Influence of biologically relevant ligands on oxidation of reduced glucose oxidase by electrochemically generated [RuIII(bpy)2XY] complexes

Complex formation between cis-[Ru(bpy)2(H2O)2]2+ (bpy=2,2′-bipyridyl) and some biologically relevant ligands (pyridines, imidazole, histidines) increases the rate constant for the oxidation of reduced glucose oxidase (generated in situ by d-glucose from the native enzyme) by the corresponding RuIII derivatives generated electrochemically. Almost a 20-fold rate acceleration is demonstrated by the cyclic voltammetry for histidine as ligand, the rate constant being ca. 106 M−1 s−1 at pH 7 (0.1 M phosphate).