A redox hydrogel integrated PQQ-glucose dehydrogenase based glucose electrode

The present work describes the design and characteristics of a glucose elec trode based on a newly isolated and purified, oxygen-independent, pyrrole q uinoline quinone glucose dehydrogenase (PQQ-GDH) integrated in a redox hydr ogel (poly(1-vinylimidazole) complexed with Os(4-4'-dimethylbipyridine)(2)C l) using poly(ethylene glycol)diglycidyl ether (PEGDGE) as a crosslinker. T he influence of the buffer's nature and the presence of PQQ and Ca2+ ions o n the enzyme stability were considered. The characteristics of the optimal electrode design were compared to those obtained for similarly prepared, gl ucose oxidase based electrodes. The optimal electrode configuration inserte d in a single manifold flow injection system, was characterised by a linear range up to 100 mu M, a sensitivity of 5.9 mA M-1 cm(-2), and a detection limit of 5 mu M (calculated as three times the signal-to-noise ratio).