Glucose oxidation catalyzed by FAD-dependent glucose dehydrogenase within Os complex-tethered redox polymer hydrogel

FAD-dependent glucose dehydrogenase (FAD-GDH) from Aspergillus terreus was co-immobilized on a glassy carbon (GC) electrode surface with a poly(1-vinylimidazole)-tethered Os(2,2′-bipyridine)2Cl complex as a redox mediator. The steady-state catalytic current for glucose oxidation was 2.6 mA cm−2 at pH 7 and 25 °C. This value increased 1.6-fold after oxidative deglycosylation of the enzyme, which is the highest value so far reported for a GC-electrode-based glucose anode. The deglycosylation process did not decrease the stability of the FAD-GDH dissolved in the buffer solution and immobilized within the hydrogel. A 10% decrease in the catalytic current was observed after 24 h continuous operation.