Directional affinity of a spherical Gold nanoparticle for the adsorption of DNA bases

Publication date: 1 January 2019Source: Colloids and Surfaces B: Biointerfaces, Volume 173Author(s): Hossein Farrokhpour, Soraya Abedi, Hamidreza JouypazadehAbstractIn this work, the adsorption activities of different facets of a spherical gold nanoparticle (Au(111), Au(100) and Au(110)) for adenine (ADE) and cytosine (CYT) in two different environments including gas phase and in the presence of solvent (water) have been investigated, separately. It has been found that the adsorption energy (Ead) and geometry of the DNA bases depend strongly on the kind of nanoparticle facet. The Au (110) facet showed the highest adsorption affinity for the ADE and CYT in both gas phase and water compared to Au(111) and Au(100) facets. Comparison of the Eads of bases calculated in the gas phase with those obtained in the presence of water showed that the electrostatic field of solvent decreases the Eads of bases, especially, for the Au (110) facet. The adsorption geometry of the CYT showed strong dependency on the kind of nanoparticle facet compared to ADE. Also, it has been shown that the direction and amount of charge transfer (CT) between the molecule and nanoparticle strongly depends on the kind of nanoparticle facet and environment. The CT is from the Au (111) facet to the ADE while the CT direction is reversed when the ADE is adsorbed on the Au (110) and Au (100) facets in the gas phase. The CT is from the CYT to three facets in the gas phase while its direction for the ADE and CYT adso...
Source: Colloids and Surfaces B: Biointerfaces - Category: Biochemistry Source Type: research