New measurements modalities for multi-parametric, label-free and non-contact detection of biofilm formation on stainless steel and glass surfaces

Monitoring of bacterial biofilm formation on liquid-solid interfaces is crucial in microbiology and infection prevention. Many common measurement techniques are not able to detect biofilms in situ and require removal of them from the surface, and their detection principles are destructive and contact-based. This research focuses on new measurement modalities such as: scanning Kelvin probe, digital holographic tomography, and infrared microscopy for monitoring biofilm formation. For the study of surface colonization on stainless-steel and glass surfaces, E. coli was used as a microbial model organism. Simultaneously, an examination of the biofilms was performed after 24, 48, and 72 h using classical methods. It will be demonstrated that, depending on the surface properties (conductivity, transparency), proposed modalities allow multi-parameter characterization of the dy-namics of biofilm formation, or even viability of bacteria cells, in a label-free, non-contact, non-destructive manner, which makes them an alternative to classical biochemical and fluorescence methods.