A Sensitive Isoniazid Capped Silver Nanoparticles-Selective Colorimetric Fluorescent Sensor for Hg2+ Ions in Aqueous Medium

Novel isonicotinic acid hydrazide functionalized silver nanoparticles (INH-AgNPs) were synthesized by wet chemical method and used for the detection of Hg2+ ions in aqueous medium. The INH-AgNPs exhibit good absorbance and emission peaks by sensing Hg2+ ions with visible color changes. The detection of Hg2+ ions was confirmed by FT-IR, EDAX spectra and by the changing morphology of INH-AgNPs, and after addition of Hg2+ was confirmed by SEM and TEM imaging studies. Based on the emission intensity the probe INH-AgNPs exhibit a lowest detection limit (LOD) of Hg2+ to 0.18 nM. The association constant (K-a) of INH-AgNPs + Hg2+ ions is calculated using the Bensei-Hildebrand equation. Also, the probe is successfully utilized for the detection of Hg2+ ions in real water samples obtained from different fields, which showed good results.