Biointerphases

Journal for Biophysical Chemistry

Biointerphases Cover Image
Open Access

Probing surfaces with single-polymer atomic force microscope experiments

Biointerphases1:10100063

https://doi.org/10.1116/1.2171996

Received: 18 November 2005

Accepted: 20 December 2005

Abstract

In the past 15 years atomic force microscope (AFM) based force spectroscopy has become a versatile tool to study inter- and intramolecular interactions of single polymer molecules. Irreversible coupling of polymer molecules between the tip of an AFM cantilever and the substrate allows one to study the stretching response up to the high force regime of several nN. For polymers that glide or slip laterally over the surface with negligible friction, on the other hand, the measured force profiles exhibit plateaus which allow one to extract the polymer adsorption energies. Long-term stable polymer coatings of the AFM tips allow for the possibility of repeating desorption experiments from solid supports with individual molecules many times, yielding good sampling statistics and thus reliable estimates for adsorption energies. In combination with recent advances in theoretical modeling, a detailed picture of the conformational statistics, backbone elasticity, and the adsorption characteristics of single polymer molecules is obtained.