Fast detection of SARS-CoV-2 RNA via the integration of plasmonic thermocycling and fluorescence detection in a portable device

The current gold standard for COVID-19 confirmation is RT-PCR, which possesses high sensitivity and specificity, but a long turnaround time has been a drawback. Here, we introduce a nanoPCR platform that can yield breakthroughs in RT-PCR speed and decentralize the diagnostic testing. A key innovation is to exploit magneto-plasmonic nanoparticles for dual purposes: fast thermocycling through plasmonic heating and enhanced signal detection via magnetic fluorescence switch. We further integrated these functionalities into a portable system to streamline point-of-care (POC) COVID-19 diagnostics with a “one-step-finish” approach from sampling to result. When applied with clinical COVID-19 samples, nanoPCR achieved an analytical performance of sensitivity and specificity comparable to that of a benchtop instrument but completed the entire detection within 18 minutes (vs. 2.5 hours for regular RT-PCR), which makes it ideal for rapid POC diagnostics. This platform technology is readily scalable for higher throughput and expandable to other disease targets, promising broader impacts in on-site molecular testing.