Interaction of size-selected Gold nanoclusters with Dopamine

摘要

We present density functional theory based results on the interaction of size-selected gold nanoclusters, Auio and AU20, with dopamine molecule. The gold clusters interact strongly with the nitrogen site of dopamine, thereby forming stable gold-dopamine complexes. Our calculations further show that there is no site specificity on the planar Au_(10) cluster with all the edge gold atoms equally preferred. On the other hand, in the pyramidal Au_(20) cluster, the vertex metal atom is the most active site. As the size increased from Au_(10) to AU_(20), the interaction strength has shown a declining trend. The effect of aqueous environment on the interaction strengths were also studied by solvation model. It is found that the presence of solvent water stabilizes the interaction between the metal cluster and dopamine molecule, even though for Au_(10) cluster the energy ordering of the isomers changed from that of the gas-phase.