Fabrication of a Greener TiO₂@Gum Arabic-Carbon Paste Electrode for the Electrochemical Detection of Pb²⁺ Ions in Plastic Toys

Abstract

A novel greener methodology is reported for the synthesis of titanium dioxide (TiO₂) nanoparticles (NPs) using gum Arabic (<i>Acacia senegal</i>) and the characterization of the ensuing TiO₂ NPs by various techniques such as X-ray diffraction (XRD), Fourier transform infrared, Raman spectroscopy, scanning electron microscopy-energy dispersive X-ray, transmission electron microscopy (TEM), high resolution-TEM, and UV-visible spectroscopy. The XRD analysis confirmed the formation of TiO₂ NPs in the anatase phase with high crystal purity, while TEM confirmed the size to be 8.9 ± 1.5 nm with a spherical morphology. The electrode for the electrochemical detection of Pb²⁺ ions was modified by a carbon paste fabricated using the synthesized TiO₂ NPs. Compared to the bare electrode, the fabricated electrode exhibited improved electro-catalytic activity toward the reduction of Pb²⁺ ions. The detection limit, quantification limit, and the sensitivity of the developed electrode were observed by using differential pulse voltammetry to be 506 ppb, 1.68 ppm, and 0.52 ± 0.01 μA μM^-1, respectively. The constructed electrode was tested for the detection of lead content in plastic toys.