Microfluidic assay to quantify the adhesion of marine bacteria.

For both, environmental and medical applications, the quantification of bacterial adhesion is of major importance to understand and support the development of new materials. For marine applications, the demand is driven by the quest for improved fouling-release coatings. To determine the attachment strength of bacteria to coatings, a microfluidic adhesion assay has been developed which allows probing at which critical wall shear stress bacteria are removed from the surface. Besides the experimental setup and the optimization of the assay, we measured adhesion of the marine bacterium Cobetia marina on a series of differently terminated self-assembled monolayers. The results showed that the adhesion strength of C. marina changes with surface chemistry. The difference in critical shear stress needed to remove bacteria can vary by more than one order of magnitude if a hydrophobic material is compared to an inert chemistry such as polyethylene glycol.