Highly efficient singlet oxygen generation of AIE luminogens enable mitochondria-targeted photodynamic therapy

The development of aggregation-induced emission luminogens (AIEgens) with high brightness and efficient photodynamic therapy (PDT) is of great value for the precise diagnosis and treatment of cancers. In this contribution, two novel AIEgens, TBBCyP and TBTCyP with D-A-pi-A structure, were designed and prepared based on molecular rational design of electron-donating receptors. Experimental and theoretical results indicated that both TBBCyP and TBTCyP own bright AIE feature, satisfy photos ability, and generate efficient singlet oxygen (1O2). Notably, TBBCyP exhibited brighter emission and higher 1O2 yield in compared with TBTCyP, which could be ascribed to its weaker twisted intramolecular charge transfer (TICT) effect and narrower singlet-triplet energy gap (Delta EST). Moreover, it was proved that TBBCyP and TBTCyP showed a great mitochondrial specificity and desired intracellular ROS productivity for realizing the effective mitochondria-targeted PDT of cancer cells.