Electrocatalytic Oxidation of NADH at Glassy Carbon Electrodes Modified with Transition Metal Complexes Containing 1,10-Phenanthroline-5,6-dione Ligands

TLDR: In this paper, the preparation and electrochemical characterization of glassy carbon electrodes modified with 1,10-phenanthroline-5,6-dione complexes of transition metals including [M(phen-dion)3]2+ (M = Fe, Ru, Co, Cr, Ni), [Re(phendione)(CO)3Cl], and [Ru(v-bpy)2(phen -dione)](PF6)2 (V-Bpy is 4-vinyl-4'4'methyl-2,2

Abstract: The preparation and electrochemical characterization of glassy carbon electrodes modified with 1,10-phenanthroline-5,6-dione (phen-dione) complexes of transition metals including [M(phen-dione)3]2+ (M = Fe, Ru, Co, Cr, Ni), [Re(phen-dione)(CO)3Cl], and [Ru(v-bpy)2(phen-dione)](PF6)2 (v-bpy is 4-vinyl-4‘-methyl-2,2‘-bipyridine) as well as their behavior as electrocatalysts toward the oxidation of NADH are described. The above-mentioned materials could be deposited by electrochemical deposition or electropolymerization. The resulting modified electrodes exhibited redox responses very similar to those of the complexes in solution, including the pH-dependent response ascribed to the pendant o-quinone groups. The deposited films also showed potent and persistent electrocatalytic activity toward NADH oxidation. In all cases, NADH oxidation took place at potentials around 0.0 V vs SSCE, which represents a dramatic diminution in the overpotential. In addition, interference effects due to ascorbate could be signif...