Degradation response and bioactivity assessment of antimicrobial copper coatings in simulated hand sweat environment

Abstract

The antimicrobial copper coatings were deposited on AISI 304 stainless steel (SS) using electrodeposition technique for touch surface applications. Electrodeposition was performed using a non-cyanide electrolyte, with varying copper concentrations. The copper coatings were investigated for their microstructure, in vitro degradation in the simulated hand sweat environment, and antimicrobial activity in an agar medium. It is noted that all the coatings have nanostructures in their microstructure. The microstructure of the coatings along with the contact period with the bacteria affects the antimicrobial activity measured against Escherichia coli and Staphylococcus aureus. The nanostructured morphology has resulted in an increased surface area with enhanced copper toxicity. The degradation behavior of coatings in the simulated hand sweat solution was further probed using potentiodynamic polarization test and electrochemical impedance spectroscopy (EIS).