Stainless steel surface functionalized with silver by cathodic sputtering

This study aimed to functionalize the stainless steel surface with silver and to evaluate its antimicrobial capacity. For this purpose, stainless steel coupons coated or not with silver films were exposed to the presence of Escherichia coli and Staphylococcus aureus. The results of bacterial adhesion on the silver functionalized coupons showed lower counts of adhered S. aureus cells when compared to E. coli. The atomic force microscopy allowed to measure the thickness of the silver film deposited (31 nm). Although all surfaces were considered hydrophobic, the silver-functionalized stainless steel coupons presented an increase in surface hydrophobicity. Changes in the surface of the stainless steel coupons were observed by cyclic voltammetry after the silver sputtering procedure, thus evidencing the silver deposition on the surface of the stainless steel coupons. Therefore, the cathodic sputtering has proven to be effective to reduce the microbial load adhered. Practical Applications Cathodic sputtering proved to be efficient to functionalize stainless steel with silver surface. The modification of the surface of the stainless steel coupon with sputtering of the silver proved to deposition of the silver on the surface by cathodic deposition. Silver ions reduced bacterial load, both gram-positive and gram-negative, on the surfaces analyzed. Therefore, the food industry can prevent the risk of microbial adhesion and the biofilm formation using surface functionalized with a silver-based antimicrobial agent and thus reduces the use of chemical sanitizers in the second stage of the hygiene process. This process is interesting because it dont cause deleterious effects on human health and the environment.