Multiplexed Magnetofluorescent Bioplatform for the Sensitive Detection of SARS-CoV-2 Viral RNA without Nucleic Acid Amplification.

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