Chinese scientists ‘invent Covid-19 test that gives result within four minutes’

It is as accurate as a PCR test but cuts out the need for lab analysis, according to Fudan University team. New testing device uses mechanical components made of DNA combined with microelectronics and sends results to a phone or computer. — SCMP

Chinese scientists say they have developed a new Covid-19 testing device that can return accurate results within four minutes and is as accurate as the widely used PCR tests.

Researchers from Fudan University in Shanghai said that, if developed further, their device could be used for testing in airports, clinics, emergency departments and homes. Unlike the polymerase chain reaction (PCR) tests currently in use, samples would not require time-consuming laboratory analysis, they said.

The researchers said the new test device used tiny mechanical components made of DNA combined with microelectronics to detect genetic material in a swab sample and convert it to an electrical signal. The device is connected to a computer or smartphone to show a result.

“(The test) may be advantageous in that it offers rapid detection of Sars-CoV-2 nucleic acids, easy operation, high sensitivity and specificity, and portability,” the team wrote in an article published in the peer-reviewed journal Nature Biomedical Engineering.

Demand for coronavirus testing kits has intensified as the world grapples with a spike in Covid-19 cases caused by the highly infectious Omicron and Delta variants. China’s manufacturers of testing kits have been racing to keep up with surging demand, both domestically and abroad.

A PCR test is the most accurate way so far to diagnose Covid-19, according to the World Health Organisation. Samples are tested for viral genetic material in a lab by trained personnel, with the results usually taking between one and several days.

Meanwhile, antigen tests, or rapid diagnostic tests, detect specific proteins on the surface of the coronavirus and can be done anywhere. Because samples do not need to be sent to a lab, they are cheaper and more convenient, and results are available in as short a time as 15 to 30 minutes. But they are generally less accurate than PCR tests.

The Fudan researchers said their test could detect the virus in under four minutes – with an average time of one minute – in all swab samples from 33 people who had been confirmed by the gold-standard PCR tests to have Covid-19.

The new test did not return false positives from the 54 samples from people who did not have Covid-19, the report said. This group included 23 people who had a fever but negative PCR test results, along with six people with influenza and 25 healthy volunteers.

“The overall agreement with the (PCR) results was perfect,” the team said.

The report said the device could also be used in future to quickly detect other diseases.

“Besides Covid-19, the development of the molecular electromechanical system could allow for the ultraprecise diagnosis of other diseases in a few minutes, without the need for target purification, amplification or culture, which normally requires hours or days,” they said. – South China Morning Post