Toward bacteriorhodopsin based photocells

Bacteriorhodopsin from purple membrane has unique photochromic and photoele ctric properties and a capability of providing light-induced proton pumping . These features make it one of the most promising biological molecules for developing a bioelectronic photocell. In a recent work, we have shown that the BR molecules can be oriented by applying, with the traditional Langmui r-Blodgett technique, an electric field at the air-water interface. This wo rk is aimed at the development of a BR-based photocell. The monolayers depo sited by the electric field-assisted LB technique were further characterize d by Brewster Microscopy at the air-water interface prior to their transfer onto solid supports. The photoresponse measurements of such a BR-based pho tocell confirmed that the BR molecules in the film were oriented. For sugge sted possible applications, molecular electrodes were fabricated by deposit ing thin films of doped poly(o-anisidine) (POAS) conducting polymer. (C) 19 99 Elsevier Science S.A. All rights reserved.