基于外在超手性Plasmonic纳米结构的生物分子构象传感技术研究

In this project, we propose a biomolecular conformation sensing technology based on the extrinsic super-chiral plasmonic nanostructures (ESCPSs) to overcome the limitation of the traditional enantiomers, where the super-chiral field excited near ESCPSs can enhance the asymmetric interactions between chiral substrates and the circular parilation light, and the extrinsic chiroptical effect from ESCPSs can improve the detection efficiency. This technology is suitable for the the ultrasensitive, real time and high-throughput detection, and can meet the requirement of the current scientific and technological development, especially for the genomics, proteomics, drug screening and so on. We will start with some ESCPSs with representative topological morphology, focus on the conformation sensing requirement, and research the formation mechanism of the extrinsic chiroptical effect and super-chiral field by the relatively theoretical and experimental method.Through clarifying the relationship between the super-chiral field, extrinsic chiroptical effect and the structure dependent properties, such as the topological morphology of ESCPSs, the surrounding refractive index and surface plasmonic polariton, we will set up a biomolecule conformation sensing model based on ESCPSs, and develop the designing method of the idea super-chiral field and the conformation sensing substrate.Based the characteristic research accumulation on the research of chiral metamaterials and the interaction between chiral plasmonic nanostructures and chiral molecules, we will carry out the experimental research on controlling the conformational variants and the orientation of biomolecules and the enantiomer sensor, and verify the developed theory and the method that used in experiment.The research of this project will also promote the theoretical development and applications of super-chiral field and ESCPSs in other fields, such as asymmetric synthesis and Raman optical activity.

针对传统对映体传感技术的局限性，提出基于外在超手性Plasmonic纳米结构（ESCPS）的生物分子构象传感技术，利用超手性场对手性物质与电磁场之间非对称相互作用的增强作用和外手性效应在对映体传感方面的高效性，实现高灵敏、实时和高通量的构象检测。本项目将以构象传感为出发点，深入研究外手性效应和超手性场的形成机理；厘清外手性效应、超手性场与ESCPS的拓扑形貌、环境折射率、SPP类别（局域SPP、传播SPP等）等影响因素之间的内在规律，建立基于ESCPS的生物分子构象传感模型，进而发展生物分子构象传感的理想超手性场和传感基底的设计方法。结合实验室在手性超材料及其与生物分子相互作用方面的特色积累，开展生物分子取向和构象变异调控、以及生物分子构象传感实验，验证理论和方法的正确性。本课题研究，还将推动外手性效应和超手性场的理论发展，及其在非对称化学合成、Raman散射光活性等领域的应用。

Plasmonic增强手性效应不仅为设计和实现新型手性超材料提供新途径，也为实现高灵敏的手性分子空间结构检测提供新的可能。本项目通过结合理论、数值模拟和实验研究，开展并获得以下研究成果：1、开展了光栅和纳米孔阵列的外手性效应研究，给出相对于光入射面的结构对称性与外手性效应、超手性场之间的关联；2、从任意体系的内部耗散出发，通过重新推导圆偏振激发下的麦克斯韦方程组，得到手性场与体系CD信号之间的定量解析关系。并结合数值模拟，验证了理论推导的正确性；3、针对低对称性的手性介质和金属复合系统，首次阐明了体系对称性与诱导手性效应精细成份之间的对应关系，给出体系参数对诱导手性效应精细成份的影响规律，为开发新型生物分子传感器提供理论支撑。相关研究成果发表在Physical Review B 100 (12), 125424；4、首次发现基于自然界手性介质的新型非对称传输效应——即非对称手性光学效应。研究发现玻璃基底和介质截面上电磁波交叉耦合效应明显依赖于电磁波的入射方向，并导致相同体系中前向和后向照射的CD信号强度有明显差异。此项研究探测界面上发生的事件提供新的理论支撑，相关研究结果发表在Optics Letters 45 (6), 1330-1333；5、在高性能传感基底研究中，提出基于手性FP腔的高品质手性效应增强方案。研究发现，各向异性手性微结构、介质层和金属膜的三明治结构，能够有效增强体系的手性效应和信号品质，为获得高品质手性光学共振提供可行的方案。相关理论研究结果发表在Optics express 27 (5), 6801-6814。实验研究结果已投递SCI期刊杂志在审；6、结合理论和实验研究，首次将高品质的SPP晶格共振与手性共振相结合，实现了高品质、高强度的手性共振，为生物分子构象传感提供了可行性方案。相关研究结果已投递SCI期刊杂志在审。总之，在本项目的支持下，我们搭建角度依赖的光谱测试系统一套，发表SCI期刊论文5篇（在审论文3篇），获国家发明专利2项。