Method for Effective Immobilization of Ru(bpy)32+ on an Electrode Surface for Solid-State Electrochemiluminescene Detection

A novel method for effective immobilization of Ru(bpy)32+ on an electrode surface is developed. The whole process involves two steps: the electrostatic interactions between citrate-capped gold nanoparticles (AuNPs) and Ru(bpy)3Cl2 in aqueous medium were used to fabricate Ru(bpy)32+AuNP aggregates (Ru-AuNPs) first, and then the Au-S interactions between as-formed Ru-AuNPs and sulfhydryl groups were used to effectively immobilize the Ru-AuNPs on a sulfhydryl-derivated indium tin oxide (ITO) electrode surface. As-prepared ITO electrode shows excellent stability, and the ECL active species Ru(bpy)32+ contained therein exhibit excellent ECL behaviors.