DNA Translocation through Hydrophilic Nanopore in Hexagonal Boron Nitride

Zhi Zhou,Ying Hu,Zhi Xu,Xinyan Shan,Xuedong Bai,Wenlong Wang,Xinghua Lu,Hao Wang

doi:10.1038/srep03287

Zhi Zhou, Ying Hu + Show 6 more

Open Access

https://doi.org/10.1038/srep03287

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Abstract

Ultra-thin solid-state nanopore with good wetting property is strongly desired to achieve high spatial resolution for DNA sequencing applications. Atomic thick hexagonal boron nitride (h-BN) layer provides a promising two-dimensional material for fabricating solid-state nanopores. Due to its good oxidation resistance, the hydrophilicity of h-BN nanopore device can be significantly improved by UV-Ozone treatment. The contact angle of a KCl-TE droplet on h-BN layer can be reduced from 57° to 26° after the treatment. Abundant DNA translocation events have been observed in such devices, and strong DNA-nanopore interaction has been revealed in pores smaller than 10 nm in diameter. The 1/f noise level is closely related to the area of suspended h-BN layer, and it is significantly reduced in smaller supporting window. The demonstrated performance in h-BN nanopore paves the way towards base discrimination in a single DNA molecule.

Highlights

The single- and few-layer hexagonal boron nitride (h-BN) membranes have been obtained by cleavage[18], epitaxial growth[19,20], or chemical synthesis[21], which provides a new material for nanopore applications
We show that the hydrophilicity of h-BN nanopores can be improved by UV-ozone (UVO) treatment and hundreds of DNA translocation events have been observed in single experimental runs
The size of the Si3N4 www.nature.com/scientificreports window is about 20–40 mm with a 100–1000 nm sized hole drilled by focused ion beam (FIB)

Summary

Introduction

Atomic thick hexagonal boron nitride (h-BN) layer provides a promising two-dimensional material for fabricating solid-state nanopores. To achieve base discrimination in a single DNA molecule, the effective thickness of a solid-state nanopore has to be reduced down to sub-nanometer. For such propose, atomic thick graphene layers has been employed in fabricating nanopore devices featured with high resolution and geometrical sensitivity[9,10,11,12]. Liu et al firstly reported the fabrication of solid-state nanopores based on few-layer BN membrane[22], and totally about one hundred DNA translocation events have been observed. Our finding suggests further promise to utilize h-BN nanopore as ultra-thin solid-state device for future applications

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