An electrochemiluminescence sensing platform combining entropy-driven amplification strategy and inverted DNA tetrahedral nanomachines for detecting SARS-CoV-2 specific gene

Abstract

In this work, we propose a Ti3C2Tx-based electrochemiluminescence (ECL) sensing platform, combined with a programmable entropy-driven cycling strategy and inverted DNA tetrahedral nanomachines to detect the SARS-CoV-2 RdRp gene. The use of Ti3C2Tx in the ECL sensing platform provides unique advantages that improve the assay's sensitivity. Firstly, the SARS-CoV-2 RdRp gene triggers an entropy-driven cyclic amplification reaction to obtain a large number of Output strands. Subsequently, the Output strand reacts with an inverted DNA tetrahedral swing arm strand to start the self-driven process. Finally, the ferrocene (Fc)-labeled hairpin DNA strand of the inverted DNA tetrahedron is severed to achieve the signal change. Under optimal conditions, the ECL platform integrated with entropy-driven cycle amplification reaction and inverted DNA tetrahedral nanomachines obtained a wide range of 100 aM to 10 nM and a limit of detection (LOD) of 48.3 aM for the SARS-CoV-2 RdRp gene. Moreover, the recovery rates of 97% to 103.3% and 98.34% to 103% were obtained in real environments and human pharyngeal swabs, respectively. This ECL sensing platform, which combines an entropy-driven cycle amplification reaction and inverted DNA tetrahedral nanomachines, opens up new opportunities for the detection of other substances.