Detection of organophosphorus pesticides by a fluorescent sensing assay coupled with enzyme inhibition

Glyphosate (Gly), as a common organophosphorus pesticides (OPs), is being overly put into usage and it should be monitored in a timely manner. Herein, optically well-performing quantum dots (QDs) were prepared by hydrothermal synthesis to create a fluorescent sensing assay that responds to OPs and quantitatively detects Gly. The mechanism of sensing is based on OPs inhibiting enzyme activity and accompanying pH changes in the system. It can respond to multiple OPs (trichlorphon, methamidophos and chlorpyrifos). Particularly, the quantification of Gly is outstanding with a detection range of 0.2 ∼ 1.8 mg/L and the detection limit as low as 0.015 mg/L. This system has not only good selectivity and repeatability, but also reliable application potential. In spiked experiments, a recovery of 96.50∼107.00% was demonstrated. Fluorescent sensing assay coupled with enzyme inhibition provides a novel choice for pesticide detection and offers considerable value in related fields. •Enzyme inhibition-sensor for detecting organophosphorus pesticides (OPs).•The fluorescence sensing signal output has ultra-long stability (∼40 days).•The sensor is highly quantitative and specifically selective.