基于半导体棒的异质手性纳米结构构筑与性质调控

Chiral nanomaterials exhibit material crystals compositions, types and nanostructures correlated spectroscopic properties, and overall displayed strong chiroptical activity, which shows important significance and bright prospect in the field of basic science and applied science research. This project will carry out through controllable nanocrystals synthesis technology, the anisotropic and isotropic growth technology, and controllable self-assembly technology, we design and construct high yield, strong optical activity of semiconductor nanorods and semiconductor nanorods-noble metal nanostructures, various semiconductor nanorods and semiconductor nanorods-noble metal nanostructure growth kinetics, dynamic structure and spectroscopy laws study will be performed. The project will focus on the relation mechanism between the nanostructure compositions, crystal types, nanostructure configurations and circular dichroism, circularly polarized luminescence as well as fluorescence detected circular dichroism, construction of chiral quantum and Plasmon induction chiral models. Based on electromagnetic model, we will aim to reveal the mechanism and laws of optical activity. Finally, the study on optical activity enhancement and directional modulation as well as mechanism of light interaction with the chiral medium will be performed. This project will target to gain significant progresses in methodology of chiral nanostructures and structural parameters-properties relationship as well as properties regulations to obtain important research achievements.

手性纳米材料呈现出与材料晶体组成、类型及纳米结构相关联的光谱学性质，整体上表现出较强的光学活性，对基础科学和应用科学研究都具有重要意义和前景。本项目拟采用纳米晶体可控制备技术、各向异性和各项同性生长制备技术及可控自组装技术，设计和构建高产率、强光学活性的半导体棒及半导体棒-贵金属纳米结构，进行多种半导体棒及半导体棒-贵金属纳米结构动力学过程和动态结构与光谱学规律研究。重点研究手性纳米结构中材料组成和晶体类型及结构构型与圆二色性、圆偏振发光、荧光圆二色性关联规律及解析，构建量子手性和等离子诱导手性模型。结合电磁场模型，揭示光学活性产生机制和规律。最后，进行光学活性定向增强、调制及光和手性介质作用机制研究。通过项目实施，期望在手性纳米结构方法学、结构参数与性质构效关系及性质调控等方面取得重要进展。

手性半导体纳米棒及其异质结构引起了人们的广泛关注。在本项目中，我们证明了手性氨基酸修饰的CdSe@CdS半导体纳米棒（SNR）诱导圆二色谱（CD，200–480nm）。半导体棒越长，CD强度越强，而半导体棒直径越大，CD波段红移越明显。我们设计了一种策略，同时使用半胱氨酸和组氨酸相转移，以提高CD的强度。铂（Pt）和金（Au）的多点后生长进一步增强了CD的强度，并诱导圆二色谱峰波带跃迁。观察到的荧光猝灭现象表明，后生长沉积的金属促使能量转移，增强了光激发电子和空穴的分离。电磁场计算表明，金属纳米点生长产生了较强的电磁场增强，铂的增强作用强于金。这些发现表明，多点沉积金属纳米点提供了一种通过调整半导体纳米棒的形貌从而产生强光学活性的方法，对未来在光学偏振方面的器件、催化及传感方面有重要的应用前景。