Bioinspired photocatalytic ZnO/Au nanopillar-modified surface for enhanced antibacterial and antiadhesive property

Biological contamination of surfaces is a thorny issue that brings series of adverse factors to the daily life and industrial manufacture. A dragonfly-wing-mimicking nanopillar array of ZnO/Au on Polydimethylsiloxane (PDMS-ZnO/Au) with two-fold bactericidal activity as well as the antiadhesive property has been developed. In this process, ZnO nanopillar is obtained using a hydrothermal method followed by the introduction of plasmonic gold nanoparticles (AuNPs) via a photo-reduction protocol. The obtained PDMS-ZnO/Au surface demonstrates physical antibacterial performance, resulting in a killing rate of 65.5% in dark. Furthermore, the surface effectively inactivates bacteria under visible light irradiation, yielding a lethality > 99.9% in 30 min. The advantages of high lethality rate and short action time are endowed to PDMS-ZnO/Au by a two-fold antibacterial action combining the enhanced photocatalysis upon the introduction of Au nanoparticles and the mechanical property of biomimetic nanostructure. Meanwhile, the nanopillar-modified PDMS can also function as a superhydrophobic surface and efficiently impede bacterial adhesion by over 99.9%. Therefore, the approach presented here holds a promising solution to tackle biological contamination for medical paint, catheter and implant equipment.