Univ. of Maryland researchers develop 'naked eye' COVID-19 test

Researchers at the University of Maryland are developing a simple, experimental diagnostic test for COVID-19 that could provide a visual result in 10 minutes, without any laboratory equipment.

Using gold nanoparticles suspended in liquid, the test is designed to react in the presence of the novel coronavirus’s specific genetic material and help diagnose an active infection.

After extracting RNA from a nasal swab or saliva sample, the nanoparticles begin to bind to the virus’s specific proteins—and as the gold begins to cluster, it changes the color of the liquid from purple to blue, a process visible to the naked eye.

“Based on our preliminary results, we believe this promising new test may detect RNA material from the virus as early as the first day of infection,” said Dipanjan Pan, professor of diagnostic radiology and nuclear medicine and pediatrics at the university’s school of medicine. 

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"The accuracy of any COVID-19 test is based on being able to reliably detect any virus. This means it does not give a false negative result if the virus actually is present, nor a false-positive result if the virus is not present," said Pan. "Many of the diagnostic tests currently on the market cannot detect the virus until several days after infection. For this reason, they have a significant rate of false-negative results."

Pan helped create the company VitruVian Bio to develop the test for widespread use and plans to hold pre-submission meetings with the FDA in the coming weeks in pursuit of an emergency authorization. However, additional studies are still needed to validate the assay, he said. 

The test could be far less expensive to produce than standard COVID-19 molecular tests, and its ease of use could make it well-suited for daycare centers, nursing homes, college campuses or the workplace, according to the researchers, who published their work in the American Chemical Society's nanotechnology journal, ACS Nano.