Silver nanoparticles-based colorimetric array for the detection of Thiophanate-methyl

Schematic presentation of Thiophanate-methyl (TM) induces citrate capped silver nanoparticles (Cit-AgNPs) aggregation and triggers a visible color change. The Cit-AgNPs bind up with TM through hydrogen bonding and π-π bonding, resulting in the color change from yellow to cherry red. Under optimum conditions, the absorbance ratio at A525nm/A394nm was related linearly to the concentration of TM in the range of 2-100 μM, with a detection limit of 0.12 μM. The spiked recoveries were obtained in water and vegetable samples ranged from 81% to 105.3% and relative standard deviation (RSD) were lower than 5.0%.338