Silver implantation on AISI 304 stainless steel surface using low-energy doses and the antimicrobial effect against Salmonella Enteritidis and Listeria monocytogenes

Silver has antimicrobial properties and when implemented on the stainless steel surface can inactivate microorganisms and consequently prevent biofilm formation and cross-contamination of food. Therefore, in this study we evaluated the antibacterial properties of silver ions implanted on AISI 304 stainless steel surfaces using low-energy doses against Salmonella Enteritidis and Listeria monocytogenes, two foodborne pathogens. AISI 304 stainless steel coupons were treated using energy of 2 and 4 keV for silver implantation and simulations were performed to estimate its dose distribution. Coupons containing silver ions were contaminated with S. Enteritidis and L. monocytogenes and incubated at 25 °C for 1 and 24 h. Results demonstrated that 4 keV treatment were able to reduce S. Enteritidis, but not L. monocytogenes. However, the 2 keV treatment showed significant reductions of both pathogens and the depth profiles of surfaces treated with 2 keV of energy showed 3.5×10 silver atoms/cm2 implanted in up to 5 nm from the stainless steel surface. Silver implanted on stainless steel using low-energy doses demonstrated antimicrobial properties against foodborne pathogens and this strategy can be used to reduce adhered cells and biofilm formation in food industries.