GAINESVILLE, Fla. – With any highly infectious disease, the weather can be a killer.
It is crucial to get a test result for a pathogen quickly, lest someone continue in their daily life to infect others. And delays in testing have undoubtedly exacerbated the COVID-19 pandemic.
Unfortunately, the most accurate COVID-19 test often takes 24 hours or more to return results from a lab.
Home test kits offer results in minutes but are much less accurate or sensitive.
Researchers at the University of Florida, however, have helped develop a COVID-19 testing device that can detect coronavirus infection in as little as 30 seconds with as much sensitivity and accuracy as a PCR or blood test. polymerase chain reaction, the gold standard of testing. They are working with scientists from National Yang Ming Chiao Tung University in Taiwan.
According to the researchers, the device could transform public health officials’ ability to quickly detect and respond to the coronavirus – or the next pandemic.
UF has entered into a licensing agreement with a New Jersey company, Houndstoothe Analytics, in hopes of eventually manufacturing and selling the device, not only to medical professionals but also to consumers.
Like PCR tests, the device is 90% accurate, the researchers said, with the same sensitivity, according to a recent peer-reviewed study published by the UF group.
“There’s nothing quite like it,” said Josephine Esquivel-Upshaw, DMD, a professor in the department of restorative dental sciences at UF College of Dentistry and a member of the research team that developed the device. “It’s a real point of service. It is access to care. We believe this will revolutionize diagnostics.
The device is not yet approved by the United States Food and Drug Administration. First, the researchers said, they need to make sure the test results aren’t skewed by cross-contamination with other pathogens that might be found in the mouth and saliva. These include other coronaviruses, staph infections, influenza, pneumonia and 20 others. This work is ongoing.
The handheld device is powered by a 9-volt battery and uses an inexpensive test strip, similar to those used in blood glucose meters, with anti-coronavirus antibodies attached to a gold-plated film on its end. The strip is placed on the tongue to collect a small sample of saliva.
The tape is then inserted into a reader connected to a circuit board with the brain of the device.
If someone is infected, the coronavirus in the saliva binds to the antibodies and begins a sort of dance as they are driven by two electrical impulses processed by a special transistor. A higher concentration of coronavirus changes the electrical conductance of the sample. This, in turn, changes the voltage of the electrical impulses.
The voltage signal is amplified a million times and converted into a digital value – in a sense, the electrochemical fingerprint of the sample. This value will indicate a positive or negative result, and the lower the value, the higher the viral load. The device’s ability to quantify viral and antibody load makes it particularly useful for clinical purposes, the researchers said.
The product can be built for less than $50, Esquivel-Upshaw said. In contrast, PCR test equipment can cost thousands of dollars.
The research team is also studying its ability to detect specific proteins that could be used to diagnose other diseases, including cancer, heart attack and immune health.
Fan Ren, Ph.D., a distinguished professor in the department of chemical engineering at the Herbert Wertheim College of Engineering, and his team had been developing semiconductor-based sensing devices long before COVID-19 for non-medical purposes.
He noted that he is inspired in his work by the recent death of his wife, which was unrelated to COVID-19. He connects his grief to the mourning of the whole world.
“Nearly a million people have died from COVID” in the United States, Ren said. “These are all tragedies. The elderly. Young people. You name it. I said, ‘No, that’s it.’ It’s too much.”
He said several institutions have worked on devices using a field-effect transistor, or FET, like the one found in the COVID-19 test device his team is developing. But these devices are essentially one-offs – a sample is applied directly to the FET, which means the transistor is not reusable and must be discarded.
This makes such devices expensive and impractical for mass testing, Ren said.
Then he came up with the idea of separating the transistor from the sample, like blood glucose meters that use test strips to collect a drop of blood after a lancet pierces a finger. This innovation, Ren said, makes the UF device unique, affordable and easy to use.
Ren said the device could be used in high-traffic locations, such as concerts, sporting events, classrooms, in addition to medical environments. The researchers say the unit would also provide access to accurate and inexpensive tests in rural areas or in developing countries.
And the personal uses, the researchers say, are limitless — parties, baby showers and other small gatherings.
“Yes or no. You are infected or not infected. You get the answer right away,” Ren said.