A SARS-CoV-2 NFC ePAD Biosensor

PROJECT SUMMARY The current SARS-CoV-2 outbreak has begun to reshape how we think about and use diagnostic assays for preventing the spread of infectious diseases. Early diagnostic efforts specific to SARS focused almost solely on detecting the virus using nucleic acid amplification tests; more recently detection of circulating antibodies using ELISA to complete serological screening. While these techniques can provide accurate results, they require laboratory facilities and equipment, creating a significant delay between sampling and results. Rapid diagnostic tests in the form of lateral flow assays have appeared more recently but so far have lacked the sensitivity and selectivity to be useful for slowing disease spread. Another challenge with current approaches is that they require different molecular approaches for different markers making creation of a single test that can determine if an individual is or has been infected is challenging. As a result, there is a clear and pressing need to develop a single sensing platform that can quantitatively detect ng/mL levels of both viral antigens produced during infection and circulating antibodies at the point-of-care from blood, saliva, or nasal swabs that can be used by essentially anyone with little or no training. The goal of this project is to create a simple, inexpensive, and deployable electrochemical paper-based analytical device (ePAD) for detecting SARS-CoV-2 antigens and antibodies in blood, saliva, and nasopharyngeal swabs. Our device will combine three innovative components: a label-free electrochemical biosensor, a disposable near field communication (NFC) potentiostat, and a self-powered microfluidic device that performs complex sample preparation steps without user intervention. This system, the NFC-ePAD, will allow a user to literally add sample and press a button on the sensor and then place their phone on the unit to initiate the measurement. The phone activates the sensor and reports the results to the user. To achieve our goal, we are collaborating with colleagues at Chulalongkorn University and Silicon Craft™ in Thailand. Our aims are 1) demonstrate a sensitive label-free biosensor for circulating SARS-CoV-2 nucleocapsid protein and anti-spike receptor binding domain (RBD) antibodies, 2) create a self-power microfluidic device for sample processing, and 3) validate the system using deidentified, banked clinical samples. Once developed, the system will provide a fast, simple, and easy-to-use platform for healthcare providers and individuals alike to rapidly determine the infection and immune status of potential COVID-19 patients.