Hermetic microfluidic device for point-of-care viral nucleic acid testing

Abstract

There is an unmet clinical and public health need for rapid and accurate point-of-care (POC) diagnosis and management of infectious pathogens, especially in resource-limited environments. In this work, we present a microfluidic deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) rapid test (μDART) device for POC detection of various viral pathogens. This platform hermetically integrates the modules of extraction-free sample lysis, loop-mediated isothermal amplification (LAMP) with lyophilized reagent beads, and real-time colorimetric signal sensing to realize "sample-in and result-out" in 15–30 min. Test results can be sent to a mobile phone for remote monitoring. Automated high-precision liquid handling is achieved by a combination of negative-pressure-driven microchambers and self-sealing valves, thus simplifying manual operations and eliminating the leakage of nucleic acid aerosols. The limit of detection (LOD) of the device is as low as ∼53 copies/mL or ∼2 copies/reaction for SARS-CoV-2, which is as sensitive as the gold standard of nucleic acid testing. To validate our device’s clinical applications, we tested both DNA and RNA viruses as representative pathogens including 537 clinical nasal swab samples for SARS-CoV-2, 74 cervical swab samples for human papillomavirus 16/18 (HPV16/18) and 82 pet swab samples for feline cupripoxvirus (FCV) and feline herpesvirus (FHV). Across these tests, the clinical sensitivity and specificity were 92.5% - 97.7% and 99.7%-100%, respectively. We demonstrate that the μDART is able to provide a quick and accurate result for POCT and self-testing, and can connect to health care wirelessly to achieve remote monitoring.