Near-infrared (NIR) aggregation-induced emission (AIE) of previous organic photosensitizers is usually weak because of the competition between twisted intramolecular charge transfer (TICT) effect and AIE. Herein, we report a rational molecular design strategy to boost NIR AIE of photosensitizers and still to keep strong ¹O₂ production capacity via rotor effect. To this end, one new triphenylamine (TPA)-based AIE photosensitizer, TPAM-1, is designed to give strong ability to generate ¹O₂ but weak NIR fluorescence in the aggregate state due to the strong TICT effect. Another new TPA-based AIE photosensitizer, TPAM-2, is designed by introducing three p-methoxyphenyl units as rotors into the structure of TPAM-1 to modulate the competition between AIE and TICT. TPAM-1 and TPAM-2 exhibit stronger ability to generate ¹O₂ in the aggregate state than the commercial photosensitizer, Ce6. Furthermore, TPAM-2 gives much brighter NIR luminescence (25-times higher quantum yield) than TPAM-1 in the aggregate state due to the rotor effect. TPAM-2 with strong NIR AIE and ¹O₂ production capability was encapsulated by DSPE-PEG₂₀₀₀ to give good biocompatibility. The DSPE-PEG₂₀₀₀-encapsulated TPAM-2 nanoparticles show good cell imaging performance and remarkable photosensitive activity for killing HeLa cells. This work provides a new way for designing ideal photosensitizers for AIE imaging-guided photodynamic therapy.

由于扭曲的分子内电荷转移（TICT）效应和AIE之间的竞争，以前的有机光敏剂的近红外（NIR）聚集诱导发射（AIE）通常较弱。本文中，我们报告了一种合理的分子设计策略，以提高光敏剂的NIR AIE并仍通过转子效应保持强大的¹ O ₂生产能力。为此，一种新的基于三苯胺（TPA）的AIE光敏剂TPAM-1被设计为具有强大的生成¹ O _2的能力，但由于强的TICT效应，在聚集状态下的NIR荧光很弱。另一个新的基于TPA-AIE光敏剂，TPAM-2，通过引入3个设计p-甲氧基苯基单元作为TPAM-1结构的转子，以调节AIE和TICT之间的竞争。与商用光敏剂Ce6相比，TPAM-1和TPAM-2在聚集状态下具有更强的生成¹ O _2的能力。此外，由于转子效应，TPAM-2在聚集状态下比TPAM-1产生的NIR发光要亮得多（量子产率高25倍）。具有强近红外AIE和¹ O ₂生产能力的TPAM-2被DSPE-PEG ₂₀₀₀封装，具有良好的生物相容性。DSPE-PEG ₂₀₀₀包封的TPAM-2纳米颗粒具有良好的细胞成像性能，并具有杀死HeLa细胞的显着光敏活性。这项工作为设计用于AIE成像引导的光动力疗法的理想光敏剂提供了新途径。