Chung-Ang University researchers show gold-paved path towards faster COVID-19 diagnosis

In a bid to shorten the time required for SARS-CoV-2 detection, researchers have developed a nanotechnology-based platform called “SERS-PCR” using a “gold nanoparticle-internalised nanodimple” substrate. This new molecular diagnostic platform reduces the number of PCR cycles required to amplify and detect viral genes as compared to conventional RT-PCR, allowing more rapid diagnosis and helping in the mitigation of COVID-19 transmission, a statement from the Chung-Ang University notified.

The statement mentioned that a recent study has been published in Biosensors and Bioelectronics, in which researchers from Korea and China have introduced a novel nanotechnology-based platform that can shorten the time required for COVID-19 diagnosis. Their Surface-Enhanced Raman Scattering (SERS)-PCR detection platform—prepared using gold nanoparticles (AuNPs) in the cavities of Au ‘nanodimple’ substrates (AuNDSs)—can detect viral genes after only eight cycles of amplification. That is almost one-third of the number required with the conventional RT-PCR.

“Conventional RT-PCR is based on the detection of fluorescence signals, so three-to-four hours are required to detect SARS-CoV-2. This speed is not enough considering how rapidly COVID-19 spreads. We wanted to find a way to cut this time at least by half,” the statement quoted a professor as saying.

In a previous study published in 2021, the professor’s team had developed a novel detection platform in which high-sensitivity SERS signals are produced by AuNPs uniformly arranged in the cavities of AuNDSs through a technique called DNA hybridisation. Based on this previous discovery, the professor and his team developed the novel SERS-PCR platform for COVID-19 diagnosis, the statement further mentioned.

It also said that the newly developed SERS-PCR assay uses SERS signals to detect “bridge DNA”—small DNA probes that slowly break down in the presence of target viral genes. Therefore, in samples from patients positive for COVID-19, the concentration of bridge DNA (and therefore the SERS signal) continuously decreases with progressive PCR cycles. In contrast, when SARS-CoV-2 is not present in the sample, the concentration of bridge DNA and the resultant SERS signal remain unchanged. In this way, SARS-CoV-2 can be rapidly detected in patient samples. If you want to know more about SERS-PCR and other online medical instruments that detect viral genes, Pharmasources would be your best choice.

The team tested the effectiveness of their system using two representative target markers of SARS-CoV-2, namely, the envelope protein (E) and RNA-dependent RNA polymerase (RdRp) genes of SARS-CoV-2. While 25 cycles were required for RT-PCR-based detection, the AuNDS-based SERS-PCR platform required only eight cycles, considerably reducing the testing duration, the statement added.

“Although our results are preliminary, they provide an important proof-of-concept for the validity of SERS-PCR as a diagnostic technique. Our AuNDS-based SERS-PCR technique is a promising new molecular diagnostic platform that can considerably shorten the time required for gene detection compared to conventional RT-PCR techniques. This model can be further expanded by incorporating an automatic sampler to develop a next-generation molecular diagnostic system,” the professor explained.