Acta Chimica Sinica ›› 2021, Vol. 79 ›› Issue (2): 192-199.

Article

### DNA步行器调控的纳米粒子超晶格

1. a 中国科学院软物质化学重点实验室 能源材料化学协同创新中心 中国科学技术大学高分子科学与工程系 合肥 230026
b 合肥微尺度物质科学国家实验室 合肥 230026
• 投稿日期:2020-09-14 发布日期:2020-10-29
• 通讯作者: 姚东宝, 梁好均
• 作者简介:
• 基金资助:
国家自然科学基金(21991132); 国家自然科学基金(52003264); 中央高校基本业务费(WK20602000026)

### DNA Walker-Programmed Nanoparticle Superlattice

Yijun Guoa, Bing Weia,b, Xiang Zhoua, Dongbao Yaoa,*(), Haojun Lianga,b,*()

1. a CAS Key Laboratory of Soft Matter Chemistry, Collaborative Innovation Center of Chemistry for Energy Materials, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei 230026, China
b Hefei National Laboratory for Physical Sciences at the Microscale, Hefei 230026, China
• Received:2020-09-14 Published:2020-10-29
• Contact: Dongbao Yao, Haojun Liang
• About author:
Yijun Guo and Bing Wei contributed equally to this work.
• Supported by:
National Natural Science Foundation of China(21991132); National Natural Science Foundation of China(52003264); Fundamental Research Funds for the Central Universities(WK20602000026)

As a kind of sophisticated dynamic DNA nanomachine, DNA walker has shown powerful application ability in many aspects due to its excellent structural designability and programmability. Taking advantage of stochastic DNA tracks on surface and adaptable DNA outputs of the well-known catalytic hairpin assembly (CHA) circuits, the DNA walkers that move along DNA-coated three-dimensional particle surfaces have attracted much interests. On the other hand, in the field of DNA-mediated nanoparticle assembly, self-assembly of nanoparticles is a thermodynamically driven nonequilibrium process, which is easily trapped at intermediate local free-energy minima, resulting in a disordered structure. Therefore, effective strategies to evade each local free-energy minimum are highly desired. In addition to the traditional annealing strategy, the time-dependent strategy relied on toehold-mediated strand-displacement DNA circuit recently reported by our group has been proven an alternative solution, where interactions between nanoparticles can be tuned in a time-dependent manner for programming dynamic pathway to achieve a free-energy minimum. Through integrating a CHA-based bipedal DNA walker with a DNA-functionalized gold nanoparticle (i.e., spherical nucleic acid; SNA) assembly, a time-dependent strategy for assembly of SNAs programmed by DNA walker at constant temperature was developed in this work. In our strategy, the active sticky ends used for assembly of SNAs can be gradually generated on nanoparticle surface after the walking of the bipedal DNA walker driven by the CHA reaction to induce the synchronization of assembly and bonding between SNAs, thereby obtaining ordered nanoparticle superlattice structure. Take a one-component SNA assembly system for example, the dynamic walking process of the bipedal DNA walker on the surface of SNA was proved to be stable with good walking ability and persistence at first. Then, the SNA assembly kinetics results showed that the bipedal walker concentrations and DNA linker ratios could greatly influence the aggregation of SNA conjugates. Finally, the performance of the integrated SNA assembly system driven by the bipedal DNA walker was investigated under varied concentrations of bipedal walker. In the presence of lower concentrations of the walker strand, the assembly process of SNAs could have a long residence time to switch between the binding and unbinding of the generated sticky ends and achieved a series of near-equilibrium states. Thus, as the interaction between particles grows, the dynamic pathway of nanoparticles assembly can be programmed to achieve a free-energy minimum to form ordered face-centered cubic (FCC) superlattice structure. Based on similar design principle, an asymmetric two-component SNA assembly system programmed by the bipedal DNA walker was constructed to obtain CsCl superlattice structure. Our DNA walker-programmed SNA assembly strategy will have great potential in the creation of functional nanoscale superlattice materials and in the construction of SNA structures with complex phase behaviors.