A biofilm sealant is provided imparting a residual biocidal property. The biofilm sealant is used to treat a surface to impart a film having a capacity to quickly kill bacteria and other germs for at least 24 hours after deposit of the film on a treated surface. The disinfectant formulation biofilm sealant comprises a polymer binder, wherein the polymer binder is an oxazoline homopolymer or an extended or a modified polymer based on an oxazoline homopolymer, and a biocidal compound.
