Anodic Stripping Voltammetry for simultaneous the Determination of Lead and Cadmium with Graphene Oxide Nanoparticles

Abstract

A highly sensitive electrochemical sensing system was developed for the quantitative determination of lead (Pb²⁺) and cadmium (Cd²⁺) ions using a glassy carbon electrode modified with graphene oxide nanoparticles (GONPs/GCE). The Graphene Oxide Nanoparticles GONPs were synthesized by the well-known Hummers’ method, then dispersed in 0.5wt% Nafion solution in 1:1DI water/ethanol mixture and drop-cast onto the surface of GCE. Square-wave anodic stripping voltammetry (SWASV) was employed to take advantage of the improved electrochemical behavior of the GONPs/GCE. Best operating conditions include pre-concentration at -1.2 V for 50\s in pH=7 phosphate buffer/ electrolyte supporting medium.

Well-separated oxidation peaks are observed at about for lead Ions and  for cadmium ions. The sensor showed very good linearity over a range between    for both metals with low detection limits found as only 0.09  for   in . Precision, reported as relative standard deviation (RSD) of 1.84% for Pb⁺² and 1.90 % for Cd⁺² was also obtained, highly reproducible results. The developed GONPs/GCE-based method was effectively applied to the analysis of tap and industrial water samples, yielding satisfactory recovery values.