A simple, selective and fast colorimetric assay using gold nanoparticles for trace determination of tolyltriazole in aqueous media

Document Type: Research Article


1 Department of Chemistry, North Tehran Branch, Islamic Azad University, Tehran, Iran

2 Department of Chemistry, Islamic Azad University, North Tehran Branch, Tehran, Iran

3 Department of Chemistry, North Tehran branch, Islamic Azad university, Tehran, Iran


In this study, a simple and fast colorimetric assay based on the aggregation of gold nanoparticles (AuNPs) was achieved for determination of μg L−1 of tolyltriazole (TTA). The aggregation of AuNPs is due to the high affinity between gold surface and nitrogen atoms of TTA and intermolecular bonding formation between TTA molecules. The plasmon peak of AuNPs at 520 nm was decreased with formation of a band about 620 nm owing to aggregation phenomenon. The affective parameters on the peak shift such as ionic strength, pH of sample and AuNPs concentration was investigated. The proposed method is capable of determining TTA over a concentration range of 10-100 µg L-1 with a limit of detection of 5.0 µg L-1 based on the absorbance ratio at 620 nm to 520 nm. The relative standard deviation of the method was 3.0% and 1.5% for 20 and 80 µg L-1, respectively. A comparison between the outlined method and the previously published methods for TTA determination has also been made. The obtained results from this study proved to be effectively successful in determination of TTA in water.