Enhancing antibacterial and anticorrosion properties of 304 stainless steel surfaces: a multi-modification approach based on DA/PEI/SiO2/AMPs

Marine fouling can cause a series of hazards in the marine industrial field, and the traditional antifouling methods do not fulfill the green antifouling requirement. Herein, a novel DA/PEI/SiO₂/antibacterial peptide antifouling coating was prepared by a multi-modification approach. Initially, the nanocoatings were prepared by depositing DA, PEI, and SiO₂ on the dopamine (DA)-modified 304 stainless steel (SS) surface, and finally, the DA/PEI/SiO₂/AMPs composite coatings were prepared by grafting antimicrobial peptides (AMPs). The surfaces of SS before and after modification were characterized by Fourier transform infrared spectrometer (FTIR), X-ray photoelectron spectrometer (XPS), field emission scanning electron microscopy (SEM), contact angle measurement, and 3D optical profilometer. SSN-1 cells were used to evaluate the cytocompatibility of the modified surface. The results revealed that the cells cultured on the modified surface still maintained a good adhesion morphology, demonstrating the superior cytocompatibility of the composite coating. The anti-biofilm and antimicrobial properties of the modified samples were evaluated using Vibrio natriegens. The antibacterial efficiency of SS-DA/PEI/SiO₂ surfaces before and after AMPs modification reached 78.39 and 95.90%, and anti-biofilm efficiency of AMPs modified surface achieved 72.87% corresponding to 44.19% of SS-DA/PEI/SiO₂. The successful grafting of AMPs improved the antibacterial and anti-biofilm properties of the modified sample surfaces. Electrochemical and stability tests indicated that the modified sample surfaces exhibited excellent corrosion resistance and antifouling stability properties. This research could provide a novel green anti-fouling and anti-corrosion strategy for the marine industry and other related fields.