'Wiring' of glucose oxidase and lactate oxidase within a hydrogel made with poly(vinyl pyridine) complexed with [Os(4,4'-dimehtoxy-2,2'-bipyridine)(2)Cl](+/2+)

Glucose and lactate electrodes based on hydrogels made by crosslinking glucose oxidase and the redox polymer formed upon complexing poly(vinyl pyridine) (PVP) with [Os(dmo-bpy)(2)Cl](+/2+) (dmo-bpy = 4,4'-dimethoxy-2,2'-bipyridine) on vitreous carbon electrode surfaces have been investigated. The redox potential of the hydrogels was +35 mV vs. SCE and their glucose electrooxidation current reached a plateau at +150 mV vs. SCE. Urate and acetaminophen were not electrooxidized at this potential at rates that would interfere with the glucose and lactate assays. At a glucose concentration of 1 mM, the addition of 0.1 mM ascorbate increased the current by 17%. At 5 mM glucose, switching the atmosphere from argon to oxygen reduced the currents by 11%.