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COVID-Killing Coating Gets Job Done in One Hour

Electron microscope showing virus leaving cells
This scanning electron microscope image shows SARS-CoV-2 (round blue objects) emerging from the surface of cells cultured in the lab. SARS-CoV-2, also known as 2019-nCoV, is the virus that causes COVID-19. The virus shown was isolated from a patient in the U.S. Image captured and colorized at NIAID’s Rocky Mountain Laboratories (RML) in Hamilton, Montana. NIAID

While research is ongoing into the survivability of SARS-CoV-2 (the virus that causes COVID-19), according to a study done by a team of researchers in May, the bug can remain alive on certain smooth surfaces for up to seven days. A new coating created by William Ducker—a chemical engineering professor at Virginia Tech—looks like it can slash that time down dramatically.

In the study referenced above, it was determined that SARS-CoV-2 could live on plastic, stainless steel, glass, ceramics, wood, latex gloves, and surgical masks for up to seven days. A previous study had determined that the germs could live on plastic and stainless steel for two to three days; cardboard for 24 hours; and copper for four hours. 

Killer Copper

Ducker’s coating, which is made from polyurethane and cuprous oxide, cuts the lifespan of the virus down to just one hour—or possibly even longer. “It probably already kills on contact,” Ducker told MindBounce. “The virus was tested in a droplet to mimic a respiratory droplet. It may have taken up to 30 minutes for the virus to even contact the solid within the droplet.”

Ducker is currently researching just why the coating is so effective. One possible reason might be linked to the cuprous oxide found in the coating. An oxide of copper, cuprous oxide is already employed in antifouling coatings that are used to keep the hulls of ships free from marine growth, and as the one study showed, SARS-CoV-2 simply doesn’t like to live on copper surfaces. 

Nor do other bugs.

In fact, according to Smithsonian Magazine, the metal has been known to be an effective infection killing agent for thousands of years, with the first written mention of using it for that purpose dating from around 1700 BC. In fact, there are reports of the Phoenicians shaving their bronze swords (bronze is a copper alloy) into wounds to fight off infection.  

Virus and Bacteria Blaster

In 2016, William Keevil from the University of Southampton showed that copper could destroy the drug-resistant Staphylococcus aureus (MRSA) on contact. While MRSA is a bacteria, Keevil did further research that showed copper to be effective in disabling the HCoV-229E coronavirus as well by acting, among other ways, to disperse the virus’s spikes.

Keevil, at the time of the first study, said:

“It’s important to understand the mechanism of copper’s antimicrobial efficacy because microorganisms have evolved various mechanisms to convey resistance to disinfectants and antibiotics. Our work shows that copper targets various cellular sites, not only killing bacterial and viral pathogens, but also rapidly destroying their nucleic acid genetic material so there is no chance of mutation occurring and nothing to pass on to other microbes, a process called horizontal gene transfer. Consequently, this helps prevent breeding the next generation of superbug.”

Duker, too, previously worked on coatings to zap bacteria before moving on to the new virus-blasting coating. What’s interesting about his new approach is that by forming a paintable coating, hospitals and other areas at high risk for COVID-19 transmission could simply treat existing fixtures like faucets and doorknobs without having to swap them out for copper versions.

Ghostly Researchers

Interestingly, Ducker and his team had to brave possible exposure to the virus itself while conducting their research.  He reports:

“It was an interesting experience. Almost the entire campus was shut down, and we were like ghosts wandering the empty halls of Goodwin Hall. But it was very exciting to have such a clear goal. I know that it was a difficult time for many people who were bored, unhappy, or scared. We were just focused on making a coating.”

The finding has been reported in the ACS journal, Applied Materials & Interfaces