用于金刚石表面单分子有序固定的DNA折纸制备

Preparation of DNA Origami for Ordered Immobilization of Single Molecules on Diamond Surface

近年来兴起的以金刚石氮-空位(NV)色心为量子传感器的微观磁共振技术得到快速发展,已经实现单个生物分子磁共振谱的探测,正在向单分子结构和功能的研究推进.这其中需要解决一个重要的技术问题,即单分子在金刚石表面的有序分散和固定. DNA的自组装为解决这一问题提供了可行途径,本文使用DNA折纸技术,制备了一种60 nm边长的正方形双层DNA折纸作为单分子载体,并与金刚石表面结合.首先采用双层结构提高了DNA折纸的稳定性,其次通过在DNA折纸边缘添加发卡结构减少了DNA折纸结构间的聚团,最终成功将DNA折纸装配到金刚石表面.通过原子力显微镜图像进行表征显示其结构完整、分散均匀.本工作为后续的单分子磁共振技术在单分子生物物理领域的应用推广奠定了样品制备的基础.

In the recent years, the microscopic magnetic resonance technology using nitrogen-vacancy(NV)centers in diamond as quantum sensors has been developed rapidly. The detection of magnetic resonance spectrum of a single biomolecule has been achieved, and it now steps to the study of single molecule’s structure and function. Therefore, it is necessary to solve an important technical problem: how to disperse and fix biomolecules on diamond surface orderly. DNA self-assembly provides a possible way to solve this problem. In this paper,60 nm square double-layer DNA origami was prepared as a kind of single-molecule carrier and then combined to the diamond surface. Firstly, we used the double layer structure to enhance the DNA origami’s strength. Secondly,by adding hairpin structure to the edge of DNA origami, the agglomeration between DNA origami was reduced.Finally, the DNA origami was successfully assembled to the diamond surface. The atomic force microscope images showed that the structure was complete and the dispersion was uniform. This work built a foundation for the subsequent application of single-molecule magnetic resonance technology in the field of biophysics.