Abstract
The COVID-19 pandemic revealed during the first global wave of this infectious disease that mass diagnostic testing was necessary to more rapidly detect infection in patients and control the pandemic. Therefore, extra research efforts to develop reliable and more accessible techniques for disease diagnosis are of supreme importance. Here, a target-responsive assembly of gold nanoparticle-core hairpin-spherical nucleic acids (AuNP-core H-SNAs) was implemented to modify the conventional polymerase chain reaction (PCR) assay for the “naked-eye” colorimetric detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA. Two hairpin DNA ligands are designed based on the two highly conserved regions within N and E genes of SARS-CoV-2 RNA by positioning two short palindromic arms (stem) on either side of a recognition sequence (loop). In the presence of a sequence-specific probe (activator), hairpin DNAs anchored to the surface of AuNPs unfold and expose the palindromic ends to the DNA-directed assembly of AuNPs. The sequence of the activator probes was chosen to be identical to the TaqMan probe in a real-time reverse transcription PCR (RT-PCR) assay for specifically targeting the N and E genes of SARS-CoV-2 RNA. They may either be degraded by the 5′-exonuclease activity of DNA polymerase during PCR cycles or stay intact depending on the presence or absence of the target template in the sample, respectively. Post-addition of H-SNA solutions to the final PCR products of some preconfirmed clinical samples for COVID-19 generated naked-eye-observable red and blue colors for positive and negative cases, respectively, with similar sensitivity to that of the real-time RT-PCR method.
【초록키워드】 COVID-19, SARS-CoV-2, coronavirus, pandemic, COVID-19 pandemic, Infection, diagnostic, Infectious disease, severe acute respiratory syndrome Coronavirus, RT-PCR, RNA, polymerase chain reaction, colorimetric detection, nucleic acid, DNA, sensitivity, TaqMan probe, Region, PCR, Disease diagnosis, nucleic acids, Research, Patient, diagnostic testing, gold, SARS-CoV-2 RNA, real-time RT-PCR, reverse transcription PCR, Gold nanoparticle, Real-time reverse transcription PCR, exonuclease, Ligand, Chain Reaction, presence or absence, acute respiratory syndrome, acute respiratory syndrome coronavirus, acute respiratory syndrome coronavirus 2, E gene, sequence, effort, Final, activator, loop, positive, TaqMan, DNA polymerase, AuNP, probe, Arm, STEM, polymerase chain, PCR cycle, clinical sample, detect, develop, conserved, absence, PCR product, modify, 【제목키워드】 PCR, acid, simple, Conventional,