Dopamine-mediated Immobilization of Antimicrobial Peptides on Stainless Steel for Marine Antifouling Applications.

Biofouling due to marine microorganism adhesion poses significant challenges for marine vessels, necessitating innovative antifouling solutions. This study aimed to investigate the antifouling performance of an antimicrobial peptides (AMPs) immobilized on dopamine-modified stainless steel (SS) surfaces, as a novel approach for antifouling applications. Herein, dopamine was utilized to form a modification layer on SS, subsequently immersed in AMPs solution to create SS-DA-A samples. The surface characteristics were characterized through X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), contact angle measurement instrument, fourier transform infrared spectroscopy (FTIR), and confocal laser scanning microscopy (CLSM). Antimicrobial properties were assessed using plate counting, measuring bacterial adhesion, and optical density value, while algal resistance was determined through SEM and CLSM methods, specifically assessing the coverage by algae. The results demonstrated the successful modification of the SS surface, characterized by FTIR peaks corresponding to AMPs, and a significant reduction in contact angle with the introduction of dopamine. Notably, the SS-DA-A surface exhibited enhanced antimicrobial efficacy against Vibrio natriegens (V. natriegens), Staphylococcus aureus (S. aureus), and Escherichia coli (E. coli), with a marked reduction in biofilm formation, and C. pyrenoidosa and P. tricornutum coverage decreased by approximately 96.46 % and 91.61 %, respectively. Molecular dynamics simulation results reveal that antimicrobial peptides interact with the bacterial phospholipid bilayer, disrupting bacterial integrity and thus achieving surface antimicrobial activity. This study effectively demonstrates that dopamine facilitates the successful immobilization of AMPs on SS surfaces, leading to significantly improved antibacterial, anti-algal, and biofilm resistance properties, and offers a promising new strategy for antifouling technology in marine settings.