Open AccessMultiplexed Magnetofluorescent Bioplatform for the Sensitive Detection of SARS-CoV-2 Viral RNA without Nucleic Acid Amplification
Author(s) -
Riham Zayani,
Dorra Rezig,
Wasfi Fares,
Mouna Marrakchi,
Makram Essafi,
Noureddine Raouafi
Publication year - 2021
Publication title -
analytical chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.117
H-Index - 332
eISSN - 1520-6882
pISSN - 0003-2700
DOI - 10.1021/acs.analchem.1c01950
Subject(s) - rna , chemistry , virology , nucleic acid , microbiology and biotechnology , rna extraction , coronavirus , streptavidin , gene , biology , biotin , covid-19 , biochemistry , medicine , disease , pathology , infectious disease (medical specialty)
Rapid and sensitive detection of SARS-CoV-2 virus genetic material is of paramount importance to mitigate the COVID-19 pandemic outbreak and lower the death toll. Herein, we report the design of a magnetofluorescent bioplatform for the direct and specific detection of the viral RNA of SARS-CoV-2 in the total RNA extracted from nasopharyngeal swabs of COVID-19-positive patients. A higher fluorescence response was achieved using two capture probes tethered to magnetic beads using a biotin/streptavidin linkage, targeting two specific sites in the ORF1a and S genes. Two horseradish peroxidase (HRP)-conjugated reporter sequences, complementary to the loci of the S and N genes, were used to reveal the presence of the viral RNA through the oxidation of o -phenylenediamine to fluorescent 2,3-diaminophenazine. Under optimal conditions, the bioplatform showed high selectivity and sensitivity and was able to detect as low as 0.01 ng of viral RNA (1 × 10 3 copies/μL) with a linear dynamic range varying from 0.01 to 3.0 ng (1 × 10 3 to 9 × 10 7 copies/μL). The bioplatform was also able to discriminate the SARS-CoV-2 RNA from those of other related viruses such as hepatitis C, West Nile, measles, and non-polio viruses. Furthermore, the developed biosensor was validated in 46 clinical samples (36 COVID-19-positive patients and 10 COVID-19-negative subjects, as assessed with the gold standard RT-qPCR method). Both sensitivity and specificity of the developed method reached 100%. Finally, making such a simple and specific method available in the field, at a primary point of care, can better help the detection of SARS-CoV-2 infection in low-resource settings.