Electric charge transport in the symmetric metal–enzyme junctions affected by biochemical interaction

Electrical properties of symmetric metal–enzyme (pyrroloquinoline quinone-dependent and heme-c containing alcohol dehydrogenase) junctions are experimentally investigated in planar structures in gaseous surrounding. Gas sensitive state in the junctions is induced by temporal connection of an external dc-voltage to the electrodes. A model linking the electron transfer with chemical processes in metal–ADH junction is proposed. Fundamental aspects of the electron transfer in the junctions are discussed.