Light induced singlet oxygen production and detection generated by bacterial reaction centre-carbon nanotubes composites

Nowadays the photoelectric energy transformation is one of the most promising alternative energy sources. Plants and bacteria have their unique apparatus,the photosynthetic reaction centreprotein (RC)to convert the light into chemical potential. Generation of singlet oxygen accompanying the photochemistry of isolated reaction centre protein of non-sulfur purple bacteria(Rhodobacter(Rb.) sphaeroides) have been studied by measuring oxygen uptake by conventional oxygen electrode. In case of oversaturated illuminating conditionsbesides the RC photochemistry the excess energy is captured by triplet states of chlorophyll molecules. The triplet energyisthen dissipated by heat or by sensitizingthe formation of various reactive oxygen species (ROS), especially by singlet oxygen (1O2). Under these conditions the protein subunits are damaged and the efficiency of photochemistry decreases. The aims of our work are to find conditions in which the concentration of these harmful compounds can be reduced. The possible role of carbon nanotubes (CNT), which are known to quench the singlet oxygen is investigated in the CNT/RC hybrid bio-nanocomposites