Determination Of P-Aminobenzenesulfonic Acid Based On The Electrochemiluminescence Quenching Of Tris (2,2 '-Bipyridine)- Ruthenium (Ii)

This study describes the quenching effects of p-aminobenzenesulfonic acid (p-ABSA) based on electrochemiluminescence (ECL) of the tris (2,2'-bipyridyl)-ruthenium(II)(Ru(bpy)32+)/tri-n-propylamine (TPrA) system in aqueous solution. Quenching behaviours were observed with a 200-fold excess of p-ABSA over Ru(bpy)32+. In the presence of 0.1M TPrA, the Stern-Volmer constant (KSV) of ECL quenching was as high as 1.39x104M-1 for p-ABSA. The logarithmic plot of inhibited ECL versus concentration of p-ABSA was linear over the range of 6.0x10-6 -3.0x10-4mol/L. The corresponding limit of detection was 1.2x10-6mol/L for p-ABSA (S/N=3). The mechanism of quenching is believed to involve an energy transfer from the excited-state luminophore to a dimer of p-ABSA and the adsorption of free radicals of p-ABSA at the electrode surface that impeded the oxidation of the Ru(bpy)32+/TPrA system. Copyright (c) 2012 John Wiley & Sons, Ltd.