Fabrication of Ultra-Sensitive Modified Electrode for Eco-Friendly Determination of Neurotoxic Heavy Metals in Beef, Dairy Products and Biological Samples

Abstract

Trace levels of cadmium, lead and mercury heavy metals are toxic to the human nervous system. These metals occur naturally and as a result of inappropriate agricultural and industrial practices. In response to this problem, a novel modified electrode was constructed for the simultaneous determination of cadmium, lead and mercury. The modified electrode was prepared by incorporating zirconium oxide nanoparticles (ZrO2 NPs) and multi-walled carbon nanotubes (MWCNTs) into carbon paste electrode. Transmission electron microscope and electrochemical impedance spectroscopy were employed for the characterization of the modified electrode. Different variables that affect the electrochemical response were studied and optimized. The proposed electrode exhibits wide linear range and lower detection limits obtained were 2.77 × 10−10, 2.46 × 10−10 and 4.15 × 10−10 mol L−1 for cadmium, lead and mercury, respectively. The method was successfully applied for the determination of these neurotoxic heavy metals in beef, milk, urine, plasma and omega-3 capsules.