Generation of Faradaic Photocurrents at the Bacteriorhodopsin Film Electrodeposited on a Platinum Electrode

Abstract

Bacteriorhodopsin (bR)-containing purple membranes (PMs) were electrodeposited on a platinum electrode to form an oriented PM film. In an aqueous solution of supporting electrolyte, illumination of the electrode with green light that excites bR caused cathodic photo current. The photocurrent was a steady-state faradaic current and occurred at electrode potentials close to E_H+/H2, suggesting that proton pumping through the PM film assists the proton reduction at the platinum cathode.