Silver nanoparticles as colorimetric probe for selective determination of Hg2+ from milk samples with ultrasound-assisted extraction protocol

The present investigation demonstrates a simple, sensitive and selective colorimetric probe for the detection of Hg2+ in milk samples employing redox interaction of Hg2+ ions with citrate-stabilised silver nanoparticles, inducing colour change from yellow to colourless. Milk samples were pretreated by ultrasound assistance in acidic media. The detection limit (LOD) was 6.17 ppb using UV-Visible spectrophotometer with linear correlation (R-2 = 0.9901) at 10-2000 ppb solution of Hg2+ ions. Developed probe was highly selective to Hg2+ over different interfering metal ions and can be effectively employed to identify Hg2+ in milk samples.