香港中文大学唐本忠团队报道了构建具有超高摩尔吸光率和光热效应的近平面NIR-II AIEgen，用于多模光疗的范式转变。相关研究成果发表在2025年1月15日出版的《美国化学会杂志》。

自然界中这两个相互矛盾的实体往往遵循对立统一的原则，从而实现最佳的整体性能。特别是，具有供体-受体（D–A）结构的聚集诱导发射发光原（AIEgens）表现出可调的光学性质和多功能性，为癌症治疗提供了巨大的变革潜力。然而，由于扭曲的构型导致的低摩尔吸光系数（ε），其光子捕获能力的上限和相应的光散射性能仍然不足。因此，AIEgens的发展迫切需要一种从扭曲构型到具有高ε的近平面结构的研究范式。

该文中，研究人员通过将“运动与静止”的策略引入高度平面的a-D-a骨架，成功开发了Y5-2BO-2BTF的近红外（NIR）-II AIEgens，其ε为1.06×10⁵ M^–1 cm^–1，光热转换效率（PCE）为77.8%。聚集受体单元中苯环上的空间位阻的改变导致对应物Y5-2BO淬灭为间-CF₃取代的萘基，导致Y5-2BO-2BTF中出现反向交错堆积和各种分子间非共价构象锁（“静止”）。此外，CF₃部分作为一个具有超低能量势垒的柔性运动单元，显著促进了松散Y5-2BO-2BTF聚集体中的光热过程（“运动”）。因此，Y5-2BO-2BTF纳米颗粒通过NIR-II荧光光声光热成像导航I型光动力光热疗法实现了肿瘤根除和肺转移抑制。

该项工作提供了第一个证明具有反向交错堆叠排列的高度平面构象，可以作为AIEgens的一个新的分子设计方向的证据，为构建用于生物成像和癌症治疗的优良光电转换器试剂，提供了新的线索。

附：英文原文

Title: Integration of Motion and Stillness: A Paradigm Shift in Constructing Nearly Planar NIR-II AIEgen with Ultrahigh Molar Absorptivity and Photothermal Effect for Multimodal Phototheranostics

Author: Shiping Yang, Qian Jia, Xinwen Ou, Fang Sun, Chaoqi Song, Tingxing Zhao, Ryan T. K. Kwok, Jianwei Sun, Zheng Zhao, Jacky W. Y. Lam, Zhongliang Wang, Ben Zhong Tang

Issue&Volume: January 15, 2025

Abstract: The two contradictory entities in nature often follow the principle of unity of opposites, leading to optimal overall performance. Particularly, aggregation-induced emission luminogens (AIEgens) with donor–acceptor (D–A) structures exhibit tunable optical properties and versatile functionalities, offering significant potential to revolutionize cancer treatment. However, trapped by low molar absorptivity (ε) owing to the distorted configurations, the ceilings of their photon-harvesting capability and the corresponding phototheranostic performance still fall short. Therefore, a research paradigm from twisted configuration to near-planar structure featuring a high ε is urgently needed for AIEgens development. Herein, by introducing the strategy of “motion and stillness” into a highly planar A–D–A skeleton, we successfully developed a near-infrared (NIR)-II AIEgen of Y5-2BO-2BTF, which boasts an impressive ε of 1.06 × 105 M–1 cm–1 and a photothermal conversion efficiency (PCE) of 77.8%. The modification of steric hindrance on the benzene ring in the acceptor unit of the aggregation-caused quenching counterpart Y5-2BO, to a meta-CF3-substituted naphthyl, leads to reversely staggered packing and various intermolecular noncovalent conformational locks in Y5-2BO-2BTF (“stillness”). Furthermore, the CF3 moiety acted as a flexible motion unit with an ultralow energy barrier, significantly facilitating the photothermal process in loose Y5-2BO-2BTF aggregates (“motion”). Accordingly, Y5-2BO-2BTF nanoparticles enabled tumor eradication and pulmonary metastasis inhibition through NIR-II fluorescence-photoacoustic-photothermal imaging-navigated type I photodynamic-photothermal therapy. This work provides the first evidence that the highly planar conformation with a reversely staggered stacking arrangement could serve as a novel molecular design direction for AIEgens, shedding new light on constructing superior phototheranostic agents for bioimaging and cancer therapy.

DOI: 10.1021/jacs.4c15216

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.4c15216