Antiviral Effects of Silver, Copper Oxide, Cerium Oxide, and Cobalt Oxide Nanoparticles and Silver and Copper Sheets Against COVID‐19

Abstract COVID‐19 the most devastating pandemic of the current millennium, can survive from hours to months in environment, devices, and surface. Its transmission by asymptomatic carriers has significantly strained the existing testing resources. At present, there are no clinically proven therapeutic methods that effectively inhibit the effects of this virus. Nanoparticles (NPs) have been extensively utilized in various medical applications, including biosensing, drug delivery, imaging, and antimicrobial/antiviral treatment. Synthetic NPs can closely resemble the virus and strongly interact with its proteins due to their similar morphology. Therefore, NP‐based strategies for combating this virus hold immense potential and may reduce the survivability of the virus in the environment due to unique physicochemical features and surface modification properties. In this study, antiviral properties of silver (Ag), copper oxide (CuO), cobalt oxide (Co 3 O 4 ), and cerium oxide (CeO 2 ) NPs besides Ag and Cu sheets against COVID‐19 in nasopharyngeal samples were investigated. All NPs suspensions were prepared in Virus Transporter Media (VTM) in 25, 50, and 100 mg/mL concentrations, additionally, Cu and Ag sheets were added to SARS‐CoV‐2 virus pooled and then incubated at room temperature. Viral RNA was extracted from those suspensions after different incubation times and concentrations and quantitative polymerase chain reaction (qPCR) analysis was performed. For virucidal activity evaluation, the estimated lysed virus copy number was assessed according to the pooled virus sample serial dilution and eventually based on changes in the cycle threshold (CT) of qPCR. According to CT number changing after incubation of NPs with pooled virus sample, CuO NPs had the greatest virus inactivation on virus lysis at all concentrations and times while Co 3 O 4 NPs showed moderate antiviral activity (P<0.05). The antiviral activity of other NPs was less than CuO and Co 3 O 4 and were almost identical at similar concentrations and times. Cu and Ag sheets have shown a direct linear relationship between incubation time and antiviral activity. Cu nanoparticles had significant destructive effects on the SARS‐CoV‐2 virus among all nanoparticles, and the Cu sheet had considerably less antiviral activity than its own Cu NPs. These findings might make it helpful to use CuO NPs in masks, and air/water filters, make coated surfaces with effective NPs, and manufacture disinfectant solutions to combat coronaviruses and other viruses that can cause respiratory infections.