Theoretical study of the adsorption of histidine amino acid on graphene

20th Argentinean Bioengineering Society Congress

物理学;生物科学

Rodriguez, S.J.^1,2 ; Makinistian, L.^3 ; Albanesi, E.^1,2

IFIS-CONICET, Güemes

3450, Argentina^1

Facultad de Ingenieria, Universidad Nacional de Entre Rios, 3101 Oro Verde (ER), Santa Fe

3000, Argentina^2

Departamento de Fisica, Instituto de Fisica Aplicada (INFAP), Universidad Nacional de San Luis-CONICET, Ejército de los Andes 950, San Luis

D5700BWS, Argentina^3

关键词: Adsorption energies;    Amino group;    Density of state;    Exchange and correlation;    Functionalizations;    Generalized gradients;    Local density;    Theoretical study;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/705/1/012012/pdf
DOI  :  10.1088/1742-6596/705/1/012012

学科分类：生物科学（综合）

来源: IOP

【 摘 要 】

Previous studies have demonstrated how the interactions between biomolecules and graphene play a crucial role in the characterization and functionalization of biosensors. In this paper we present a theoretical study of the adsorption of histidine on graphene using density functional theory (DFT). In order to evaluate the relevance of including the carboxyl (-COOH) and amino (-NH2) groups in the calculations, we considered i) the histidine complete (i.e., with its carboxyl and its amino groups included), and ii) the histidine's imidazole ring alone. We calculated the density of states for the two systems before and after adsorption. Furthermore, we compared the results of three approximations of the exchange and correlation interactions: local density (LDA), the generalized gradients by Perdew, Burke and Ernzerhof (GGA-PBE), and one including van der Waals forces (DFT-D2). We found that the adsorption energy calculated by DFT-D2 is higher than the other two: Eads-DFT-D2>Eads-LDA>Eads-GGA. We report the existence of charge transfer from graphene to the molecule when the adsorption occurs; this charge transfer turns up to be greater for the complete histidine than for the imidazole ring alone. Our results revealed that including the carboxyl and amino groups generates a shift in the states of imidazole ring towards EF.