In this paper, a reproducible method for depositing and immobilizing b
iomolecules of interest on a supporting substrate for biological scann
ing tunneling microscopy (STM) and atomic force microscopy (AFM) studi
es is discussed. Adaptations of the thiol-gold chemistry introduced by
Nuzzo and Allara (J. Am. Chem. Soc. 1983,105, 4481) are investigated
as deposition methods for adsorbing deoxyribonucleic acid (DNA) molecu
les onto a Au(111) surface. The technique of Auger electron spectrosco
py (AES) was utilized for these investigations to determine the amount
of adsorption. These results demonstrate that thiol-gold chemistry ca
n be employed for attachment of DNA to gold and illustrate that electr
on spectroscopy can be used to verify and quantify biomolecule deposit
ion.