LAUSR

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.