Sensitive and selective colorimetric detection of Pb2+ by silver nanoparticles synthesized from Aconitum violaceum plant leaf extract

Abstract In this work, we propose a simple and cost effective colorimetric method for the detection of Pb 2+ using silver nanoparticles (AgNPs) prepared from the leaf extract of Aconitum violaceum . Due to the presence of significant amount of polyphenols in the extract, the AgNPs were successfully synthesized and were then characterized by UV–vis spectroscopy, Fourier transform infrared spectroscopy (FT-IR), X-Ray diffraction (XRD) and transmission electron microscopy (TEM). The as prepared AgNPs were employed as colorimetric probes for the detection of Pb 2+. In the presence of Pb2+, the biosynthesized AgNPs showed a color transformation from yellow to red, which was readily determined by UV–vis spectroscopy. The novel sensor exhibited good linearity for the detection of Pb2+ in the concentration range of 0.5 ˗ 25 μM (R2 = 0.996) with a detection limit (LOD) of 0.1 μM. Also, this sensing system presented a highly selective response for Pb2+ determination.