An Exo III-assisted catalytic hairpin assembly-based self-fluorescence aptasensor for pesticide detection

This study proposed a self-fluorescence aptasensor (SFA) based on an Exo III-assisted catalytic hairpin assembly (EACHA) for pesticide detection. The aptamer in this sensor can specifically recognize the target due to the favorable biological binding affinity and also can drive the EACHA by modifying the spatial configuration. EACHA was designed as a cyclic amplification process that improved the rate of reused aptamer beacon fuel, and increased the detection efficiency and sensitivity. The signal was applied using the 2-aminopurine (2AP) molecule, the fluorescence of which could be quenched via stacking interaction with the adjacent bases in the beacon. Given its fluorescent properties, this design achieved low background analysis with high sensitivity. Chlorpyrifos was used as a model to explore the SFA proof-of-concept. By replacing the aptamer, this method can be extended to other pesticide molecules. Therefore, this study may become a powerful tool for quantitative detection of various targets for different purposes.