Amomum subalatum leaf extract derived silver nanoparticles for eco-friendly spectrophotometric detection of Hg (II) ions in water

Herein, biologically synthesized silver nanoparticles (AgNP) from amomum subalatum (AS) leaf extract (i.e. AgNP-AS) for spectrophotometric detection of Hg2+ ions. The formation of AgNP-AS has been confirmed by UV -Visible, X-ray diffraction (XRD), Fourier transform infrared (FTIR) and Transmission electron microscopy (TEM). The different characterization results showed that AgNP-AS exhibit a strong absorption band at 432 nm, crys-tallinity and spherical morphology with 4.9 nm average particle size. The AgNP-AS shows a good sensitivity towards Hg2+ ions by a decrease in its absorption intensity with a limit of detection (LOD) of 0.41 mu M. Also besides, AgNP-AS shows a good selectivity towards Hg2+ ions over other heavy metal ions. The detection mechanism was thoroughly investigated with increasing Hg2+ ions concentration by observing the variation in the zeta potential. Moreover, to extend the applicability, the AgNP-AS was successfully applied to river and tap water samples treated with known concentrations of Hg2+ ions with a percentage recovery and relative standard deviation (RSD) values in the range of 96-101.1% and 1.6-6.2%, respectively. Therefore, the as-prepared AgNP-AS can be practically applied to samples of drinking water for the detection of Hg2+ ions.