A monolayer of nucleic acid base adenine adsorbed on a graphite surface has been studied by noncontact-atomic-force-microscopy (AFM). The noncontact-AFM images showed molecular lattice that adenine molecules pack into a rectangular lattice. The detailed features in the adenine molecule were resolved with higher resolution imaging. Furthermore, the adenine molecules with different registry to the graphite lattice appeared differently even on the noncontact-AFM image.

• Received 29 March 1999

DOI:https://doi.org/10.1103/PhysRevB.60.8309