Theoretical Modelling of Dna Base Super-structures on the Gold (111) Surface

The DNA double helix, one of the most amazing and important self-assembled structures found in nature is dependendent on the interaction between the DNA base molecules: Adenine (A) and Thymine (T); and Cytosine (C) and Guanine (G). Recently there have been a number of Scanning Tunneling Microscope (STM) experiments on the gold (111) surface in which the DNA base molecules (Adenine (A), Cytosine (C), Guanine (G) and Thymine (T)) were investigated [1-3]. The STM images show very distinct super-structures of these molecules on the surface. Whereas Adenine [1] and Guanine [1,2] show amazing self-assembled periodic monolayers in the form of flowerbeds, Thymine [3] and Cytosine [1] form long filaments, which are very mobile at room temperature.