Benzothiazolium‐based NIR AIE photosensitizers with type I and II ROS generation for efficient mitochondria‐targeted photodynamic therapy

In this work, a near‐infrared emissive photosensitizer of 3,3‐dimethyl‐N,N‐diphenyl‐2‐(thiophen‐2‐yl)‐3H‐indol‐6‐amine functionlized benzothiazolium (DPITT) was developed. DPITT exhibited aggregation‐induced emission effect and potent type I and II reactive oxygen species generation capacities after white light irradiation. Taking advantage of the cationic feature, DPITT penetrated the cell membrane and selectively accumulated in the mitochondria in living cells. Upon white light irradiation, the photosensitized DPITT was able to induce mitochondrial dysfunction, leading to cell death. Photosensitized DPITT was further applied to disrupt the multicellular tumour spheroids, demonstrating its potential application in inhibiting hypoxic solid tumours.