Electrochemical Aptamer Biosensor Based on ATP-Induced 2D DNA Structure Switching for Rapid and Ultrasensitive...

Herein, a two-dimensional (2D) DNA structure with multiple ATP aptamers was elegantly designed to establish an electrochemical biosensor for rapid and sensitive detection of ATP based on ATP-induced structure switching. Concretely, the prepared 2D DNA structure containing numerous ATP aptamers as ATP-specific toehold switches could not only immobilize a large number of methylene blue (MB) for generating a remarkable electrochemical signal, but also greatly increase the local concentration of ATP aptamers to obviously enhance the capture efficiency of ATP. Once the target ATP interacted with the toehold switches, the 2D DNA structure could be sharply collapsed to trigger the burst release of MB from the electrode surface, ultimately resulting in a significantly decreased electrochemical signal for ultrasensitive detection of target ATP over a short period of time. Impressively, by dexterously adjusting the length of the ATP-specific toehold switches to 15-base, optimization of the binding affinity between ATP and the toehold switches was achieved for cutting down the detection time to 30 min and achieving a low detection limit of 0.3 pM, which addressed the shortcoming of time-consuming and poor sensitivity in the previous sensors with a small quantity of ATP aptamers and deficient binding affinity to ATP. Consequently, this strategy opened a promising avenue for ultrasensitive and rapid detection of various biomolecules in biomedical application and disease diagnosis.