NOVELTY - An aqueous photoelectrolysis-biocatalysis device (1) for producing electric power in response to incident light, comprises a biocathode (12) in contact with water, where the biocathode comprises an electrode coated with a conducting polymer matrix (14) comprising an oxidoreductase and a redox mediator and; a photoanode (16) in contact with the water, where the photoanode comprises nanocrystalline titanium dioxide (TiO2) adhered to a fluorine tin oxide (FTO) electrode (20).    USE - As an aqueous photoelectrolysis-biocatalysis device for producing electric power in response to incident light (claimed).    ADVANTAGE - The system enables its continuous operation in the presence of light. Unlike other photovoltaics utilizing enzyme catalysis, the system does not require a separator which generally increases ohmic resistance and the costs of the device. The system has a higher OCP (~1 V) compared to conventional systems (0.6-0.75 V). The system has a simple structure and does not require a fuel supply. The system uses a laccase immobilized electrode, whereas conventional systems generally require a platinum electrode. This device is based on the continuous photocatalytic oxidation of water to oxygen at a TiO2-photoanode and bioelectrocatalytic reduction of oxygen to water at a biocathode. This device demonstrates a novel method for energy harvesting, which couples inexpensive photoactive materials such as TiO2 with ubiquitous oxidoreductases such as laccase to produce small amounts of electrical power autonomously. This device is amenable to a variety of photocatalysts and biocatalysts selected for specific environments and applications.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for producing electric power from an aqueous photoelectrolysis-biocatalysis device involving exposing the device to UV light in the presence of water.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic diagram of an energy-conversion device.    Aqueous photoelectrolysis-biocatalysis device (1)    Biocathode (12)    Polymer matrix (14)    Photoanode (16)    Fluorine tin oxide electrode (20)