CONTROL OF PROTEIN ORIENTATION IN MOLECULAR PHOTOELECTRIC DEVICES USING LANGMUIR-BLODGETT-FILMS OF PHOTOSYNTHETIC REACTION CENTERS FROM RHODOPSEUDOMONAS-VIRIDIS

A photoelectric device was prepared using Langmuir-Blodgett (LB) films of photosynthetic reaction centers (RCs). Monolayers of RCs from Rhod opseudomonas viridis were deposited on transparent electrodes. The ori entation of the RCs on the electrode surface was controlled using vari ous substrates with different surface wettabilities. The degree of ali gnment was evaluated by measuring the polarities of light-induced elec tric responses. The orientation was also measured by means of an enzym e-linked immunosorbent assay that uses antibodies to distinguish oppos ite sites of the RCs. Photocells comprised of RC-LB films showed a ste ady-state photocurrent. The direction of the current flow was regulate d by altering the orientation of the RCs.