(577c) Nanostructured Photosystem Complexes As Biological Fuel Cell Catalysts

Manipulating photosynthesis for electricity generation is an interesting concept. Here we report for the first time, the demonstration of light to electrical power conversion in photosynthetic biological fuel cell using plant photosystems complexes and enzyme biocatalysts. The system works by combining the photo-induced water oxidation reaction on nanostructured photosystem protein based anode and oxygen reduction reaction onbio-cathode. Both the photosystem complex and cathode biocatalyst molecules were immobilized onto multiwalled carbon nanotubes through molecular tethers on gold electrodes. The nanostrcutured electrodes possess high surface area for high biomolecule loading and the carbon nanotubes served as excellent immobilization support for the biocatalysts. The photosystem-carbon nanotube composite exhibited high photo-electrochemical activity upon light illumination. For the first time ever, direct electrochemical communication was observed between plant proteins and the electrode. The photo-induced water splitting reaction has been confirmed to be the main source of electrons for photo-current generation. The favorable electron transfer pathways in the photosynthetic process for photo-electrochemical activity have been identified. The direct redox electrochemistry observed has significant impact in artificial photosynthesis research.