Visual colorimetric detection of cyromazine in river water using citrate-stabilized gold nanoparticles

In this paper, citrate-stabilized gold nanoparticles (AuNPs) were used to develop a method for rapidly and visually detecting cyromazine in river water. AuNPs could strongly interact with cyromazine, which causes an apparent color change observable by the naked eye, and their absorbance spectra could be measured by UV-vis spectroscopy. The citrate reduction method was used to synthesize different sizes of AuNPs and the optimized AuNP size for the visual detection sensor was determined to be 30 nm. The linear range of this method was from 0.1 to 1 mg L-1 and the limit of detection (LOD) was 0.1 mg L-1. The recoveries of cyromazine ranged from 83% to 117% with a good RSD of less than 6% for the river water samples spiked with three different concentrations of cyromazine. This method provided a simple and sensitive technique for screening environmental cyromazine contamination on site.