Application of atomic force microscopy in microscopic analysis of polysaccharide

Polysaccharides are one of the major group of bioactive macromolecular derived from plants, bacteria, fungi and seaweeds. Atomic force microscopy (AFM), a type of scanning probe microscopy, is a powerful technology to visualize biopolymers, such as polysaccharides and proteins, up to a single molecular level in “near-native” conditions. This review gives a brief description of AFM technology involved in polysaccharide research in addition to discussion of factors that might influence polysaccharide imaging. More importantly, its contribution to research progress of a variety of well characterized polysaccharides, including pectin, xanthan, carrageenan, curdlan, scleroglucan, xyloglucan, arabinoxylan, starch, etc., and the detailed nanostructure information was summarized. AFM provides a unique insight into polysaccharide studies in terms of morphological features and molecular characteristics, such as heights (diameters), width, contour length, end-to-end distance, polydispersity, etc. Besides, other promising aspects included probing molecular motion and assemblies, as well as visualizing conformation behavior under different conditions.