Biosensor Detects the Presence of Coronavirus in the Air in Just 5 Minutes

In 2020, the world was shaken by an unprecedented pandemic that has severely affected human health and caused numerous deaths across the globe. COVID-19 has also devastated various industries, which led to economic and social disruptions. Although the pandemic is likely to wane in the future, its impact on human lives will likely persist for a long time. Fortunately, experts are now more equipped to protect from coronavirus infection.

A Rapid COVID-19 Air Detector

COVID-19 is caused by the SARS-CoV-2 virus, which can thrive in different environments and surfaces. It is not easy to detect exactly where the viruses are lurking, so a person could get exposed to infection without them knowing.

In response to this challenge, a team of researchers at Washington University St. Louis has a mobile device that can detect the COVID-19 virus in a given space in real-time. Led by associate professor Rajan Chakrabarty, they developed a prototype device almost the size of a microwave that can effectively pick up the presence of SARS-CoV-2 within five minutes.

Commercial air detectors use offline air sampling techniques, which require additional PCR testing, taking as long as 24 hours before getting the results. Such devices are also costly, ranging from thousands to tens of thousands of dollars per unit. Because of this, there is a need for an automated real-time airborne SARS-CoV-2 detection device that can perform better than the commercial lab testing methods and will only cost a few cents per test.

The new device's success lies in a super-fast method of circulating the air into the detector, mimicking the mechanism of a cyclone. The device also contains a biosensor that takes advantage of tiny molecules that attaches to the coronavirus spike protein. An electric current pass through the biosensor and oxidizes a specific amino acid in the spike protein to verify the presence of the SARS-CoV-2 virus.

Upon testing the effectiveness of the air monitor, it was found that the device has a 77% to 83% accuracy rate, although it cannot distinguish between the different variants of coronavirus. When the research team tested different concentrations of coronavirus on their device and two commercial detectors, their monitor was the only one able to detect low levels of genetic materials from the virus. The device is ultra-sensitive, detecting the virus even from a mildly infected person in a room.

Chakrabarty and his team are confident that their portable device can be used anywhere, such as in homes, classrooms, hospitals, and other crowded areas. In the future, they plan to develop a device that can identify the presence of influenza and RSV.

What is a SARS-CoV-2 Aerosol?

COVID-19 can spread in the form of airborne particles and droplets, according to the U.S. Environmental Protection Agency (EPA). The droplets of respiratory fluids are also called aerosols, with particles that measure 10 micrometers in diameter.

An infected person can release the aerosol during quiet breathing, speaking, coughing, sneezing, and discharging the particles as they exhale. These aerosol droplets carry the SARS-CoV-2 virus and transmit infection. In an enclosed space, the droplets can continuously spread through the air in the room and accumulate over time.