Antibacterial surfaces obtained through dopamine and fluorination functionalizations

Self-polymerized dopamine was used to form a thin layer onto stainless steel (SS) and poly(ethylene terephthalate) (PET) sheets followed by covalent grafting of pentadecafluorooctanoyl chloride by esterification and amidation reactions. The surface functionalization was characterized at each step by contact angle measurements, X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The anti-adhesive properties of native surfaces, polydopamine-coated surfaces and hydrophobic fluorinated surfaces were tested against Gram-negative (Pseudomonas aeruginosa) and Gram-positive bacteria (Listeria monocytogenes and Staphylococcus aureus). The results reveal an inhibition of bacteria growth towards Gram-negative bacteria on fluorinated surfaces. This work proposes a novel method to easily fluorinate in two steps both metallic and organic surfaces using “universal” polydopamine coating as a key step.