Synthesis of phenylbenzotriazole derivative stabilized silver nanoparticles for chromium (III) detection in tap water

A selective and sensitive colorimetric method was developed for the detection of chromium (III) in tap water using phenylbenzotriazole (PBT) derivative functionalized silver nanoparticles (PBT-AgNPs). The PBT functionalized nanoparticles were synthesized at room temperature by reducing with sodium borohydride (NaBH4). The nanoparticles were characterized by UV–Vis spectroscopy, Zetasizer, Fourier Transformer InfraRed (FTIR), Scanning Electron Microscope (SEM) and Atomic Force Microscopy (AFM). The elevated temperature, pH and higher ionic strength of electrolyte had insignificant effect on stability of the nanoparticles. The PBT-AgNPs were then tested as a probe and were found highly sensitive to the presence of Cr (III) and showed excellent selectivity in the presence of other interfering metals ions. The Jobs plot confirmed the binding ratio between the nanoparticles and Cr (III) to be 1:2. The Surface Plasmonic Resonance (SPR) band quenching as function of concentration showed good linear response (R2 = 0.9992) with limit of detection of 0.2 µM. The PBT-AgNPs were also applied as sensing probe for determination of Cr (III) in tap water samples. These experimental finding showed the supramolecular stabilized silver nanoparticles as a simple, selective, and easy alternative for detection of Cr (III).