Integrated sensor for continuous flow electrochemiluminescent measurementsof codeine with different ruthenium complexes

Batch and continuous-flow measurements of codeine were performed by electro chemiluminescence, using a miniaturized sensor combining transduction elect rodes and a photodetector on the same silicon chip. In the case of how meas urements, a flow channel was additionally integrated on chip using the EPON SU-8 technology. Three different ruthenium complexes have been tested as c o-reactants and compared to a commercially available ruthenium (II) tris(2, 2'-bipyridyl) complex [Ru(bpy)(3)(2+)]. All synthesized compounds exhibited similar electrochemical properties and emission spectra. Concerning the ab ility of the synthesized complexes to catalyze electrochemiluminescence in the presence of codeine, best results were achieved using ruthenium (II) bi s(2,2'-bipyridyl) (1,10-phenanthroline) dichloride tris-hydrate [Ru(bpy)(2) (phen)(2+)] as light intensity was 2.5-times higher than that obtained with Ru(bpy)32+. In batch mode and flow injection analysis, a detection limit o f 0.1 and 50 mu M was found, respectively. The linear ranges extended over 2 or 3 decades and reproducibility of the assays was satisfactory. Codeine measurements were successfully performed in pharmaceutical samples. (C) 199 9 Elsevier Science B.V. All rights reserved.