An Instrument-free CRISPR-based Face Mask Sensor for COVID-19

Rapid, accurate, and wide-spread COVID-19 testing is essential for contact tracing, timely triaging of patients, and viral monitoring. The current gold standard for COVID-19 testing is RT-PCR. However, such nucleic acid amplification tests (NAATs) require a laboratory, severely limiting large-scale implementation. Our lab thus focused our efforts on this pandemic challenge, with the goal of engineering a decentralized CRISPR-based NAAT solution that can be used by anyone without the need for complex laboratory instruments. We have designed, developed, and validated a point-of-care lyophilized COVID-19 NAAT sensor that can be integrated into any face mask for detecting the virus from a user’s breath. The sensor employs isothermal amplification and Cas12a-based SHERLOCK reactions to achieve a detection sensitivity on par with that of current CDC-approved RT-PCR COVID-19 tests. Breath aerosols collected on the interior surface of the face mask are used for analysis and all reactions operate at ambient temperatures. The freeze-dried synthetic biology reactions are shelf-stable, eliminating the need for cold-chain distribution or storage. The system executes autonomously without any power through passive capillary forces, eliminating operator steps such as liquid handling. All the user needs to do is press a button to start the sensor analysis and the output is a simple visual result. Importantly for practical implementation, the sensor is compact (smaller than a business card), lightweight (equal in weight to a penny), and inexpensive (currently at $5 per sensor). We envision our face mask sensors can be used as a widespread disposable COVID-19 diagnostic, combining the protective functions of a mask with the capabilities of NAATs for sensitive, specific and convenient high-frequency testing. 

Learning Objectives:

1. Discuss the key functional steps for the COVID-19 face mask sensor.

2. Discuss some of the advantages of integrating COVID-19 diagnostics into a face mask.