A flexible label-free electrochemical aptasensor based on target-induced conjunction of two split aptamers and enzyme amplification

In this work, a flexible and label-free electrochemical biosensing platform had been developed based on split aptamers and the cleavage effect of exonuclease I, which was applied for the detection of different targets in parallel. In the presence of targets, the two split aptamers could specifically recognize targets to form a ternary complex, which cannot be digested by exonuclease I, resulting in significant impedance signal output. The proposed label-free aptasensor realized sensitive and selective detection of thrombin, adenosine triphosphate and mercury ion with the detection limits of 32 fM, 1.43 pM and 1.65 pM, respectively. The designed strategy provided a simple and powerful tool for multiple targets detection, holding promising applications in disease diagnosis and environmental monitoring.