基于扫描圆二色显微成像技术的单个手性物质的圆二色性及其调控研究

由于溶液和薄膜中手性物质的取向杂乱无章，单个手性物质的表观圆二色性存在差异，导致溶液和薄膜的圆二色性是不同取向手性物质的平均，因此，非常有必要在单个物质的层面上开展圆二色性研究。此外，对于单个手性物质，可以非常方便的改变其外在环境，实现对圆二色性的调控。基于以上认识，本项目将首先基于偏振调制技术搭建可探测单个手性物质的扫描吸收圆二色显微成像系统和扫描发射圆二色显微成像系统，然后利用所搭建的两个系统分别研究表面上单个手性分子、单个手性超分子自组装体和单个手性纳米结构的吸收圆二色性和发射圆二色性，获得单个手性物质的吸收圆二色不对称因子和发射圆二色不对称因子及其与取向、形貌等的关系，揭示表面上个体圆二色性与溶液中平均圆二色性的异同及其来源，并在个体层面阐释手性分子自组装时的圆二色性放大机制与规律。最后，研究基底、电场等环境因素对圆二色不对称因子的影响，揭示利用环境调控圆二色性的机制与规律。

Due to various orientations of chiral materials in solution and film, the measured circular dichroism (CD) of single chiral materials is different depending on its orientation, and CD of chiral materials’ solution and film is the average from individual chiral materials with different orientations. Therefore, it is necessary to study CD at single level. Besides, it is very convenient to change the surroundings of single chiral materials, and to modulate CD by surroundings. Here, we will build scanning absorption circular dichroism microscope and scanning luminescence circular dichroism microscope based on polarization modulation technique, which has the sensitivity of single chiral materials. By using the two microscopes, we will study single chiral molecules, single chiral supermolecules assemblies and single chiral nanostructures to obtain their absorption CD dissymmetry and luminescence CD dissymmetry, and its dependence on orientation and morphology. The CD differences and its origin between single and average will be revealed. The mechanism of CD amplification during molecule assembly will be elucidated at single level. In the end, the influence of substrate and electric field on CD dissymmetry will be studied to reveal the mechanism of CD modulation by surroundings.