Cyano Positional Isomerism Strategy for Constructing Mitochondria-Targeted AIEgen with Type I Reactive Oxygen Species Generation Capability

Abstract

In this work, a series of cationic luminogens (designated as PSMP isomers) were developed based on cyano positional isomerism strategy. The isomerism of cyano substituent on the molecular skeleton can finely regulate the optical behaviour, the type of photoinduced reactive oxygen species (ROS), and mitochondria-targeted capability of isomers. Interestingly, PSMP-4, with cyano group installed at appropriate location, exhibits special aggregation-induced emission effect and potent O2•− generation efficacy through type I photochemistry pathway. Notably, PSMP-4 accumulates in mitochondria with high specificity. Taking advantage of excellent photostability, PSMP-4 realizes in situ mitochondria imaging in washing-free manner and sensitive response to the change of mitochondrial membrane potential. The integration of comprehensive photophysical and mitochondrial specificity endow PSMP-4 to successfully trigger the demise of cancer cells through efficient type I photodynamic therapy process both in vitro and in multicellular tumor spheroid models.