Electrochemical modification of high contact stainless steel 304 surfaces for antimicrobial applications

Abstract

High-contact or high-touch surfaces are usually associated with higher risk of microbial contamination and subsequent infection, especially during global pandemics. Previous studies have shown that changing the surface roughness or topography at the micro or even nano-scale to enrich antimicrobial properties on the high-contact surfaces has been widely considered. In this work, we have used electrochemical techniques to modify the surface of metals that are commonly used in high contact situations such as stainless steel 304 (SS304). The aim of this study was to systematically elucidate the optimal electrochemical parameters such as anodizing current density and electrolyte composition needed for different types of metals. Surface morphology and topography profiles were observed by scanning electron microscopy and atomic force microscopy. Fabricated surface nanostructures were studied to evaluate the effect it has on the antimicrobial properties. The colony forming units with Escherichia coli were investigated. The results indicated that SS304 anodized at 3.5 V for 20 mins resulted in the fabrication of nanostructures up to 556 nm in size and was the optimized candidate due to its highest surface roughness (Ra) of 262.28 nm and 52.6% reduction of bacterial adhesion after 24 h incubation.