BIOMOLECULES AND SURFACES

The majority of the processes that occur in living systems take place at surfaces or interfaces. Biomolecules at surfaces exhibit crystallization, reconstruction, contraction, diffusion in the surface plane, sorption, epitaxy, phase transitions, catalysis, catalytic fouling, electron tunneling, work function shifts, oxidation, and contamination. However, these terms from the jargon of surface science are rarely used to describe the phenomena occurring in living systems. In this review, the terminology and phenomenology that biologists deal with will be placed in the context of contemporary surface science. Methods to maintain the structural integrity of biomolecules under ultrahigh vacuum (UHV) conditions (analogous to efforts by catalysis researchers to relate their UHV studies to high-pressure processes in liquids) will be discussed. Data will be presented on biomolecules at organic and inorganic interfaces obtained by x-ray photoelectron spectroscopy, static secondary ion mass spectrometry, attenuated total reflectance infrared spectroscopy, and scanning tunneling microscopy. The nature and kinetics of protein reorganization at interfaces will be emphasized. Methods to study these geometric reorganizations include classical biochemical elution, angular dependent XPS, and infrared absorption spectroscopy. © 1990, American Vacuum Society. All rights reserved.