Improvement of Heterogeneous Sensitizer Photobactericidal Activity by Elongation of Linker between Phthalocyanine and Silica Gel Support

Aminopropyl groups on the surface of aminopropylated silica gel were lengthened by grafting of additional propyleneimine units and applied to immobilize singlet oxygen sensitizers of cationic phthalocyanine series. The absorption and fluorescence spectra, generation of singlet oxygen and photobactericidal activity were studied for aqueous suspensions of these new heterogeneous systems. The effect of spacer length upon absorption and emission spectra as well as on efficacy of singlet oxygen generation by tethered phthalocyanines was not observed. However, the photobactericidal function of the supported phthalocyanines was markedly increased along with length of spacer.