Photoelectrochemical conversion using reaction-centre electrodes

Recent reports have demonstrated the possibility of using photoactive, biological membrane components in photoelectro-chemical cells 1 . Such systems have produced small photovoltages and photocurrents. The present studies in our laboratories have led to the attachment of a much simpler biological complex, the bacterial photosynthetic reaction centre isolated from Rhodopseudomonas sphaeroides , directly onto an SnO 2 electrode. The light-induced, primary-charge-separation processes which occur across the reaction-centre macromolecule have been coupled to the electrode, and in a two-electrode configuration photovoltages of 70 mV and photocurrents of 0.3 µcm −2 have been observed in an external circuit. The phenomena are not due to Dember effects, and ‘reactor-centre electrodes’ may serve as a model system for future photovoltaic devices.