强手性贵金属-半导体三聚体的制备及其光学机制

Nanoparticles assemblies showed composition and structure dependent strong optical properties, in which the collective interactions of the nanoparticles exhibited synergistic amplification effect that give rise to strong optical signals. This project will perform nanoparticle controllable synthesis, nanoparticle interface modification for functionalization and stablization. Through molecular recognition (DNA hybridization, antigen-antibody reaction and molecular charge interactions) based nanoparticle self-assembly technology, this project will construct noble nanoparticles and quantum dots trimers assembly system, and investigate the dynamic assembly process. This project will also perform the relationship and mechanism study between optical properties and different constituted structures of nanoparticle trimers. Then, the optical models will be established to demonstrate the effect and mechanism of Plasmon-exciton interaction and the energy resonance transfer with relation to the circular dichroism. Finally, this project will construct noble metal nanoparticles and quantum dots trimer optical system with strong circular dichroism.

纳米粒子可控自组装表现出与组成和结构相关联的优异光学特性，纳米粒子的相互作用呈现协同放大效应，产生强的光学信号。本项目拟通过纳米粒子可控合成、纳米粒子界面功能化和稳定化修饰。基于分子识别（核酸杂交、抗原-抗体反应及分子电荷作用）纳米材料自组装技术，构筑贵金属纳米粒子与半导体量子点三聚体组装体系，进行动态组装过程研究。研究贵金属纳米粒子与半导体量子点组装体的不同组成结构和光谱学关联及机制，建立光学模型，阐释贵金属纳米粒子与半导体量子点之间的等离子-激子相互作用及能量共振转移对圆二色性的影响效应及机制，构建强圆二色性的贵金属纳米粒子和量子点三聚体光学体系。

利用金属纳米结构集中电磁辐射的能力，促进光放大和光学检测中的各种应用是目前等离子激元研究的热点之一。本项目围绕贵金属纳米颗粒与半导体纳米颗粒（量子点、上转换纳米颗粒UCNP）的组装和光学信号调制开展研究，通过设计并控制核酸的修饰位点、杂交长度，发展了可控、高产率组装方法，深入研究了等离子体激元诱导的共振能量转移（PIRET）过程及其偶极 - 偶极相互作用，将等离子体消逝场耦合到半导体吸收体，实现了多重光谱信号的协同增强，尤其是通过控制颗粒等大小控制LSPR波长，通过颗粒间隙控制实现强耦合，上转换双光子增强系数达12.4，为目前报道的最高值。协同增强的圆二色光谱信号、上转换发光信号以及荧光信号，对介质环境敏感，具有较强的抗干扰能力，基于此，申请人建立了超敏检测方法，并实现了活细胞中miRNA， 端粒酶、ATP等生命物质的原位探测。项目执行期间，发表SCI收录论文22篇，申请中国发明专利3件，美国发明专利1件，培养研究生5名。