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

The electrochemiluminescence (ECL) of tris(2,2'-bipyridine)ruthenium(II) [Ru(bpy)3(2+)] 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)3(2+) 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 micromol 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.