基于表面等离激元光学驱动的纳米自组装镜像对称破缺新现象和机理研究

Chiral origin at nanoscale is a challenging topic in the self-assembly of soft materials, which is intimately related with the origin of life on earth. This proposal aims to study the important role of photonic momentum transfers in the chiral assembly of metallic nanoparticles, and explore the possibility of using plasmon-enhanced chiral optical forces and torques to enable mirror symmetry breaking of chiral enantiomeric pairs. The physical mechanisms involved in this chiral phenomenon are new, in contrast to previous studies where photochemistry with circularly polarized light was thought to play predominant role in the observations of mirror symmetry breaking. Here we attempt to establish the relationship between optomechanical effect induced by photonic momentum transfers and mirror symmetry breaking phenomenon occurring in the chiral assembly of nanoparticles, providing a new insight into the chiral origin of soft materials at the nanoscales. We believe that this study is not only of important implications in a fundamental study of light-matter interactions, but also helpful for exploiting optically manipulating of chiral assembly of metallic nanoparticles, with aims to create novel plasmonic chiral nanostructures and devices for applications in the fields of biological sensing and imaging, chiral drugs, and optical information communications.

软凝聚态物质有序自组装体系在纳米尺度上的手性起源，是与生命起源研究紧密相关的一个极具挑战的课题。本项目拟研究光子角动量传递产生的光力学效应在金属纳米颗粒手性自组装结构构建中的作用和影响，探索基于表面等离激元增强的不对称光学力驱动的手性镜像对称破缺效应和机理。不同于以前的光化学分解/催化诱导的手性物质镜像对称破缺现象研究，本研究试图通过建立光与物质之间动量交换这一基本光力学效应与纳米手性自组装镜像对称破缺之间的联系，从一个新的角度理解软物质在纳米尺度上的手性起源。我们相信，这项研究不仅在揭示光与物质作用新的现象和机理方面具有重要的科学意义，还有助于探索用光学操控纳米颗粒自组装来构建新型表面等离激元手性功能微/纳器件，拓展金属纳米结构材料在生物传感和成像、手性制药、信息传输等方面的重要应用。

本项目研究了光子的手性信息传递在构建纳米金属手性自组装结构中的作用和影响，探索了基于表面等离激元增强的不对称光学力驱动的手性镜像对称破缺效应和机理。对于分子介导的金纳米棒手性组装模型体系，本研究建立起光与纳米颗粒之间动量交换这一基本光力学效应与手性自组装镜像对称破缺之间的联系，由此提供一个新的角度理解软物质在纳米尺度上的手性起源。这种基于光力学效应的手性信息传递在构筑可调控纳米等离激元手性态及其光学活性方面具有重要应用价值。本研究提出的新型光控表面等离激元手性开关及自组装超结构的光控手性策略，将有助于拓展人工纳米功能结构材料在手性传感、光催化、微纳光子器件等方面的应用。