Solid-state electrochemiluminescence sensor through the electrodeposition of Ru(bpy)32+/AuNPs/chitosan composite film onto electrode Original Research Article

Tris(2,2′-bipyridyl)ruthenium(II) (Ru(bpy)32+) has been successfully immobilized onto electrode through the electrodeposition of Ru(bpy)32+/AuNPs/chitosan composite film. In the experiments, chitosan solution was first mixed with Au nanoparticles (AuNPs) and Ru(bpy)32+. Then, during chronopotentiometry experiments in this mixed solution, a porous 3D network structured film containing Ru(bpy)32+, AuNPs and chitosan has been electrodeposited onto cathode due to the deposition of chitosan when pH value is over its pKa (6.3). The applied current density is crucial to the film thickness and the amount of the entrapped Ru(bpy)32+. Additionally, these doping Ru(bpy)32+ in the composite film maintained their intrinsic electrochemical and electrochemiluminescence activities. Consequently, this Ru(bpy)32+/AuNPs/chitosan modified electrode has been used in ECL to detect tripropylamine, and the detection limit was 5 × 10−10 M.