The application of gold surfaces and particles in nanotechnology

Gold is widely used in nanotechnology, for example as a substrate in forming self-assembled monolayers or as nanoparticles for their unique optical and chemical properties. In this paper we give an overview of the properties of gold relevant to its potential application in molecular-scale devices and present some of our recent computational predictions. Density functional calculations of molecular adsorption onto gold surfaces were used to investigate the effect of surface symmetry and identify new linking schemes for self-assembled monolayers. Adsorption energies of methylthiolate (SCH3) onto the (111), (100) and (110) surfaces of gold are predicted to be 39.3, 48.4 and 51.1 kcal/mol respectively and demonstrate that selective functionalization of the surfaces is possible. Phosphine molecules with at least two hydrogen atoms substituted for methyl groups are predicted to form Au-P surface bonds with energies of about 13-20 kcal/mol.