Washington University Scientists Developed Air Monitor to Detect COVID

Researchers and scientists at Washington University in St. Louis developed an air monitor to detect COVID-19 variants in the surrounding air. The researchers published a proof-of-concept study in Nature Communications describing the device, its implications, and potential future usage.

Despite declining rates of COVID-19 infection in the United States, clinicians, healthcare professionals, and public health officials continue to discuss concerns about the viral spread. Social distancing, good air ventilation, and staying outdoors have effectively minimized disease spread; however, these strategies are not always an option.

The newest invention by Washington University researchers addresses a detection gap by identifying SARS-CoV-2 variants aerosolized in closed indoor spaces within five minutes.

“There is nothing at the moment that tells us how safe a room is,” John Cirrito, PhD, professor of neurology at the School of Medicine, told Washington University’s The Source newsroom. “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 5 minutes, if there is a live virus in the air.”

Repurposing previously developed micro-immunoelectrode biosensors that detect amyloid beta, the researchers replaced the antibodies that detected the peptides with a llama nanobody that recognizes spike proteins from the SARS-CoV-2 viruses.

“The nanobody-based electrochemical approach is faster at detecting the virus because it doesn’t need a reagent or a lot of processing steps,” Carla Yuede, PhD, associate professor of psychiatry at the School of Medicine explained to The Source. “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.”

After developing the preliminary test, researchers incorporated the biosensor into an air sampler.

Samples were taken from the air in COVID-positive patient homes to test the device's efficacy. Each sample was run through the machine and tested via PCR. The air sampler detected levels of viral RNA in a room. The device detects COVID with a 77–83% sensitivity.

“We are starting with SARS-CoV-2, but there are plans to also measure influenza, RSV, rhinovirus, and other top pathogens that routinely infect people,” Cirrito added. “In a hospital setting, the monitor could be used to measure for staph or strep, which cause all kinds of complications for patients. This could really have a major impact on people’s health.”