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Electronic transport in a graphene single layer: an application in amino acid sensing


We modeled a type field-effect transistor device based on graphene for the amino acids recognition with a potential application in a protein sequencer building. The theoretical model used is a combination of density functional theory (DFT) with non-equilibrium Green's function (NEGF) in order to describe the coherent transport in the molecular devices. First, we studied the physisorption of each amino acid on graphene sheet and we reported adsorption energy, adsorption distances, equilibrium configuration and charge transfer —of ten amino acids that can be considered as representative of all amino acids: Histidine (His), Alanine (Ala), Aspartic acid (Asp), Tyrosine (Tyr), Arginine (Arg), Glutamic acid (Glu), Glycine (Gly), phenylalanine (Phe), Proline (Pro) and Lysine (Lys)—. As a result, significant differences were found in the density of states (DOS) after adsorption and a change in the semi-metallic character of graphene by Lysine and Arginine interaction. Furthermore, we noticed changes in the electrical characteristics of devices, as amino acid adsorbs onto the surface of the graphene. The curves current vs bias voltage (I-Vb) display a distinct response for each amino acid, i.e., the I-Vb curves result a characteristic footprint to each amino acid. We identified a possible rectification mechanism related to the voltage profile asymmetry, where the amino acids can control the transport characteristics in the device, i.e., Lys and Phe amino acids physisorbed on graphene act as a molecular diode, where electrons can easily flow in one direction and decrease in the other. This may be promising for the prospect of biosensors: graphene as a amino acid detector.

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Publication details

The article was received on 09 Aug 2018, accepted on 27 Nov 2018 and first published on 03 Dec 2018

Article type: Paper
DOI: 10.1039/C8CP05093G
Citation: Phys. Chem. Chem. Phys., 2018, Accepted Manuscript
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    Electronic transport in a graphene single layer: an application in amino acid sensing

    S. Rodríguez and E. A. Albanesi, Phys. Chem. Chem. Phys., 2018, Accepted Manuscript , DOI: 10.1039/C8CP05093G

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