Structural Modification Orientated Multifunctional AIE Fluorescence Probes: Organelles Imaging and Effective Photosensitizer for Photodynamic Therapy

Abstract Luminogens with aggregation‐induced emission feature (AIEgens) are highly demanded because of its excellent performance in fluorescent bioprobes. In this work, three AIEgens based on tetraphenylethylene isoquinolinium (TPE‐IQ) derivatives by introducing different electron donor and sterically hindered groups to replace the phenyl ring of the isoquinolinium core are prepared in a one‐pot reaction with a high yield and characterized systematically. By the analysis of photophysical properties and theoretical calculations, the structure‐property relationships among them become clear. Although they all inherit AIE feature as expected, these similar structural AIEgens present different organelle‐targets, which is attributed to their different cellular uptake way and energy barrier to cell membrane by detailed experiments. In addition, these TPE‐IQ‐based AIEgens are potential candidates for photodynamic therapy originating from their activities of generating reactive oxygen species under visible light irradiation.