Imaging and Characterization of Self-Assembled Soft Nanostructures by Atomic Force Microscopy

Abstract

The atomic force microscope (AFM) obtains its topographical information from the short-ranged repulsion resulting from the overlap of electronic shells between tip and hard samples. However, scanning soft samples such as surfactants or biological material within liquid media leads to a very different scenario due to the long-ranged double layer interactions and the specific tip penetration through the scanned layers. We show that AFM images and force vs. distance curves can be used to obtain relevant information on formation, characteristics and behavior of soft self-assembled nanostructures of surfactants, phospholipids and of cells under physiological conditions.