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ECL Detection (ecl + detection)

Distribution by Scientific Domains

Chemistry	50%

Selected Abstracts

Study on the enhancement of Ru(bpy)32+ electrochemiluminescence by nanogold and its application for pentoxyverine detection

ELECTROPHORESIS, Issue 23 2005
Yingju Liu
Abstract In this work, CE separation with end-column Ru(bpy)32+ ECL detection for the quantitative determination of pentoxyverine was firstly performed. The experimental conditions, such as the applied potential, injection voltage, injection time, and the pH of separation buffer, were discussed in detail. Gold nanoparticles were found to enhance the ECL intensity at an appropriate volume ratio of nanogold with Ru(bpy)32+ but without changing their nanoproperties proved by transmission electron microscopy (TEM) and UV-vis spectra. The detection limits with or without nanogold were 6,nM and 0.6,,M, respectively. Successful separation of pentoxyverine, chlorpheniramine, and lidocaine was achieved. This method was also applied to monitor drug binding with HSA, and the binding constant for pentoxyverine was estimated as 1.8×103/M. [source]

Simultaneous electrochemical and electrochemiluminescence detection for microchip and conventional capillary electrophoresis

ELECTROPHORESIS, Issue 3 2005
Haibo Qiu
Abstract A simultaneous electrochemical (EC) and electrochemiluminescence (ECL) detection scheme was introduced to both microchip and conventional capillary electrophoresis (CE). In this dual detection scheme, tris(2,2'-bipyridyl)ruthenium(II) (Ru(bpy)32+) was used as an ECL reagent as well as a catalyst (in the formation of Ru(bpy)33+) for the EC detection. In the Ru(bpy)32+ -ECL process, Ru(bpy)33+ was generated and then reacted with analytes resulting in an ECL emission and a great current enhancement in EC detection due to the catalysis of Ru(bpy)33+. The current response and ECL signals were monitored simultaneously. In the experiments, dopamine and three kinds of pharmaceuticals, anisodamine, ofloxacin, and lidocaine, were selected to validate this dual detection strategy. Typically, for the EC detection of dopamine with the presence of Ru(bpy)32+, a ,5 times higher signal-to-noise ratio (S/N) can be achieved than that without Ru(bpy)32+, during the simultaneous EC and ECL detection of a mixture of dopamine and lidocaine using CE separation. The results indicated that this dual EC and ECL detection strategy could provide a simple and convenient detection method for analysis of more kinds of analytes in CE separation than the single EC or ECL detection alone, and more information of analytes could be achieved in analytical applications simultaneously. [source]

Signal-On Electrochemiluminescence Biosensors Based on CdS,Carbon Nanotube Nanocomposite for the Sensitive Detection of Choline and Acetylcholine

ADVANCED FUNCTIONAL MATERIALS, Issue 9 2009
Xiao-Fei Wang
Abstract This work describes for the first time signal-on electrochemiluminescence (ECL) enzyme biosensors based on cadmium sulfide nanocrystals (CdS NCs) formed in situ on the surface of multi-walled carbon nanotubes (MWCNTs). The MWCNT,CdS can react with H2O2 to generate strong and stable ECL emission in neutral solution. Compared with pure CdS NCs, the MWCNT,CdS can enhance the ECL intensity by 5.3-fold and move the onset ECL potential more positively for about 400,mV, which reduces H2O2 decomposition at the electrode surface and increases detection sensitivity of H2O2. Furthermore, the ECL intensity is less influenced by the presence of oxygen in solution. Benefiting from these properties, signal-on enzyme-based biosensors are fabricated by cross-linking choline oxidase and/or acetylcholine esterase with glutaraldehyde on MWCNT,CdS modified electrodes for detection of choline and acetylcholine. The resulting ECL biosensors show wide linear ranges from 1.7 to 332,µM and 3.3 to 216,µM with lower detection limit of 0.8 and 1.7,µM for choline and acetylcholine, respectively. The common interferents such as ascorbic acid and uric acid in electrochemical enzyme-based biosensors do not interfere with the ECL detection of choline and acetylcholine. Furthermore, both ECL biosensors possess satisfying reproducibility and acceptable stability. [source]

Determination of galanthamine in Bulbus Lycoridis Radiatae by coupling capillary electrophoresis with end-column electrochemiluminescence detection

JOURNAL OF SEPARATION SCIENCE, JSS, Issue 15 2010
Biyang Deng
Abstract A novel method for the determination of galanthamine (GAL) in Bulbus Lycoridis Radiatae has been developed based on coupling CE with an end-column tris(2,2,-bipyridyl)ruthenium(II) electrochemiluminescence (ECL). Parameters affecting CE separation and ECL detection were investigated and optimized. Baseline separation of GAL from other components in the Bulbus Lycoridis Radiatae sample was achieved with an 18,mmol/L phosphate running buffer at pH 9.0. Under the optimized conditions: 12,kV CE-separation voltage, ECL detection potential at 1.25,V with 5,mmol/L and 50,mmol/L phosphate buffer at pH 7.5 in the detection reservoir, the linear range of GAL concentration was from 0.8,ng/mL to 2,,g/mL, whereas the detection limit was 0.25,ng/mL (S/N=3). The proposed method was successfully demonstrated for the determination of GAL in Bulbus Lycoridis Radiatae. [source]

Simultaneous determination of methylephedrine and pseudoephedrine in human urine by CE with electrochemiluminescence detection and its application to pharmacokeinetics

BIOMEDICAL CHROMATOGRAPHY, Issue 11 2009
Yan-Ming Liu
Abstract A novel method for the determination of ephedra alkaloids (methylephedrine and pseudoephedrine) was developed by electrophoresis capillary (CE) separation and electrochemiluminesence detection (ECL). The use of ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate, BMIMBF4) improved the detection sensitivity markedly. The conditions for CE separation, ECL detection and effect of ionic liquid were investigated in detail. The two ephedra alkaloids with very similar structures were well separated and detected under the optimum conditions. The limits of detection (signal-to-noise ratio = 3) in standard solution were 1.8 × 10,8 mol/L for methylephedrine (ME) and 9.2 × 10,9 mol/L for pseudoephedrine (PSE). The limits of quantitation (signal-to-noise ratio = 10) in human urine samples were 2.6 × 10,7 mol/L for ME and 3.6 × 10,7 mol/L for PSE. The recoveries of two alkaloids at three different concentration levels in human urine samples were between 81.7 and 105.0%. The proposed method was successfully applied to the determination of ME and PSE in human urine and the monitoring of pharmacokinetics for PSE. The proposed method has potential in therapeutic drug monitoring and clinical analysis. Copyright © 2009 John Wiley & Sons, Ltd. [source]

[Ru(bpy)2(dcbpy)NHS] Labeling/Aptamer-Based Biosensor for the Detection of Lysozyme by Increasing Sensitivity with Gold Nanoparticle Amplification

CHEMISTRY - AN ASIAN JOURNAL, Issue 11 2008
Jianguo Bai
Abstract A novel [Ru(bpy)2(dcbpy)NHS] labeling/aptamer-based biosensor combined with gold nanoparticle amplification for the determination of lysozyme with an electrochemiluminescence (ECL) method is presented. In this work, an aptamer, an ECL probe, gold nanoparticle amplification, and competition assay are the main protocols employed in ECL detection. With all the protocols used, an original biosensor coupled with an aptamer and [Ru(bpy)2(dcbpy)NHS] has been prepared. Its high selectivity and sensitivity are the main advantages over other traditional [Ru(bpy)3]2+ biosensors. The electrochemical impedance spectroscopy (EIS) and atomic force microscopy (AFM) characterization illustrate that this biosensor is fabricated successfully. Finally, the biosensor was applied to a displacement assay in different concentrations of lysozyme solution, and an ultrasensitive ECL signal was obtained. The ECL intensity decreased proportionally to the lysozyme concentration over the range 1.0×10,13,1.0×10,8,mol,L,1 with a detection limit of 1.0×10,13,mol,L,1. This strategy for the aptasensor opens a rapid, selective, and sensitive route for the detection of lysozyme and potentially other proteins. [source]