Copper and silver thin film systems display differences in antiviral and antibacterial properties -- implications for the prevention of SARS-CoV-2 infections

TL;DR

This study compares copper and silver thin films, revealing copper's antiviral effectiveness against SARS-CoV-2, while silver shows no antiviral effect despite antibacterial properties, highlighting the importance of material choice for infection prevention.

Contribution

The paper demonstrates that copper coatings exhibit antiviral activity against SARS-CoV-2, whereas silver coatings do not, emphasizing the need to consider different antimicrobial mechanisms in surface design.

Findings

Copper surfaces reduce SARS-CoV-2 titers

Silver surfaces do not affect SARS-CoV-2

Enhanced silver ion release does not improve antiviral activity

Abstract

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.