DNA tweezers aptasensor with split aptamer for the dual detection of Enrofloxacin and Kanamycin

Currently, the technology for detecting antibiotics is developing rapidly, with good sensitivity and selectivity. However, some detection methods still have issues with cumbersome pretreatment and high experimental costs. Herein, A “turn-off” bifunctional DNA tweezer was constructed through the design of DNA sequence and self-assembly technology for the dual detection of Enrofloxacin (ENR) and Kanamycin (KANA) in a food matrix. The operation is simple, which increases the detection speed and reduces the detection cost. The two ends of the bifunctional DNA tweezers are connected with specific split aptamer sequences, and the split aptamer forms a specific ternary complex with the target. The tweezers “clip” ENR and KANA at their respective ends, causing a structural change. Under the optimal experimental conditions, the linear range of detection ENR is 0.2 ng/mL-1000 ng/mL with an LOD of 0.18 ng/mL, the linear range of detection KANA is 0.5 ng/mL-1000 ng/mL with an LOD of 0.36 ng/mL. The bifunctional DNA tweezers involved provide a new idea for the construction of DNA nanomachines, which is also suitable for the recognition and detection of other small molecules.