Translocation of DNA Through 2D Nanoslits

We report recent and ongoing work on DNA translocation through 2D nanoslit [1]. 2D nanoslit devices [2], where two crystals with atomically flat surfaces are separated by only a few nanometers, have attracted considerable attention because of their tunable control over the confinement and the discovery of unusual transport behavior of gas, water, and ions. The nanoslits fabricated from exfoliated 2D materials, such as graphene or hexagonal boron nitride, allow for the study of the passage of ds-DNA to be examined in this tight confinement, mimicking the environments found in biological systems. Two types of events are observed in the ionic current: long current blockades that signal DNA translocation and short spikes where DNA enters the slits but withdraws. DNA translocation events exhibit three distinct phases in their current-blockade traces—loading, translation, and exit. Coarse-grained molecular dynamics simulation allows the different polymer configurations of these phases to be identified. DNA molecules, including folds and knots in their polymer structure, are observed to slide through the slits with near-uniform velocity without noticeable frictional interactions of DNA with the confining graphene surfaces. We propose future work through integrated optical and ionic sensing techniques for the study of DNA and other biopolymers. We anticipate that this new class of 2D-nanoslit devices will provide unique ways to study polymer physics and enable lab-on-a-chip biotechnology.<br/>[1] Yang, Wayne, et al. "Translocation of DNA through Ultrathin Nanoslits." <i>Advanced Materials</i> 33.11 (2021): 2007682.<br/>[2] Radha, B. <i>et al.</i> Molecular transport through capillaries made with atomic-scale precision. <i>Nature</i> <b>538</b>, 222–225 (2016).