Single xanthan molecule preparation and atomic force microscopy observation

A newly developed sample preparation technique termed multi-step spin-coating method was used to prepare well-dispersed xanthan molecules on bare mica, 3-aminopropyl triethoxysilane treated mica, nickel ion treated mica and highly oriented pyrolytic graphite, which are widely used as supporting surfaces in the atomic force microscopy (AFM) study. The substrate effects on conformation of single xanthan molecules were also investigated. We believe that this study is of great importance for the in-depth studies on xanthan molecules at the single-molecular level.