329 resultados para peroxyoxalate chemiluminescence
Resumo:
本研究工作基于发展新型固定化毗陡钉的方法和材料,并可应用于实际样品的高灵敏度测定,在以下几方面进行了研究。 1.将毗咤钉用层层自组装方法固定在纳米SiO2/Ru(bpy)32+}n多层膜中,发展了一种灵敏、稳定的电化学发光传感器。研究了毗睫钉在多层膜中的电化学及电化学发光行为,并对多层膜进行了表征。此多层膜修饰电极用于电化学发光法测定三丙胺和草酸时具有很高的灵敏度。多层膜至少一个月保持较好的稳定性。2.通过交替吸附带正电荷的毗陡钉和带负电荷的粘土,组装了稳定的clay/Ru(bpy)32+n多层膜,实现了毗睫钉在电极表面的固定化。研究了此修饰电极的电化学及电化学发光行为。毗咤钉在膜中保持其高的电化学和电化学发光活性。此多层膜修饰电极用于电化学发光法测定三丙胺和草酸。这种新的固定化方法具有稳定性好、重现性好及灵敏度高等优点。3.吡啶钌以离子交换方式固定在碳纳米管/Nafion复合物膜中。和纯Nafion 膜相比,碳纳米管的加入使毗咙钉的氧化还原电流大大增加,同时电化学发光信号也很强。Nofion在复合物中充当成膜剂、离子交换剂及碳纳米管的溶剂,而碳纳米管的加入大大改善了Nafion膜的性锹袱纳米管/Nofion复合物膜修饰电极用于电化学发光法测定三蔑胺时,具有赢的灵敏度。碳纳米管/Nafion复合物膜修饰电极也具有高的稳定性。4.基于多巴胺和肾上腺素对吡啶钌一三丙胺电化学发光体系的抑制作用、碳纳米管的优良胜能及Nafion膜的阳离子交换能力及选择渗透性,建立了一种在碳纳米管/Nafion-吡啶钌复合物膜修饰电极上、抗坏血酸存在条件下,电化学发光抑制法测定多巴胺和肾上腺素的新方法。结果表明这种方法测定多巴胺和肾上腺素具有高的灵敏度和好的选择性。 5.基于四环素类抗生素对碱性光泽精水溶液电化学氧化产生微弱的电化学发光有强的增敏作用,建立了一种新的光泽精电化学发光模式,并用于灵敏、选择的测定四环素、金霉素、土霉素和强力霉素。传统光泽精电化学发光体系中存在的电极污染问题可以用电化学方法很方便的解决。
Resumo:
Phenothiazine drugs, chlorpromazine hydrochloride (CPZ) and promethazine hydrochloride (PMZ), were determined with Ru(bpy)(3)(2+) electrochemiluminescene by the capillary electrophoresis (CE-ECL). It was found that both CPZ and PMZ could produce an intermediate that acted as coreactants to react with Ru(bpy)(3)(2+) to produce excited states which were capable of emitting light. This CE-ECL detection method had high sensitivity, good selectivity and reproducibility for CPZ and PMZ determination.
Resumo:
A series of seven ruthenium complexes with different ligands were synthesized and their optical, electrochemical and photoluminescent properties were characterized. Electroluminescent properties of these complexes were further evaluated using a light-emitting electrochemical cell with a configuration of indium tin oxide (ITO)/complex (100 nm)/Au (100 nm).
Resumo:
For the first time, we report a sensitive and selective method to detect Cu2+ based on the electrochemiluminescence quenching of CdTe quantum dots (QDs) in aqueous solution. The mercaptosuccinic acid (MSA) protected CdTe QDs were prepared and characterized with UV, fluorescence and ECL. The anodic ECL quenching mechanism was attributed to the fact that MSA capping was removed from the surface of the CdTe QDs and preferentially bound with Cu2+. The displacement of MSA capping layer created imperfections on the CdTe QDs surface, and eventually led to the ECL quenching.
Resumo:
The novel nanoparticles, [Ru(bPY)(3)](2)SiW12O40 center dot 2H(2)O(2) were firstly synthesized and characterized by elemental analysis, IR, and TEM. The nanoparticles were used to fabricate a chemically modified carbon paste electrode (CPE) by dispersing nanoparticles and graphite powder in silicone grease. Thus-prepared CPE shows bifunctional electrocatalytic activities towards the reduction of nitrite and the oxidation of oxalate, and exhibits sensitive electrochemiluminescence (ECL).
Resumo:
Electrochemiluminescence (ECL) of tris(2,2'-bipyridyl) ruthenium [Ru(bpy)(3)(2+)] has received considerable attention. By immobilizing Ru(bpy)(3)(2+) on an e electrode surface, solid-state ECL provides several advantages over solution-phase ECL, such as reducing consumption of expensive reagent, simplifying experimental design and enhancing the ECL signal.This review presents the state of the art in solid-state ECL of Ru(bpy)(3)(2+).
Resumo:
[Ru(bpy)(3)](2+)-doped silica (RuSi) nanoparticles were synthesized by using a water/oil microemulsion method. Stable electrochemiluminescence (ECL) was obtained when the RuSi nanoparticles were immobilized on a glassy carbon electrode by using tripropylamine (TPA) as a coreactant. Furthermore, the ECL of the RuSi nanoparticles with layer-by-layer biomolecular coatings was investigated. Squential self-assembly of the polyelectrolytes and biomolecules on the RuSi nanoparticles gave nanocomposite suspensions, the ECL of which decreased on increasing the number of bilayers.
Resumo:
In this work, an electrochemiluminescence (ECL) reagent bis(2,2'-bipyridine)(5,6-epoxy-5,6-dihydro-[1,10]phenanthroline)ruthenium complex (Ru-1) was synthesized, and its electrochemical and ECL properties were characterized. The synthesis of Ru-1 was confirmed by IR spectra, element analysis, and H-1 NMR spectra. For further study, its UV-vis absorption and fluorescence emission spectra were investigated. Ru-1 also exhibited quasi-reversible Ru-II/Ru-III redox waves in acetonitrile solution. The aqueous ECL behaviors of Ru-1 were also studied in the absence and in the presence of tripropylamine.
Resumo:
In this paper, we attempt to construct a simple and sensitive detection method for both phenolic compounds and hydrogen peroxide, with the successful combination of the unique property of quantum dots and the specificity of enzymatic reactions. In the presence Of H2O2 and horseradish peroxidase, phenolic compounds can quench quantum dots' photoluminescence efficiently, and the extent of quenching is severalfold to more than 100-fold increase. Quinone intermediates produced from the enzymatic catalyzed oxidation of phenolic compounds were believed to play the main role in the photoluminescence quenching.
Resumo:
Amphetamines including methamphetamine, 3,4-methylenedioxyamphetamine and 3,4-methylenedioxymethamphetamine were separated and detected by CE using simultaneous electrochemical (EC) and electrochemiluminescence (ECL) detection (CE-EC/ ECL). Factors that influenced the separation and detection performance, such as the detection potential, the pH value and concentration of the running buffer, the separation voltage and the pH of the detection buffer, were investigated.
Unique electrochemiluminescence behavior of Ru(bpy)(3)(2+) in a gold/Nafion/Ru(bpy)(3)(2+) composite
Resumo:
The unique electrochemiluminescence (ECL) behavior of tris(bipyridine) ruthenium(II) (Ru(bpy)(3)(2+) immobilized in a gold/Nafion/Ru(bpy)(3)(2+) composite material was investigated. In this composite, the Ru(bpy)(3)(2+) ECL was found mainly occurred at 0-0.4 V during the cathodic scan process and the ECL peak was at about 0.1 V, which was quite different to the reported Ru(bpy)(3)(2+) ECL. Similar to the generally observed Ru(bpy)(3)(2+) ECL, the present ECL also could be enhanced by tri-n-propylarnine (TPA). It is also unique that in the presence of TPA, another ECL peak at about 0.38 V occurred.
Resumo:
Quantitative electrochemilumineseence (ECL) detection of a model protein, bovine serum albumin (BSA) was achieved via biotin-avidin interaction using an avidin-based sensor and a well-developed ECL system of tris(2,2'-bipyridine) ruthenium(II) derivative as label and tri-n-propylamine (TPA) as coreactant. To detect the protein, avidin was linked to the glassy carbon electrode through passive adsorptions and covalent interaction with carboxylate-terminated carbon nanotubes that was used as binder to immobilize avidin onto the electrode. Then, biotinylated BSA tagged with tris(2,2'-bipyridine) ruthenium(II) label was attached to the prepared avidin surface.
Resumo:
Capillary electrophoresis (CE) with electrochemiluminescence (ECL) detection was used to explore the kinetics ofthe enzymatic reaction. The different effects ofreaction conditions including the concentration of Mn2l, incubation temperature and pH on PFOlidase (PLD, EC 3.4.13.9) activity in erythrocyte lysates against three different substrates, Gly-Pro, Val-Pro and Leu-Pro were investigated. Also, the effects of colchicine which can prevent or delay cancer ofliver on the PLD activity were studied.
Resumo:
A unique multilabeling at a single-site protocol of the Ru(bpy)(3)(2+) electrochemiluminescence (ECL) system is proposed. Nanoparticles (NPs) were used as assembly substrates to enrich ECL co-reactants of Ru(bpy)(3)(2+) to construct nanoscale-enhanced ECL labels. Two different kinds of NP substrates [including semiconductor NPs (CdTe) and noble metal NPs (gold)] capped with 2-(dimethylamino)ethanethiol (DMAET) [a tertiary amine derivative which is believed to be one of the most efficient of co-reactants of the Ru(bpy)(3)(2+) system] were synthesized through a simple one-pot synthesis method in aqueous media.
Resumo:
A novel electrochemiluminescence (ECL) aptasensor was proposed for sensitive and cost-effective detection of the target thrombin adopted an aptamer-based sandwich format. To detect thrombin, capture aptamers; labeled with gold nanoparticles (AuNPs) were first immobilized onto the thio-silanized ITO electrode surface through strong Au-S bonds. After catching the target thrombin, signal aptamers; tagged with ECL labels were attached to the assembled electrode surface. As a result, an AuNPs-capture-aptamer/thrombin/ECL-tagged signal-aptamer sandwich type was formed.