Antibacterial surface based on hierarchical polyurethane acrylate/zinc oxide structures

In this study, we fabricated hierarchical structures on the surface of polyurethane acrylate (PUA) film and demonstrated that the film displays antibacterial properties. PUA resin was coated on a commercial porous anodized aluminum oxide (AAO) template and was UV-cured using nanoimprint lithography. This led to the formation of 150 nm diameter pillars on the surface of PUA film. Following this, zinc oxide structures were grown on the surface of this imprinted PUA sample using a hydrothermal method. The scanning electron microcopy and Fourier transform infrared spectroscopy results confirmed the presence of ZnO on the surface of the PUA film. The antibacterial behavior of the fabricated sample was demonstrated against Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa) as model bacteria. The results show that PUA film with 150 nm diameter pillars had moderate antibacterial properties against both S. aureus and P. aeruginosa. The presence of zinc oxide (ZnO) structures improved the film's antibacterial property to ∼100% against P. aeruginosa. However, the presence of ZnO structures on PUA film is shown to have no effect against S. aureus. This can be attributed to the shape and size of the fabricated ZnO structures.