Potential of light-harvesting of bacteriorhodopsin co-sensitized with green fluorescence protein: A new insight into bioenergy application

Herein we report for the first time on efficient and environmentally friendly bioenergy production from bacteriorhodopsin (bR) and green florescent protein (GFP) as co-sensitizers. bR as a transmembrane protein, acts like a light-driven proton pump in Halobacterium salinarum, converting light energy into a proton gradient. Employing GFP beside bR can enhance the photo-bioenergy production efficiency in two aspects: GFP can increase short circuit current by improvement in light absorption either by extending the sensitizingspectrumor making fluorescence in absorption region of bR. It can also enhance open circuit voltage more than 150 mV by improvement in photoelectrode converging and extending electron lifetime in photoelectrode. Maximum photovoltage of 680 mV and photocurrent of 1.2 mA cm−2 have been achieved upon co-sensitization with bR/GFP. With the power conversion efficiency of 0.45%, the highest efficiency of photovoltaic cell based on bR has been reported in this research.