Electrochemiluminescence of tris(2,2′-bipyridine)ruthenium(ii) immobilized in poly(p-styrenesulfonate)–silica–Triton X-100 composite thin-films

Abstract

The electrochemiluminescence (ECL) of tris(2,2′-bipyridine)ruthenium(II) [Ru(bpy)₃²⁺] immobilized in poly(p-styrenesulfonate) (PSS)–silica–Triton X-100 composite films was investigated. The cooperative action of PSS, sol–gel and Triton X-100 attached Ru(bpy)₃²⁺ to the electrode strongly, and the presence of Triton X-100 prevented drying fractures of the sol–gel films during gelation and even on repeated wet–dry cycles. The modified electrode was used for the ECL detection of oxalate, tripropylamine (TPA) and NADH in a flow injection analysis (FIA) system with a newly designed flow cell. The detection scheme exhibited good stability, short response time and high sensitivity. Detection limits were 0.1, 0.1 and 0.5 μmol L⁻¹ for oxalate, TPA and NADH, respectively, and the linear concentration range extended from 0.001 to 1 mmol L⁻¹ for the three analytes. Applications of the flow cell in ECL and electrochemical detection, as well as the immobilization of reagents based on the cooperative action, are suggested.