A Simple, Selective, and Fast Colorimetric Assay Using Gold Nanoparticles for Trace Determination of Tolyltriazole in Aqueous Media

In this study, a simple and fast colorimetric assay based on the aggregation of gold nanoparticles (AuNPs) was achieved for the determination of μg/L of tolyl triazole (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 the formation of a band about 620 nm owing to the aggregation phenomenon. The effective parameters on the peak shift such as ionic strength, pH of the sample, and AuNPs concentration was investigated. The proposed method is capable of determining TTA over a concentration range of 10-100 μg/L 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, 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 the determination of TTA in water.