Portable, affordable, accurate COVID-19 test can detect virus in just 30 minutes

CHAMPAIGN, Ill. — Although much of the focus during the coronavirus pandemic is turning to vaccinations, testing for the virus still plays a major role in society. Unfortunately, the COVID testing process has tended to be a slow and imperfect process, sometimes leaving patients waiting for results for days. Now, researchers from the University of Illinois have developed a COVID testing device they say can accurately detect the virus in under 30 minutes. Moreover, their test doesn’t rely on uncomfortable nasal swabs, only the patient’s saliva.

“We developed a rapid, highly sensitive and accurate assay, and a portable, battery-powered device for COVID-19 testing that can be used anywhere at any time,” says chemical and biomolecular engineering professor Huimin Zhao in a university release.

The lead researcher adds this new hand-held testing device can spot a single viral particle in every microliter drop of saliva it scans. Making production of the Scalable and Portable Testing (SPOT) device even more convenient, study authors say many of its components can be 3D-printed.

While SPOT is still in the prototype phase, the U of I team estimates this testing kit would cost $78 to build. The chemicals and supplies needed to carry out each test would come out to under $7 per use.

Anyone will be able to use SPOT

Human Zhao research group – rapid, accurate, scalable and portable testing system device for COVID-19 diagnosis. (Photo by L. Brian Stauffer)

Zhao notes current COVID-19 testing kits are generally complex, expensive, and take too much time to produce results. Additionally, most high-end testing uses bulky equipment and needs a lab expert to process the patient’s sample. SPOT, on the other hand, will require little training to operate, according to the professor.

Researchers made their breakthrough after discovering a system for creating artificial restriction enzymes which they can program to recognize and split specific genes. SPOT uses these enzymes to carry DNA guidelines which tag suspicious viral genes with a special dye.

The enzyme then splits these genes, which start to glow after the cleaving process. The resulting fluorescence signals such genes produce equals a positive COVID test.

More accurate than the current tests

Study authors say SPOT can also detect multiple virus genes in each sample. This makes it more accurate than single-gene tests that can give patients inconclusive or even wrong information.

Out of 104 clinical saliva samples, SPOT correctly identified 28 out of 30 SARS-CoV-2-positive samples. The portable test also accurately determined that 73 out of 74 clean samples did not carry the virus.

“Based on the data reported in the literature, the accuracy of our test is comparable to or better than other SARS-CoV-2 tests,” Zhao reports.

The Illinois team went a step further with SPOT, testing its abilities to examine samples with the flu and three other coronavirus strains in them. The hand-held testing kit could still spot COVID-19 regardless of other viruses appearing in the saliva.

“We are interested in exploring this technology for detection of other diseases as well,” Zhao concludes. “One key advantage to this technology is its multiplexing capability, so in principle, we can detect many viruses simultaneously using the same device.”

Researchers are hopeful their new invention may even be able to scan for biomarkers of cancer in the future.

The study appears in the journal Nature Communications.