Photodynamic therapy(PDT) is an emerging treatment modality that uses a light source to activate lightsensitivephotosensitizers to treat cancer and other diseases,such as age-related macular degeneration,portwinestain and localized infection.Photosensitizers are excited to the long-lived triplet state,and they reactwith biomolecules via type I or II mechanism resulted in cell death and tumor necrosis.