Antibacterial Activity of Copper Coating Electrodeposited on 304 Stainless Steel Substrate

The utilization of copper as antimicrobial touch surfaces offers a solution that can serve as an additional line of defense against hospital acquired infections. In order to make use of the antimicrobial ability of copper, touch surfaces should compose of copper either solid copper or copper coating. In general, cost considerations favor copper coating over solid copper. In this study, copper coating was deposited on 304 stainless steel substrate using chronoamperometry technique performed in a typical three-electrode cell. Electrodeposition process was obtained in pH 8 EDTA solution containing 0.01 M Cu2+ ions at -1.1 V vs Ag/AgCl for 15 min. A uniform, compact and dense nano-sized (38-66 nm) coating was deposited on 304 stainless steel surface, as observed by FESEM. EDX analysis showed a high percentage of copper (97.95 wt.%) with uniform distribution on the entire surface of 304 stainless steel. Surface topography and roughness of the sample were investigated by AFM. Numerous 3D copper clusters can be recognized on 304 stainless steel surface with the average roughness of 24.23 nm. The antibacterial result indicated that the copper coating has excellent antibacterial activity against E. coli (100 % reduction within 5 min of exposure) and S. aureus (100 % reduction within 10 min of exposure) compared to 304 stainless steel (no reduction even after 30 min of exposure).