Type I AIE photosensitizers: Mechanism and application

Abstract Photodynamic therapy (PDT) with plenty of advantages is expected to become a promising modality for cancer treatment, but challenges still remain. In the past decade, abundant photosensitizers (PSs) with aggregation‐induced emission (AIE) property make the development of PSs enter upon a new phase, offering incomparable merits. Recently, Type I AIE PSs with capability of generating radical reactive oxygen species (ROS) have emerged as strong candidates to overcome the inherent hypoxia nature of solid tumors. In this review, detailed discussions on the mechanisms of PDT are drawn to highlight the basic advantages of Type I pathway over Type II one in hypoxic PDT, followed by a summary of frequently‐used detection methods for the accurate distinguishing of the nature of ROS. Finally, the latest representative advances are summarized, and future perspectives of Type I AIE PSs are discussed.