One-step modification method of a superhydrophobic surface for excellent antibacterial capability

In this study, micro/nanostructures are fabricated on the surface of 3Cr13 stainless steel via laser etching, and a superhydrophobic coating with silver nanoparticles (AgNPs) is prepared by utilizing the reduction–adsorption properties of polydopamine (PDA). We investigate the effect of soaking time from the "one-step method" on the reduction of nano-Ag, surface wettability, and antibacterial properties. Scanning electron microscopy is performed to analyze the distribution of nano-Ag on the surface, whereas X-ray energy dispersive spectroscopy and X-ray photoelectron spectroscopy are used to analyze the crystal structures and chemical compositions of different surfaces. Samples deposited with PDA on their surface are soaked in a 1H,1H,2H,2H-perfluorodecyltriethoxysilane water–alcohol solution containing AgNO₃ for 3 h. Subsequently, a "one-step method" is used to prepare low-adhesion superhydrophobic surfaces containing AgNPs. As immersion progresses, more AgNPs are deposited onto the surface. Compared with the polished surface, the samples prepared via the "one-step method" show significant antibacterial properties against both gram-negative Escherichia coli and gram-positive Staphylococcus aureus. The antibacterial properties of the surface improve as immersion progresses.