糖类超分子模板法构建可控可逆的手性无机纳米超结构

Construction of chiroptical switches is one of the most challenging frontier topics in the field of chiral science and technology. Classic chiroptical switches were fabricated using chiral or achiral molecules as building blocks, in recent years, research on construction of chiral inorganic nanoparticle superstructures using chiral or achiral inorganic nanoparticles as building blocks has greatly broadened the research scope of the chiroptical switches. Due to the structural designability and spatial addressing capability, DNA origami nano-templates have shown significant advantages in precise guidance of inorganic nanoparticles self-assembly into predesigned structures and properties. However, compared to the DNA origami nano-templates, the source of carbohydrate supramolecular templates are more abundant, which are suitable for large-scale preparation of chiral inorganic nanoparticle superstructure materials; The carbohydrate supramolecular templates are rich in glycosyl groups, which can provide enough binding sites for the sequential inorganic nanoparticles self-assembly; Stimuli-responsive groups can also be introduced into the carbohydrate supramolecular templates by conventional chemical methods, which will greatly broaden the applications of the chiral inorganic nanoparticle superstructures in the chiroptical switches. This project will focus on developing the controllable reversible chiral inorganic nanoparticle superstructures based on the carbohydrate supramolecular templates using the carbohydrate molecules as chiral sources, and exploring their applications in the chiroptical switches, establishing a kind of low-cost, general, quick and effective carbohydrate supramolecular template technology for the construction of controllable reversible chiral inorganic nanoparticle superstructures.

构建手性光学开关是手性科学与技术领域最具有挑战性的前沿课题之一。经典的手性光学开关是以手性或非手性的分子为基材，近年来，以手性或非手性的无机纳米颗粒为基材构筑手性无机纳米超结构的研究极大地拓宽了手性光学开关的研究范畴。DNA折纸纳米模板由于结构可设计性和空间寻址能力，在精确引导无机纳米颗粒自组装形成预设结构和性能方面具有显著的优势。然而，与之相比，糖类超分子模板来源更加丰富，适用于大规模制备手性无机纳米超结构材料；糖类超分子模板富含糖基，可为后续组装无机纳米颗粒提供丰富的结合位点；糖类超分子模板可通过常规的化学方法引入刺激响应基团，将极大拓宽手性无机纳米超结构在手性光学开关中的应用。本项目将利用糖类分子为手性源，开发基于糖类超分子模板的可控可逆的手性无机纳米超结构，发展其在手性光学开关中的应用，为构筑可控可逆的手性无机纳米超结构建立一种廉价、普适、快捷有效的糖类超分子模板技术。

构建可重构的手性无机纳米超结构是手性科学与技术领域最具挑战性的前沿课题之一。本项目以手性糖肽超分子调控无机纳米颗粒自组装为切入点，研究了糖肽两亲分子的自组装行为，构建了互为镜像异构体的左手、右手螺旋的糖肽超分子组装体，进而基于手性糖肽超分子模板构筑了可重构的手性等离子体纳米超结构，此外还开展了生物学效应的研究。取得的主要研究进展如下：（1）利用结构简单的序列异构的三肽（即Ala-Gly-Gly-OH、Gly-Ala-Gly-OH、Gly-Gly-Ala-OH），研究了序列上的细微变化如何影响糖肽两亲分子自组装成高度有序的纳米结构。三肽的N端和C端分别用正丁基偶氮苯和N-甲基-D-葡糖胺残基修饰，其中偶氮苯基团为自组装提供了π-π作用和刺激响应性。当Ala残基的位置在三肽中变化时，在相同条件下我们观察到两亲分子出现三种不同的自组装一维形貌：纳米扭带、纳米带和纳米纤维。我们还通过透射电子显微镜、原子力显微镜、傅里叶变换红外光谱、X射线衍射和圆二色光谱对这些糖肽组装体的结构细节进行了表征，并使用Martini粗粒度分子动力学模拟研究了组装机制的差异。此外，我们还研究了糖肽组装体在响应光、热或主客体化学时的可逆的组装-解组装过程，考察了可调控的生物膜抑制和清除活性。（2）基于手性糖肽超分子模板构筑了可重构的手性等离子体纳米超结构，系统考察了手性超结构对温度、光、pH和葡萄糖响应的手性光学活性。通过执行本项目，不仅为制备可重构的手性无机纳米超结构提供了简便、有效的超分子化学手段，也为糖肽超分子组装体的手性结构精确调控和功能探索奠定了基础。在Chem. Sci.，Chem. Commun.，J. Mater. Chem. B，ACS Biomater. Sci. Eng.，Compos. Sci. Technol.等学术期刊发表SCI论文5篇，申请中国发明专利1项。