Downey T M, Nieman T A
Department of Chemistry, University of Illinois, Urbana 61801.
Anal Chem. 1992 Feb 1;64(3):261-8. doi: 10.1021/ac00027a005.
The development of a detection method based on the electrogenerated chemiluminescence of tris(2,2'-bipyridine)ruthenium(II), (Ru(bpy)3(2+], immobilized in a Nafion film coated on an electrode is discussed. Control of the electrode potential controls creation of the reactive reagent Ru(bpy)3(3+) which reacts with certain analytes to yield chemiluminescence emission of intensity proportional to the analyte concentration. The reaction results in Ru(bpy)3(3+) being converted to Ru(bpy)3(2+), which then is recycled to Ru(bpy)3(3+) again at the electrode. This sensor has been used in flow injection to determine oxalate, alkylamines, and NADH. Detection limits are 1 microM, 10 nM, and 1 microM, respectively, with working ranges extending over 4 decades in concentration. Sensitivity is constant over the wide pH range from 3 to 10. With oxalate, and to a small extent with amines, emission intensities increase with increasing ionic strength; this was shown to be a phenomenon related to the Nafion film and not to the chemiluminescence reaction. Emission intensities increase with temperature. The sensor remains stable for several days with suitable storage conditions. Significant amounts of Ru(bpy)3(3+) are shown to be capable of storage within the film.
本文讨论了一种基于固定在电极上涂覆的Nafion膜中的三（2,2'-联吡啶）钌（II）（Ru(bpy)₃²⁺）的电化学发光检测方法的开发。通过控制电极电位来控制反应试剂Ru(bpy)₃³⁺的生成，Ru(bpy)₃³⁺与某些分析物反应产生强度与分析物浓度成正比的化学发光发射。该反应导致Ru(bpy)₃³⁺转化为Ru(bpy)₃²⁺，然后Ru(bpy)₃²⁺在电极上再次循环转化为Ru(bpy)₃³⁺。这种传感器已用于流动注射分析中以测定草酸盐、烷基胺和NADH。检测限分别为1 μM、10 nM和1 μM，工作浓度范围跨越4个数量级。在pH值为3至10的宽范围内灵敏度保持恒定。对于草酸盐，在一定程度上对于胺类，发射强度随离子强度的增加而增加；这表明这是一种与Nafion膜相关的现象，而不是化学发光反应。发射强度随温度升高而增加。在合适的储存条件下，该传感器可保持稳定数天。结果表明，大量的Ru(bpy)₃³⁺能够存储在膜内。
