Ultrasensitive colorimetric detection of triazophos based on the aggregation of silver nanoparticles

A simple colorimetric sensing assay was constructed for quantitative detection of triazophos via aggregation of citrate capped silver nanoparticles (Cit-AgNPs) with an On-Off type. In the presence of triazophos, the Cit-AgNPs was aggregated, resulting in the obvious color change from yellow to prunosus via hydrogen bonding, π-π interactions and substitution. The theoretical investigations between the triazophos and Cit-AgNPs were also validated by density functional theory (DFT) approach. Meanwhile, the calibration curve was found to be linear over the range of 0.1–280   μM and this proposed colorimetric sensing was demonstrated an excellent sensitivity with a detection limit of 5   nM. The recoveries obtained from complex sample matrices were in the range 82%–100.8%. Significantly, the colorimetric probe has been successfully applied for visual detection of triazophos, which validated the excellent potential for real-time and on-site application and possessed considerable advantages of simplicity, rapid detection, portability, cost efficiency and visualization. It can be applied into determining triazophos in environmental samples.