Biofilms By E.coli & S.Epidermidis and Its Sensing Possibility By Graphene-Dispersed Silane Coating

We already found that graphene is very sensitive to biofilm formation by bacterial activities. The problem is how to constitute proper sensing systems to detect biofilms in various cases. In this study, we focussed on the silane compound coating in which nano graphene powder would be dispersed in its free volume. The concentration of graphene powders in silane compound coating was changed from 0.1 wt % to 30 wt% and the graphene dispersed silane compounds were coated on glass and pure copper substrates. And biofilms were formed on those specimens in the well plates filled with liquid cultures containing Staphylococcus epidermis (S.epidermidis) as gram-positive bacteria and Escherichia coli (E.coli) as gram-negative ones. And the formation process was checked by the specimens' potential change in liquid cultures, color changes by staining with Crystal violet and some electrical measurement (capacitance etc.). Finally, we compared all of them each other and discussed about the advantage and disadvantage among the methods for the application as sensing method.