Covalent bonding of AgNPs to 304 stainless steel by reduction in situ for antifouling applications

Silver nanoparticles (AgNPs) have been known to have a broad spectrum of antifouling activity. In this study, AgNPs were generated in situ on the surface of dopamine modified 304 stainless steel (DA-SS AgNPs) in weak alkaline aqueous solution. Field emission scanning electron microscopy, atomic force microscope and X-ray photoelectron spectroscopy were utilized to analyze the surface morphology and chemical composition of modified stainless steel and the results demonstrated that stainless steel surface were successfully coated with AgNPs. Antimicrobial assays showed that these modified surfaces possessed resistance against Escherichia coli and Staphylococcus aureus, to an effectiveness of 99.9 and 99.5%, respectively. The presence of silver offered the coatings excellent capability for effectively inhibiting the adhesion of marine algae Chlorella pyrenoidosa, Phaeodactylum tricornutum, and Naviculaceae spp, with the amount of the three algae decreased 98.5, 98.2 and 98.7%, respectively. This strategy demonstrated a realistic paradigm for the further improving the performance of antifouling materials.