ELECTROGENERATED CHEMILUMINESCENCE USING SOLUTION-PHASE AND IMMOBILIZED L-1,10-PHENANTHROLINEDISULFONIC-ACID)RUTHENIUM(II)

Electrogenerated chemiluminescence (ECL) with tris(4,7-diphenyl-1,10-p henanthrolinedisulfonic acid)ruthenium(II) (RuBPS) in solution and imm obilized on an electrode surface is investigated. Flow injection analy sis with a thin layer electrochemical cell modified for ECL detection is used to determine the analytical utility of solution phase RuBPS an d RuBPS immobilized in a cationic polypyrrole derivative. The solution phase reaction of RuBPS with oxalate is investigated with regard to t he dependence of ECL emission on RuBPS concentration, carrier stream f low rate, and pH. In the parameter range studied, ECL intensity is not linear with the concentration of RuBPS in the sample. A maximum ECL i ntensity is observed with a RuBPS concentration of approximately 250 m u M. Slower linear velocities give greater ECL intensities which is th e opposite of what is observed for Ru(bpy)(3)(3+) and oxalate. Greater ECL intensity is observed at lower pHs for oxalate and at higher pHs for proline. RuBPS ECL with oxalate yields a working curve with a line ar range from 0.1-100 mu M oxalate. Solution phase ECL is observed for RuBPS and other amines such as NADH, proline, tripropylamine, and ant ibiotics including streptomycin and gentamicin. RuBPS is also immobili zed by electrochemical polymerization of 1-methyl-3-(pyrrol-1-ylmethyl )pyridinium chloride (MPP) in the presence of RuBPS. This polymer-modi fied electrode yields ECL for oxalate and for amines.