Quantum Conversion and Image Detection by a Bacteriorhodopsin-Based Artificial Photoreceptor

Science  17 Jan 1992:
Vol. 255, Issue 5042, pp. 342-344
DOI: 10.1126/science.255.5042.342


A thin film (50 to 500 angstroms thick) comprising fragments of bacteriorhodopsin (bR)-containing purple membrane was formed on an SnO2 conductive electrode by the Langmuir-Blodgett method. The film was put into contact with a thin, aqueous electrolyte gel to construct an electrochemical sandwich-type photocell with a junction structure SnO2/bR/electrolyte/Au electrode. Under visible light irradiation, the bR-based photocell produced an efficient rectified photocurrent that proved to have unique differential responsivity to light intensity, which is characteristic of in vivo biological photoreceptors. An artificial photoreceptor comprising a pixel network of the bR photocell was fabricated in an attempt to study image-detecting and processing abilities of bR.