Enzyme electrode can be prepared using 4-aminodiphenylamine derivatives (N,N’-diphenyl-p-phenylenediamine; DPPD) as mediator molecules without covalent immobilization on the electrode. The proposed system was applied to carbon fabric to produce a glucose oxidation current of 7 mA/cm2, while the electrode catalytic activity was maintained at approximately 100% for over 4 h.
A novel enzyme electrode system for glucose oxidation was constructed by co-immobilization of glucose dehydrogenase (GDH) and N,N’-diphenyl-p-phenylenediamine (DPPD) on carbon electrodes. This enzyme electrode system was applied to porous carbon fabric to produce a glucose oxidation current of 7 mA/cm2, while the electrode catalytic activity was maintained at approximately 100% for more than 4 h, indicating that DPPD molecules were stably retained on the electrodes during the continuous redox cycling. Further, a stable mediation was also observed for other 4-aminodiphenylamine derivatives similar to DPPD. The difference was found in the adsorptivity between the reduced and oxidized forms of DPPD on the carbon electrode, suggesting that a portion of oxidized DPPD can access the active center of GDH without desorbing to solution. This electrode system with 4-aminodiphenylamine derivatives can be used in sensors for glucose monitoring and to anodes of separator-free glucose fuel cells.Zum Volltext