Multiplexed reverse-transcriptase quantitative polymerase chain reaction using plasmonic nanoparticles for point-of-care COVID-19 diagnosis

Nat Nanotechnol. 2022 Sep;17(9):984-992. doi: 10.1038/s41565-022-01175-4. Epub 2022 Jul 25.

Abstract

Quantitative polymerase chain reaction (qPCR) offers the capabilities of real-time monitoring of amplified products, fast detection, and quantitation of infectious units, but poses technical hurdles for point-of-care miniaturization compared with end-point polymerase chain reaction. Here we demonstrate plasmonic thermocycling, in which rapid heating of the solution is achieved via infrared excitation of nanoparticles, successfully performing reverse-transcriptase qPCR (RT-qPCR) in a reaction vessel containing polymerase chain reaction chemistry, fluorescent probes and plasmonic nanoparticles. The method could rapidly detect SARS-CoV-2 RNA from human saliva and nasal specimens with 100% sensitivity and 100% specificity, as well as two distinct SARS-CoV-2 variants. The use of small optical components for both thermocycling and multiplexed fluorescence monitoring renders the instrument amenable to point-of-care use. Overall, this study demonstrates that plasmonic nanoparticles with compact optics can be used to achieve real-time and multiplexed RT-qPCR on clinical specimens, towards the goal of rapid and accurate molecular clinical diagnostics in decentralized settings.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, N.I.H., Extramural

MeSH terms

  • COVID-19 Testing
  • COVID-19* / diagnosis
  • DNA-Directed RNA Polymerases
  • Fluorescent Dyes
  • Humans
  • Nanoparticles*
  • Point-of-Care Systems
  • RNA, Viral / genetics
  • Real-Time Polymerase Chain Reaction
  • Reverse Transcriptase Polymerase Chain Reaction
  • SARS-CoV-2 / genetics
  • Sensitivity and Specificity

Substances

  • Fluorescent Dyes
  • RNA, Viral
  • DNA-Directed RNA Polymerases

Supplementary concepts

  • SARS-CoV-2 variants