Voltammetric determination of Hg (II) using poly (methane disulfide)/Au nanoparticle/MWCNT modified glassy carbon electrode by differential pulse anodic stripping voltammetry (DPASV) technique

Abstract

In the present work, surface of a glassy carbon electrode (GCE) was modified by a poly (methanedisulphide)/Au–nanoparticles/multiwall carbon nanotubes (PMDS/AuNPs/MWCNT) to improve its ability for the determination of trace mercury cations in polluted water. The produced electrode was characterized with FESEM, HR-TEM, AFM, XRD, and FT-IR techniques. The obtained results proved the successfulness of the modification process and revealed that the process had a significant effect on the morphology of the electrode and its surface roughness. EIS studies demonstrated the improvement of the electrochemical properties of the surface modified sample. Accordingly, the electrical resistance to charge transfer (Rct) of the GCE-based samples decreased from 477.1 Ohm.cm2 for the bare sample to 83.4 Ohm.cm2 for the modified-GCE sample. The modified-GCE sample was employed as an ultra-sensitive electrode for determining the concentration of Hg2+ cation based on DPASV technique. It exhibited linear behaviour for the concentration determination in the range of 5.98×10− 12 M to 1.00×10− 9M with correlation coefficient of 0.996. Limit of detection (LOD) and limit of quantitation (LOQ) of the method were found 2.73×10− 13 M and 9.19×10− 13 M, respectively.