Product-induced dual amplification strategy for chloramphenicol detection based on catalytic hairpin assembly and DNA tetrahedron nanomachines

A product-induced dual amplification strategy was developed for detecting chloramphenicol (CAP). It combines catalytic hairpin assembly (CHA) and a DNA tetrahedron nanomachine (DTN). CAP binds to an aptamer-hairpin, triggering CHA and forming a tripedal Y-shaped DNA. This tripedal Y-shaped DNA can catalytically cleave the substrate DNA on DTN, significantly restoring fluorescent intensity. Notably, the dual-amplification time is greatly reduced by the increased amount of DNA fragments, which elevates the kinetic rate constant. Moreover, the detection limit was improved to 0.2 pM using this strategy. Additionally, it shows considerable potential for real-sample applications.