Photo-bioelectrochemical Cells for Energy Conversion, Sensing, and Optoelectronic Applications

The native photosynthetic reaction centers photosystemI (PSI) and photosystemII (PSII) act as functional nanostructures for the assembly of photo-biofuel cells. By electrical wiring of PSI and/or PSII with electrodes, the conversion of light energy into electrical power has been demonstrated. Different methodologies to electrically contact the photosystems with the electrodes have been developed, including the reconstitution of the photosystems on relay units, the application of redox-active polymers as charge-transport matrices, and the use of metallic nanoparticles or nanoclusters as electron-transfer relays. Electrical contact of the photosystems with the electrodes facilitates charge separation of the redox intermediates generated upon illumination of the assemblies, thus retarding destructive back electron-transfer reactions and enhancing the conversion of light energy into electrical power. Recent advances to fabricate electrically wired PSI and/or PSII electrodes are surveyed, and different approaches to assemble photo-bioelectrochemical cells are discussed. The limitations and future perspectives of the systems will also be presented.