Electrochemical Aptasensing of SARS-CoV-2 Based on Triangular Prism DNA Nanostructures and Dumbbell Hybridization Chain Reaction.

Development of convenient, accurate, and sensitive methods for rapid screening of severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) infection is highly desired. In this study, we have developed a facile electrochemical aptasensor for the detection of the SARS-CoV-2 S1 protein amplified by dumbbell hybridization chain reaction (DHCR). A triangular prism DNA (TPDNA) nanostructure is first assembled and modified at the electrode interface. Due to the multiple thiol anchors, the immobilization is quite stable. The TPDNA nanostructure also provides an excellent scaffold for better molecular recognition efficiency on the top single-strand region (DHP0). The aptamer sequence toward the SARS-CoV-2 S1 protein is previously localized by partial hybridization with DHP0. In the presence of the target protein, the aptamer sequence is displaced and DHP0 is exposed. After further introduction of the fuel stands of DHCR, compressed DNA linear assembly occurs, and the product can be stacked on the TPDNA nanostructure for the enrichment of electrochemical species. This electrochemical method successfully detects the target protein in clinical samples, which provides a simple, robust, and accurate platform with great potential utility.