无机纳米粒子手性自组装及其结构与性质调控

Thanks to the synergistic effect of nanoscale compositional and structural configurations, nanoparticle chiral assemblies could display excellent and intense optical activities. This project will carry out through controlable nanomaterials synthesis, nanoparticle interface modification for functionalization and stabilization, DNA hybridization programmable assembly technology, this project will construct six types of plasmonic, fluorescent and magnetic nanoparticles chiral self-assembled pyramids, and study the dynamic assembly process of various nanoparticles pyramids. The project will focus on the relation between the energy resonance transfer, plasmon coupling, plasmon-exciton coupling, and electromagnetic coupling, electromagnetic enhancement and optical activityenhancement with regarding to plasmonic circular dichroism, circularly polarized luminescence, fluorescence detected circular dichroism as well as magnetic circular dichroism and their relations to demonstrate the mechanism of optical activity enhancement, and establish models. Finally, Based on optical activity enhanced pyramids, multi-signal biomarkers recognitiontechnology will be constructed, and the interaction system between the chiral pyramids and the cell growth and differentiation will be developed. This project will target to gain significant progresses in methodology of chiral superstructure assemblies and structural configuration-activity relationship as well as properties regulations, and obtain original scientific researchachievements. The implementation of the project has important scientific significance in the exploration of the chiral nature of inorganic nanostructures, the regulation of the chirality and biological effects.

纳米粒子手性自组装表现出与组成和结构构型相关联的优异光学特性，纳米粒子协同效应产生强的光学活性。本项目通过纳米粒子可控合成、纳米界面功能化和稳定化修饰，DNA程序化杂交组装技术，构建六种类型的等离子、荧光及磁性纳米材料四面体手性自组装结构，进行多种纳米粒子四面体的动态组装过程研究。重点研究手性自组装中能量共振转移、等离子耦合、等离子-激子及电磁耦合，电磁场增强和光学活性增强相关的等离子圆二色性、圆偏振发光、荧光圆二色性及磁圆二色性及其关联规律，阐释光学活性增强机制，建立理论模型。最后，建立基于光学活性增强纳米四面体多信号甄别生物标志物传感方法，发展手性四面体与细胞生长、分化互作体系。通过项目实施，期望在手性纳米超结构组装方法学、结构构型与性质的构效关系及性质调控等方面取得重要进展，获得原创性科研成果。项目研究在探索无机纳米结构手性本质、手性调控及生物效应等方面具有重要科学意义。

项目围绕无机纳米粒子手性自组装及其结构与性质调控开展研究，研究了手性纳米超结构的构筑方法。将不同材质、尺度、形貌的纳米颗粒通过核酸杂交组装，形成四面体、卫星式或扭转构象的结构，通过控制核酸的长度和锚定位点，调制颗粒间的耦合强度，实现了强光学活性纳米结构的构筑。我们研究了人工手性结构与细胞的相互作用：发现神经细胞在L/D手性界面上的差异性分化，D-手性纳米四面体在细胞内的大量富集，并导致更为严重的细胞自噬效应。解析了“扭转”构象手性纳米二聚体在细胞内外扭转方向反转的内在机制。制备了对细胞内mRNA响应的卫星式手性结构，随着手性结构在细胞内的构象变化产生的光学力可达10 pN， 在圆偏振光刺激下可诱导干细胞的定向分化。我们制备了与生物大分子如核酸、蛋白特定构象和尺度匹配的单一手性纳米颗粒。 例如，切角四面体CdTe纳米颗粒（～4.5 nm）精确识别 DNA上的GATATC片段，并在偏振光下特异性剪切GAT^ATC，媲美限制性内切酶。 这种精巧的剪切效应可拓展到蛋白的高特异性剪切中，上述研究工作弥合了无机材料与生命科学的界限，为无机手性纳米材料的制备和功能化应用指出了新方向。