPLC effluent is converted to aerosol and then generated CL emission on the surface of porous alumina, is composed of three main processes: nebulization of HPLC effluent, CL emission on surface of porous alumina material, and optical detection. To demonstrate the utility of the aerosol chemiluminescence detector, some compounds such saccharides, poly(ethylene glycol)s, amino acids, and steroid pharmaceuticals are determined by the present aerosol chemiluminescence detection method. Compared with an evaporative light scattering detector, the proposed detector shows the following features: (a) extensive CL emissions on porous alumina by many compounds tested, which leads to the potential application for the determination of volatile and nonvolatile chemicals with or without UV-visible absorbance; (b) a CL mechanism based on the catalytic oxidation of analytes, not on the light scattering, which suggests the present detector be free from the interference of the inorganic and nonvolatile mobile-phase modifiers. The CL characteristics and effect of different parameters, such as temperature and nebulizer gas flow rate, were also discussed in this paper. Furthermore, this aerosol chemiluminescence-based detector was successfully applied to the determination of raffinose, glucose, sucrose, maltose, and alpha-lactose. PMID:15732939

Lv, Yi; Zhang, Sichun; Liu, Guohong; Huang, Minwen; Zhang, Xinrong

2005-03-01

345

Chemiluminescence microarrays in analytical chemistry: a critical review.  

PubMed

Multi-analyte immunoassays on microarrays and on multiplex DNA microarrays have been described for quantitative analysis of small organic molecules (e.g., antibiotics, drugs of abuse, small molecule toxins), proteins (e.g., antibodies or protein toxins), and microorganisms, viruses, and eukaryotic cells. In analytical chemistry, multi-analyte detection by use of analytical microarrays has become an innovative research topic because of the possibility of generating several sets of quantitative data for different analyte classes in a short time. Chemiluminescence (CL) microarrays are powerful tools for rapid multiplex analysis of complex matrices. A wide range of applications for CL microarrays is described in the literature dealing with analytical microarrays. The motivation for this review is to summarize the current state of CL-based analytical microarrays. Combining analysis of different compound classes on CL microarrays reduces analysis time, cost of reagents, and use of laboratory space. Applications are discussed, with examples from food safety, water safety, environmental monitoring, diagnostics, forensics, toxicology, and biosecurity. The potential and limitations of research on multiplex analysis by use of CL microarrays are discussed in this review. PMID:25002333

Seidel, Michael; Niessner, Reinhard

2014-09-01

346

Chemiluminescent simultaneous determination of phosphatidylcholine hydroperoxide and phosphatidylethanolamine hydroperoxide in the liver and brain of the rat  

Microsoft Academic Search

The quantification of phospholipid hydroperoxides in biological tissues is important in order to know the degree of peroxidative damage of membrane lipids. For this purpose, op- timal conditions for the chemiluminescent simultaneous assay of phosphatidylcholine hydroperoxide (PCOOH) and phos- phatidylethanolamine hydroperoxide (PEOOH) in rat liver and brain were determined. A chemiluminescence detection-high performance liquid chromatography (CL-HPLC) method that incorporates cytochrome

Teruo Miyazawa; Toshihide Suzuki; Kenshiro Fujimoto; Keiichi Yasuda

347

Chemiluminescence. 1977-April 1980, 1980 (citations from the International Aerospace Abstracts data base). Report for 1977-April 1980  

SciTech Connect

Cited works describe the use of chemiluminescence for aurora and upper-atmosphere analyses, evaluation of chemical laser candidates, studies of jet and combustor dynamics, smog analysis and other work. Sources and forms of chemiluminescence and measurement techniques are described. (Contains 92 citations)

Young, C.G.

1980-05-01

348

Determination of Catalase Activity at Physiological Hydrogen Peroxide Concentrations  

Microsoft Academic Search

A method for the determination of catalase activity (EC 1.11.1.6.) in homogenates and cell suspensions is described by following the decomposition of H2O2at physiological H2O2levels. This first chemiluminescence assay for catalase activity is based on the reaction of luminol (5-amino-2,3-dihydro-1,4-phthalazinedione) and NaOCl. The chemiluminescence of this reaction specifically depends on the H2O2concentration and shows fast kinetics of less than 2

Sebastian Mueller; Hans-Dieter Riedel; Wolfgang Stremmel

1997-01-01

349

Development of Chemiluminescent Lateral Flow Assay for the Detection of Nucleic Acids  

PubMed Central

Rapid, sensitive detection methods are of utmost importance for the identification of pathogens related to health and safety. Herein we report the development of a nucleic acid sequence-based lateral flow assay which achieves a low limit of detection using chemiluminescence. On-membrane enzymatic signal amplification is used to reduce the limit of detection to the sub-femtomol level. To demonstrate this assay, we detected synthetic nucleic acid sequences representative of Trypanosoma mRNA, the causative agent for African sleeping sickness, with relevance in human and animal health in sub-Saharan Africa. The intensity of the chemiluminescent signal was evaluated by using a charge-coupled device as well as a microtiter plate reader. We demonstrated that our lateral flow chemiluminescent assay has a very low limit of detection and is easy to use. The limit of detection was determined to be 0.5 fmols of nucleic acid target.

Wang, Yuhong; Fill, Catherine; Nugen, Sam R.

2012-01-01

350

Chemiluminescence analysis of menadione sodium bisulfite and analgin in pharmaceutical preparations and biological fluids.  

PubMed

A novel chemiluminescence (CL) flow system for two sulfite-containing drugs, namely, menadione sodium bisulfite (MSB) and analgin is described. It is based on the weak chemiluminescence induced by the oxidation of sulfite group in drugs with dissolved oxygen in the presence of acidic Rh6G. Tween 80 surfactant micelles showed a strong enhancement effect on this weak chemiluminescence. For MSB analysis, online conversion of MSB in alkaline medium into sodium bisulfite was necessary, whereas analgin could be determined directly. The proposed method allowed the measurement of 0.05-50 microg/ml(-1) MSB and 0.05-10 microg/ml(-1) analgin. The limits of detection (3sigma) were 0.01 microg/ml(-1) MSB and 0.003 microg/ml(-1) analgin. The method was applied satisfactorily to pharmaceutical preparations as well as biological fluids. PMID:10701947

Huang, Y; Zhang, C; Zhang, X; Zhang, Z

1999-12-01

351

Intensified biochip system using chemiluminescence for the detection of Bacillus globigii spores  

PubMed Central

This paper reports the first intensified biochip system for chemiluminescence detection and the feasibility of using this system for the analysis of biological warfare agents is demonstrated. An enzyme-linked immunosorbent assay targeting Bacillus globigii spores, a surrogate species for Bacillus anthracis, using a chemiluminescent alkaline phosphatase substrate is combined with a compact intensified biochip detection system. The enzymatic amplification was found to be an attractive method for detection of low spore concentrations when combined with the intensified biochip device. This system was capable of detecting approximately 1?×?105Bacillus globigii spores. Moreover, the chemiluminescence method, combined with the self-contained biochip design, allows for a simple, compact system that does not require laser excitation and is readily adaptable to field use. Figure Schematic diagram of the miniature biochip detection system PMID:18224472

Griffin, Guy D.; Mobley, Joel

2008-01-01

352

Effect of fuel type on equivalence ratio measurements using chemiluminescence in premixed flames  

NASA Astrophysics Data System (ADS)

Local temporally-resolved measurements of chemiluminescent intensity from OH ?, CH ? and C ?2 radicals were obtained in premixed counterflow flames operating with propane and prevaporised fuels (isooctane, ethanol and methanol), for different equivalence ratios and strain rates. The results quantified independently the effects of fuel type, strain rate and equivalence ratio on chemiluminescent emissions from flames. The ability of chemiluminescent intensity from OH ?, CH ? and C ?2 radicals to indicate heat release rate depends strongly on fuel type. The intensity ratio OH ?/CH ? has a monotonic decrease with equivalence ratio for all fuels and can be used to measure equivalence ratio of the reacting mixture. For propane and isooctane, the OH ?/CH ? ratio remains independent of flame strain rate, whereas some dependence is observed for ethanol and methanol.

Orain, Mikaël; Hardalupas, Yannis

2010-05-01

353

Simultaneous particle image velocimetry and chemiluminescence visualization of millisecond-pulsed current-voltage-induced perturbations of a premixed propane/air flame  

NASA Astrophysics Data System (ADS)

The effects of millisecond-wide, pulsed current-voltage-induced behavior in premixed laminar flames have been investigated through the simultaneous collection of particle image velocimetry (PIV) and chemiluminescence data with particular attention paid to the onset mechanisms. Disturbances caused by applied voltages of 2 kV over a 30-mm gap to a downward propagating, atmospheric pressure, premixed propane/air flame with a flow speed near 2 m/s and an equivalence ratio of 1.06 are investigated. The combined PIV and chemiluminescence-based experimental data show the observed disturbance originates only in or near the cathode fall region very close to the burner base. The data also suggest that the coupling mechanism responsible for the flame disturbance behavior is fluidic in nature, developing from the radial positive chemi-ion distribution and an ion-drift current-induced net body force that acts along the annular space discharge distribution in the reaction zone in or near the cathode fall. This net body force causes a reduction in flow speed above these near cathodic regions causing the base of the flame to laterally spread. Also, this effect seems to produce a velocity gradient leading to the transition of a laminar flame to turbulent combustion for higher applied current-voltage conditions as shown in previous work (Marcum and Ganguly in Combust Flame 143:27-36, 2005; Schmidt and Ganguly in 48th AIAA aerospace sciences meeting. Orlando, 2010).

Schmidt, Jacob; Kostka, Stanislav; Lynch, Amy; Ganguly, Biswa

2011-09-01

354

Highly efficient electrogenerated chemiluminescence of Au38 nanoclusters.  

PubMed

An investigation of mechanisms for the near-infrared (NIR) electrogenerated chemiluminescence/electrochemiluminescence (ECL) of Au38(SC2H4Ph)24 (Au38, SC2H4Ph = 2-phenylethanethiol) nanoclusters both in annihilation and coreactant paths is reported. Essentially, no ECL emission was produced in the annihilation route over the potential range of the accessible redox states of Au38, because of the short lifetime and/or low reactivity of the electrogenerated Au38 intermediates necessary for ECL. Highly efficient light emission with a nominal peak wavelength of 930 nm in the NIR region was observed in the anodic region upon addition of tri-n-propylamine (TPrA) as the coreactant. The ECL mechanisms were elucidated by means of ECL-potential curves and spooling ECL spectroscopy. It was discovered that the Au38(+*) (and also Au38(3+*)) were electrogenerated as the major excited species in the light emission processes. Benzoyl peroxide was also used as a coreactant in the cathodic potential range from which benzoate radicals, with a high oxidizing power, were formed. These radicals accepted electrons from the electrogenerated Au38(2-) HOMO, resulting in the Au38(-*) excited state that emitted light at 930 nm. The photoluminescence of the various Au38 charge states, namely, Au38(2-), Au38(-), Au38(0), Au38(+), Au38(2+), and Au38(4+), electrogenerated in situ, indicated no significant difference in the emission peak wavelength. This information allowed a careful mapping of the relevant ECL mechanisms. It was found that the ECL efficiency could reach an efficiency of 3.5 times as high as that of the Ru(bpy)3(2+)/TPrA system. PMID:25088234

Hesari, Mahdi; Workentin, Mark Steven; Ding, Zhifeng

2014-08-26

355

Mechanism for the reaction of hydroxyl radicals with dimethyl disulfide  

NASA Astrophysics Data System (ADS)

Strong infrared chemiluminescence from the reactions of OH and OD radicals with CH 3SSCH 3 was observed in a discharge flow reactor viewed by a Fourier transform spectrometer. The recorded spectra were identical to the H 2O and HDO plus D 2O emission spectra from the OH+CH 3SH and OD+CH 3SD reactions, respectively. These observations strongly suggest that the primary reaction in the OH and OD+CH 3SSCH 3 system generates CH 3SH and CH 3SD molecules with the observed emission arising from the OH+CH 3SH and OD+CH 3SD secondary reactions.

Butkovskaya, N. I.; Setser, D. W.

1999-10-01

356

The Synthesis and Chemiluminescence of a Stable 1,2-Dioxetane.  

ERIC Educational Resources Information Center

Background information, laboratory procedures, and discussion of results are provided for the synthesis and chemiluminescence of adamantylideneadamantane-1,2-dioxetane (I). Results provided were obtained during a normal junior level organic laboratory course. All intermediates and products were identified using routine spectroscopic analysis.…

Meijer, E. W.; Wynberg, Hans

1982-01-01

357

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

358

Automated Flow-Injection Instrument for Chemiluminescence Detection Using a Low-Cost Photodiode Detector  

ERIC Educational Resources Information Center

The development of an FI analyzer for chemiluminescence detection using a low-cost photoiodide is presented. The experiment clearly demonstrates in a single interdisciplinary project the way in which different aspects in chemical instrumentation fit together to produce a working analytical system.

Economou, A.; Papargyris, D.; Stratis, J.

2004-01-01

359

Novel chemiluminescence assay for serum periostin levels in women with preeclampsia and in normotensive pregnant women  

Microsoft Academic Search

Objective: We recently developed a novel sandwich chemiluminescence assay to determine serum concentrations of periostin. Periostin has high amino acid homology with transforming growth factor-?–induced protein ?igh3, a molecule induced by transforming growth factor-?1, which promotes the adhesion and spreading of fibroblasts. It is also homologous with the insect cell adhesion molecule fasciclin I. We determined serum periostin concentrations in

Hidefumi Sasaki; James Roberts; Daves Lykins; Yoshitaka Fujii; Daniel Auclair; Lan Bo Chen

2002-01-01

360

A homogeneous immunoassay for cyclic nucleotides based on chemiluminescence energy transfer.  

PubMed Central

A chemiluminescent derivative of cyclic AMP, aminobutylethylisoluminol succinyl cyclic AMP (ABEI-scAMP), was synthesized in order to develop a homogeneous immunoassay based on non-radiative energy transfer. ABEI-scAMP was chemiluminescent (5.1 X 10(18) luminescent counts X mol-1 at pH 13), pure (greater than 95%) stable and immunologically active. A conventional immunoassay was established using ABEI-scAMP and a solid-phase anti-(cyclic AMP) immunoglobulin G which could detect cyclic AMP at least down to 25fmol. A homogeneous immunoassay for cyclic AMP was established by measuring the shift in wavelength from 460 to 525nm which occurred when ABEI-scAMP was bound to fluorescein-labelled anti-(cyclic AMP) immunoglobulin G. The assay was at least as sensitive as the conventional radioimmunoassay using cyclic [3H]AMP and could measure cyclic AMP over the range 1-1000nM. The homogeneous chemiluminescent energy transfer assay was also able to quantify the association and dissociation of antibody-antigen complexes. Chemiluminescence energy transfer occurred between fluorescein-labelled antibodies and several other ABEI-labelled antigens (Mr values 314-150000) including progesterone, cyclic GMP, complement component C9 and immunoglobulin G. The results provide a homogeneous immunoassay capable of measuring free cyclic AMP under conditions likely to exist inside cells. PMID:6316935

Campbell, A K; Patel, A

1983-01-01

361

Anal. Chem. 1994,66, 303-306 End-Column Chemiluminescence Detector for Capillary  

E-print Network

Anal. Chem. 1994,66, 303-306 End-Column Chemiluminescence Detector for Capillary Electrophoresis Ra of Chemistry, State University of New York, Buffalo, NY 14214. (1) Jorgenson, J. W.; Lukacs, K. D. Anal. Chem,S. L., Jr.; a r e ,R. N.; Quint,J. Anal. Chem. 1989,61, 1642-1647. (7) Kobayashi, S I . ; Imai, K. Anal

Zare, Richard N.

362

Fabrication technology of chemiluminescent sensitive elements for rocket-borne ozone detectors  

NASA Astrophysics Data System (ADS)

Attention is given to the technology behind the fabrication of chemiluminescent sensitive elements for rocket-borne ozone detectors. High-silica microporous glass is the basic material required for these detectors. It is noted that the luminophor consists of rhodamine-C and gallic acid, and that the desired ratio of these components depends on the sensitivity of a particular specimen to ozone.

Kononkov, V. A.; Lelikova, A. I.; Perov, S. P.

363

Chemiluminescence detection of 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX) and related nitramine explosives.  

PubMed

A simple controlled chemical reduction of 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX) and related nitramine compounds with zinc amalgam generates species that elicit intense chemiluminescence with tris(2,2'-bipyridine)ruthenium(III), which extends this widely utilised chemiluminescence reagent to a new class of analyte and presents a sound chemical basis for a screening test for nitramine high explosives. Examination of the chemiluminescence profiles under stopped-flow conditions revealed contributions from multiple transient species formed in the initial reduction step. PMID:22265569

Donaldson, David N; Barnett, Neil W; Agg, Kent M; Graham, Duncan; Lenehan, Claire E; Prior, Chad; Lim, Kieran F; Francis, Paul S

2012-01-15

364

Rate Determination of the CO2* Chemiluminescence Reaction CO + O + M = CO2* + M  

E-print Network

, and its detection can lead to valuable information; however, due to its broadband characteristics, CO2* is difficult to isolate experimentally, and the chemical kinetics of this species is not well known. Although numerous works have monitored CO2...

Kopp, Madeleine Marissa, 1987-

2012-10-15

365

Response surface optimized peroxyoxalate chemiluminescence of octahydro-Schiff base derivative as new luminophor and study of the quenching effect of some cations, amino acids and cholesterol.  

PubMed

We report the first detailed study of the characteristics of an octahydro-Schiff base derivative as a new luminophor in the peroxyoxalate chemiluminescence (POCL) system. The effect of reagents on this new POCL system was investigated. In addition, the response surface methodology was used for evaluating the relative significance of variables in this POCL system, establishing models and determining optimal conditions. The quenching effect of some cations and compounds such as Cu(2+), Fe(3+), Hg(2+), imidazole, histidine and cholesterol on an optimized POCL reaction were studied. The dynamic ranges were up to approximaterly 100 and 175 × 10(-6) M for Cu(2+) and cholesterol respectively. The detection limits were 3.3 × 10(-6) m and 2.58 × 10(-6) m for Cu(2+) and histidine, respectively. In all cases the relative standard deviations were 4-5% (n = 4). PMID:24723462

Yeganeh Faal, Ali; Jamalyan, Bahare; Bordbar, Maryam; Shayeste, Tavakol Heidary; Salavati-Niasari, Masoud

2014-12-01

366

Development of a wireless, self-sustaining damage detection sensor system based on chemiluminescence for structural health monitoring  

NASA Astrophysics Data System (ADS)

A novel application of chemiluminescence resulting from the chemical reaction in a glow-stick as sensors for structural health monitoring is demonstrated here. By detecting the presence of light emitting from these glow-sticks, it is possible to develop a low-cost sensing device with the potential to provide early warning of damage in a variety of engineering applications such as monitoring of cracks or damage in concrete shear walls, detecting of ground settlement, soil liquefaction, slope instability, liquefaction-related damage of underground structure and others. In addition, this paper demonstrates the ease of incorporating wireless capability to the sensor device and the possibility of making the sensor system self-sustaining by means of a renewable power source for the wireless module. A significant advantage of the system compared to previous work on the use of plastic optical fibre (POF) for damage detection is that here the system does not require an electrically-powered light source. Here, the sensing device, embedded in a cement host, is shown to be capable of detecting damage. A series of specimens with embedded glow-sticks have been investigated and an assessment of their damage detection capability will be reported. The specimens were loaded under flexure and the sensor responses were transmitted via a wireless connection.

Kuang, K. S. C.

2014-03-01

367

A 3D-printed device for a smartphone-based chemiluminescence biosensor for lactate in oral fluid and sweat.  

PubMed

Increasingly, smartphones are used as portable personal computers, revolutionizing communication styles and entire lifestyles. Using 3D-printing technology we have made a disposable minicartridge that can be easily prototyped to turn any kind of smartphone or tablet into a portable luminometer to detect chemiluminescence derived from enzyme-coupled reactions. As proof-of-principle, lactate oxidase was coupled with horseradish peroxidase for lactate determination in oral fluid and sweat. Lactate can be quantified in less than five minutes with detection limits of 0.5 mmol L(-1) (corresponding to 4.5 mg dL(-1)) and 0.1 mmol L(-1) (corresponding to 0.9 mg dL(-1)) in oral fluid and sweat, respectively. A smartphone-based device shows adequate analytical performance to offer a cost-effective alternative for non-invasive lactate measurement. It could be used to evaluate lactate variation in relation to the anaerobic threshold in endurance sport and for monitoring lactic acidosis in critical-care patients. PMID:25343380

Roda, Aldo; Guardigli, Massimo; Calabria, Donato; Calabretta, Maria Maddalena; Cevenini, Luca; Michelini, Elisa

2014-12-21

368

Single and multiplexed immunoassays for the chemiluminescent imaging detection of animal glues in historical paint cross-sections.  

PubMed

The characterization of the organic components in a complex, multilayered paint structure is fundamental for studying painting techniques and for authentication and restoration purposes. Proteinaceous materials, such as animal glue, are of particular importance since they are widely used as binders, adhesives and for gilding. Even though proteins are usually detected by chromatographic and proteomic techniques, immunological methods represent an alternative powerful approach to protein analysis thanks to the high specificity of antigen-antibody reactions. Our previous studies demonstrated that ovalbumin and casein could be localized in paint cross-sections with high sensitivity and good spatial resolution (i.e. within the single painting layers) by using chemiluminescent (CL) immunochemical microscope imaging. In the present research work, we describe for the first time the immunolocalization of collagen (the main protein of animal glue) in paint cross-sections by CL imaging microscopy. Two different analytical protocols have been developed, allowing either the detection of collagen or the simultaneous detection of collagen and ovalbumin in the same paint sample. The assays were used to detect collagen and ovalbumin in cross-sections from model samples and historical paintings (a wall painting dated to 1773-1774 and a painted wood panel of the Renaissance period) in order to achieve information on paint techniques and past restoration interventions. PMID:23064674

Sciutto, G; Dolci, L S; Guardigli, M; Zangheri, M; Prati, S; Mazzeo, R; Roda, A

2013-01-01

369

A novel system of galangin-potassium permanganate-polyphosphoric acid for the determination of tryptophan and its chemiluminescence mechanism.  

PubMed

A novel galangin-potassium permanganate (KMnO4 )-polyphosphoric acid (PPA) system was found to have an outstanding response to tryptophan (Trp). Trp determination using this KMnO4 -PPA system was enhanced significantly in the presence of galangin. A highly sensitive flow-injection chemiluminescence (CL) method to determine Trp was developed based on the CL reaction of galangin-KMnO4 -Trp in PPA media. The presence of galangin, a member of the flavonol class of flavonoid complexes, greatly increased the luminous intensity of Trp in KMnO4 -PPA systems. Under optimized conditions, Trp was determined in the 0.05-10?µg/mL range, with a detection limit (3?) of 5.0?×?10(-3) ?µg/mL. The relative standard deviation (RSD) was 1.0% for 11 replicate determinations of 1.0?µg/mL Trp. Two synthetic samples were determined selectively with recoveries of 98.4-100.1% in the presence of other amino acids. The possible mechanism is summarized as follows: excited states of Mn(II)(*) and Mn(III) (*) types are the main means of generating chemical luminescent species, and Trp concentration and luminescence intensity have a linear relationship, which enables quantitative analysis. Copyright © 2014 John Wiley & Sons, Ltd. PMID:25271024

Li, Li; Guo, Ruibin; Zhang, Dongxia; Du, Xinzhen

2014-10-01

370

Free Radicals and Chemiluminescence as Products of the Spontaneous Oxidation of Sulfide in Seawater, and Their Biological Implications  

PubMed Central

The discovery of symbioses between marine invertebrates and sulfide-oxidizing bacteria at deep-sea hydrothermal vents and in other high-sulfide marine environments has stimulated research into the adaptations of metazoans to potentially toxic concentrations of sulfide. Most of these studies have focused on a particular action of sulfide—its disruption of aerobic metabolism by the inhibition of mitochondrial respiration—and on the adaptations of sulfide-tolerant animals to avoid this toxic effect (1). We propose that sulfidic environments impose another, hitherto overlooked type of toxicity: exposure to free radicals of oxygen, which may be produced during the spontaneous oxidation of sulfide, thus imposing an oxidative stress. Here we present evidence that oxygen- and sulfur-centered free radicals are produced during the oxidation of sulfide in seawater, and we propose a reaction pathway for sulfide oxidation that is consistent with our observations. We also show that chemiluminescence at visible wavelengths occurs during sulfide oxidation, providing a possible mechanism for the unexplained light emission from hydrothermal vents (2, 3). PMID:25575385

TAPLEY, DAVID W.; BUETTNER, GARRY R.; SHICK, J. MALCOLM

2014-01-01

371

Characterization and mitigation of water vapor effects in the measurement of ozone by chemiluminescence with nitric oxide  

NASA Astrophysics Data System (ADS)

Laboratory experiments were conducted to investigate the effects of water vapor on the reaction of nitric oxide with ozone in a gas-phase chemiluminescence instrument used for fast response and high sensitivity detection of atmospheric ozone. Water vapor was introduced into a constant level ozone standard and both ozone and water vapor signals were recorded at 10 Hz. The presence of water vapor was found to reduce, i.e. quench, the ozone signal. A dimensionless correction factor was determined to be 4.15 ± 0.14 × 10-3, which corresponds to a 4.15% increase in the corrected ozone signal per 10 mmol mol-1 of co-sampled water vapor. An ozone-inert water vapor permeable membrane (a Nafion dryer with a counterflow of dry air from a compressed gas cylinder) was installed in the sampling line and was shown to remove the bulk of the water vapor in the sample air. At water vapor mole fractions above 25 mmol mol-1, the Nafion dryer removed over 75% of the water vapor in the sample. This reduced the required ozone signal correction from over 11% to less than 2.5%. The Nafion dryer was highly effective at reducing the fast fluctuations of the water vapor signal (more than 97%) while leaving the ozone signal unaffected, which is a crucial improvement for minimizing the quenching interference of water vapor fluxes and required density correction in the determination of ozone fluxes by the eddy covariance technique.

Boylan, P.; Helmig, D.; Park, J.-H.

2014-05-01

372

High-performance liquid chromatographic assay of parabens in wash-off cosmetic products and foods using chemiluminescence detection  

Microsoft Academic Search

A new method for the simultaneous determination of parabens including methylparaben, ethylparaben, propylparaben, and butylparaben by high-performance liquid chromatography (HPLC) coupled with chemiluminescence detection was developed. The procedure was based on the chemiluminescent enhancement by parabens of the cerium(IV)–rhodamine 6G system in the strong sulfuric acid medium. The good separation of parabens was carried out with an isocratic elution using

Qunlin Zhang; Mei Lian; Lijuan Liu; Hua Cui

2005-01-01

373

On use of CO{sub 2} chemiluminescence for combustion metrics in natural gas fired reciprocating engines.  

SciTech Connect

Flame chemiluminescence is widely acknowledged to be an indicator of heat release rate in premixed turbulent flames that are representative of gas turbine combustion. Though heat release rate is an important metric for evaluating combustion strategies in reciprocating engine systems, its correlation with flame chemiluminescence is not well studied. To address this gap an experimental study was carried out in a single-cylinder natural gas fired reciprocating engine that could simulate turbocharged conditions with exhaust gas recirculation. Crank angle resolved spectra (266-795 nm) of flame luminosity were measured for various operational conditions by varying the ignition timing for MBT conditions and by holding the speed at 1800 rpm and Brake Mean effective Pressure (BMEP) at 12 bar. The effect of dilution on CO*{sub 2}chemiluminescence intensities was studied, by varying the global equivalence ratio (0.6-1.0) and by varying the exhaust gas recirculation rate. It was attempted to relate the measured chemiluminescence intensities to thermodynamic metrics of importance to engine research -- in-cylinder bulk gas temperature and heat release rate (HRR) calculated from measured cylinder pressure signals. The peak of the measured CO*{sub 2} chemiluminescence intensities coincided with peak pressures within {+-}2 CAD for all test conditions. For each combustion cycle, the peaks of heat release rate, spectral intensity and temperature occurred in that sequence, well separated temporally. The peak heat release rates preceded the peak chemiluminescent emissions by 3.8-9.5 CAD, whereas the peak temperatures trailed by 5.8-15.6 CAD. Such a temporal separation precludes correlations on a crank-angle resolved basis. However, the peak cycle heat release rates and to a lesser extent the peak cycle temperatures correlated well with the chemiluminescent emission from CO*{sub 2}. Such observations point towards the potential use of flame chemiluminescence to monitor peak bulk gas temperatures as well as peak heat release rates in natural gas fired reciprocating engines.

Gupta, S. B.; Bihari, B.; Biruduganti, M.; Sekar, R.; Zigan, J. (Energy Systems); (Cummins Technical Center)

2011-01-01

374

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

PubMed

One of the current concerns with the application of nanoparticles in sunscreens, and in particular nano-TiO2 and ZnO, is their potential to photogenerate free radicals and reactive oxygen species (ROS) when they absorb ultraviolet wavelengths from sunlight. Free radicals and ROS are known to be associated with UV-induced skin damage and oxidative stress, from which sunscreens are expected to offer significant protection. Here we describe a simple method, based on chemiluminescence emission, for detecting free radicals generated in commercial sunscreens alone, and when applied to various substrates, following exposure to UVA (320-400nm) radiation. This photo-induced chemiluminescence (PICL) technique could be used to optimise sunscreen formulations so as to minimise free radical photogeneration during exposure to sunlight. PMID:24667184

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

2014-04-01

375

Effect of glutathione on peroxyoxalate chemiluminescence of hypericin as the fluorophore  

NASA Astrophysics Data System (ADS)

Herein, the effect of amino acid Glutathione (GSH) on Peroxyoxalate Chemiluminescence was studied for the first time. Hypericin (HYP) was employed as the efficient fluorophore. The investigated parameters included rise and fall rate constant for the chemiluminescence burst, theoretical and experimental maximum intensity, the time-needed to reach maximum intensity and the total light yield emission which theoretically was evaluated using the pooled intermediate model by a computerized non-linear least-squares curve fitting program (KINFIT). Furthermore, based on observed quenching effect of GSH, the Stern-Volmer plot in quencher concentration range of 2.8 × 10-6 to 3.4 × 10-5 M with KQ value of 1.59 × 104 was calculated. The bimolecular quenching rate constant (Kq) was also estimated about 2.8 × 1012 and M-1 S-1. Moreover the system was applied successfully to determine glutathione in biological samples.

Kazemi, Sayed Yahya; Abedirad, Seyed Mohammad

2014-01-01

376

Determination of acetylcholinesterase activity by a new chemiluminescence assay with the natural substrate.  

PubMed Central

A chemiluminescence method for determining acetylcholinesterase activity is described. It is an adaptation of the chemiluminescence assay of acetylcholine described by Israël & Lesbats [(1981) Neurochem. Int. 3, 81-90; (1981) J. Neurochem. 37, 1475-1483]. The acetylcholinesterase activity is measured by monitoring the increase in light emission produced by the accumulation of choline or by determining the amount of choline generated after a short interval. The assay is rapid and sensitive, and uses the natural substrate of the enzyme. Kinetic data obtained with this procedure for acetylcholinesterase from Torpedo and Electrophorus electric organs were comparable with those obtained by using the method of Ellman, Courtney, Andres & Featherstone [(1961) Biochem. Pharmacol. 7, 88-95]. In addition, it was shown that sodium deoxycholate totally inactivated Torpedo acetylcholinesterase but not the Electrophorus enzyme. Competitive inhibitors of acetylcholinesterase protected the enzyme from inactivation. PMID:3977858

Birman, S

1985-01-01

377

Chemiluminescent activation of the antiviral activity of hypericin: a molecular flashlight.  

PubMed Central

Hypericin is a naturally occurring photosensitizer that displays potent antiviral activity in the presence of light. The absence of light in many regions of the body may preclude the use of hypericin and other photosensitizers as therapeutic compounds for the treatment of viral infections in vivo. The chemiluminescent oxidation of luciferin by the luciferase from the North American firefly Photinus pyralis was found to generate sufficiently intense and long-lived emission to induce antiviral activity of hypericin. Light-induced virucidal activity of hypericin was demonstrated against equine infectious anemia virus, a lentivirus structurally, genetically, and antigenically related to the human immunodeficiency virus. The implications for exploiting chemiluminescence as a "molecular flashlight" for effecting photodynamic therapy against virus-infected cells and tumor cells are discussed. PMID:7991618

Carpenter, S; Fehr, M J; Kraus, G A; Petrich, J W

1994-01-01

378

Determination of selected neurotransmitter metabolites using monolithic column chromatography coupled with chemiluminescence detection.  

PubMed

The oxidation of selected clinically important neurotransmitter metabolites with acidic potassium permanganate in the presence of polyphosphates evokes chemiluminescence of sufficient intensity to enable the sensitive determination of these species. Limits of detection for 5-hydroxyindole-3-acetic acid (5-HIAA), vanilmandelic acid (VMA; alpha,4-dihydroxy-3-methoxybenzeneacetic acid), 4-hydroxy-3-methoxyphenylglycol (MHPG), homovanillic acid (HVA, 4-hydroxy-3-methoxyphenylacetic acid) and 3,4-dihydroxyphenylacetic acid (DOPAC) were between 5x10(-9) and 4x10(-8)M, using flow-injection analysis methodology. In addition, we demonstrate the rapid determination of homovanillic acid and 5-hydroxyindole-3-acetic acid in human urine - without the need for extraction procedures - using monolithic column chromatography with chemiluminescence detection. PMID:18970210

Adcock, Jacqui L; Barnett, Neil W; Costin, Jason W; Francis, Paul S; Lewis, Simon W

2005-09-15

379

An on-line reduction HPLC/chemiluminescence detection system for nitropolycyclic aromatic hydrocarbons and metabolites.  

PubMed

Various metal powders were batch screened as possible on-line reducers for nitropolycyclic aromatic hydrocarbons (NPAHs), in particular 1,3-dinitropyrene (1,3-DNP, 1,8-DNP and 1-nitropyrene (1-NP) and it metabolites. Zinc was found to be an excellent reducer in chemiluminescent compatible mobile phases without any associated disposal problems. Zinc reducer column parameters, namely pH, buffer concentration, packing composition (zinc:glass beads or zinc:silica gel) and column length were all optimized for the HPLC determination system with chemiluminescence detection, named NPAH analyser. The system consisted of three pumps, sample injector, reducer column packed with zinc:glass beads switching valve with a cutting loop, separation column (ODS), chemiluminescence detector and integrator. The mobile phase for the separation column and chemiluminescence reagent solution were respectively acetonitrile:imidazole-HClO44 and acetonitrile containing bis(2,4,6-trichlorophenyl)oxalate and H2O2. When the reducer column was introduced before the separation column, 1,3-, 1,6- 1,8-DNPs and 1-NP in benzene:ethanol extracts from airborne particulates were separately determined with detection limits of 2-50 fmol, respectively, in a 100 microL sample. When the reducer column was introduced just after the separation column, 1-NP, 1-nitrosopyrene and 1-aminopyrene in the incubation mixture of 1-NP and the Salmonella typhimurium YG1021 strain were separately determined with detection limits as low as sub fmol levels. 1,8-DNP and its metabolite were also separately determined in the incubation mixture of 1,8-DNP and the S. typhimurium TA98 strain. PMID:8949918

Hayakawa, K; Terai, N; Dinning, P G; Akutsu, K; Iwamoto, Y; Etoh, R; Murahashi, T

1996-01-01

380

Chemiluminescence aptasensor for cocaine based on double-functionalized gold nanoprobes and functionalized magnetic microbeads  

Microsoft Academic Search

A novel chemiluminescence (CL) aptasensor for highly sensitive detection of small-molecule targets using cocaine as a model\\u000a analyte was developed in the present study. For the proposed aptasensor, the aptamers were immobilized on the surface of gold\\u000a nanoparticles (AuNPs) functionalized magnetic microbeads (MB-AuNPs) and then hybridized with the signal DNA on the double-functional\\u000a gold nanoprobes (DF-AuNPs) modified with horseradish peroxidase

Ying Li; Xiaoting Ji; Bangwei Liu

2011-01-01

381

Flow-injection system for automated dissolution testing of isoniazid tablets with chemiluminescence detection  

Microsoft Academic Search

A simple and sensitive flow-injection chemiluminescence (CL) system for automated dissolution testing is described and evaluated for monitoring of dissolution profiles of isoniazid tablets. The undissolved suspended particles in the dissolved solution were eliminated via on-line filter. The novel CL system of KIO4-isoniazid was also investigated. The sampling frequency of the system was 120 h?1. The dissolution profiles of isoniazid

Baoxin Li; Zhujun Zhang; Wei Liu

2001-01-01

382

Gas chromatographic measurement of carbon monoxide in hydrocarbon matrices with a redox chemiluminescence detector.  

PubMed

The rapid measurement of trace levels of carbon monoxide in ethylene by gas chromatography with redox chemiluminescence detection is described. Linear response for carbon monoxide over three decades and a detection limit in the sub-parts per million by volume (ppmv) concentration range were observed without methanation or preconcentration of the sample. Samples containing 0.2 ppmv of carbon monoxide in ethylene were readily quantitated. PMID:3624368

Sievers, R E; Shearer, R L; Barkley, R M

1987-06-12

383

Electrogenerated chemiluminescence aptamer-based biosensor for the determination of cocaine  

Microsoft Academic Search

A novel electrogenerated chemiluminescence aptamer-based (ECL-AB) biosensor for the determination of a small molecule drug is designed employing cocaine-binding aptamer as molecular recognition element for cocaine as a model analyte and ruthenium complex served as an ECL label. A 5?-terminal cocaine-binding aptamer with the ECL label at 3?-terminal of the aptamer was utilized as an ECL probe. The ECL-AB biosensors

Yan Li; Honglan Qi; Yage Peng; Jia Yang; Chengxiao Zhang

2007-01-01

384

Time course of superoxide generation by leukocytes—The MCLA chemiluminescence system  

Microsoft Academic Search

This study was performed to examine the pattern of Superoxide (O2-·) generation from leukocytes using the O2-· specific chemiluminescence (CL) method.Cypridina luciferin analog, 2-methyl-6-(p-methoxyphenyl)-3,7-dihydroimidazo[1,2-alpha]pyrazin-3-one (MCLA) was used as a CL probe. The appropriate conditions of the MCLA method was first determined for the evaluation of the time course of O2-· generation by leukocytes. The time course of O2-· generation obtained

László Prónai; Hiroe Nakazawa; Kohji Ichimori; Yoshinori Saigusa; Tomoichi Ohkubo; Kazuko Hiramatsu; Shigeru Arimori; János Fehér

1992-01-01

385

A fast chemiluminescent method for H 2O 2 measurement in exhaled breath condensate  

Microsoft Academic Search

Background: Breath condensate can give useful information on volatile compounds produced at alveolar level. Actual concentration of H2O2 in breath condensate is dependent on its production at alveolar level and on the efficacy of the detoxifying systems, catalase, glutathione peroxidase, etc. Methods: In the present paper, a simple chemiluminescent method for the determination of the H2O2 collected in exhaled breath

Bruno Zappacosta; Silvia Persichilli; Flaminio Mormile; Angelo Minucci; Andrea Russo; Bruno Giardina; Pasquale De Sole

2001-01-01

386

A Chemiluminescent Flow Sensing Device for Determination of Choline and Phospholipase D Activity in Biological Samples  

Microsoft Academic Search

A chemiluminescent flow-sensing device for the determination of phospholipase D (PLD) activity and\\/or choline (Ch) in biological samples using choline oxidase (ChO) and horseradish peroxidase (HRP) immobilized on Eupergit C (polymer beads of methacrylamide,N-methylene-bis-methacrylamide, and allyl-glycidyl-ether) was developed. The best results were obtained with immobilized ChO and HRP at a polymer beads wet weight ratio of 16:1. The optimized parameters

Pavel Rauch; Elida N. Ferri; Stefano Girotti; Hana Rauchova; Giacomo Carrea; Roberto Bovara; F. Fini; Aldo Roda

1997-01-01

387

Analysis of chemiluminescence measurements by grey-scale ICCD and colour digital cameras  

NASA Astrophysics Data System (ADS)

Spectral, grey-scale and colour chemiluminescence measurements of C2* and CH* radicals' emission are carried out on the flame front of a methane-air premixed flame at different equivalence ratios. To this purpose, properly spatially resolved optical equipment has been implemented in order to reduce the background emission from other burned gas regions. The grey-scale (ICCD + interference filters) and RGB colour (commercial digital camera) approaches have been compared in order to find a correspondence between the C2* and the green component, as well as the CH* and the blue component of the emission intensities. The C2*/CH* chemiluminescence ratio has been investigated at different equivalence ratios and a good correlation has been obtained, showing the possibility of sensing the equivalence ratio in practical systems. The grey-scale and colour chemiluminescence analysis has then been applied to a meso-scale not premixed swirl combustor fuelled with a methane-air mixture and operating at 0.3 MPa. 2D results are presented and discussed in this work.

Migliorini, F.; Maffi, S.; De Iuliis, S.; Zizak, G.

2014-05-01

388

Assessment of a chemiluminescent universal probe for taxonomical and epidemiological investigations of Aeromonas sp isolates.  

PubMed Central

AIMS--To assess a chemiluminescent universal probe for taxonomical and epidemiological investigations of Aeromonas sp isolates. METHODS--Total DNA was extracted from 69 well characterised Aeromonas sp strains and digested with the restriction endonucleases Sma I or Pst I. Following electrophoresis, the resulting fragments were transferred to a nylon membrane where they were hybridised to a commercially available universal probe of 16S + 23S rRNA. The banding patterns (ribotypes) were made visible by enhanced chemiluminescence. RESULTS--Both restriction endonucleases produced heterogeneous ribotypes so that no allocation could be made to any of the control genospecies tested. For A hydrophila and A caviae, however, groups of strains (mostly from the same patient) could be identified by indistinguishable banding patterns. A relatively high proportion (36%) of A sobria strains were non-typable. CONCLUSIONS--Although this universal chemiluminescent probe is user friendly, it is unsuitable for taxonomical investigations of Aeromonas sp. It is useful in epidemiological studies of A hydrophila and A caviae, but is of less value for A sobria. Images PMID:8089222

Carey, P E; Eley, A; Wilcox, M H

1994-01-01

389

Development of ultrasensitive direct chemiluminescent enzyme immunoassay for determination of aflatoxin M1 in milk.  

PubMed

A direct competitive chemiluminescent enzyme-linked immunosorbent assay (CL-ELISA) for detecting aflatoxin M1 (AFM1) was developed. To improve the sensitivity of the assay, a mixture of 3-(10'-phenothiazinyl)-propane-1-sulfonate (SPTZ) and 4-morpholinopyridine (MORPH) was used to enhance peroxidase-induced CL. The concentrations of the coating anti-AFM1 antibody and the conjugate of AFB1 with horseradish peroxidase the conditions of the chemiluminescent assay were varied to optimise the condition of the chemiluminescent assay. The lower detection limit values and dynamic working range of CL-ELISA of AFM1 were 0.001 ng mL(-1) and 0.002-0.0075 ng mL(-1), respectively. A 20-fold dilution of milk samples prevented a matrix effect of the milk and allowed measurement of AFM1 at concentrations below than the maximum acceptable limit. Values of recovery within and between assays were 81.5-117.6% and 86-110.6%, respectively. The results of using the developed CL-ELISA to analyse samples of six brands of milk that were purchased in Taiwan revealed that AFM1 was absent from all studied samples. PMID:24731347

Vdovenko, Marina M; Lu, Chuan-Chen; Yu, Feng-Yih; Sakharov, Ivan Yu

2014-09-01

390

Effects of sphingosine and sphingosine analogues on the free radical production by stimulated neutrophils: ESR and chemiluminescence studies  

PubMed Central

Sphingolipids inhibit the activation of the neutrophil (PMN) NADPH oxidase by protein kinase C pathway. By electron spin resonance spectroscopy (ESR) and chemiluminescence (CL), we studied the effects of sphingosine (SPN) and ceramide analogues on phorbol 12-myristate 13-acetate (PMA, 5 × 10-7M) stimulated PMN (6 × 106 cells). By ESR with spin trapping (100 mM DMPO: 5,5-dimethyl-1-pyrroline-Noxide), we showed that SPN (5 to 8 × 10-6M), C2-ceramide (N-acetyl SPN) and C6-ceramide (N-hexanoyl SPN) at the final concentration of 2 × 10-5 and 2 × 10-4M inhibit the production of free radicals by stimulated PMN. The ESR spectrum of stimulated PMN was that of DMPO-superoxide anion spin adduct. Inhibition by 5 × 10-6M SPN was equivalent to that of 30 U/ml SOD. SPN (5 to 8 × 10-6M) has no effect on in vitro systems generating superoxide anion (xanthine 50 mM/xanthine oxidase 110 mU/ml) or hydroxyl radical (Fenton reaction: 88 mM H2O2, 0.01 mM Fe2+ and 0.01 mM EDTA). SPN and N-acetyl SPN also inhibited the CL of PMA stimulated PMN in a dose dependent manner (from 2 × 10-6 to 10-5M), but N-hexanoyl SPN was less active (from 2 × 10-5 to 2 × 10-4M). These effects were compared with those of known PMN inhibitors, superoxide dismutase, catalase and azide. SPN was a better inhibitor compared with these agents. The complete inhibition by SPN of ESR signal and CL of stimulated PMN confirms that this compound or one of its metabolites act at the level of NADPH-oxidase, the key enzyme responsible for production of oxygen-derived free radicals. PMID:18472867

Mouithys-Mickalad, A.; Deby-Dupont, G.; Hoebeke, M.; Mathy-Hartert, M.; Lamy, M.; Deby, C.

1997-01-01

391

Slope effects on the fluid dynamics of a fire spreading across a fuel bed: PIV measurements and OH* chemiluminescence imaging  

NASA Astrophysics Data System (ADS)

Slope is among the most influencing factor affecting the spread of wildfires. A contribution to the understanding of the fluid dynamics of a fire spreading in these terrain conditions is provided in the present paper. Coupled optical diagnostics are used to study the slope effects on the flow induced by a fire at laboratory scale. Optical diagnostics consist of particle image velocimetry, for investigating the 2D (vertical) velocity field of the reacting flow and chemiluminescence imaging, for visualizing the region of spontaneous emission of OH radical occurring during gaseous combustion processes. The coupling of these two techniques allows locating accurately the contour of the reaction zone within the computed velocity field. The series of experiments are performed across a bed of vegetative fuel, under both no-slope and 30° upslope conditions. The increase in the rate of fire spread with increasing slope is attributed to a significant change in fluid dynamics surrounding the flame. For horizontal fire spread, flame fronts exhibit quasi-vertical plume resulting in the buoyancy forces generated by the fire. These buoyancy effects induce an influx of ambient fresh air which is entrained laterally into the fire, equitably from both sides. For upward flame spread, the induced flow is strongly influenced by air entrainment on the burnt side of the fire and fire plume is tilted toward unburned vegetation. A particular attention is paid to the induced air flow ahead of the spreading flame. With increasing the slope angle beyond a threshold, highly dangerous conditions arise because this configuration induces wind blows away from the fire rather than toward it, suggesting the presence of convective heat transfers ahead of the fire front.

Morandini, F.; Silvani, X.; Honoré, D.; Boutin, G.; Susset, A.; Vernet, R.

2014-08-01

392

Experiments concerning the laser-enhanced reaction between vibrationally excited O3 and NO  

NASA Technical Reports Server (NTRS)

The enhancement in reaction rate between O3 and NO is studied for the case of O3 vibrationally excited by a CO2 laser. Chemiluminescence observations of a vibrationally excited and an electronically excited nitrogen dioxide reaction product provide information on the separate contributions to the overall reaction rate of these two reactive channels. The contribution of the stretching and bending modes of O3 to the reaction rate enhancement is also discussed. In addition, consideration is given to the nonreactive vibrational deactivation of vibrationally excited O3.

Hui, K.-K.; Cool, T. A.

1978-01-01

393

Multiplexed chemiluminescent assays in ArrayPlates for high-throughput measurement of gene expression  

NASA Astrophysics Data System (ADS)

Multiplexed Molecular Profiling (MMP) assays for drug discovery are performed in ArrayPlates. ArrayPlates are 96- well microtiter plates that contain a 16-element array at the bottom of each well. Each element within an array measures one analyte in a sample. A CCD imager records the quantitative chemiluminescent readout of all 1,536 elements in a 96-well plate simultaneously. Since array elements are reagent modifiable by the end-user, ArrayPlates can be adapted to a broad range of nucleic acid- and protein-based assays. Such multiplexed assays are rapidly established, flexible, robust, automation-friendly and cost-effective. Nucleic acid assays in ArrayPlates can detect DNA and RNA, including SNPs and ESTs. A multiplexed mRNA assay to measure the expression of 16 genes is described. The assay combines a homogeneous nuclease protection assay with subsequent probe immobilization to the array by means of a sandwich hybridization followed with chemiluminescent detection. This assay was used to examine cells grown and treated in microplates and avoided cloning, transfection, RNA insolation, reverse transcription, amplification and fluorochrome labeling. Standard deviations for the measurement of 16 genes ranged from 3 percent to 13 percent in samples of 30,000 cells. Such ArrayPlates transcription assays are useful in drug discovery and development for target validation, screening, lead optimization, metabolism and toxicity profiling. Chemiluminescent detection provides ArrayPlates assays with high signal-to-noise readout and simplifies imager requirements. Imaging a 2D surface that contains arrays simplifies lens requirements relative to imaging columns of liquid in microtiter plate wells. The Omix imager for ArrayPlates is described.

Martel, Ralph R.; Rounseville, Matthew P.; Botros, Ihab W.; Seligmann, Bruce E.

2002-06-01

394

Measurement of proteases using chemiluminescence-resonance-energy-transfer chimaeras between green fluorescent protein and aequorin.  

PubMed Central

Homogeneous assays, without a separation step, are essential for measuring chemical events in live cells and for drug discovery screens, and are desirable for making measurements in cell extracts or clinical samples. Here we demonstrate the principle of chemiluminescence resonance energy transfer (CRET) as a homogeneous assay system, using two proteases as models, one extracellular (alpha-thrombin) and the other intracellular (caspase-3). Chimaeras were engineered with aequorin as the chemiluminescent energy donor and green fluorescent protein (GFP) or enhanced GFP as the energy acceptors, with a protease linker (6 or 18 amino acid residues) recognition site between the donor and acceptor. Flash chemiluminescent spectra (20--60 s) showed that the spectra of chimaeras matched GFP, being similar to that of luminous jellyfish, justifying their designation as 'Rainbow' proteins. Addition of the protease shifted the emission spectrum to that of aequorin in a time- and dose-dependent manner. Separation of the proteolysed fragments showed that the ratio of green to blue light matched the extent of proteolysis. The caspase-3 Rainbow protein was able to provide information on the specificity of caspases in vitro and in vivo. It was also able to monitor caspase-3 activation in cells provoked into apoptosis by staurosporine (1 or 2 microM). CRET can also monitor GFP fluor formation. The signal-to-noise ratio of our Rainbow proteins is superior to that of fluorescence resonance energy transfer, providing a potential platform for measuring agents that interact with the reactive site between the donor and acceptor. PMID:11463339

Waud, J P; Bermúdez Fajardo, A; Sudhaharan, T; Trimby, A R; Jeffery, J; Jones, A; Campbell, A K

2001-01-01

395

Thermal chemiluminescence from ?-irradiated polytetrafluoroethylene and its emission mechanism: Investigation by multichannel Fourier-transform luminescence spectroscopy  

NASA Astrophysics Data System (ADS)

Thermal chemiluminescence spectra of polytetrafluoroethylene powder irradiated by ? rays in air at room temperature were measured with a multichannel Fourier-transform chemiluminescence spectrometer. The luminescence appeared immediately after heating the irradiated samples at 160, 180 and 200 °C in dry air and in N2 and then disappeared within a few minutes, whereas virgin samples showed no luminescence. The lifetime of luminescence decreased as the heating temperature increased, but the total amount of luminescence at each temperature was nearly constant. From this observation an emission mechanism was derived with the aid of ESR and IR spectroscopy.

Noguchi, Tsuyoshi; Yamada, Emi; Akai, Nobuyuki; Ishii, Hiroshi; Satoh, Chikahiro; Hironiwa, Takayuki; Millington, Keith R.; Nakata, Munetaka

2014-10-01

396

Thermal chemiluminescence from ?-irradiated polytetrafluoroethylene and its emission mechanism: Kinetic analysis and bond dissociation energy of fluoroperoxide group  

NASA Astrophysics Data System (ADS)

Temperature dependence of the time evolution of chemiluminescence intensity from ?-irradiated polytetrafluoroethylene was examined by heating isothermally in the range of 150 and 200 °C. Kinetic analysis was carried out to estimate the rate constants, from which the dissociation energy of the Osbnd O bond in the fluoroperoxide group was determined to be 97 ± 4 kJ mol-1, being consistent with the corresponding value for small fluorocarbon model systems obtained by quantum chemical calculations. This strongly supports the emission mechanism [sbnd CF(OOF)sbnd CF2sbnd ? sbnd COsbnd CF2sbnd + OF2 + h?] proposed in our previous paper to explain chemiluminescence from the ?-irradiated polytetrafluoroethylene.

Yamada, Emi; Noguchi, Tsuyoshi; Akai, Nobuyuki; Ishii, Hiroshi; Satoh, Chikahiro; Hironiwa, Takayuki; Millington, Keith R.; Nakata, Munetaka

2014-11-01

397

Red-green-blue electrogenerated chemiluminescence utilizing a digital camera as detector.  

PubMed

Exploiting the distinct excitation and emission properties of concomitant electrochemiluminophores in conjunction with the inherent color selectivity of a conventional digital camera, we create a new strategy for multiplexed electrogenerated chemiluminescence detection, suitable for the development of low-cost, portable clinical diagnostic devices. Red, green and blue emitters can be efficiently resolved over the three-dimensional space of ECL intensity versus applied potential and emission wavelength. As the relative contribution ratio of each emitter to the photographic RGB channels is constant, the RGB ECL intensity versus applied-potential curves could be effectively isolated to a single emitter at each potential. PMID:24512565

Doeven, Egan H; Barbante, Gregory J; Kerr, Emily; Hogan, Conor F; Endler, John A; Francis, Paul S

2014-03-01

398

Sonochemical fabrication of 8-hydroxyquinoline aluminum (Alq3) nanoflowers with high electrogenerated chemiluminescence.  

PubMed

Well-defined Alq(3) nanoflowers were fabricated via a facile and fast sonochemical route. X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to characterize the structure and shape of the as-prepared product. The results showed that the resulting Alq(3) was composed of nanobelts with thickness about 50 nm, average widths of 200 nm, and length up to 10 ?m. The Alq(3) nanoflowers exhibited good electrogenerated chemiluminescence behavior. PMID:20805037

Mao, Chang-Jie; Wang, Dan-Chen; Pan, Hong-Cheng; Zhu, Jun-Jie

2011-03-01

399

Determination of picomolar levels of cobalt in seawater by flow injection analysis with chemiluminescence detection  

SciTech Connect

Flow injection analysis (FIA) was used to automate the determination of cobalt in seawater by the Co-enhanced chemiluminescent oxidation of gallic acid in alkaline hydrogen peroxide. A preconcentration/separation step in the FIA manifold with an in-line column of immobilized 8-hydroxyquinoline was included to separate the Co from alkaline-earth ions. One sample analysis takes 8 min, including the 4-min sample load period. The detection limit is approximately 8 pM. The average standard deviation of replicate analyses at sea of 80 samples was +/- 5%. The method was tested and intercalibrated on samples collected off the California coast.

Sakamoto-Arnold, C.M.; Johnson, K.S.

1987-07-15

400

Development of an automatic multi-channel ink-jet ejection chemiluminescence system and its application to the determination of horseradish peroxidase.  

PubMed

In this work, an automatic multi-channel ink-jet for chemiluminescence (CL) analysis was developed. The four-channel ink-jet device was controlled by a home-made circuit. Differing from the classic flow injection CL, the whole procedure for CL analysis was automatically completed on a hydrophobic glass side. CL reaction of luminal and hydrogen peroxide for the determination of horseradish peroxidase (HRP) was selected as an application to automatic CL analysis platform. All solutions delivered by different channels were precisely ejected to the same position of the glass slide for the CL analysis. The consumption of reaction solution was reduced to nanoliter level. The whole CL analysis could be completed in less than 4min, which was benefited from the prompt solution mixing in small size of droplet. The CL intensity increased linearly with HRP concentration in the range from 0.01 to 0.5?gmL(-1). The limit of detection (LOD) (S/N=3) was 0.005?gmL(-1). Finally, the automatic CL system could also be used for the detection of HRP in HRP-protein conjugates, which showed its practical application in immunoassay. PMID:22819052

Chen, Fengming; Lin, Zhen; Zheng, Yongzan; Zeng, Hulie; Nakajima, Hizuru; Uchiyama, Katsumi; Lin, Jin-Ming

2012-08-20

401

Ultrasensitive detection of cancer cells and glycan expression profiling based on a multivalent recognition and alkaline phosphatase-responsive electrogenerated chemiluminescence biosensor  

NASA Astrophysics Data System (ADS)

A multivalent recognition and alkaline phosphatase (ALP)-responsive electrogenerated chemiluminescence (ECL) biosensor for cancer cell detection and in situ evaluation of cell surface glycan expression was developed on a poly(amidoamine) (PAMAM) dendrimer-conjugated, chemically reduced graphene oxide (rGO) electrode interface. In this strategy, the multivalency and high affinity of the cell-targeted aptamers on rGO provided a highly efficient cell recognition platform on the electrode. The ALP and concanavalin A (Con A) coated gold nanoparticles (Au NPs) nanoprobes allowed the ALP enzyme-catalyzed production of phenols that inhibited the ECL reaction of Ru(bpy)32+ on the rGO electrode interface, affording fast and highly sensitive ECL cytosensing and cell surface glycan evaluation. Combining the multivalent aptamer interface and ALP nanoprobes, the ECL cytosensor showed a detection limit of 38 CCRF-CEM cells per mL in human serum samples, broad dynamic range and excellent selectivity. In addition, the proposed biosensor provided a valuable insight into dynamic profiling of the expression of different glycans on cell surfaces, based on the carbohydrates recognized by lectins applied to the nanoprobes. This biosensor exhibits great promise in clinical diagnosis and drug screening.A multivalent recognition and alkaline phosphatase (ALP)-responsive electrogenerated chemiluminescence (ECL) biosensor for cancer cell detection and in situ evaluation of cell surface glycan expression was developed on a poly(amidoamine) (PAMAM) dendrimer-conjugated, chemically reduced graphene oxide (rGO) electrode interface. In this strategy, the multivalency and high affinity of the cell-targeted aptamers on rGO provided a highly efficient cell recognition platform on the electrode. The ALP and concanavalin A (Con A) coated gold nanoparticles (Au NPs) nanoprobes allowed the ALP enzyme-catalyzed production of phenols that inhibited the ECL reaction of Ru(bpy)32+ on the rGO electrode interface, affording fast and highly sensitive ECL cytosensing and cell surface glycan evaluation. Combining the multivalent aptamer interface and ALP nanoprobes, the ECL cytosensor showed a detection limit of 38 CCRF-CEM cells per mL in human serum samples, broad dynamic range and excellent selectivity. In addition, the proposed biosensor provided a valuable insight into dynamic profiling of the expression of different glycans on cell surfaces, based on the carbohydrates recognized by lectins applied to the nanoprobes. This biosensor exhibits great promise in clinical diagnosis and drug screening. Electronic supplementary information (ESI) available: CV and EIS during the electrode assembly, activity of the nanoprobes and the glycan-binding specificities of the lectins. See DOI: 10.1039/c4nr03053b

Chen, Xiaojiao; He, Yao; Zhang, Youyu; Liu, Meiling; Liu, Yang; Li, Jinghong

2014-09-01

402

FI-photoinduced chemiluminescence method for diuron determination in water samples.  

PubMed

A new method for the determination of the herbicide diuron, using a flow injection manifold and photoinduced chemiluminescence detection, is presented. The pesticide, in basic medium, was irradiated on-line with UV light (254 nm) for 53 s. A short discussion about the possible irradiation products is included. The chemiluminescent response of the photoproducts was induced by oxidation with potassium ferricyanide in phosphate buffer at pH 11.5. The method permitted the quantification of diuron over the 0.1-4.0 mg L(-1) range, with a detection limit (S/N = 3) of 20 µg L(-1) when the method was applied directly. However, the use of solid phase extraction (SPE) performed with C(18) cartridges allowed us to achieve a limit of detection of 0.4 µg L(-1) and a 1.5-30 µg L(-1) dynamic range. The method was successfully applied to the diuron determination in samples of water from different sources (spring, ground, mineral, irrigation, sea and tap waters) with a low consumption of reagents. PMID:21415512

Catalá-Icardo, Mónica; López-Paz, José Luis; Peña-Bádena, Andrea

2011-01-01

403

Preparation methods to optimize the performance of sensor discs for fast chemiluminescence ozone analyzers.  

PubMed

Fast ozone (O(3)) measurements (1-50 Hz) in the atmosphere are required for airborne studies and for the measurement of ground-based O(3) fluxes by the eddy covariance technique. Fast response analyzers, based on heterogeneous chemiluminescence, need dye coated sensor discs on which the chemiluminescence is generated. In this study, we present three new preparation methods for those sensor discs. Currently available sensor discs exhibit a fast temporal decay of sensitivity, resulting in short duty times which is troublesome for many field applications. To produce sensor discs that provide more stable signals over time, three dyes and nine energy transfer reagents were tested (as well as different stoichiometric mixtures). The resulting optimal method saves 80% of the solid chemicals and shows a duty ozone dose that is prolonged by a factor of 3.5, revealing the same average sensitivity as currently available discs. In addition, we observed a strong effect of the adsorption matrix on the O(3) sensitivity, although silica discs from the same manufacturer were used. Application of the new sensor discs during field measurements showed that the results are consistent with the laboratory data. PMID:23343053

Ermel, M; Oswald, R; Mayer, J-C; Moravek, A; Song, G; Beck, M; Meixner, F X; Trebs, I

2013-02-19

404

Flow injection chemiluminescent determination of clenbuterol using GoldMag particles as carrier.  

PubMed

A novel flow injection chemiluminescent (CL) enzyme immunoassay for clenbuterol analysis based on GoldMag particles is described. GoldMag is a new type of super-paramagnetic Fe3O4/Au composite particle used as a carrier in a flow injection CL system. Clenbuterol conjugated with ovalbumin (OVA) was immobilized onto GoldMag particles and the particles fixed in a micro-channel by an external electromagnetic field. The clenbuterol test sample and clenbuterol polyclonal antibody (Ab) were injected into the channel and incubated with GoldMag particles. Clenbuterol, immobilized on the magnetic particle surfaces, competes for polyclonal antibodies with clenbuterol in the test sample. The free Ab or Ab combined with the clenbuterol sample was washed away and the magnetic particles conjugated with Ag-Ab left in the micro-channel. Horseradish peroxidase (HRP)-labelled goat anti-rabbit immunoglobulin G (IgG) was added and reacted with clenbuterol polyclonal antibodies; excess goat anti-rabbit-HRP was then washed off. When chemiluminescent reagents were injected into the channel, emitted light from the magnetic particle surface was measured and recorded using a photomultiplier-based apparatus. The linear range of this novel method was 0.01-0.1 ng g(-1) and recovery of clenbuterol was 85-105% with a RSD of 3.2% (n = 11). PMID:17164213

Li, Zhefei; Jian, Liru; Wang, Huirong; Cui, Yali

2007-01-01

405

Microplate-reader method for the rapid analysis of copper in natural waters with chemiluminescence detection  

PubMed Central

We have developed a method for the determination of copper in natural waters at nanomolar levels. The use of a microplate-reader minimizes sample processing time (~25 s per sample), reagent consumption (~120 ?L per sample), and sample volume (~700 ?L). Copper is detected by chemiluminescence. This technique is based on the formation of a complex between copper and 1,10-phenanthroline and the subsequent emission of light during the oxidation of the complex by hydrogen peroxide. Samples are acidified to pH 1.7 and then introduced directly into a 24-well plate. Reagents are added during data acquisition via two reagent injectors. When trace metal clean protocols are employed, the reproducibility is generally less than 7% on blanks and the detection limit is 0.7 nM for seawater and 0.4 nM for freshwater. More than 100 samples per hour can be analyzed with this technique, which is simple, robust, and amenable to at-sea analysis. Seawater samples from Storm Bay in Tasmania illustrate the utility of the method for environmental science. Indeed other trace metals for which optical detection methods exist (e.g., chemiluminescence, fluorescence, and absorbance) could be adapted to the microplate-reader. PMID:23335917

Durand, Axel; Chase, Zanna; Remenyi, Tomas; Quéroué, Fabien

2013-01-01

406

Exhaled nitric oxide monitoring by quantum cascade laser: comparison with chemiluminescent and electrochemical sensors  

NASA Astrophysics Data System (ADS)

Fractional exhaled nitric oxide (FENO) is considered an indicator in the diagnostics and management of asthma. In this study we present a laser-based sensor for measuring FENO. It consists of a quantum cascade laser (QCL) combined with a multi-pass cell and wavelength modulation spectroscopy for the detection of NO at the sub-part-per-billion by volume (ppbv, 1?10-9) level. The characteristics and diagnostic performance of the sensor were assessed. A detection limit of 0.5 ppbv was demonstrated with a relatively simple design. The QCL-based sensor was compared with two market sensors, a chemiluminescent analyzer (NOA 280, Sievers) and a portable hand-held electrochemical analyzer (MINO®, Aerocrine AB, Sweden). FENO from 20 children diagnosed with asthma and treated with inhaled corticosteroids were measured. Data were found to be clinically acceptable within 1.1 ppbv between the QCL-based sensor and chemiluminescent sensor and within 1.7 ppbv when compared to the electrochemical sensor. The QCL-based sensor was tested on healthy subjects at various expiratory flow rates for both online and offline sampling procedures. The extended NO parameters, i.e. the alveolar region, airway wall, diffusing capacity, and flux were calculated and showed a good agreement with the previously reported values.

Mandon, Julien; Högman, Marieann; Merkus, Peter J. F. M.; van Amsterdam, Jan; Harren, Frans J. M.; Cristescu, Simona M.

2012-01-01

407

A fast screening method for the presence of atrazine and other triazines in water using flow injection with chemiluminescent detection.  

PubMed

Atrazine is a triazine herbicide which contains two secondary aliphatic amine groups. Previous studies have shown that aliphatic amines react with tris(2,2'-bipyridyl)ruthenium(III) to produce chemiluminescence. This paper describes the application of tris(2,2'-bipyridyl)ruthenium(III) to the detection of atrazine and related triazine herbicides in water by flow injection chemiluminescence analysis. The optimised experimental conditions were determined to be: sample and carrier flow rates of 4.6 mL min(-1), sample at pH 9 buffered with 50mM borax, and reagent concentration of 1mM tris(2,2'-bipyridyl)ruthenium(III) in 20mM H(2)SO(4) (pH 1). Under these conditions, the logarithm of the chemiluminescence intensity versus concentration was linear in the range of 2.15-2150 microg L(-1) for samples in MilliQ water, and the limit of detection of atrazine in water was determined to be 1.3+/-0.1 microg L(-1). Validation of the method was performed using direct injection HPLC. The presence of natural organic matter (NOM) significantly increased the chemiluminescence, masking the signal generated by atrazine. Isolating the target analyte via solid phase extraction (SPE) prior to analysis removed this interference and concentrated the samples, resulting in a greatly improved sensitivity with a detection limit of 14+/-2 ng L(-1). PMID:19203593

Beale, David J; Porter, Nichola A; Roddick, Felicity A

2009-04-30

408

Fluorescence and chemiluminescence detection of oxazole-labelled amines and thiols.  

PubMed

Fluorescence and chemiluminescence analyses of amino acids and thiols derivatized with 2-fluoro-4,5-diphenyloxazole (DIFOX) and 2-chloro-4,5-bis(p-N,N-dimethylaminosulphonylphenyl)oxazole (SAOX-Cl) were investigated. Thirteen diphenyloxazole (DIOX)-derivatized amino acids were separated within 38 min by a linear gradient elution from 100% A [0.05 M phosphate (pH 7.0): CH3CN (75:25)] to 100% B [0.05 M phosphate (pH 7.0):CH3CN (1:1)] over 30 min and an isocratic elution of 100% B for 30 min. The detection limits (S/N = 2) with fluorescence detection were in the range of 19-64 fmol. Thiols derivatized with SAOX-Cl were separated by an isocratic elution using 0.1 M H3PO4:CH3CN (65:35) and detected fluorimetrically. The detection limits (S/N = 2) of reduced glutathione, N-acetylcysteine, 2-mercaptopropionylglycine, cysteine, homocysteine and captopril were 1.2, 1.5, 1.9, 5.7, 6.4 and 7.9 fmol, respectively. Peroxyoxalate chemiluminescence (CL) intensities of sulphonyl-5-N,N-dimethylaminonaphthalene (DNS), SAOX and DIOX derivatives were compared using three different oxalate esters (DFPO, TCPO and TDPO) by flow injection analysis. The relative chemiluminescence intensity (RCL) of SAOX-proline and DIOX-proline were 76-80% and 19-25% of DNS-proline (100%), respectively. Other SAOX and DIOX derivatives showed lower CL intensities (< 12%). Extremely low CL intensities were obtained for the fluorescent tagging reagents (< 0.11%) and their hydrolysis products (< 0.80%). Secondary amino acids and peptides, derivatized with DIFOX in aqueous media at room temperature for 1 h, were detected using DFPO/H2O2. TCPO/H2O2 and TDPO/H2O2 after separation by high performance liquid chromatography.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8219699

Toyo'oka, T; Chokshi, H P; Givens, R S; Carlson, R G; Lunte, S M; Kuwana, T

1993-01-01

409

Determination of ferulic acid by flow injection chemiluminescence analysis based on enhancement of the N-bromobutanimide-eosin-CrCl3 system in alkaline solution.  

PubMed

A simple and sensitive flow injection chemiluminescence method has been developed for the determination of ferulic acid (FA) based on the significant enhancement effect of FA on the CL signal of the N-bromobutanimide (NBS)-eosin-CrCl3 system in alkaline solution. Under optimum conditions, the enhanced CL intensity is linearly related to the concentration of FA in its pharmaceutical preparations and human plasma samples. The corresponding linear regression equations were established over the 4.0 × 10(-10)-1.0 × 10(-7) g/mL for FA tablets and 2.0 × 10(-10)-1.0 × 10(-7) g/mL for plasma samples. The limit of detection for FA tablets and limit of quantification for plasma samples were 2.8 × 10(-10) g/mL (3 ?) and 3.04 × 10(-10) g/mL (10 ?), respectively. A complete analysis could be performed within 40 s, including washing and sampling, giving a throughput of ?90/h. The proposed method was successfully applied to the determination of FA in pharmaceutical preparations and human plasma samples with satisfactory results. The recoveries of pharmaceutical preparations and human plasma samples at three different concentrations were 97.8-102.6% and 96.7-104.0%, respectively. Furthermore, the possible mechanism of CL reactions was also discussed briefly. PMID:23436468

Shen, Guopeng; Jia, Xin; Jin, Jianwen; Pang, Li; Chen, Zheng; Du, Bin

2013-01-01

410

Determination of ammonia in water based on chemiluminescence resonance energy transfer between peroxymonocarbonate and branched NaYF4:Yb3+/Er3+ nanoparticles.  

PubMed

The ultraweak chemiluminescence (CL) from the reaction of hydrogen peroxide and carbonate is strongly enhanced by the branched NaYF(4):Yb(3+)/Er(3+) nanoparticle (NP) in the presence of aqueous ammonia. It was explained that ammonia catalyzes the decomposition of peroxymonocarbonate, which is the product of hydrogen peroxide mixing with bicarbonate, making the formation of (CO(2))(2)*, (O(2))(2)*, and (1)O(2). The excitation energy, carried by these emitter intermediates, can be transferred to NaYF(4):Yb(3+)/Er(3+) NP. The CL intensity is directly proportional to the concentration of ammonia present in the solution. A flow-injection CL system with high sensitivity, selectivity, and reproducibility is proposed for the determination of aqueous ammonia. The proposed method exhibited advantages in a larger linear range from 0.5 ?mol L(-1) to 50 ?mol L(-1) and a lower detection limit of 1.1 × 10(-8) mol L(-1) (S/N = 3). This method has been successfully applied to the evaluation of ammonia in water samples with recoveries from 95% to 108%. The relative standard deviations are 1.8% and 4.1% for intra-assay and inter-assay precision, respectively. PMID:23039193

Chen, Hui; Li, Haifang; Lin, Jin-Ming

2012-10-16

411

Determination of thiram and aminocarb pesticides in natural water samples using flow injection with tris(2,2'-bipyridyl)ruthenium(II)-diperiodatoargentate(III) chemiluminescence detection.  

PubMed

A simple and sensitive flow-injection (FI) method is reported for the determination of thiram and aminocarb pesticides in natural water samples based on the strong enhancing effects of these pesticides on the tris(2,2'-bipyridyl)ruthenium(II)-diperiodatoargentate(III) (Ru(bipy)3(2+)-DPA) chemiluminescence (CL) system. Under the optimum experimental conditions, the CL intensity was linear over the range of 1.0 - 1000 and 1.0 - 10000 ng mL(-1) (R(2) = 0.9998 (n = 7) and 0.9994 (n = 11)) for thiram and aminocarb, respectively, with relative standard deviations (RSDs; n = 3) in the range 1.0 - 2.6%. The limits of detection (S/N = 3) were 0.1 ng mL(-1) for both pesticides with injection throughputs of 150 h(-1). The key chemical and physical variables (reagent concentrations, flow rates, sample volume, PMT voltage) were optimized and potential interferences investigated. The method was successfully applied to natural water samples and the results obtained were not significantly different (95% confidence interval) from results obtained by the previously reported FI-CL and HPLC methods. Thiram could be determined in the presence of aminocarb using Triton X-100. The possible CL reaction mechanism is also discussed briefly. PMID:24212732

Asghar, Mohammad; Yaqoob, Mohammad; Haque, Naheed; Nabi, Abdul

2013-01-01

412

Sensitive determination of 2-methoxyestradiol in pharmaceutical preparations and serum samples using flow injection chemiluminescence.  

PubMed

A rapid and sensitive flow injection chemiluminescence (FI-CL) method is described for the determination of 2-methoxyestradiol (2ME) based on enhancement of the CL intensity from a potassium ferricyanide-calcein system in sodium hydroxide medium. The optimum conditions for the CL emission were investigated. Under optimized conditions, a linear calibration graph was obtained over the range 1.0?×?10(-8) to 1.0?×?10(-6) mol/L (r?=?0.998) 2ME with a detection limit (3?) of 5.4?×?10(-9) mol/L. The relative standard deviation (RSD) for 5.0?×?10(-7) mol/L 2ME was 1.7%. As a preliminary application, the proposed method was successfully applied to the determination of 2ME in injection solutions and serum samples. The possible CL mechanism was also proposed. PMID:23836511

Yao, Hanchun; Zhang, Min; Zeng, Wenyuan; Zeng, Xiaoying; Zhang, Zhenzhong

2014-05-01

413

Direct chemiluminescence of carbon dots induced by potassium ferricyanide and its analytical application.  

PubMed

The chemiluminescence (CL) of water-soluble fluorescent carbon dots (C-dots) induced by direct chemical oxidation was investigated. C-dots were prepared by solvothermal method and characterized by fluorescence spectra and transmission electron microscopy. It was found that K3Fe(CN)6 could directly oxidize C-dots to produce a relatively intense CL emission. The mechanism of CL generation was investigated based on the fluorescence and CL emission spectra and the effect of radical scavengers on the CL intensity. The inhibitive effect of some metal ions and biologically important molecules on the CL intensity of the system was examined and the potential of the system for the determination of these species at trace levels was studied. In order to evaluate the capability of method to real sample analysis, it was applied to the determination of Cr(VI) and adrenaline in water and injection samples, respectively. PMID:24370936

Amjadi, Mohammad; Manzoori, Jamshid L; Hallaj, Tooba; Sorouraddin, Mohammad H

2014-03-25

414

A rapid and sensitive chemiluminescent immunoassay of total thyroxin with DMAE x NHS-Labeled.  

PubMed

A novel chemiluminescence immunoassay (CLIA) of total thyroxin (TT4) with the acridinium ester of DMAE x NHS [2',6'-dimethyl-4'-(n-succinimidyloxycarbonyl) phenyl-10-methyl-acridinium-9-carboxylate methosulfate] labeled has been developed. In our method, microwells were coated with anti-T4 monoclonal antibody (McAb) and DMAE x NHS synthesized by our laboratory was conjugated with streptavidin (SA). T4-BSA was conjugated with biotin-N-hydroxysuccinimide (B x NHS), T4-BSA- B x NHS and the T4 in the standard or sample competitively react with anti-T4 McAb. Streptavidin-biotin separation and enhanced techniques were applied in this assay. The presented approach shows many excellent characteristics, particularly, rapid assay process and high detection sensitivity. PMID:18569374

Yin, Dongguang; Cui, Daxiang; Gao, Feng; He, Rong; He, Youfeng; Liu, Yibing; Shen, Decun; Wu, Minghong

2008-01-01

415

Effect of blood handling conditions on progesterone assay results obtained by chemiluminescence in the bitch.  

PubMed

Assay of blood progesterone (P4) is commonly practiced to determine the time of ovulation, diagnose luteal insufficiency, and predict time of parturition in bitches. Because of practical constraints, most blood samples cannot be assayed on site immediately after collection. The aim of this work was to evaluate the effects of various sampling and storage conditions on concentrations of P4 as determined by chemiluminescence immunoassay. The blood of 5 Beagle bitches was collected from the jugular vein to study the effect of the type of collection tube (silicone, lithium heparin, EDTA), the storage time of unseparated or separated plasma (2 h to 14 d), and the number of freeze-thaw cycles (1-10) on P4. The effect of each factor was tested within one assay session. None of the factors significantly affected P4. Thus, P4 appears to remain relatively stable in canine blood samples exposed to various processing and storage conditions. PMID:23988180

Tahir, M Z; Thoumire, S; Raffaelli, M; Grimard, B; Reynaud, K; Chastant-Maillard, S

2013-10-01

416

Development of an Electrogenerated Chemiluminescence Biosensor using Carboxylic acid-functionalized MWCNT and Au Nanoparticles  

PubMed Central

A COOH-F-MWCNT-Nafion-Ru(bpy)32+-Au-ADH electrogenerated chemiluminescence (ECL) electrode using COOH-functionalized MWCNT (COOH-F-MWCNT) and Au nanoparticles synthesized by the radiation method was fabricated for ethanol sensing. A higher sensing efficiency for ethanol for the ECL biosensor prepared by PAAc-g-MWCNT was measured compared to that of the ECL biosensor prepared by PMAc-g-MWCNT, and purified MWCNT. Experimental parameters affecting ethanol detection were also examined in terms of pH and the content of PAAc-g-MWCNT in Nafion. Little interference of other compounds was observed for the assay of ethanol. Results suggest this ECL biosensor could be applied for ethanol detection in real samples. PMID:22573979

Piao, Ming-Hua; Yang, Dae-Soo; Yoon, Kuk-Ro; Lee, Seung-Ho; Choi, Seong-Ho

2009-01-01

417

Direct chemiluminescence of carbon dots induced by potassium ferricyanide and its analytical application  

NASA Astrophysics Data System (ADS)

The chemiluminescence (CL) of water-soluble fluorescent carbon dots (C-dots) induced by direct chemical oxidation was investigated. C-dots were prepared by solvothermal method and characterized by fluorescence spectra and transmission electron microscopy. It was found that K3Fe(CN)6 could directly oxidize C-dots to produce a relatively intense CL emission. The mechanism of CL generation was investigated based on the fluorescence and CL emission spectra and the effect of radical scavengers on the CL intensity. The inhibitive effect of some metal ions and biologically important molecules on the CL intensity of the system was examined and the potential of the system for the determination of these species at trace levels was studied. In order to evaluate the capability of method to real sample analysis, it was applied to the determination of Cr(VI) and adrenaline in water and injection samples, respectively.

Amjadi, Mohammad; Manzoori, Jamshid L.; Hallaj, Tooba; Sorouraddin, Mohammad H.

2014-03-01

418

Absolute rate constant for the O plus NO chemiluminescence in the near infrared  

NASA Technical Reports Server (NTRS)

Infrared chemiluminescence from the process O + NO (+M) NO2 + hv (+M) has been studied between 1.3 and 4.1 micrometer. The wavelength dependence of the continuum between 1.3 and 3.3 micrometer is in fair agreement with previous studies and the measured radiative rate constant at 1.51 micrometer establishes the NO-O glow in this spectral range as a secondary emission standard. Comparison with previous studies of the visible region of the glow implies that the overall radiative rate constant lies in the range (9.4 to 11.2) x 10 to the minus 17 power cu cm sec/1. In the region 3.3 to 4.1 micrometer, the previously observed broad band, peaking at 3.7 micrometer, shows a complex kinetic dependence on O and M.

Golde, M. F.; Roche, A. E.; Kaufman, F.

1973-01-01

419

A preliminary study of ester oxidation on an aluminum surface using chemiluminescence  

NASA Technical Reports Server (NTRS)

The oxidation characteristics of a pure ester (trimethyolpropane triheptanoate) were studied by using a chemiluminescence technique. Tests were run in a thin-film micro-oxidation apparatus with an aluminum alloy catalyst. Conditions included a pure oxygen atmosphere and a temperature range of 176 to 206 C. Results indicated that oxidation of the ester (containing 10 to the minus 3 power M diphenylanthracene as an intensifier) was accompanied by emission of light. The maximum intensity of light emission (I sub max) was a function of the amount of ester, the concentration of intensifier, and the test temperature. The induction period or the time to reach one-half of maximum intensity (t sub 1/2) was an inverse function of test temperature. Decreases in light emission at the later stages of a test were caused by depletion of the intensifier.

Jones, W. R., Jr.; Meador, M. A.; Morales, W.

1986-01-01

420

A preliminary study of ester oxidation on an aluminum surface using chemiluminescence  

NASA Technical Reports Server (NTRS)

The oxidation characteristics of a pure ester (trimethyolpropane triheptanoate) were studied by using a chemiluminescence technique. Tests were run in a thin-film micro-oxidation apparatus with an aluminum alloy catalyst. Conditions included a pure oxygen atmosphere and a temperature range of 176 to 206 C. Results indicated that oxidation of the ester (containing 10 to the minus 3rd power M diphenylanthracene as an intensifier) was accompanied by emission of light. The maximum intensity of light emission (I sub max) was a function of the amount of ester, the concentration of intensifier, and the test temperature. The induction period or the time to reach one-half of maximum intensity (t sub 1/2) was an inverse function of test temperature. Decreases in light emission at the later stages of a test were caused by depletion of the intensifier.

Jones, William R., Jr.; Meador, Michael A.; Morales, Wilfredo

1987-01-01

421

Anodic electrogenerated chemiluminescence behavior of graphite-like carbon nitride and its sensing for rutin.  

PubMed

In this paper, the anodic electrogenerated chemiluminescence (ECL) behavior of graphite-like carbon nitride (g-C3N4) is studied using cyclic voltammetry with triethanolamine (TEA) as a coreactant. The possible anodic ECL response mechanism of the g-C3N4/TEA system is proposed. Furthermore, it is observed that the anodic ECL signal can be quenched efficiently in the presence of rutin, on the basis of which a facile anodic ECL senor for the determination of rutin is developed. This ECL sensor is found to have a linear response in the range of 0.20-45.0 ?M and a low detection limit of 0.14 ?M (at signal-to-noise of 3). These results suggest that semiconductor g-C3N4 has great potential in extending the application in the ECL field as an efficient luminophore. PMID:23373468

Cheng, Changming; Huang, Ying; Wang, Jun; Zheng, Baozhan; Yuan, Hongyan; Xiao, Dan

2013-03-01

422

Chemiluminescence determination of tetracyclines using Fenton system in the presence europium(III) ions.  

PubMed

A new simple chemiluminescent method for the determination of chlortetracycline (Chlor-TC), oxytetracycline (Oxy-TC) and doxycycline (Doxy-TC) is described. This method is based on the europium(III) emission as a result of the energy transfer process from the excited product of the tetracyclines oxidation to the uncomplexed Eu(III). Under the optimum conditions, calibration graphs were obtained for 4x10(-7) to 2x10(-5) mol L(-1) of Chlor-TC; 2x10(-7) to 2x10(-5) mol L(-1) of Oxy-TC and 1x10(-7) to 3x10(-5) mol L(-1) of Doxy-TC. The method was successfully applied to the determination of these drugs in pharmaceutical and veterinary formulation and honey. PMID:19345765

Kaczmarek, Malgorzata; Lis, Stefan

2009-04-20

423

Chemiluminescence determination of fluoroquinolones using Fenton system in the presence of terbium(iii) ions.  

PubMed

A simple new chemiluminescent, CL, method is described for the determination of fluoroquinolones such as: ciprofloxacin (CF), norfloxacin (NF), and ofloxacin (OF). This method is based on the measurement of terbium(iii) emission. This emission follows an energy transfer to the uncomplexed terbium(iii) ions from the excited products of fluoroquinolone oxidations. Under optimum conditions, calibration graphs were obtained for 2 × 10(-8)-2 × 10(-6) mol L(-1) of NF; 3 × 10(-8)-2 × 10(-6) mol L(-1) of CF and 4 × 10(-7)-5 × 10(-5) mol L(-1) of OF. The detection limits are 7 × 10(-9) mol L(-1) norfloxacin, 1 × 10(-8) mol L(-1) ciprofloxacin and 1.5 × 10(-7) mol L(-1) ofloxacin. The method was successfully applied to the determination of these drugs in pharmaceutical formulations. PMID:21519592

Kaczmarek, Ma?gorzata; Lis, Stefan

2011-06-21

424

Development of an aerosol chemiluminescent detector coupled to capillary electrophoresis for saccharide analysis.  

PubMed

A novel aerosol chemiluminescent (CL) detector coupling to capillary electrophoresis (CE) for the detection of saccharides is reported. This CL detector is composed of a postcapillary nebulizer and porous alumina as catalyzer in quartz tube. The CL emission could be generated due to the catalyzing oxidization of saccharides on the surface of porous alumina. The saccharides such as sucrose, alpha-lactose, maltose, raffinose, galactose, xylose, and glucose with only weak UV absorbance can be successfully detected. The linear ranges of those saccharides are from 30-2000 to 50-2000 mg/L; relative standard deviations range from 2.1 to 3.7% (200 mg/L, n = 11). Compared with the traditional UV detector currently used in CE, this novel detector shows the advantage of high sensitivity to the compounds with only weak UV absorption. Thus, it could be an important supplement of CE detectors for UV-lacking compounds. PMID:16285686

Huang, Guangming; Lv, Yi; Zhang, Sichun; Yang, Chengdui; Zhang, Xinrong

2005-11-15

425

Optimization of condition for conjugation of enrofloxacin to enzymes in chemiluminescence enzyme immunoassay  

NASA Astrophysics Data System (ADS)

In this study, in order to find out a proper method for conjugation of enrofloxacin to label enzymes, two methods were compared and carbodiimide condensation was proved to be better. The results showed that the binding ratio of enrofloxacin and alkaline phosphatase (ALP) was 8:1 and that of enrofloxacin and horseradish peroxidase (HRP) was 5:1. This indicated that conjugate synthesized by carbodiimide condensation was fit for chemiluminescence enzyme immunoassay (CLEIA). Furthermore, data revealed that dialysis time was an important parameter for conjugation and 6 days was best. Buffer to dilute conjugate had little effect on CLEIA. The storage condition for conjugates was also studied and it was shown that the conjugate was stable at 4 °C with no additive up to 30 days. These data were valuable for establishing CLEIA to quantify enrofloxacin.

Yu, Songcheng; Yu, Fei; Zhang, Hongquan; Qu, Lingbo; Wu, Yongjun

2014-06-01

426

Analysis of parabens in cosmetics by low pressure liquid chromatography with monolithic column and chemiluminescent detection.  

PubMed

This paper presents an application of chromatographic separation based on an ultra-short monolithic column and chemiluminescent detection in an FIA type instrument manifold for the determination of four paraben mixtures: methylparaben (MP), ethylparaben (EP), propylparaben (PP) and butylparaben (BP). The separation is achieved in 150 s using two consecutive carriers: first 12% ACN:water that changes 75 s after injection to 27% ACN:water. The detection is based on the oxidation of the hydrolysis product of parabens, p-hydroxybenzoic acid, with Ce(IV) in the presence of Rhodamine 6G which evokes chemiluminescence of sufficient intensity to enable a sensitive determination of these species. After optimization of the variables involved, the analytical method is characterized, displaying the following values for concentration ranges, detection limits and precision, as relative standard deviation at low concentration (0.15 mg l(-1))-MP: from 9.9x10(-7) to 3.3x10(-4)M; 1.9x10(-8); 5.6%; EP: from 9.0x10(-7) to 3.3x10(-4)M; 2.8x10(-8); 3.5%; PP: from 8.3x10(-7) to 9.9x10(-5)M; 2.3x10(-8); 4.2%; and BP: from 7.7x10(-7) to 9.9x10(-5)M; 4.2x10(-8)M; 6.2%. The method was applied and validated satisfactorily for the determination of these parabens in cosmetic samples, comparing the results against a liquid chromatography reference method. PMID:19559911

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

2009-07-15

427

Drug Reactions  

MedlinePLUS

... version Drug Reactions Drug Reactions What is an adverse drug reaction? Medicines can treat or prevent illness and ... medicines can cause problems. These problems are called adverse drug reactions. You should know what to do if ...

428

Stimulatory effect of some plant extracts used in homeopathy on the phagocytosis induced chemiluminescence of polymorphonuclear leukocytes.  

PubMed

Some plant extracts on a large range of dilutions as used in Homeopathy were tested on the chemiluminescence emission produced by polymorphonuclear leukocytes. The high stimulatory action was noticed when extracts from Uvae Ursi and Saponaria were tested, as the classical effect exerted by zymosan was exceeded. A moderate stimulatory action comparable with that of zymosan was found when extracts from Echmaceea, Aleo and Prumis were used, as well as in the case of Propolis. The relationship between stimulatory effect and the concentration range is modulated as function of the extract source, several peaks being observed for some dilutions (Saponana), but generally no quantitative relations were obtained. By studying the time when a chemiluminescence peak was observed, it is possible to estimate wether the weight of the NADPH oxidase or myeloperoxidase pathways are involved in the stimulatory effect on polymorphonuclear leukocytes. PMID:11712436

Crocnan, D O; Greabu, M; Olinescu, R

2000-01-01

429

High-density assembly of chemiluminescence functionalized gold nanodots on multiwalled carbon nanotubes and their application as biosensing platforms  

NASA Astrophysics Data System (ADS)

A one-step strategy was developed for high-density assembly of N-(aminobutyl)-N-(ethylisoluminol) (ABEI) functionalized gold nanodots onto the sidewalls of chitosan-grafted multiwalled carbon nanotubes (cs-MWCNTs) via the reduction of HAuCl4 with ABEI in the presence of cs-MWCNTs, resulting in novel hybrid nanomaterials with excellent chemiluminescence and electrochemiluminescence properties.A one-step strategy was developed for high-density assembly of N-(aminobutyl)-N-(ethylisoluminol) (ABEI) functionalized gold nanodots onto the sidewalls of chitosan-grafted multiwalled carbon nanotubes (cs-MWCNTs) via the reduction of HAuCl4 with ABEI in the presence of cs-MWCNTs, resulting in novel hybrid nanomaterials with excellent chemiluminescence and electrochemiluminescence properties. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr05574d

Zhang, Hongli; Cui, Hua

2014-02-01

430

Chemiluminescence behavior of CdTe-hydrogen peroxide enhanced by sodium hypochlorite and sensitized sensing of estrogens  

NASA Astrophysics Data System (ADS)

It has been found that sodium hypochlorite enhanced the chemiluminescence (CL) of the CdTe nanocrystal (NC)-hydrogen peroxide system and that estrogens inhibited these CL signals in alkaline solution. CL spectra were used to investigate the mechanism of the CL enhancement. On the basis of the inhibition, a flow-injection CL method has been established for determination of three natural estrogens.