基于长波长吸收全氟二芳烯衍生物/近红外荧光染料的新型智能超分子组装体的构筑及其刺激响应性能研究

The use of organic photochromic Diarylethene derivatives (DAEs) as the building blocks for forming the self-assembled structures has potential applications in information storage and intelligent materials for their unique stimulus-response and controllable intelligent. However, it remains a challenge for most DAEs-based photo-control fluorescent supramolecular assemblies to construct high matching molecular switches with near-infrared fluorescent dyes accompanied by high energy transfer efficiency and more stable assembly bodies. In this project, a series of long wavelength absorption DAEs with melamine group or crown ring will be designed and synthesized to overcome the above problems. And then the stable near-infrared fluorescent dyes with high fluorescence quantum efficiency will be modified by diimide group or the secondary amine cations. By assembling the above designed long wavelength absorption DAEs derivatives and near-infrared fluorescent dyes, the stable assembly bodies with high match property will be achieved through strong ternary hydrogen bonding or host-guest interaction between melamine and diimide or crown and the secondary amine cations respectively. The supramolecular assemblies based on diarylethenes derivatives/near-infrared fluorescent dyes constructed in this project would combine the advantages of diarylethenes derivatives and near-infrared fluorescent dyes, so they have potential applications in smart sensors, optical information storage and high-resolution fluorescence microscope due to their sensitive responsiveness, durable fatigue resistance, low excitation energy, strong fluorescent signal and anti-disturbance.

二芳烯类光致变色分子为构筑板块构建的光控荧光超分子组装体，具有独特的环境刺激响应性和良好的智能可控性，在信息存储、智能材料等领域有巨大的应用前景。然而，二芳烯类光控荧光超分子组装体目前依然存在异构体与近红外荧光染料匹配度不高、能量传递效率低以及组装体不稳定等问题。本项目针对上述问题，在设计合成新型的长波长吸收的全氟二芳烯基础上，将三聚氰胺基团、冠醚环分别引入所合成的二芳烯骨架中。同时，选取稳定性好、荧光量子产率高的近红外染料，分别修饰上能与三聚氰胺基团、冠醚环发生强络合作用的二酰亚胺基团和二级胺正离子，从而通过三重氢键、主客体相互作用来构筑高匹配、高效率、稳定的光控近红外荧光超分子智能组装体。本项目所构筑的上述超分子组装体能够结合二者的优势，其不仅具有灵敏的响应性、耐久的抗疲劳性而且拥有荧光信号强、背景干扰小的优点，在智能传感器、光学信息存储及高分辨荧光显微镜等方面具有巨大的应用前景。

针对现有长波长光响应荧光分子开关构筑方法的不足，结合“积小为大”的超分子组装技术，发展出高度匹配、高耐疲劳性、高灵敏性的基于二芳烯/荧光染料体系的高级长波长光响应荧光分子开关。按照研究计划，我们设计合成了含吲哚官能团，噻吩官能团、三联吡啶官能团、萘酰胺官能团修饰的长波长吸收的新型二芳基乙烯光致变色分子以及脂质体和大环主体柱芳烃修饰的超分子光响应纳米粒子，将这类功能化纳米粒子应用到细胞成像中，制备得功能化纳米细胞成像试剂和高效的纳米探针。从而一方面能够有效提高光敏剂二芳基乙烯的稳定性；另一方面大幅度改善纳米探针灵敏性能。实验结果表明，这类新型光学纳米组装体表现出低细胞毒性，高的耐疲劳性等，同时这类优化后纳米粒子表现出更高的光学稳定性，更好的光吸收性能，从而具有重要的商用价值。这有可能为制备智能光响应性超分子组装体的研究研发开拓了一个新的方向。