Spatial distribution of serum solutes on dry latex sub-monolayers determined by SEPM, SNOM and SC microscopy

Scanning probe microscopies are widely used for colloidal particle investigation, although non-particulate solutes are not usually detected by microscopy. With the continuing development of microscopy techniques, there are now powerful optical and scanning probe imaging modes in which the image contrast depends on the chemical composition and ion distribution rather than on the size or topography of the sample constituents. To verify the applicability of the scanning probe electric potential microscopy (SEPM), scanning near-field optical microscopy (SNOM) and scanning confocal microscopy (SCM) techniques to determine the spatial distribution of latex serum solute constituents on particle sub-monolayers, a poly(styrene-co-acrylamide) (PS-AAM) latex was examined using these microscopy techniques. The images show the deposition of solutes on the particle cluster borders, in a thin layer surrounding the particle clusters and in scattered patches well away from the particle clusters.