Ag nanoparticles electrodeposition on graphenized pencil lead electrode as a sensitive and low cost sensor for iodate determination

In this study, a novel, sensitive and low-cost iodate electrochemical sensor based on graphenized pencil lead electrode modified with silver nanoparticles (AgNPs/GPLE) was presented. The GPLE was simply prepared via electrochemical exfoliation of pencil lead electrode by applying an optimized potential in acidic media. Afterward, silver nanoparticles were electrochemically deposited on the surface of GPLE using chronoamperometry technique. The fabricated AgNPs/GPLE was carefully characterized by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) techniques. Electrochemical behavior and also electrocatalytic performance of the AgNPs/GPLE toward the reduction of iodate were studied in details using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. The fabricated sensor responds efficiently to iodate over the concentration range of 50 to 75000 μM with a detection limit of 17 μM and sensitivity of 0.26 µA µM-1 cm-2. Remarkably enhanced electrocatalytic performance of the AgNPs/GPLE was ascribed to synergistic effect of graphene nanostructures with high surface to volume ratio and excellent conductivity and also excessive electrocatalytic behavior of AgNPs. It is noted that modification of electrode surfaces with metal nanoparticles has received considerable attention because of their excellent chemical stability, reversible redox properties, and electrocatalytic activities [1].The modified electrode was successfully employed for the determination of iodate in table and sea salt samples.