Highly sensitive electrochemical sensor based on hydrazine-functionalized metal-organic framework for simultaneous...

Heavy metals, such as Pb²⁺ and Cd²⁺, pose significant risks to human health and ecosystems due to their toxicity and bioaccumulation. This study presents a novel electrochemical sensor utilizing a hydrazine-functionalized metal-organic framework (MOF-Hydrazine) modified glassy carbon electrode for the simultaneous detection of Pb²⁺ and Cd²⁺ ions in food and environmental samples. The MOF-Hydrazine composite, synthesized via a solvothermal method, exhibits high surface area, tunable porosity, and enhanced electrocatalytic properties, enabling superior sensitivity and selectivity. Square wave anodic stripping voltammetry (SWASV) was employed, optimized through Plackett-Burman and Box-Behnken designs, to achieve detection limits of 0.0005 nmol L^-1 for Pb²⁺ and 0.004 nmol L^-1 for Cd²⁺, surpassing many conventional methods. The sensor demonstrated excellent linearity (0.002-200 nmol L^-1 for Pb²⁺, 0.01-100 nmol L^-1 for Cd²⁺), repeatability (RSD <2.43%), and stability (retaining >94% response after four weeks). Real-sample analysis of food and water matrices showed results consistent with ICP-OES, with no significant interference from common ions. This cost-effective, rapid, and sensitive sensor offers a sustainable alternative for trace metal monitoring, with potential for portable, on-site applications in environmental and food safety assessments.