Molecular engineering of asymmetric aza-BODIPY dyes for high-performance phototherapy

Achieving both anti-fluorescence and anti-ROS quenching effects remains a challenge for conventional small-molecule dyes. In this work, we proposed an "asymmetric hierarchical modulation" strategy for the aza-BODIPY core to address the issues of aggregation-caused fluorescence quenching (ACQ-FL) and aggregation-caused ROS quenching (ACQ-ROS), enabling its high-performance phototherapy. Compound BT-4 exhibited long-wavelength absorption and good anti-fluorescence and anti-ROS quenching abilities. The tumor growth in mouse models was significantly suppressed after treatment with BT-4 plus 808 nm laser irradiation, while maintaining minimal systemic toxicity.