Fiorani Andrea, Valenti Giovanni, Kamoshida Naoki, Paolucci Francesco, Einaga Yasuaki
Department of Chemistry , Keio University , 3-14-1 Hiyoshi , Yokohama 223-8522 , Japan.
Department of Chemistry "G. Ciamician" , University of Bologna , Via Selmi, 2 , Bologna 40126 , Italy.
J Am Chem Soc. 2020 Jan 22;142(3):1518-1525. doi: 10.1021/jacs.9b11842. Epub 2020 Jan 10.
An electrogenerated chemiluminescence (ECL) system by in situ coreactant production, where Ru(bpy) emission is generated at a boron-doped diamond (BDD) electrode, is presented. The system takes advantage of the unique properties of BDD to promote oxidation of carbonate (CO) into peroxydicarbonate (CO), which further reacts with water to form hydrogen peroxide (HO), which acts as a coreactant for Ru(bpy) ECL. Investigation of the mechanism reveals that ECL emission is triggered by the reduction of HO to hydroxyl radicals (OH), which later react with the reduced Ru(bpy) molecules to form excited states, followed by light emission. The ECL signal was found to increase with the concentration of CO; therefore, with the concentration of electrogenerated HO, although at the same time, higher concentrations of HO can quench the ECL emission, resulting in a decrease in intensity. The carbonate concentration, pH, and oxidation parameters, such as potential and time, were optimized to find the best emission conditions.
本文介绍了一种通过原位共反应剂生成的电化学发光（ECL）系统，该系统在硼掺杂金刚石（BDD）电极上产生Ru(bpy)发射。该系统利用BDD的独特性质，将碳酸盐（CO）氧化为过氧二碳酸盐（CO），后者进一步与水反应生成过氧化氢（HO），作为Ru(bpy) ECL的共反应剂。对该机理的研究表明，ECL发射是由HO还原为羟基自由基（OH）引发的，羟基自由基随后与还原态的Ru(bpy)分子反应形成激发态，继而发光。研究发现，ECL信号随CO浓度的增加而增强；因此，也随电化学产生的HO浓度增加，尽管与此同时，较高浓度的HO会淬灭ECL发射，导致强度降低。对碳酸盐浓度、pH值以及氧化参数（如电位和时间）进行了优化，以找到最佳发射条件。
