Metal–ligand complex copolymer as photocurable antimicrobial coatings for infection-resistant surface

Photografting coating is capable of introducing a potent functionality to the interface of inert materials e.g. antimicrobial, antioxidant, and antifouling. In this context, a curable ligand copolymer coating was synthesized using surfactant-free emulsion polymerization to realize an infection-resistant surface on an inert substrate. Accordingly, an l-lysine derivative was adapted to synthesize a curable ligand copolymer. The existence of butyl acrylate and 4-benzoylphenyl methacrylate in the copolymer with nitrilotriacetic acid ligand moiety imparted one-step ultraviolet-curable coating via a short process of UV irradiation (365 nm, 90 s). Subsequently, the metal ions (Zn²⁺ and Cu²⁺) were successfully coordinated on the ligand film, and the metal–ligand complex structure was fabricated on the PP film surface, which enabled the feature of infection-resistance against Escherichia coli (99.91 ± 5.4%) and Staphylococcus aureus (99.11 ± 3.1%). The chemistry and microstructural characterization of the metal–ligand complex film indicated the existence of a ligand copolymer with a breath-figure-array morphology and high wettability. Moreover, X-ray photoelectron spectroscopy detected changes in the peak intensity and peak shifts, which indicate the successful coordination of the metal ligands on the solid substrate. As this ligand copolymer can be produced via an industrial scalable method, it can be applied as an infection-resistant coating for various purposes such as packaging, cosmetics, and biomedical applications.