Rapid Direct Detection of SARS-CoV-2 Aerosols in Exhaled Breath at the Point of Care
Dishit P. Ghumra, Nishit Shetty, Kevin R. McBrearty, Joseph V. Puthussery, Benjamin J. Sumlin, Woodrow D. Gardiner, Brookelyn M. Doherty, Jordan P. Magrecki, David L. Brody, Thomas J. Esparza, Jane A. O’Halloran, Rachel M. Presti, Traci L. Bricker, Adrianus C. M. Boon, Carla M. Yuede, John R. Cirrito, Rajan K. Chakrabarty
Abstract
Airborne transmission via virus-laden aerosols is a dominant route for the transmission of respiratory diseases, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Direct, non-invasive screening of respiratory virus aerosols in patients has been a long-standing technical challenge. Here, we introduce a point-of-care testing platform that directly detects SARS-CoV-2 aerosols in as little as two exhaled breaths of patients and provides results in under 60 s. It integrates a hand-held breath aerosol collector and a llama-derived, SARS-CoV-2 spike-protein specific nanobody bound to an ultrasensitive micro-immunoelectrode biosensor, which detects the oxidation of tyrosine amino acids present in SARS-CoV-2 viral particles. Laboratory and clinical trial results were within 20% of those obtained using standard testing methods. Importantly, the electrochemical biosensor directly detects the virus itself, as opposed to a surrogate or signature of the virus, and is sensitive to as little as 10 viral particles in a sample. Our platform holds the potential to be adapted for multiplexed detection of different respiratory viruses. It provides a rapid and non-invasive alternative to conventional viral diagnostics.