Mussel-inspired superhydrophobic surfaces with enhanced corrosion resistance and dual-action antibacterial properties

- A multilayer antibacterial film was fabricated based on PDA and Ag nanoparticles.
- The PDA nanoparticles provided necessary hierarchical micro/nanostructures.
- The air film in the superhydrophobic surface resisted the bacterial adhesion.
- The rapid release of Ag ions was controlled by superhydrophobic surface.
- The synergistic antibacterial actions and mechanisms were explored.

In this study, a multilayer antibacterial film was assembled onto 316L stainless steel via mussel-inspired depositions of polydopamine (PDA) and silver (Ag) nanoparticles followed by post-modification with 1H, 1H, 2H, 2H-perfluorodecanethiol. The resulting surface exhibited excellent superhydrophobicity with hierarchical micro/nanostructures that were constructed by both PDA and Ag nanoparticles. The crystal structure and chemical composition of these surfaces were investigated using X-ray photoelectron spectroscopy (XPS) analysis. Potentiodynamic polarization measurements revealed that the corrosion resistance of the as-prepared surfaces were sequentially increased after each step of the fabrication process. Compared with the surface covered with only Ag nanoparticles, the superhydrophobic surfaces exhibited substantially enhanced antibacterial activity against the Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus, resulting from the synergistic antibacterial actions of the superhydrophobic surface and Ag nanoparticles. The superhydrophobic surface exhibited lower cytotoxicity, compared to the surface covered with Ag nanoparticles.