Rapid and Ultra-Sensitive SARS-CoV-2 Subgenomic RNA Detection Using Single-Molecule With a Large Transistor-SiMoT Bioelectronic Platform

Abstract

The replication of Coronaviridae viruses depends on the synthesis of structural proteins expressed through the discontinuous transcription of subgenomic RNAs (sgRNAs). Thus, detecting sgRNAs, which reflect active viral replication, provides valuable insights into infection status. Current diagnostic methods, such as PCR-based assays, often involve high costs, complex equipment, and reliance on highly trained personnel. Additionally, their specificity can be compromised by technical limitations in kit design. While viral culture remains highly accurate, it is impractical for routine diagnostics. In this study, the single-molecule-with-a-large-transistor (SiMoT) technology is presented for detecting sgRNA encoding the nucleocapsid (N) protein in clinical samples. SiMoT incorporates a stable layer of complementary DNA strands on the sensing gate electrode, facilitating rapid, sensitive, and specific sgRNA detection. Among 90 tested samples, SiMoT achieved a diagnostic sensitivity of 98.0% and a specificity of 87.8%, delivering results within 30 min. This user-friendly platform requires minimal sample preparation and offers a cost-effective point-of-care (POC) diagnostic solution. With its demonstrated diagnostic accuracy and scalability, SiMoT represents a promising tool for detecting active viral replication in SARS-CoV-2 and other coronaviruses. It addresses the limitations of existing molecular and culture-based methods while enhancing accessibility to reliable diagnostics.