کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5346924 | 1503551 | 2017 | 6 صفحه PDF | دانلود رایگان |
- Electronic transport of graphene is altered by amino acids adsorption.
- Adsorption of different amino acids leads to different I-V curves.
- Graphene is a weak electron donor when amino acids are adsorbed.
- Vertical and horizontal dipoles on graphene surface are generated after adsorption.
- The modeled device is highly selective for a bias voltage of â2Â V.
The study of biosensors based on graphene has increased in the last years, the combination of excellent electrical properties and low noise makes graphene a material for next generation electronic devices. This work discusses the application of a graphene-based biosensor for the detection of amino acids histidine (His), alanine (Ala), aspartic acid (Asp), and tyrosine (Tyr). First, we present the results of modeling from first principles the adsorption of the four amino acids on a graphene sheet, we calculate adsorption energy, substrate-adsorbate distance, equilibrium geometrical configurations (upon relaxation) and densities of states (DOS) for each biomolecule adsorbed. Furthermore, in order to evaluate the effects of amino acid adsorption on the electronic transport of graphene, we modeled a device using first-principles calculations with a combination of Density Functional Theory (DFT) and Nonequilibrium Greens Functions (NEGF). We provide with a detailed discussion in terms of transmission, current-voltage curves, and charge transfer. We found evidence of differences in the electronic transport through the graphene sheet due to amino acid adsorption, reinforcing the possibility of graphene-based sensors for amino acid sequencing of proteins.
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Journal: Applied Surface Science - Volume 419, 15 October 2017, Pages 540-545