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*
• , and 
• 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.

https://pubs.acs.org/doi/10.1021/acssensors.3c00512