Abstract
Fast, cost effective, single-shot DNA sequencing could be the prelude of a new era in genetics. As DNA encodes the information for the production of proteins in all known living beings on Earth, determining the nucleobase sequences is the first and necessary step in that direction. Graphene-based nanopore devices hold great promise for next-generation DNA sequencing. In this work, we develop a novel approach for sequencing DNA using bilayer graphene to read the interlayer conductance through the layers in the presence of target nucleobases. Classical molecular dynamics simulations of DNA translocation through the pore were performed to trace the nucleobase trajectories and evaluate the interaction between the nucleobases and the nanopore. This interaction stabilizes the bases in different orientations, resulting in smaller fluctuations of the nucleobases inside the pore. We assessed the performance of a bilayer graphene nanopore setup for the purpose of DNA sequencing by employing density functional theory and non-equilibrium Green’s function method to investigate the interlayer conductance of nucleobases coupling simultaneously to the top and bottom graphene layers. The obtained conductance is significantly affected by the presence of DNA in the bilayer graphene nanopore, allowing us to analyze DNA sequences.
Highlights
Sequencing DNA is the first step on the route towards so-called personalized or precision medicine[1,2] as well as fields of research where genetic information is the key
One possibility to simplify the fabrication process and simultaneously increase the transverse current is the use of a graphene nanopore to identify single nucleobases[19,30,31,32]; DNA translocating through the graphene nanopore can modulate the edge current in graphene nanoribbons (GNRs)[25,33]
The nanopore diameter could play an important role in electronic transport; the sensitivity of electrical nucleobase detection significantly decreases as the nanopore size is increased from 1.2 nm to 1.7 nm[34]. We address these issues by investigating an alternative setup, namely a pair of aligned nanopores in bilayer graphene arranged in the Bernal (AB) stacking
Summary
Sequencing DNA is the first step on the route towards so-called personalized or precision medicine[1,2] as well as fields of research where genetic information is the key. As the nucleobase from a single-stranded DNA molecule is placed in the bilayer graphene nanopore, the local interlayer conductance is modulated by the nucleotide bridging the two graphene layers, revealing the DNA sequence. Using the MD simulations, we can trace the nucleobase trajectory as the DNA is translocated through the bilayer graphene nanopore.
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