SCANNING-TUNNELING-MICROSCOPY MODIFICATION OF PURPLE MEMBRANES

Imaging, manipulation, and modification at atomic and nanometer scales of some semiconductor and metallic surfaces are features of scanning tunneling microscopy. These properties have stimulated a variety of methods for generation of nanometer-scale structures. The poor electronic conductivity of biological molecules has prevented the extension of these methods to them. Here, it is described how a low current scanning tunneling microscope operating in the near field emission regime can perform reproducible imaging with a lateral resolution of about 20 nm and selective modification of biological membranes. Marks are generated by removing the proteins and lipids from a selected region of the membrane. The removal takes place by establishing tip-membrane mechanical contact. Structures with 40 nm lateral dimensions have been generated. © 1995, American Vacuum Society. All rights reserved.