FUNCTIONAL-GROUP IMAGING BY ADHESION AFM APPLIED TO LIPID MONOLAYERS

Recently developed adhesion atomic force microscopy was used as a tech nique to map the spatial arrangement of chemical functional groups at a surface with a lateral resolution of 20 nm. The ratio of the adhesio n forces for different functional groups can be compared with values d etermined from the known surface energies. This concept was demonstrat ed by mapping the adhesive interaction of domains in a phase-separated lipid monolayer with the AFM tip. The ratio of the adhesion forces fo r both phases corresponds with the theoretical number for the CH2 and CH3 groups.