Advent and fast spread
of pandemic diseases draw worldwide attention
to rapid, prompt, and accurate molecular diagnostics with technical
development of ultrafast polymerase chain reaction (PCR). Microfluidic
on-chip PCR platforms provide highly efficient and small-volume bioassay
for point-of-care diagnostic applications. Here we report ultrafast,
real-time, and on-chip nanoplasmonic PCR for rapid and quantitative
molecular diagnostics at point-of-care level. The plasmofluidic PCR
chip comprises glass nanopillar arrays with Au nanoislands and gas-permeable
microfluidic channels, which contain reaction microchamber arrays,
a precharged vacuum cell, and a vapor barrier. The on-chip configuration
allows both spontaneous sample loading and microbubble-free PCR reaction
during which the plasmonic nanopillar arrays result in ultrafast photothermal
cycling. After rapid sample loading less than 3 min, two-step PCR
results for 40 cycles show rapid amplification in 264 s for lambda-DNA,
and 306 s for plasmids expressing SARS-CoV-2 envelope protein. In
addition, the in situ cyclic real-time quantification
of amplicons clearly demonstrates the amplification efficiencies of
more than 91%. This PCR platform can provide rapid point-of-care molecular
diagnostics in helping slow the fast-spreading pandemic.
Point-of-care real-time reverse-transcription polymerase
chain
reaction (RT-PCR) facilitates the widespread use of rapid, accurate,
and cost-effective near-patient testing that is available to the public.
Here, we report ultrafast plasmonic nucleic acid amplification and
real-time quantification for decentralized molecular diagnostics.
The plasmonic real-time RT-PCR system features an ultrafast plasmonic
thermocycler (PTC), a disposable plastic-on-metal (PoM) cartridge,
and an ultrathin microlens array fluorescence (MAF) microscope. The
PTC provides ultrafast photothermal cycling under white-light-emitting
diode illumination and precise temperature monitoring with an integrated
resistance temperature detector. The PoM thin film cartridge allows
rapid heat transfer as well as complete light blocking from the photothermal
excitation source, resulting in real-time and highly efficient PCR
quantification. Besides, the MAF microscope exhibits close-up and
high-contrast fluorescence microscopic imaging. All of the systems
were fully packaged in a palm size for point-of-care testing. The
real-time RT-PCR system demonstrates the rapid diagnosis of coronavirus
disease-19 RNA virus within 10 min and yields 95.6% of amplification
efficiency, 96.6% of classification accuracy for preoperational test,
and 91% of total percent agreement for clinical diagnostic test. The
ultrafast and compact PCR system can decentralize point-of-care molecular
diagnostic testing in primary care and developing countries.
The outbreak of new viral strains promotes advances in universal diagnostic techniques for detecting infectious diseases with unknown viral sequence. Long double-stranded RNA (dsRNA), a hallmark of infections, serves as a virus marker for prompt detection of viruses with unknown genomes. Here, we report on-chip paper electrophoresis for ultrafast screening of infectious diseases. Negatively charged RNAs pass through the micro and nanoscale pores of cellulose in order of size under an external electric field applied to the paper microfluidic channel. Quantitative separation of long dsRNA mimicking poly I:C was analyzed from 1.67 to 33 ng·μL−1, which is close to the viral dsRNA concentration in infected cells. This paper-based capillary electrophoresis chip (paper CE chip) can provide a new diagnostic platform for ultrafast viral disease detection at the point-of-care (POC) level.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.