Nanomolar simultaneous determination of Cd(II) and Pb(II) using composite carbon material based on PEG-functionalized...

In this paper, a highly sensitive and selective sensor based on a nanocomposite of cation exchanger Nafion polymer, polyethylene glycol modified Fe₃O₄ magnetic nanoparticles (PEG-Fe₃O₄) and multi-walled carbon nanotubes (MWCNTs),electrochemically deposited with bismuth film (Nafion@MWCNTs@PEG-Fe₃O₄/BiF) was fabricated for simultaneous trace analysis of Cd(II) and Pb(II). The individual effect of each composite component on the obtained signals, electronic properties, and surface morphology was investigated using voltammetric, impedance, and electron microscopy techniques. The developed differential-pulse anodic stripping voltammetry (DPASV) procedure is characterized by wide linear ranges of calibration curves (2-500 nmol L^-1) for both ions, low detection limits (0.49 nmol L^-1 for Cd(II) and 0.46 nmol L^-1 for Pb(II)) and high sensitivities equal to 85.14 μA/μmol L^-1 and 74.21 μA/μmol L^-1 for Cd(II) and Pb(II), respectively. The DPAdSV procedure was successfully applied to analyse standard reference material and drinking water samples compared to the inductively coupled plasma atomic emission spectroscopic (ICP-OES) measurements.