A glassy carbon electrode modified with bismuth oxide nanoparticles and chitosan as a sensor for Pb(II) and Cd(II)

A glassy carbon electrode (GCE) modified with bismuth oxide nanoparticles (BiONPs) and the chitosan (CS) was fabricated, and used to simultaneously determine lead and cadmium by differential pulse anodic stripping voltammetry. This modified electrode can be self-designed and prepared at low-costs. Scanning electron microscopy image shows that the mean diameter of BiONPs is about 235 nm. The sensitivity of the BiONPs-CS-GCE is much better than that of the bare GCE and the CS-GCE. The effects of deposition potential, pH of the solution, and deposition time were optimized. Under the optimized conditions (pHABS = 5.0, Edep = −1.7 V, tdep = 180 s), the composite film electrode was then applied to the analysis of lead (II) and cadmium (II). The linear range of the electrode was 0.4–2.8 μM for Pb (II) and 0.8–5.6 μM for Cd (II), with a limit of detection of 0.15 μM for Pb (II) and 0.05 μM for Cd (II), respectively. The determination of Pb (II) and Cd (II) in spiked tap water was performed and gave recoveries ranging from 99 to 122 % for Pb (II), and from 96 to 120 % for Cd (II).