Effects of protonation degree on photodynamic activity of zinc phthalocyanine substituted with 1,2-diethylamino

Abstract This work reports on the effects of protonation degree on the photodynamic activity of zinc phthalocyanine substituted with 1,2-diethylamino ( ZnPc1 ). Photophysical properties, singlet oxygen generation ability and photodynamic anticancer activity of derivatives of ZnPc1 with different protonation degree were studied and compared. Results indicated that the protonation degree can greatly influence the photophysical and photochemical properties of ZnPc1 , thereby affecting its photodynamic activity. When the mole ratio of ZnPc1 and hydrochloric acid (HCl) was 1:8, the derivative of ZnPc1 showed the best photodynamic activity.