手性光学活性金属纳米材料的制备及手性分离与传感应用

Although chirality at molecular level (like amino acid, sugar, and synthetic molecules etc) is exclusively understood, the investigation of nanoscale chirality is scarce. Metal nanoparticles (NPs) and nanoclusters (NCs),due to their size-dependent optical properties and remarkable resistance to photo-degradation, have been extensively used as alternative materials for biodetection and biolabels. However, the study on chiroptic properties of metal nanomaterials is in burgeon stage and its bioapplications nearly remain an unexplored area. In fact, passivtion of gold or silver NPs and NCs with chiral admolecules results in unique electronic and chiroptic response properties that are unlike those of the component parts. Therefore, in this project, we first plan to prepare the metal nanomaterials with excellent chiroptic properties by several strategies, including the direct growth of metal NPs or NCs on the chiral template molecules, the functionation of achiral metal nanomaterals with chiral lignands and the one-pot synthesis with chiral molecules serving as both a reducing agent and a protecting lignand. Second, the influence factors on chiroptic properties of metal NPs or NCs, such as the absorption band of chiral molecules and metal nanomaterials, the size and shape of nanomaterials, dielectric constant etc, and the efforts towards elucidating the origin of chirality or chirality transfer in these nanomaterial/molecule complexes, should be made. Third, differing from conventional chiral molecules, the potential biological applications of chiral metal NPs or NCs should be further answered. Thus, the rational design and construction of chiroptic metal NPs and NCs, on basis of measuring the optical signals, especially chiroptic signals such as circular dichroism (CD), fluorescence detected circular dichroism (FDCD) etc for enantioseparation and chiral molecules recognition, is our another important goal. Compared with the enantioseparation and chiral detection by convetional HPLC method, our current undertaking to find the simple, cost-effective approaches for chiral recognition, depite the challenging, has a profound meaning.

金属纳米材料，包括金属纳米粒子和荧光金属纳米簇等，在纳米分析化学已得到广泛发展和应用，而手性金属纳米材料的构建还仅处在初期探索阶段，基于手性金属纳米材料的应用研究更是留下了巨大的创新空间。本项目拟借鉴现代纳米材料功能化修饰的相关技术和手性纳米材料研究已有的发展成果，通过手性模板分子上的生长、手性配体分子修饰或置换、手性分子同时作为还原剂和稳定剂一步合成等途径，制备具有优良手性光学性质的金属纳米材料。探索手性配体分子与金属纳米材料吸收光谱性质、纳米粒子组成、大小、形貌、周围介质环境等对金属纳米材料手性光学性质的影响规律，阐明手性发生和转移的机制。进而基于设计和构建的手性金属纳米材料为光谱探针，借助手性分子识别过程中圆二色、荧光圆二色、荧光偏振等光谱信号分辨，建立简单、经济、快速的重要药靶蛋白识别、对映体药物拆分与传感新方法。与传统HPLC法相比，本项目的实施既有理论研究价值又有广阔应用前景。

金属纳米材料，在纳米分析化学已得到广泛发展和应用，而手性金属纳米材料的构建还仅处在初期探索阶段，基于手性金属纳米材料的应用研究更是留下了巨大的创新空间。本项目借鉴手性纳米材料研究已有的发展成果，通过手性模板分子上的生长、手性配体分子修饰或置换、手性分子同时作为还原剂和稳定剂一步合成等途径，制备了系列具有优良手性光学性质的金属纳米材料，并阐明手性发生机制和探索其对映体拆分与传感新方法。具体结果包括：① 发现组氨酸对映体能介导合成具有手性光学活性的荧光金纳米簇，通过含巯基手性分子的配体置换，阐述了其手性发生的机制；② 以青霉胺对映体合成了稳定的手性荧光铜纳米簇，研究了其从复合物到铜簇过程中手性光学活性的演化，阐述了其聚集诱导荧光的特征及其应用；③ 以青霉胺对映体分别制备了具有手性光学活性的金铜、金银纳米合金，观察了合金效应对手性光学性质的影响，且发现手性金银合金对青霉胺对映体具有自识别能力，从而建立了色度检测对映体分子的光学分析新方法。上述研究结果在合成方法、手性光学活性发生机制及其影响因素等方法，进一步丰富了对纳米尺度手性金属材料的理解，并为基于手性金属纳米材料的对映体分子光学传感提供了新的思路。