Complexes of DNA Bases and Small Gold Clusters
  DNA base-gold interactions are studied theoretically at the DFT level using Au3 and Au4 clusters as simple catalytic models for Au particles. The bonding between DNA bases and gold clusters occurs via the anchoring of a Au atom to the N or O atoms of the bases. In the most stable planar base-Au3 complexes, the Au-N or Au-O anchor bonds are reinforced by N-H...Au bonds. The mechanism of formation of these nonconventional H-bonds is discussed. 
E. S. Kryachko and F. Remacle