COVID precautions have been lifted nearly everywhere, but that doesn’t mean the virus has gone away. It may be lingering in any given room that’s seen frequent visitors or is host to large crowds. We’ll be living with COVID for the foreseeable future—including any threatening variants that may arise. But a new device built by scientists at Washington University in St. Louis aims to help us manage that new future by providing real-time monitoring of indoor spaces and detecting any traces of the COVID virus in the air in just five minutes.
The new device, described in a paper published in Nature Communications on Monday, is said by its makers to be relatively small and inexpensive to build. It also has the potential to be easily modified to monitor other kinds of aerosolized viruses, such as influenza and RSV.
“It can be effectively utilized in hospitals, ICU wards with symptomatic patients, airports, office spaces, crowded bars, or any crowded indoor environment with poor ventilation and a high risk of virus transmission,” Washington University researchers and study co-authors Joseph Puthussery and Rajan Chakrabarty told The Daily Beast in a joint email. According to the pair, the device could be used for both short duration “spot checks” for COVID, as well as long duration monitoring over an entire day.
Puthussery, Chakrabarty and their colleagues built the device based on designs for a previously built biosensor that is able to detect a protein commonly found in the brains of people with Alzheimer’s, helping to give early warning that someone may be at risk of developing symptoms of the disease. When the pandemic got underway, the team began to believe it may be possible to use the same design to detect airborne SARS-CoV-2, the virus that causes COVID infection.
With help from some airborne toxicity experts, the Alzheimer’s biosensor was converted into a tool that uses an antibody from llamas to recognize the infamous SARS-CoV-2 spike protein. Air gets sucked into the virus’ sampler at high speeds and mixes with fluid that can trap any airborne viral particles that are present.
The sample then pumps the fluid into the biosensing component of the detector, where the virus’ spike proteins bond with the llama antibodies. If the virus is present, a light goes off to indicate the COVID virus is present nearby. Anyone who is present then has a heads up to leave the room, or mask up and increase ventilation in the area for a while.
“Hospitals stand to benefit the most from this device,” said Puthussery and Chakrabarty. “In hospital wards with immunosuppressed patients, maintaining clean and virus-free air is crucial to prevent hospital-acquired infections.”
Despite being just 10 inches tall and 1 foot in length, the device has a flow rate of about 1,000 liters per minute—which basically means it’s able to find any virus that’s present in a mid-sized room within just minutes, as opposed to the other systems that can take up to 24 hours. Lab experiments conducted in confined rooms showed the device has a detection sensitivity (ability to positively identify the virus) between 77 and 83 percent, across four major variants: Beta, Delta, Omicron, and Washington (WA-1). Trials were also run in the apartments of two COVID-positive participants, and underscored the ability of the device to find aerosolized SARS-CoV-2 in a real-world setting.
Besides further testing in more kinds of indoor spaces, the team plans to make the device into a product that’s easy to manufacture and operate, including making it less noisy. Should they be successful, it would be the first commercially available real-time monitoring system for SARS-CoV-2. The research team is also interested in enabling the device to monitor other respiratory viruses.
“We are currently working on simultaneously detecting other airborne pathogens,” said Puthussery and Chakrabarty. “The remaining task involves working with industry partners to optimize production and scale up to build an affordable product.”
