聚集诱导发光金属有机骨架：从发光机理研究到传感与诊疗一体化应用

Conventional organic fluorescence probes suffer from the aggregation-caused quenching that imposes limitation on their labelling efficiency and/or concentration to achieve desired sensitivity. The recently emerged fluorogens with aggregation-induced emission (AIE) feature offer a timely remedy to tackle the challenge. Combining the merits of carboxyl-functional AIE ligands and lanthanide (Ln) ions, AIE functional MOFs (AMOFs) with the porous structure will get the utmost out of the AIE property and the merits of LnMOFs. With rational design, we will prepare multi-functional AMOFs with AIE ligands and lanthanide ions, including Eu, Tb, and Dy, known by their large Stokes shift, bright visible emission, and long lifetime. Followed by the antenna effect, the AMOFs with dual emission fluorescence are expected to be designed and prepared for chemical sensing. Thanks to the ratiometric fluorescence, the sensors will get some excellent properties such as high sensitivity, wide response range, and fast response. Visual detection of the interested targets will be achieved by naked-eyes easily. A series of AMOFs materials will be synthesized by using different AIE ligands and different metal nodes. Combining with their luminescent properties and the study of their energy transfer, the luminescence of AMOFs are explored deeply and the mechanisms of AIE and antenna effect will be creatively supplemented. We will also synthesize macroporous AMOFs with lanthanide ions, sucn as Gd and Yb, which have magnetic resonance (MR) or CT responses. The macroporous of the AMOFs can carry anticancer drugs easily. Combining the MR/CT imaging capabilities with the fluorescence of AIE ligands, multi-modality imaging is expected with the as-prepared AMOFs. In combination of the drug-loading ability, AMOFs can achieve the integration of cancer diagnosis and treatment. The results of this project obtained from AMOFs certainly provide new ideas for the application of AIE materials and the development of MOFs materials. AMOFs will be validated as a new platform for sensing and clinical application.

聚集诱导发光(AIE)克服了传统荧光材料高浓度猝灭的问题。利用羧基化AIE配体与镧系离子制备金属有机骨架(MOFs)，可充分发挥AIE染料与镧系离子的特点和优势。本项目希望制备镧系AIE-MOFs(AMOFs)，利用铕铽等镧系离子的天线效应和配体的AIE，实现双荧光发射并用于分析物的比例型荧光传感和可视化检测。通过铕铽镝等镧系AMOFs发光行为和配体发光过程单线态/三线态能量的变化，验证天线效应发光机理，补充、丰富AIE理论。利用AIE配体的荧光和钆镱等镧系离子的磁共振/CT响应，结合MOFs孔道载药，探索AMOFs的多模态成像和诊疗一体化应用。本项目创新性地将AIE配体与镧系离子结合，利用两者优势和MOFs特点，探索发光机理，研究荧光传感，实现成像及诊疗一体化应用，一方面为AIE和MOFs材料发展提供新的思路，另一方面为传感和生物医学应用提供新的平台。

发展多功能集成材料对于开发新颖应用具有重要意义。金属有机骨架（MOFs）由金属离子和配体组成的多孔材料。金属离子和配体功能的有效集成，结合孔道装载及后修饰，MOFs是实现多功能的理想材料；揭示发光机理是设计新体系、拓展新应用的基础。在项目支持下，我们合成了聚集诱导发光单体，制备聚集诱导发光金属有机骨架，提出了“配位诱导发光”概念，验证了旋转受限发光机制，修订了天线效应过程配体三线态能量与镧系离子激发态能量的阈值；设计系列多发光金属有机骨架系统，拓展其应用。开展金属有机骨架的多功能集成，实现了多模态成像引导的多模式治疗。相关成果在Acc. Chem. Res.，J. Am. Chem. Soc.，Adv. Funct. Mater.，Small，Chem. Sci.，Anal. Chem.等化学重要期刊发表SCI收录论文22篇，获授权发明专利2项。培养博士毕业生6人，硕士毕业生4人。相关研究一方面丰富了金属有机骨架的设计，另一方面为其他领域应用提供新手段。