A photo of a 3d-printed COVID-19 breath test, a small box with a straw and a patient blowing into it.

Researchers have developed this 3D-printed breath test for COVID-19. [Photo courtesy of Washington University in St. Louis]

A 3D-printed COVID-19 breath test delivers results within 60 seconds from just one or two breaths, according to Washington University in St. Louis researchers.

It’s the same team that recently developed an air monitor that can detect the COVID-19-causing SARS-CoV-2 virus in the air within minutes.

Researchers from the McKelvey School of Engineering and the School of Medicine used the same ultrasensitive biosensing technique for the breath test.

The small, portable and adaptable device could help fight the airborne virus as at-home rapid tests increasingly report false negatives for new SARS-CoV-2 variants. Most COVID-19 transmission is still pre-symptomatic and asymptomatic.

The researchers envision their device being used for rapid diagnosis by doctors or to screen people in shared spaces, such as public events, nursing halls, student housing, cruise ships or military bases.

“With this test, there are no nasal swabs and no waiting 15 minutes for results, as with home tests,” said co-corresponding author Rajan Chakrabarty, the Harold D. Jolley Career Development Associate Professor of energy, environmental and chemical engineering. “A person simply blows into a tube in the device, and an electrochemical biosensor detects whether the virus is there. Results are available in about a minute.”

The team says their breath test could be modified to detect influenza, respiratory syncytial virus (RSV) and other viruses — even saying they could test for novel pathogens within two weeks of sampling them.

The FDA granted emergency use authorization last year to the first COVID-19 breath test, the InspectIR COVID-19 Breathalyzer. But that device is larger — approximately the size of a piece of carry-on luggage — and uses gas chromatography gas mass-spectrometry.

The Washington University in St. Louis team’s device uses an antibody from llamas that recognizes a protein in the SARS-CoV-2 virus.

Testing the COVID-19 breath test

The researchers had COVID-positive individuals breathe into a straw attached to the device two, four or eight times. They reported accurate reads after two breaths, and no false negatives. The test was able to detect different SARS-CoV-2 strains, including the

The researchers also found that the breath test successfully detected several different strains, including the original strain and the omicron variant. The team is currently measuring active strains in clincal studies.

Commercializing the COVID-19 breath test

Washington University researchers John Cirrito, Rajan Chakrabarty, Joseph Puthussery and Carla Yuede stand with the SARS-CoV-2 wet cyclone aerosol sampler they developed.

Washington University researchers (from left) John Cirrito, Rajan Chakrabarty, Joseph Puthussery and Carla Yuede stand with the SARS-CoV-2 wet cyclone aerosol sampler they developed. The same team has also developed a COVID-19 breath test. [Photo by Shubham Sharma/Washington University]

The researchers awarded Y2X Life Sciences an exclusive licensing option for the technology. Y2X Life Sciences co-founder and Chair Tom Cirrito is one of the researchers on the COVID-19 detection projects.

“It’s a bit like a breathalyzer test that an impaired driver might be given,” said Cirrito, a professor of neurology at the Washington University School of Medicine in St. Louis. “And, for example, if people are in line to enter a hospital, a sports arena or the White House Situation Room, 15-minute nasal swab tests aren’t practical, and PCR tests take even longer. Plus, home tests are about 60% to 70% accurate, and they produce a lot of false negatives. This device will have diagnostic accuracy.”

The research team and members of Y2X Life Sciences have been working with each other since the beginning of the project, including during device design, to facilitate possible commercialization of the test in the future,” the university said.

More information is available from Washington University and the research team’s paper in ACS Sensors.

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