Air monitor can detect Covid-19 in a room within five minutes, scientists say

Nanobodies taken from llamas key to working of device

A Covid ward in Merseyside, UK. The device is said to allow users to take evasive action such as increasing the flows of air in rooms where viruses are detected

A new device can scan a room for the Covid-19 virus in the air and produce a result in around five minutes, Washington University said on Monday.

It is a foot wide and 10 inches tall, and lights up if the virus is detected.

The WHO declared the global health emergency sparked by the disease over in May, more than three years after its detection in Wuhan, China. Covid-19 went on to kill more than seven million people and infect about 764 million.

The device uses aerosol sampling technology and an ultrasensitive biosensing technique to take in air at a fast rate and test it for Covid-19 particles.

It is an adaptation of a micro-immunoelectrode biosensor created originally to detect amyloid beta as a biomarker for Alzheimer’s disease. In the original piece of kit, an antibody that recognises the amyloid beta was swapped for a nanobody that recognises the spike protein from the SARS-CoV-2 virus.

This nanobody, a smaller and more simplistic version of an antibody found in llamas, is tiny as well as being cheap and easy to produce.

China recorded spikes in the disease again last month, with 239 deaths from the disease. Other nations have halted free testing services, so knowing the numbers of cases is increasingly difficult.

This makes personal choice around exposure levels tricky. Many choose still to wear masks as millions return to workplaces more regularly and use public transport. But the new device, the most senstivie available according to the makers, allows users to take evasive action such as increasing airflows in rooms where viruses are detected.

Researchers lab-tested the device in room-sized chambers, one with aerosolised SARS-CoV-2 and one without, as well as in the apartments of two people who had tested positive for the virus. The machine correctly detected the presence of Covid-19, and found none in the control room.

The device has so far only been created as a proof-of-concept, but encouraging results mean it could be a step closer to becoming a part of the fight against Covid and other airborne diseases. The team is working to make a commercial version available.

The makers, from Washington University's McKelvey Schools of Engineering and Medicine, say that although Covid-19 was the first disease the product was made to detect, it could be used to monitor levels of influenza, rhinovirus, staph or strep in hospital and other settings.

“There is nothing at the moment that tells us how safe a room is,” said project researcher John Cirrito, a professor of neurology at the School of Medicine.

“If you are in a room with 100 people, you don’t want to find out five days later whether you could be sick or not. The idea with this device is that you can know essentially in real time, or every five minutes, if there is a live virus.”

The full research was published in Nature Communications on Monday.