Diffusion of DNA on Atomically Flat 2D Material Surfaces

Accurate localization and delivery of biomolecules is pivotal for building tools to understand biology. The interactions of biomolecules with atomically flat 2D surfaces offer a means to realize both the localization and delivery, yet experimental utilization of such interactions has remained elusive. By combining single-molecule detection methods with computational approaches, we have comprehensively characterized the interactions of individual DNA molecules with hexagonal boron nitride (hBN) surfaces. Our experiments directly show that, upon binding to a hBN surface, a DNA molecule retains its ability to diffuse along the surface. Further, we show that the magnitude and direction of such diffusion can be controlled by the DNA length, the surface topography, and atomic defects. By fabricating a narrow hBN ribbon structure, we achieved pseudo-1D confinement, demonstrating its potential for nanofluidic guiding of biomolecules. Our work sets the stage for engineering 2D materials for high-throughput manipulation of single biomolecules and their applications in nanobiotechnology.