Electrokinetic-Noise-Assisted Barrier Crossing in a Nanofluidic Environment

Abstract

We experimentally and theoretically study the dynamics of DNA driven by artificial electrokinetic noise back and forth between neighboring nanopits inside a nanofluidic device. The dynamics are consistent with a noise-assisted barrier-crossing process, exhibiting a rapid increase in the hopping rate with noise level beyond a threshold. A simple Arrhenius model with a fixed energy barrier of several ${k}_{B}T$ describes the hopping dynamics well at low noise levels but to accurately describe the dynamics over a wider range, we develop a numerical model that additionally accounts for the lateral extent of the free-energy landscape. The experimental and numerical methods reported here significantly expand the range of noise levels and time scales over which activated DNA hopping processes can be controlled and investigated.