Interaction of DNA Bases with Gold Substrates

The interaction of molecules with inorganic substrates is a crucial issue forapplications in molecular electronics. It influences important factors suchas the immobilization efficiency and charge injection through inter-face. Moreover, mechanical aspects connected to unfolding biologicalmolecules are important.We hereby present recent efforts our group tackle these problems,based on density functional theory calculations. In particular, we discussour results adsorption cytosine Au(111) interactionof guanine, its natural size-expanded forms, small Au clusters.We find that binds surface mechanism thatinvolves sharing, intermediate between chemisorption physisorp-tion. investigation complexes guanine gold clustersreveals formation hydrogen bonds: configurations unusualbonds relevant at corners nanoparticles, while they can probably beneglected when DNA flat extended metal surfaces.