High‑sensitivity Hg2+ sensor based on the optical properties of silver nanoparticles synthesized with aqueous leaf extract of Mimusops coriacea

Abstract

In the presented manuscript, spherical silver nanoparticles (AgNPs) which were prepared via green chemical method in a single step take only a few minutes to be ready as a Hg2+ ions detector based on the plasmon band changes. The AgNPs were obtained with the aqueous extract of Mimusops coriacea leaves. The components of the extract as tannins and polyphenolic compounds were responsible for the reduction in metal ions and the particles encapsulation. The AgNPs were characterized by UV–Vis spectroscopy, fluorescence, Fourier transform infrared, dynamic light scattering analysis and transmission electron microscopy. The AgNps presented an average diameter of 15 nm and a zeta potential value of ~ − 28 mV. They were monodispersed and stable for up to 180 days. AgNPs are used as a Hg2+ sensor with high sensitivity and selectivity. The fast, simple and low-cost method is based on changes in the AgNP surface plasmon resonance band (λ ≈ 410 nm) with LOD 6.5 ng/mL (32.5 nM), without functionalization of the AgNPs. The low LOD demonstrates its potential for Hg2+ quantification in environmental samples such as fish, soil, and effluent discharge.