# Diffusion of DNA on Atomically Flat 2D Material Surfaces

## TL;DR

This study explores how DNA molecules interact and move on flat 2D surfaces, revealing how their movement can be controlled for potential use in nanofluidic devices.

## Contribution

The paper introduces a model explaining DNA diffusion on hBN surfaces based on trapping by atomic defects and demonstrates pseudo-1D confinement for biomolecule guidance.

## Key findings

- DNA molecules can diffuse along hBN surfaces while retaining their mobility.
- Diffusion magnitude and direction are influenced by DNA length, surface topography, and atomic defects.
- A model based on temporary trapping by atomic defects explains the slower diffusion observed compared to simulations.

## Abstract

Accurate localization and delivery of biomolecules are
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 comprehensively characterize 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. We observe that the diffusion speed of the biomolecules
is significantly lower than indicated by molecular dynamic simulations.
Through computational analysis, we present the model based on temporary
trapping by atomic defects that accounts for those observations. By
fabricating a narrow hBN ribbon structure, we achieve pseudo-1D confinement,
demonstrating its potential for nanofluidic guiding of biomolecules.