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Described as a “breakthrough” by its creators at the University of Chicago (UChicago) in Illinois, the small system could also be used to detect airborne viruses or bacteria in hospitals or enable people with diabetes to read glucose levels from their breath.
“For decades, our ability to detect molecules in air has lagged behind our ability to detect the same ones in a liquid. Hence the blood tests at the doctor’s office, and the pinpricks people with diabetes often undergo daily,” a UChicago research announcement said. Other examples include home Covid tests that involve droplets of liquid.
While airborne tests could improve comfort and streamline tests for patients, they have traditionally been held back by the problem of dilution. “In air, the particles you’re looking for – such as a few viruses floating around – might be as few as one in a trillion. That’s a tall task for a detector, and until now it has required large, expensive equipment,” the announcement said.
A team of UChicago researchers set out to solve that problem by turning air into liquid, making it easier to read. Their system first uses a pump to suck in air for the reading. A humidifier then adds water vapour, and a miniature cooling system lowers the temperature, causing the air to condense into droplets – with any relevant particles suspended inside.
The droplets slide down a specially designed ultra-slick surface and collect into a small reservoir. Detectors can then pick up the concentrations of molecules in the liquid, using pre-existing and readily available equipment for liquid detection.
In tests, the team successfully detected glucose levels from breath, airborne E. coli, and inflammation markers from the cages of mice with poor microbiome gut health.
The device, known as Able (Airborne Biomarker Localisation Engine), measures just four inches by eight inches (10x20cm).
The new device created by scientists at the University of Chicago (Credit: Bozhi Tian)
“This project is among the most exciting endeavours we've pursued,” said Professor Bozhi Tian, one of the senior authors of a research paper on the work. “There are so many potential applications. We’re delighted to see it come to fruition.”
The study was initially inspired by a visit to the neonatal intensive care unit at UChicago’s Comer Children’s Hospital, Professor Tian said. The centre’s founder, Professor Erika Claud, said she wished there was a way to run tests on her patients without drawing blood or using other invasive methods.
Professor Claud now hopes to be able to put the newly developed technology to use. “Premature infants are some of the most vulnerable and fragile patients that we care for in medicine,” she said. “The promise of this technology is that we will be able to non-invasively track newly identified biomarkers, to optimise care for these infants.”
The researchers also hope to use the system for “many other” applications. Doing so will involve overcoming a challenge, however – the ability to easily detect airborne molecules is so new, they said, that scientists do not know what molecules they would need to look for.
The group is collaborating with a doctor who treats inflammatory bowel disease (IBD), for example. “It’s likely you could detect markers of inflammation from the breath of patients with IBD, but they would first need to be catalogued,” the announcement said.
The team also aims to refine the design and miniaturise it further to make it wearable.
The study was published in Nature Chemical Engineering.
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