Development of an Environmental Monitor for Real-Time SARS-CoV-2 Detection

JOSEPH V. PUTHUSSERY, Nishit Shetty, Benjamin Sumlin, Dishit Ghumra, Carla M. Yuede, John Cirrito, Rajan K. Chakrabarty, Washington University in St.Louis

     Abstract Number: 481
     Working Group: Aerosol Science of Infectious Diseases: What We Have Learned and Still Need to Know about Transmission, Prevention, and the One Health Concept

Abstract
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a strain of coronaviruses that causes coronavirus disease 2019 (COVID-19). Air-born transmission of SARS-CoV-2 is widely accepted as a high-risk transmission route for the spread of COVID-19. However, with the recent dip in the COVID-19 cases, several states in the USA and countries across the globe are moving to eliminate mask mandates in schools and public spaces. Therefore, there is an urgent need for a real-time airborne SARS-CoV-2 virus detector that can be placed inside schools and public auditoriums to screen the air to ensure a safe indoor environment for the occupants.

We developed a novel real-time environmental monitor to detect SARS-CoV-2 particles in ambient air. The environmental monitor comprises a wet cyclone-based particle into liquid sampler (PILS) coupled to a micro-immunoelectrode (MIE) technology based biosensor virus detection unit. The aerosols entering the PILS get deposited on the inner walls of the cyclone using the centrifugal forces acting on the incoming aerosols. The ambient particles are directly collected in a phosphate-buffered saline (PBS) solution. After five minutes of sampling, the concentrated particles collected inside the PILS are transferred to the virus-detection unit using an automated liquid delivery system for final virus detection. The virus detection is achieved using a nano-body-based electrochemical biosensor that selectively detects SARS-CoV-2 virions via the spike protein and has a detection limit of 50 viral particles/sample. The sensor provides instantaneous results that allow us to perform continuous near-real-time SARS-CoV-2 detection. The unit also has an inbuilt automated HOCl disinfection feature that ensures safe handling and operation of the environmental monitor, during ambient air monitoring. Here, we will be presenting the design, operation principle, and field sampling results obtained using our SARS-CoV-2 environmental monitor.