A simple AuNPs-based colorimetric aptasensor for chlorpyrifos detection

In this work, a simple gold nanoparticles (AuNPs) based colorimetric biosensor was developed for chlorpyrifos (Chl) detection using an aptamer as the capture probe. The Chl-aptamer with low dissociation constant (K-d) of 58.59 +/- 6.08 nmol/L was selected by ssDNA library immobilized systematic evolution of ligands by enrichment (SELEX). In the absence of Chl, the Chl-aptamer acted as the stabilizer for AuNPs in salt solution. In the presence of Chl, the highly specific Chl-aptamer bound with Chl targets immediately, thus a self-aggregation of AuNPs induced by salt was displayed. The fabricated colorimetric aptasensor exhibited an excellent sensitivity for Chl detection with the LOD as low as 14.46 nmol/L. In addition, the aptasensor was applied to test Chl in tap water, cucumber and cabbage samples, the excellent recoveries with acceptable RSD values below 5% demonstrated that the method can be considered as a promising tool for simple, rapid Chl detection. (C) 2022 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.

Automated summary

The authors developed a simple gold nanoparticles-based colorimetric biosensor for chlorpyrifos detection, utilizing an aptamer as the capture probe. The method exhibited excellent sensitivity and reliable detection performance, making it a promising tool for chlorpyrifos detection in water and agricultural products.