Bio-hybrid photoconverter by covalent functionalization of the photosynthetic reaction center of Rhodobacter sphaeroides with fluorescein isothiocyanate

Organic biological hybrid systems, accessible by covalent functionalization of photosynthetic proteins with molecular antennas, represent a promising novelty to enhance natural photosynthesis. In this paper, we present the successful bioconjugation of a commercial fluorophore, fluorescein isothiocyanate (FITC), to the photosynthetic reaction center RC from the bacterium Rhodobacter sphaeroides strain R26. The resulting hybrid outperforms the pristine protein in hole-electron couple generation yield, exclusively at wavelengths where the fluorophore absorbs while the protein does not.