Retaining the viability and function of wearable sensing systems based on living cells requires nutrient delivery and waste extraction, as well as temperature and gas regulation, all of which involve numerous technological hurdles. This approach encounters several limitations, particularly that of sustaining living organisms in the devices for extended periods. Only a few demonstrations of hygroscopically actuated vents and response to induction molecules have been achieved using living engineered bacteria encapsulated in flexible substrates and hydrogels in a wearable format 3, 4, 5, 6. Although genetically encoded sensors have been readily incorporated into bench-top diagnostics, examples of wearable devices using these tools are limited. In parallel, recent developments in wireless technology, wearable electronics, smart materials and functional fibers with new mechanical, electrical and optical properties have led to sophisticated biosensing systems 2. Synthetic biology has enabled unprecedented control of biological systems and has provided a rich palette of modular biosensors, genetic logic gates and output effectors for the design of custom biological circuits 1. We demonstrate the development of a face mask with a lyophilized CRISPR sensor for wearable, noninvasive detection of SARS-CoV-2 at room temperature within 90 min, requiring no user intervention other than the press of a button. The detection limits for nucleic acids rival current laboratory methods such as quantitative PCR. The wearable devices are activated upon rehydration from aqueous exposure events and report the presence of specific molecular targets by colorimetric changes or via an optical fiber network that detects fluorescent and luminescent outputs. Here we report lightweight, flexible substrates and textiles functionalized with freeze-dried, cell-free synthetic circuits, including CRISPR-based tools, that detect metabolites, chemicals and pathogen nucleic acid signatures. However, the operation of synthetic circuits generally requires the presence of living, engineered bacteria, which has limited their application in wearables.
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Integrating synthetic biology into wearables could expand opportunities for noninvasive monitoring of physiological status, disease states and exposure to pathogens or toxins.