Laboratory of Nanoscale Biology, Institute of Bioengineering, School of Engineering, EPFL, 1015 Lausanne, Switzerland.
Langmuir. 2010 Dec 7;26(23):18078-82. doi: 10.1021/la102518t. Epub 2010 Oct 26.
We used AFM to investigate the interaction of polyelectrolytes such as ssDNA and dsDNA molecules with graphene as a substrate. Graphene is an appropriate substrate due to its planarity, relatively large surfaces that are detectable via an optical microscope, and straightforward identification of the number of layers. We observe that in the absence of the screening ions deposited ssDNA will bind only to the graphene and not to the SiO(2) substrate, confirming that the binding energy is mainly due to the π-π stacking interaction. Furthermore, deposited ssDNA will map the graphene underlying structure. We also quantify the π-π stacking interaction by correlating the amount of deposited DNA with the graphene layer thickness. Our findings agree with reported electrostatic force microscopy (EFM) measurements. Finally, we inspected the suitability of using a graphene as a substrate for DNA origami-based nanostructures.
我们使用原子力显微镜（AFM）来研究聚电解质（如单链 DNA 和双链 DNA 分子）与石墨烯作为基底之间的相互作用。石墨烯是一种合适的基底，因为它的平面性、相对较大的可通过光学显微镜检测的表面，以及易于识别层数。我们观察到，在没有屏蔽离子的情况下，沉积的单链 DNA 只会与石墨烯结合，而不会与 SiO2 基底结合，这证实了结合能主要归因于π-π 堆积相互作用。此外，沉积的单链 DNA 将映射出石墨烯的底层结构。我们还通过将沉积的 DNA 量与石墨烯层厚度相关联来定量 π-π 堆积相互作用。我们的发现与已报道的静电 force microscopy（EFM）测量结果一致。最后，我们检查了使用石墨烯作为基底用于 DNA 折纸纳米结构的适用性。
