Abstract
A robust technique-methodology of electrochemical CRISPR sensing is first proposed for the rapid, highly sensitive and specific detection of SARS-CoV-2 variant without any nucleic-acid-amplification assays.
Using the DNA template identical to SARS-CoV-2 Delta spike gene sequence as model, our biosensor exhibited excellent analytical detection limit (50 fM) and high linearity (
R
2
= 0.987) without any amplification assay.
Specific crRNA was designed to match the mutation site on nucleic acid sequence of the SARS-CoV-2 Delta variant, presenting programmability, universality, and scalability for diagnosis of other emerging SARS-CoV-2 variants.
Coronavirus disease 2019 (COVID-19) is a highly contagious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The gold standard method for the diagnosis of SARS-CoV-2 depends on quantitative reverse transcription-polymerase chain reaction till now, which is time-consuming and requires expensive instrumentation, and the confirmation of variants relies on further sequencing techniques. Herein, we first proposed a robust technique-methodology of electrochemical CRISPR sensing with the advantages of rapid, highly sensitivity and specificity for the detection of SARS-CoV-2 variant. To enhance the sensing capability, gold electrodes are uniformly decorated with electro-deposited gold nanoparticles. Using DNA template identical to SARS-CoV-2 Delta spike gene sequence as model, our biosensor exhibits excellent analytical detection limit (50 fM) and high linearity (
R
2
= 0.987) over six orders of magnitude dynamic range from 100 fM to 10 nM without any nucleic-acid-amplification assays. The detection can be completed within 1 h with high stability and specificity which benefits from the CRISPR-Cas system. Furthermore, based on the wireless micro-electrochemical platform, the proposed biosensor reveals promising application ability in point-of-care testing.