BEIJING — Chinese scientists have developed a molecular system that can provide COVID-19 testing results in less than four minutes.

A research team from Shanghai-based Fudan University mentioned this portable prototype device in a study published recently in the journal Nature Biomedical Engineering, saying it can detect the traces of COVID-19-related genetic material quickly and accurately.

The device is an electromechanical biosensor consisting of a probe bound to a flexible single-stranded DNA cantilever that is linked to a self-assembled stiff double-stranded DNA structure, according to the study.

It can realize a rapid and ultrasensitive detection of nucleic acids in biofluids, and also of ions, small molecules and proteins.

Unlike the toolkit of qRT-PCR, or quantitative reverse-transcription polymerase chain reaction, the device does not require nucleic acid extraction and amplification procedures, thus substantially shortening the testing time, the researchers said.

The researchers used the device to test swab samples from 33 COVID-19 patients confirmed by traditional qRT-PCR tests, 23 samples from qRT-PCR-negative patients with fever, six samples from patients with influenza A or B, and 25 samples from healthy volunteers.

It has detected the RNA of SARS-CoV-2 in all 33 patients in only 0.1 to four minutes, and in none of the 54 COVID-19-negative controls, according to the study.