High-resolution imaging of organic monolayers using noncontact AFM

Noncontact atomic force microscopy AFM.provides useful technique for imaging organic molecules in high resolution. Here we present our recent advances in the noncontact AFM imaging of organic materials. I. Molecular packing structures, defects and domain boundaries were clearly observed on adenine and thymine films. The noncontact AFM images revealed detailed features of the individual nucleic acid base molecules, thus allowing us to distinguish between adenine and thymine. II. Both 63=63.R308 structures and c 4=2. superlattice structures were resolved on alkanethiolate self-assembled monolayer SAM.wCH3 CH2.8SHx nonanethiol.on Au 111.. We found that the c 4=2. superlattice structures changed into 63=63.R308 structures when the tip–surface distance decreased. q2000 Elsevier Science B.V. All rights reserved.