Scanning tunneling microscopy at high gap resistances and on chemically modified silicon surfaces

Abstract
Scanning tunneling microscopy (STM) studies of organic or biological molecules are difficult to reproduce because strong tip-surface interactions can displace weakly bound material at the surface. We have studied conducting organic monolayers and nucleic acids with out STM instrument at high gap resistance values (100 G-OMEGA to 1 T-OMEGA). We have succeeded in imaging chemically modified silicon surfaces. It is our desire to use these chemically modified surfaces in conjunction with higher gap values in the future to reliably image DNA.