The device can be used in hospitals and healthcare facilities, schools and public places to help detect and potentially monitor SARS-CoV-2 for other respiratory virus aerosols, such as flu and respiratory syncytial virus (RSV).
Experts in the field say it’s a useful find that could help in the medical arena incredibly quickly
Researchers have developed a real-time air monitor that they say can detect any of the SARS-CoV-2 virus variants in a room in about five minutes. The low-cost, proof-of-concept device was developed by researchers at Washington University in St. Louis, USA, by combining recent advances in aerosol sampling technology with an ultra-sensitive biosensing technique.
The device can be used in hospitals and healthcare facilities, schools and public places to help detect and potentially monitor SARS-CoV-2 for other respiratory virus aerosols, such as flu and respiratory syncytial virus (RSV). The results of their work on the monitor, which they say is the most sensitive detector available, are published in the journal Nature Communications.
There is currently nothing that tells us how safe a room is,” said John Cirrito, a professor of neurology at Washington University. ”If you are in a room with 100 people, you don’t want to know five days later whether you could be sick or not. The idea with this device is that you can essentially know in real time, or every 5 minutes if there’s a live virus,” Cirrito said.
The researchers had previously developed a microimmunoelectron (MIE) biosensor that detects amyloid beta as a biomarker for Alzheimer’s disease and wondered if it could be turned into a detector for SARS-CoV-2. To do so, they exchanged the antibody that recognizes amyloid beta for a llama nanobody that recognizes the spike protein of the SARS-CoV-2 virus.
David Brody, a former faculty member at Washington University, and an author on the paper, developed the nanobody in his lab at the National Institutes of Health (NIH). The nanobody is small, easy to reproduce and modify, and inexpensive to make, the researchers said.
“The nanobody-based electrochemical approach is faster at detecting the virus because it doesn’t require a reagent or many processing steps,” said Carla Yuede, an associate professor at Washington University. “SARS-CoV-2 binds to the nanobodies on the surface and we can induce oxidation of tyrosines on the surface of the virus using a technique called square wave voltammetry to get a measurement of the amount of virus in the sample,” said Yuede. Researchers integrated the biosensor into a air sampler based on wet cyclone technology.
Air enters the sampler at very high velocities and is centrifugally mixed with the liquid running along the walls of the sampler to create a surface vortex, trapping the virus aerosols. The wet cyclone sampler has an automated pump that collects the liquid and sends it to the biosensor for seamless detection of the virus using electrochemistry.
“The challenge with airborne aerosol detectors is that the virus level in the indoor air is so diluted that it even approaches the limit of polymerase chain reaction (PCR) detection and it is like finding a needle in a haystack,” says Rajan Chakrabarty. , a professor at Washington University. “The high virus recovery rate from the wet cyclone can be attributed to its extremely high flow rate, which allows it to sample a larger volume of air over a 5-minute sampling period compared to commercially available samplers,” said Chakrabarty.
The team tested the monitor in the apartments of two COVID-positive patients. The real-time PCR results of air samples from the bedrooms were compared to air samples from a virus-free control room. The devices detected RNA from the virus in the bedroom air samples, but not in the control air samples.
In lab experiments where SARS-CoV-2 was aerosolized in a room-sized chamber, the wet cyclone and biosensor were able to detect varying levels of virus concentrations in the air after just a few minutes of sampling.
(This story has not been edited by News18 staff and was published from a syndicated news agency feed – PTI)