Single molecule study of DNA collision with elliptical nanoposts conveyed by hydrodynamics

TL;DR

This study investigates how single DNA molecules interact with elliptical nanoposts under hydrodynamic forces, confirming that obstacle shape has minimal impact on unhooking dynamics and suggesting potential improvements for separation device performance.

Contribution

The paper provides experimental validation that elliptical nanoposts have limited effect on DNA unhooking dynamics, supporting models of electrophoresis and informing design of separation devices.

Findings

Obstacle asymmetry has minor effect on unhooking dynamics.

Disengagement dynamics align with electrophoresis models.

Elliptical posts may marginally enhance separation device performance.

Abstract

Periodic arrays of micro- or nano-pillars constitute solid state matrices with excellent properties for DNA size separation. Nanofabrication technologies offer many solutions to tailor the geometry of obstacle arrays, yet most studies have been conducted with cylinders arranged in hexagonal lattices. In this report, we investigate the dynamics of single DNA collision with elliptical nanoposts using hydrodynamic actuation. Our data shows that the asymmetry of the obstacles has minor effect on unhooking dynamics, and thus confirms recent predictions obtained by Brownian dynamics simulations. In addition, we show that the disengagement dynamics are correctly predicted by models of electrophoresis, and propose that this consistency is associated to the confinement in slit-like channels. We finally conclude that elliptical posts are expected to marginally improve the performances of separation devices.