Bioelectrocatalytic system coupled with enzyme-based biocomputing ensembles performing boolean logic operations: approaching "smart" physiologically controlled biointerfaces.

The modified electrode for electrocatalytic oxidation of NADH was developed using a pH-switchable redox interface. The operation of the modified electrode was controlled by logic operations performed by enzyme systems processing biochemical input signals. The electrocatalytic oxidation of NADH was activated upon appropriate combinations of the signals processed by the AND/OR logic operations performed by the enzymes. The modified interface was reset in a mute nonactive state by another enzyme reaction. The coupling between the enzyme logic systems and the bioelectrocatalytic interface was achieved by pH changes produced in situ by the enzyme reactions, resulting in different protonation states of the polymeric matrix associated with the electrode surface. The bioelectrocatalytic system integrated with biochemical computing systems opens the way to novel "smart" interfaces for multisignal biosensors and signal-controlled biofuel cells. In a long perspective, this approach will allow physiological control of implantable bioelectronic devices.