Local removal of oxygen for NAD(P)+ detection in aerated solutions

The mediated electrochemical reduction of NAD(P)+ in aerated solution was investigated and exploited for NAD(P)H regeneration in view of biosensing application. Oxygen was locally removed from the electrode surface with an electrochemical oxygen filter made of platinum grids positioned close to the oxygen sensitive reactions. The working electrode was a bucky paper functionalized with [Cp∗Rh(bpy)Cl]+ by diazonium electrografting. The local oxygen removal was first evaluated, before to be applied to deoxygenation for NAD+ and NADP+ reduction. A porous silica gel layer encapsulating d-sorbitol dehydrogenase was finally deposited on the top of the modified bucky paper and the resulting bioelectrode was found sensitive to the presence of d-fructose.