Hot electron-induced electrogenerated chemiluminescence of 1-aminonaphthalene-4-sulphonate at oxide-covered aluminium electrodes in aqueous solution

Electrogenerated chemiluminescence of 1-aminonaphthalene-4-sulphonate (ANS) provides a sensitive means for the detection of the ANS in aqueous solution when oxide-covered aluminium electrodes are used as tunnel emission electrodes and cathodic pulse polarisation is used for the excitation of the luminophore. During the pulse polarisation of insulating oxide film-coated aluminium cathodes, hot electrons are tunnel emitted from the aluminium to the aqueous electrolyte solution by direct field-assisted tunnelling (in the case of oxide films of thickness 2-6 nm) or by Fowler-Nordheim (FN) tunnelling in the cases of thicker oxide films. As a result of direct tunnel emission of these energetic electrons, the generation of hydrated electrons (e_aq⁻) becomes possible. These electrochemically generated, extremely strong reductants (dry hot or hydrated electrons) make the efficient excitation of various types of luminophores at thin insulating film-covered electrodes possible and provide a means for sensitive immunoassays and DNA-probing assays when these luminophores are used as label molecules.     

Flow Injection Analysis of Histidine with Enhanced Electrogenerated Chemiluminescence of Luminol

Histidine is one of the necessary basic amino acids in biological bases, which often controls the catalytic activity of enzymes and acts in holding the higher structure of proteins. Furthermore, it is also an important ingredient in pharmaceutical preparations used for treatment of hetpatosis and nephropathy. Therefore, the determination of histidine in biological fluids and pharmaceutical preparations is of great importance. Various methods have been proposed for the detection of histidine …     

流动注射电化学发光分析法测定维生素B1及在尿液分析中的应用

将在线恒电流电解产生ClO-与Luminol构成了较强的化学发光体系,基于维生素B1对该化学发光体系有抑制作用,结合流动注射技术,建立了测定维生素B1的流动注射电化学发光新方法,并把它应用于尿液分析中. 该方法在维生素B1的浓度为1.0×10-10～1.0×10-8 mmol/mL之间分段回归,呈良好的线性,检出限达到5.0×10-11 mmol/mL.     

Efficient electrocatalytic intramolecular anion radical cyclobutanation reactions

Electrochemically initiated, intramolecular anion radical cyclobutanations of bis(enones) and related substrates are presented. The formation of novel anion radical Diels-Alder adducts in minor amounts is also observed. Total yields of pericyclic products, which include both cis- and trans-cyclobutanes and a single Diels-Alder adduct, are generally high (51-88%), with electrocatalytic factors in the range of 1.5-5. Mechanistically, strong evidence for the intervention of distonic anion radical intermediates as precursors of both types of pericyclic products is presented. The scope and limitations of these reactions are rather extensively explored and defined, and in particular the tendency, in some cases, for electrogenerated base-catalyzed reactions to compete with these anion radical pericyclic reactions.     

Electrocatalytic reactions: anion radical cyclobutanation reactions and electrogenerated base reactions

Intermolecular anion radical [2+2] cyclobutanation reactions have been observed between vinyl sulfones and vinyl/propenyl ketones. The products are novel and formed electrocatalytically, although yields are at best modest (11-45%). Competing mechanisms are discussed. Additionally, the electrochemical reduction of vinyl alkyl sulfones in acetonitrile leads to near quantitative formation of cyanomethylation product cyano-sulfones. The single step approach has electrocatalytic factors in excess of thirty.     

Comparison of homoleptic and heteroleptic 2,2′-bipyridine and 1,10-phenanthroline ruthenium complexes as chemiluminescence and electrochemiluminescence reagents in aqueous solution

We have conducted a comprehensive comparative study of Ru(bipy)₃²⁺, Ru(bipy)₂(phen)²⁺, Ru(bipy)(phen)₂²⁺, and Ru(phen)₃²⁺ as chemiluminescence and electrochemiluminescence (ECL) reagents, to address several previous conflicting observations and gain a greater insight into their potential for chemical analysis. Clear trends were observed in many of their spectroscopic and electrochemical properties, but the relative chemiluminescence or ECL intensity with a range of analytes/co-reactants is complicated by the contribution of numerous (sometimes opposing) factors. Significantly, the reversibility of cyclic voltammetric responses for the complexes decreased as the number of phenanthroline ligands was increased, due to the lower stability of their ruthenium(III) form in the aqueous solvent. This trend was also evident over a longer timescale when the ruthenium(III) form was spectrophotometrically monitored after chemical oxidation of the ruthenium(II) complexes. In general, the greater stability of Ru(bipy)₃³⁺ resulted in lower blank signals, although this effect was less pronounced with ECL, where the reagent is oxidised in the presence of the co-reactants. Nevertheless, this shows the need to compare signal-to-blank ratios or detection limits, rather than the more common comparisons of overall signal intensity for different ruthenium complexes. Furthermore, our results support previous observations that, compared to Ru(bipy)₃²⁺, Ru(phen)₃²⁺ provides greater ECL and chemiluminescence intensities with oxalate, which in some circumstances translates to superior detection limits, but they do not support the subsequent generalised notion that Ru(phen)₃²⁺ is a more sensitive reagent than Ru(bipy)₃²⁺ for all analytes.     

流动注射电化学发光分析法测定左旋多巴的研究

基于左旋多巴对鲁米诺在铂电极上弱的电氧化发光信号的强增敏作用与流动注射技术的结合,建立了一种测定左旋多巴的电化学发光分析新方法。该法测定左旋多巴的检出限为2.0×10-10g/mL,线性范围为4.0×10-10~2.0×10-6g/mL,相对标准偏差为2.0%(n=11)。该法简单、快速、灵敏,已成功地用于样品中左旋多巴的测定。     

化学发光分析法应用新进展

评述了化学发光法在无机分析，有机分析，生物活性氧研究，免疫分析，核酸杂交分析和微全分析中的最新应用，引用文献44篇。     

Ultrasound-pretreatment combined with Ti3C2-TiO2-AuNPs enhancing the electrogenerated chemiluminescence of the air-saturated luminol for exosomes detection

It is still a great challenge to develop effective strategies to improve the low electrogenerated chemiluminescence (ECL) of air-saturated luminol. Herein, the synergistic effects of Ti₃C₂-TiO₂-AuNPs nano hybrid and high-intensity focused ultrasound pretreatment (ultrasound-pretreatment) were used to significantly improve the ECL emission of the air-saturated luminol, and the mechanism was proposed. The ultrasound-pretreatment as a green method with the cavitation effect could form O₂^–• and H₂O₂ in situ as an initiator. TiO₂ and Au nanoparticles (AuNPs) were in situ decorated on the Ti₃C₂ surface to form Ti₃C₂-TiO₂-AuNPs, and it was proved as a highly efficient booster which could catalyze and aggregate H₂O₂ to the O₂^–•. The utilization rate of intermediates has been greatly improved. Exosomes as model targets can be sensitively detected by the ECL sensor. The detection limit was 195 particles μL⁻¹. The detection results of exosomes in actual samples are satisfactory. We believe that the ultrasound-pretreatment strategy could be extended to the sensitive detection in the biological sample.