Sensor allows for faster, more accurate COVID-19 tests, researchers say

Sensor allows for faster, more accurate COVID-19 tests, researchers say
Researchers say they have developed a COVID-19 test that is easier to use, and just as accurate, as PCR analysis of nasal swabs. File Photo by Debbie Hill/UPI | License Photo

March 29 (UPI) -- Researchers at Johns Hopkins University announced Tuesday they have developed a sensor device they say provides faster, more accurate COVID-19 test results.

The technology combines accuracy levels approaching that of PCR testing, the current gold standard for virus screening, with the speed of self-administered, at-home rapid antigen tests, they said in an article published Tuesday by the journal Nano Letters.


The approach could be used for mass testing at airports, schools, hospitals and other large-scale settings, according to the researchers.

Unlike PCR testing, the new sensor, which is not yet available, requires no sample preparation and minimal operator expertise, the researchers said.

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"The technique is as simple as putting a drop of saliva on our device and getting a negative or a positive result," researcher Ishan Barman said in a press release.

"The sensor could eventually be used in wearable devices," said Barman, an associate professor of mechanical engineering at Johns Hopkins University in Baltimore.

PCR tests are accurate but require complicated sample preparation, with results taking hours or even days to process in a laboratory, according to the researchers.

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Rapid tests are less accurate at detecting early infections and asymptomatic cases and can lead to erroneous results in some cases, previous studies suggest.


During initial testing, the Johns Hopkins-developed sensor was 92% accurate at detecting the in the virus that causes COVID-19 in saliva, which is comparable to that of PCR tests, Barman and his colleagues said.

The sensor also was effective at identifying other viruses, including H1N1 influenza and Zika, the researchers said.

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It analyzes saliva samples using surface-enhanced Raman spectroscopy, which employs laser light to examine how molecules of the examined specimen vibrate, they said.

The system can rapidly detect the presence of a virus, even if only small traces exist in the sample. Specially developed machine learning algorithms are able to pinpoint the presence and concentration of the virus, the researchers said.

The sensor material can be placed on any type of surface for analysis, from doorknobs and building entrances to masks and textiles, they said.

It could potentially be integrated with a hand-held testing device for fast screenings at crowded places like airports or stadiums, according to the researchers.

As tests of the technology using patient samples continues, Johns Hopkins Technology Ventures has applied for patents on the intellectual property associated it and the team is pursuing license and commercialization opportunities, the researchers said.

"Our platform goes beyond the current COVID-19 pandemic," Barman said.


"We can use this for broad testing against different viruses, for instance, to differentiate between SARS-CoV-2 and H1N1, and even variants," he said.

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