Atomic force microscopy : applications to nanobiotechnology

Atomic Force Microscopy (AFM) is a microscopic technique belonging to the Scanning Probe Microscopy (SPM) family. Other SPM techniques are Near-Field Scanning Optical Microscopy (NSOM), Electrostatic Force Microscopy (EFM) and Magnetic Force Microscopy (MFM). AFM is a useful and powerful tool for studying the morphological, dynamic, and mechanical properties of biological samples, such as, living cells, biomacromolecules, and tissues under different conditions, e.g., air, liquid, and vacuum. In this article an overview of the AFM technique is first presented and then some of its applications to nanobiotechnology are discussed. Attention is focused on the morphological and physiological studies of microbial cells and biomolecules. Some of the most important results on intermolecular interactions obtained in the past ten years, and force spectroscopy measurements of the viscoelastic properties (microrheology) of soft samples, such as, living cells, are also discussed.