Physical adsorption of immunoglobulin G on gold studied by scanning tunnelling microscopy.

This paper describes a preliminary scanning tunnelling microscope (STM) study of the physical adsorption of a mouse monoclonal anti-hCG (human chorionic gonadotrophin) immunoglobulin G (IgG) on vacuum-evaporated gold surfaces in air. Ellipsoid-like protrusions of various geometric sizes assembled in different surface patterns were observed on scanning adsorbed IgG molecules. It is believed that both the adsorption process per se and the tip-molecule interactions are key factors which determine the topographical features of adsorbed IgG molecules.