This research team has designed a coating that can lower the ability of SARS-CoV-2 virus to live on solid surfaces. The coating can be applied to commonly touched objects like doorknobs, pens, phone cases, and credit card keypad buttons for example. The coating reduces the living virus by an average of 99.9% in one hour and continues to work after exposure to water and other disinfectants.
This study aims to create a coating that can prevent the spread of COVID-19 by eliminating live virus on commonly touched solid surfaces.
The virus causing COVID-19 can live on some solid surfaces for up to a week, so creating an antiviral coating could help prevent the spread. This study tried to make a coating that quickly stops the virus, can be applied to different surfaces, and can hold up well after long term use. The base of this coating is polyurethane. The active ingredient in the coating is cuprous oxide (Cu2O). SARS-CoV-2 has a short lifespan on copper anyway, and Cu2O has shown to work against other viruses. Cu2O can be harmful to marine life and used as a pesticide, but is safe for humans to use. Humans commonly interact with copper in the coins and electronics.
Results and Discussion
When the coating was applied to the glass, no virus was detectable after 1 hour in all samples tested. This means that the reduction was at least 99.98% in this case. When the stainless steel was coated, the reduction was 99.80% after one hour. These numbers are so similar because the virus is affected by the coating, not the materials underneath. The polyurethane base alone did not have antiviral properties, showing that the Cu2O is the active ingredient. It is still unclear why Cu2O is effective against SARS-CoV-2.
When the coating was better able to interact with water, it seemed like the coat was better able to make contact with the virus as well.
Viral droplets were given to the coating, then left to dry for 24 hours, and then sanitized with 70% alcohol. This was repeated 5 times. Then, the coating was tested again to see if it still had antiviral properties. The reduction was 99.89%, which tells us that the coating is just as effective after multiple sanitizations.
With heavy scratching, the coat can be removed. But with normal handling, and after tape was applied and removed, the coat was very durable.
Out of 3 different active ingredients tested, the Cu2O was the most effective.
The base of the coat is polyurethane, which was purchased at Lowes Home Improvement Store for this study. The polyurethane was bound to the Cu2O, which is described in detail in the original study. Then the coating was tested for a variety of properties, like the particle size, durability, and antiviral properties.
A polyurethane and Cu2O coating could be a very successful avenue to stop the spread of COVID-19 through solid surfaces, and reduce the public’s fear of touching things in public.