Graphene Nanoslit Device for Protein Sequencing: Ab Initio Quantum Transport Study

Abstract

Solid-state material-based protein sequencing techniques have emerged as a paradigm that is capable of decoding the sequence of amino acids in protein by electrical detection. We studied a graphene nanoslit device for ultrafast protein sequencing using electronic transport calculations. The first-principles consistent-exchange van der Waals density functional (vdW-DF-cx) calculations have been employed to study the structural and electronic properties of the pristine graphene nanoslit and graphene nanoslit + amino acid systems. Ten amino acid molecules, namely, alanine (Ala), arginine (Arg), aspartic acid (Asp), glutamic acid (Glu), glycine (Gly), histidine (His), lysine (Lys), phenylalanine (Phe), proline (Pro), and tyrosine (Tyr), are considered. The electronic quantum transport properties of pristine graphene nanoslit and graphene nanoslit + amino acid systems are studied using the nonequilibrium Green's function (NEGF) combined with the density functional theory (DFT) approach. Significant changes in the electronic transmission conductance are observed in the graphene nanoslit device in the presence of certain amino acids. The computed conductance sensitivity and current-voltage (I-V) characteristics indicate that selective identification of amino acids is possible through the graphene nanoslit device. This study may be a practical guide toward the development of a graphene nanoslit-based device for ultrafast protein sequencing applications. © 2022 American Chemical Society. All rights reserved.