Inorganic semiconductors as photosensitizers in biochemical redox reactions.

The results of studies of biochemical redox reactions photosensitized by inorganic semiconductor particles are reviewed. The mechanisms of hydrogen photoproduction, NAD+ or NADP+ photoreduction, CO2 photofixation and photosynthesis of organic and amino acids under the coupled action of TiO2, ZnO, CdS, ZnS and enzymes or bacterial cells are considered. Studies on the photocatalytic activity of ferritin, a protein containing microcrystals of hydrous ferric oxide, are described. The data on biosynthesis of cadmium sulfide by microorganisms and plants are analyzed. The possibility of the participation of inorganic semiconductors in photoprocesses in vivo is discussed.