DNA-纳米粒子体系组装动力学的理论模拟

DNA诱导的纳米粒子组装体系可实现在热力学上可逆可控自组装并形成有序的超分子结构，它在医学诊断、传感、数据存储、等离子体等领域具有广泛的应用。利用核酸具有通过经典的Watson-Crick碱基互补配对相互作用编码大量信息的能力，可以诱导纳米粒子形成复杂的晶格结构。但是在实际体系中，还存在其他的一些相互作用，比如排除体积相互作用。在氢键相互作用的基础上引入排除体积相互作用，纳米粒子组装的动力学和机理会怎样仍然不是很清楚。本项目拟构建粗粒化的DNA-纳米粒子和DNA/高分子-纳米粒子模型，采用分子动力学方法研究DNA-纳米粒子体系的组装动力学和机理；探究DNA修饰的纳米粒子之间DNA的键合性质；考虑DNA分子和高分子接枝纳米粒子的复合体系，探索引入具有排除体积相互作用的高分子对DNA-纳米粒子体系组装的协同效应。上述研究可为DNA等生物分子和纳米粒子体系的组装研究提供新思路和有力的理论依据。

The DNA-directed nanoparticle allows the thermodynamically reversible and controllable assembly of inorganic nanoparticles into ordered supramolecular structures. It provides various applications in medical diagnosis, sensing, data storage, plasmonics and photovoltaics.　In nature, nucleic acids are ubiquitous due to their ability of encoding substantial information via canonical Watson-Crick base-pairing interactions. There is no doubt that it’s just the DNA bonds that drive DNA-NP system assembling into ordered crystalline structure. But it is still unclear about the formation mechanism of the ordered lattice when other interactions besides hydrogen bond effect include in systems, such as excluded volume effect. In this proposal, we construct the coarse-grained model of DNA-nanoparticle (DNA-NP) and DNA/polymer-nanoparticle, and use molecular dynamics method to simulate the self-assembly and dynamics of the DNA-NP systems. The bonding property of the DNA-NP will be intensively studied. Considering the grating of DNA and polymers, we investigate the excluded volume effect of polymers on the crystallization of nanoparticles. The above studies provide insights into the self-assembly of nanoparticles directed by DNA, and furthermore offer promising strategies for constructing the DNA programmable systems.