Enhanced electrocatalytic activity of bismuth-doped lanthanum stannate pyrochlore for electrochemical detection of the Covid-19 drug nitazoxanide

Abstract

Nitazoxanide (NAZ) is an antiparasitic drug that reduces inflammation caused by the SARS-CoV-2 virus. The presence of nitro group in this drug makes it an environmental pollutant. Here, an electrochemical sensor for the determination of NAZ was developed based on bismuth-doped pyrochlore lanthanum stannate nanoparticles modified screen-printed carbon electrodes (BLSO NPs/SPCE). The BLSO NPs were prepared by a combination of co-precipitation and thermal calcination processes. The fabricated BLSO NPs were analyzed by different spectroscopic methods. X-ray diffraction analysis (XRD), Fourier transform-infrared spectroscopy (FT-IR), and Raman spectroscopy showed that the lattice parameters of the lanthanum stannate nanoparticles (LSO NPs) were increased after bismuth doping due to cell expansion. The morphology and oxidation state of the elements in the BLSO NPs were analyzed by field emission-scanning electron Microscopy (FE-SEM), high-resolution transmission electron microscopy (HR-TEM), and X-ray photoelectron spectroscopy (XPS). FE-SEM and HR-TEM analysis revealed that LSO, and BLSO exhibits as a nanoparticle morphology with 20–50 nm in size. Cyclic voltammetry (CV) showed that the electrochemical reduction of NAZ was enhanced after bismuth doping due to the synergistic effect of BLSO NPs. Electrochemical determination of NAZ was performed by DPV with a low detection limit of 4 nM between the linear range of 0.01–172 µM and an electrode sensitivity of 0.16 µA µM−1 cm−2. The developed NAZ sensor showed favorable results in terms of selectivity, repeatability, and stability.