Negatively charged SnO2 particles (ca. 4-nm diameter) serve as supports for bilayers composed of didodecyldimethylammonium ion in aqueous sols. An amphiphilic Ru(II) polypyridine complex incorporated into the bilayer photosensitizes electron injection into the conduction band of the SnO2, but only the population bf complex dissolved in inner monolayer, in contact with the;support, is active. The high quantum efficiency of charge transfer together with the relatively slow rate of recombination between the conduction band electron and the Ru(III) polypyridine complex makes this medium promising for studies of electron-transfer processes in surfactant bilayer assemblies.