Highly Selective and Sensitive Colorimetric Sensor for Aminotriazole Residues in Vegetables and Fruits Using Glutathione Functionalized Gold Nanoparticles

Aminotriazole is among the most popular carbamates herbicide that are widely used to boost food production, and its residues pose a great threat to human health and the environment. Herein, we presented a new colorimetric sensor for the detection of aminotriazole residues based on the aggregation of glutathione functionalized gold nanoparticles (GSH-AuNPs). The AuNPs were synthesized by the reduction of chloroauric acid (HAuCl4 · 4H2O) via trisodium citrate (C6H5Na3O7 · 2H2O) and characterized by UV-visible spectrometer and TEM. And GSH-AuNPs were prepared using simple green one-pot method. Determination of aminotriazole were carried out under optimal detection condition based on the aggregation of AuNPs induced by the synergistic effects of electrostatic interaction, hydrogen bond and size selectivity between GSH and aminotriazole, which gave the clear color and UV-vis spectrum change. The sensor showed good ability of anti-disturbance and displayed wide linear relationship with aminotriazole concentrations varying from 0.59 to 21.40 μM with low detection limit of 0.27 μM. The recovery in the spiked cabbages and apples were measured to be between 91.96% and 105.90%. These preliminary results demonstrate that as-prepared AuNPs sensor would be a promising candidate for fast aminotriazole analysis in real application.