MoS₂-DNA tetrahedral bioconjugate for high-performance DNA biosensors: application in viral infection diagnostics

An electrochemical DNA biosensor is presented for early viral infection detection, integrating molybdenum disulphide (MoS₂), tetrahedral DNA nanostructures (TDNs), and thionine-modified carbon nanodots (CNDsTy). The innovation of this work lies in the first-time integration of these nanomaterials for the preparation of a bioconjugate, whose synergy enables the biosensor's functionality. MoS₂ anchors the TDNs, which carry the capture probe for virus identification via genetic code recognition. CNDsTy allow the electrochemical detection based on their different affinity for single-stranded (ssDNA) and double-stranded DNA (dsDNA), enabling hybridization event identification. The biosensor achieves high sensitivity (detection limit of 5.00 fM) and can distinguish viral loads, validated with the SARS-CoV-2 ORF1ab sequence in human nasopharyngeal samples.