  The current Coronavirus Disease 19 (COVID-19) pandemic has exemplified the
need for simple and efficient prevention strategies that can be rapidly
implemented to mitigate infection risks. Various surfaces have a long history
of antimicrobial properties and are well described for the prevention of
bacterial infections. However, their effect on many viruses has not been
studied in depth. In the context of COVID-19, several surfaces, including
copper (Cu) and silver (Ag) coatings have been described as efficient antiviral
measures that can easily be implemented to slow viral transmission. In this
study, we detected antiviral properties against Severe Acute Respiratory
Syndrome Coronavirus-2 (SARS-CoV-2) on surfaces, which were coated with Cu by
magnetron sputtering. However, no effect of Ag on viral titers was observed, in
clear contrast to its well-known antibacterial properties. Further enhancement
of Ag ion release kinetics based on an electrochemical sacrificial anode
mechanism did not increase antiviral activity. These results clearly
demonstrate that Cu and Ag thin film systems display significant differences in
antiviral and antibacterial properties which need to be considered upon
implementation.
