A novel voltammetric platform based on dysprosium oxide for the sensitive determination of sunset yellow in the presence of tartrazine

Highlights: • A novel voltammetric platform was developed for the detection of sunset yellow. • The proposed platform (Dy₂O₃NPs/MWCNTs/GCE) exhibited excellent catalytic effect towards sunset yellow. • The novel method enables a detection limit of 3.5 × 10⁻¹⁰ M for sunset yellow. • The voltammetric platform (Dy₂O₃NPs/MWCNTs/GCE) has successfully been applied to food and pharmaceutical products. • The novel method exhibited excellent reproducibility, good selectivity and sensitivity. -- Abstract: This study reports the preparation of a novel voltammetric platform based on the modification of a glassy carbon electrode (GCE) with carbon nanotubes (MWCNTs) and dysprosium oxide (Dy₂O₃) nanoparticles. The electrode material was characterized by means of scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction method (XRD). The novel platform (Dy₂O₃NPs/MWCNTs/GCE) was applied for the voltammetric determination of sunset yellow (SY) in the presence of tartrazine (TAR). SY was first adsorbed at the surface of Dy₂O₃NPs/MWCNTs/GCE by keeping it into a solution of SY for 200 s. Afterwards, the proposed platform was washed with ultrapure water and transferred with the adsorbed species in a voltammetric cell containing only 0.1 M phosphate buffer solution (PBS). Then, the novel platform (Dy₂O₃NPs/MWCNTs/GCE) exhibited excellent electrocatalytic activity and presented improved voltammetric responses when compared to other electrodes. The novel platform produced an improved anodic peak at 0.705 V and a corresponding cathodic peak at 0.690 V for SY and an irreversible anodic peak at 0.957 V for TAR. When compared to the electrode modified with only MWCNTs, a remarkable increase in current response and a electrocatalytic activity of the proposed platform were observed for SY and TAR at a GCE modified with both MWCNTs and Dy₂O₃NPs. A linear relationship was obtained between the current response and the concentration of SY over range of 1.0 × 10⁻⁹ M − 1.4 × 10⁻⁷ M with an LOD of 3.5 × 10⁻¹⁰ M using square wave voltammetry (SWV). The proposed procedure provided an accurate and a precise quantification to the analysis of food and pharmaceutical samples.