Atomic Force Microscopy of Biopolymers on Graphite Surfaces

Themain peculiarities of the interaction of DNA and protein molecules with graphite are considered. The results of atomic force microscopy study of the adsorption of DNA and proteins on the surface of highly oriented pyrolytic graphite are analyzed. These data are compared with the results of molecular dynamics simulation and optical studies. The dehybridization of DNA and the denaturation of many proteins on the graphite surface which are predominantly associated with pi-pi-stacking interaction (for DNA and proteins) and van der Waals and hydrophobic interactions (for proteins) are discussed. It is shown that the surface of highly oriented pyrolytic graphite is strongly liable to random environmental contaminations that considerably change the properties of the surface and, therefore, influence the kinetics of adsorption of biopolymer molecules and their conformation on the surface. Considerable attention is given to analysis of the interaction of biopolymers with the surface of highly oriented pyrolytic graphite modified with monolayers of organic molecules.