Differential Response of Doped/Defective Graphene and Dopamine to Electric Fields: A Density Functional Theory Study
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- 作者：J. Ortiz-Medina ; F. L贸pez-Ur铆as ; H. Terrones ; F. J. Rodr铆guez-Mac铆as ; M. Endo ; M. Terrones
- 刊名：Journal of Physical Chemistry C
- 出版年：2015
- 出版时间：June 18, 2015
- 年：2015
- 卷：119
- 期：24
- 页码：13972-13978
- 全文大小：450K
- ISSN：1932-7455
文摘
First-principles density functional theory calculations are performed on dopamine鈥揼raphene systems in the presence of an external electric field. The graphene lattice is also modified via substitutional boron- and nitrogen-doping, and via the introduction of defects (monovacancy and Thrower鈥揝tone鈥揥ales). The geometry optimization, electronic density of states, cohesive energy, electronic charge density, and wave functions are analyzed. Our results revealed that dopamine is anchored on the surface of graphene via a physisorption mechanism, and the cohesive strength varies as B-doped > N-doped > vacancy defect > Thrower鈥揝tone鈥揥ales defect. Boron-doped graphene exhibits valence states with dopamine molecules; furthermore, this system showed the strongest cohesive energy. When an electric field is applied, we observe shifts in the valence states near the Fermi level producing a decrease in the molecule鈥搇ayer interaction. We envisage that the present results could help in developing novel biosensors based on doped/defective graphene field-effect transistor devices.