Several years ago I did some characterisation work on dragon-fly wings. The wings had nano-spikes that made them anti-microbial.
If you coat your material in a thin layer (1-3 nm) of heavy metal (e.g. gold coating) you might be able to see the morphology of your biofilm using a scanning electron microscope. In fact, not so long ago I saw a study like this using the SEM where they found a cell being pierced by the film surface.
@ P.Guru Lakshmi , hey, thanks, I was looking for a method to estimating the removal fungi biofilms through nanoparticles, The effects of different concentration of AgNPs on C. Albicans biofilm were assessed by Congo Red Agar method already by a researcher..also, Visualization of fungal biofilms by SEM, and 96 well plate with broth culture and optical density measuring...The morphological and ultrastructural alteration in C. Albicans cells after treatment with AgNPs were examined by TEM. @
@ Robert D Aughterson , thanks for your answer. I want to estimate the antibiofilm effects of nanoparticles against foodborne pathogens, a simple efficient method.. ...