Noncovalent Interactions between Dopamine and Regular and Defective Graphene

• Published in: Chemphyschem Vol. 18; no. 15; pp. 2065 - 2080
• Main Authors: Fernández, Ana C. Rossi, Castellani, Norberto J.
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 05.08.2017
• Subjects: Adsorption; Chemical bonds; density functional calculations; Density functional theory; Dopamine; Dopamine - chemistry; Drug delivery systems; Graphene; Graphite - chemistry; Hydrogen bonds; monovacancies; Orbitals; Quantum Theory; Surface chemistry; Vacancies; monovacancies; density functional calculations; adsorption; dopamine; graphene
• ISSN: 1439-4235; 1439-7641; 1439-7641
• DOI: 10.1002/cphc.201700252

The role of noncovalent interactions in the adsorption of biological molecules on graphene is a subject of fundamental interest regarding the use of graphene as a material for sensing and drug delivery. The adsorption of dopamine on regular graphene and graphene with monovacancies (GV) is theoretically studied within the framework of density functional theory. Several adsorption modes are considered, and notably those in which the dopamine molecule is oriented parallel or quasi‐parallel to the surface are the more stable. The adsorption of dopamine on graphene implies an attractive interaction of a dispersive nature that competes with Pauli repulsion between the occupied π orbitals of the dopamine ring and the π orbitals of graphene. If dopamine adsorbs at the monovacancy in the A–B stacking mode, a hydrogen bond is produced between one of the dopamine hydroxy groups and one carbon atom around the vacancy. The electronic charge redistribution due to adsorption is consistent with an electronic drift from the graphene or GV surface to the dopamine molecule. Perfectly noncovalent! The adsorption of dopamine on perfect graphene involves noncovalent interactions of π–π and CH⋅⋅⋅π character, according to the adsorption mode, as well as electron drift from substrate to adsorbate. On graphene with monovacancies, a hydrogen bond is formed involving a hydroxy group of dopamine and a carbon atom of the vacancy in the AB stacking mode.