Effects of Heteropoly Acids and Surfactant on Electrochemiluminescence of Tris(2,2'-Bipyridine) Ruthenium(II)

Abstract

ABSTRACT The effects of heteropoly acids and Triton X-100 on electrochemiluminescence (ECL) of Ru(bpy)3 2+ are investigated. Triton X-100 prevents the oxidation of oxalate and results in an increase of the ECL signal. H5SiW11VO40 prevents the direct oxidation of oxalate and makes the electrochemical behavior of Ru(bpy)3 2+ less reversible, which leads to a decrease of the ECL signal. In contrast, H3PMo12O40 has negligible effect on ECL intensity. Some possible reasons for the effects on the ECL of Ru(bpy)3 2+ are discussed based on the adsorption of SiW11VO40 5− on electrode surface and the ion association between SiW11VO40 5− and Ru(bpy)3 2+. The signal of ECL decreases linearly with the concentration of heteropoly acid in the range from 2x10−6 to 1x10−4 mol 1−1. The results indicate that ECL of Ru(bpy)3 2+ is a potential sensitive and selective detection method for heteropoly acids and hence for the elements comprised in them.