Synthesis and characterization of triazole stabilized silver nanoparticles as colorimetric probe for mercury

This study reports the synthesis and characterization of triazole stabilized silver nanoparticles and their investigation as a colorimetric sensor for Hg2+ in tap water. Benzotriazole conjugated silver nanoparticles (BT-AgNPs) were synthesized using the chemical reduction method. Techniques such as UV-visible, Zetasizer, FTIR, SEM, and AFM were used for the characterization of the nanoparticles. The nanoparticles were highly monodispersed and revealed a mean size of 40-50 nm. Further, they were found highly stable at elevated temperatures and over a wide range of electrolyte concentrations and pH. The nanoparticles were then investigated as a colorimetric sensor for Hg2+. The addition of mercury significantly suppressed nanoparticles' absorption intensity and the color change from yellow to colorless. They were found highly selective towards Hg(2+)in the presence of other interfering metal ions. The binding ratio between the nanoparticles and Hg2+ was found to be 1:1 as determined by the jobs plot experiment. The nanoparticles demonstrated sensitivity towards a wide concentration of Hg2+ with a limit of detection of 0.33 mu M. The synthesized nanoparticles were finally used as a sensing probe for Hg2+ detection in water. The limit of detection of the current sensor is lower than most of the reported methods. These findings reveal the triazole stabilized nanoparticles as an easy, selective, and sensitive sensing probe for Hg2+. [GRAPHICS]