An electrochemical aptasensor based on CRISPR-Cas12a, G-rich DNA se⁃ quence for label-free detection of bisphenol A

A label-free electrochemical aptasensor based on CRISPR-Cas12a and G-rich DNA sequence （G-quadruplex）was developed for the detection of bisphenol A（BPA）. In the presence of BPA，it can specifically bind to the aptamer sequences in double-stranded DNA probes，and releases the another DNA probe，which can activate the trans-cleavage activity of Cas12a. The activated Cas12a cleaved the DNA probe of G-quadruplex/hemin complex on the surface of the gold electrode，causing a decline of the electrochemical signal. The result illustrated that the proposed electrochemical aptasensor possesses a good linear relationship with BPA in the range of 0.1-10 nmol/L， and the detection limit was 0.05 nmol/L. The label-free electrochemical aptasensor exhibited a high specificity for BPA and can be employed to detect BPA in environmental water samples. © 2024, Youke Publishing Co.,Ltd. All rights reserved.