Orthorhombic dysprosium iron oxide decorated sulfur-doped graphitic carbon nitride for the selective electrochemical sensing of nitrofurazone in water samples

Nitrofurazone is an important antibiotic drug for medicating humans and animals. Excessive usage and excrement induce trace-level residues in the environment will cause water contamination. So, it’s necessary to monitor these drug residues in water samples. This steam successfully reports the preparation of Dysprosium ferrite (DFO) nanoparticles decorated over S-doped graphitic carbon nitride (S-gCN) for the application in the electrochemical sensing of Nitrofurazone. The nanocomposite material was well characterized through various physicochemical techniques such as X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), Field emission scanning electron microscope (FESEM), Transmission electron microscope (TEM), and X-ray photoelectron spectroscopy (XPS). For the preparation of DFO nanoparticles traditional polyol reflux method is employed using ethylene glycol as a solvent which effectively controls the growth nucleation and agglomeration of nanoparticles. EIS studies demonstrate that a higher charge transfer rate constant was observed for DFO/S-gCN/GCE (1.76 × 10⁻⁷ cm s⁻¹) than DFO/GCE (5.34 ×10⁻⁸ cm s⁻¹) and S-gCN/GCE (7.12 × 10⁻⁸ cm s⁻¹). CV demonstrates a higher electrochemical active surface area for DFO/S-gCN/GCE (0.353 cm²) than DFO/GCE (0.312 cm²) and S-gCN/GCE (0.339 cm²). The electrochemical reduction of NFZ over DFO/S-gCN/GCE was observed at the potential of −0.465 V. Electron transfer kinetics are evaluated using different scan rate studies. The proposed sensing platform exhibits admirable sensitivity 2.929 µA µM⁻¹ cm⁻², selectivity, and limit of detection (0.0071 μM) with good repeatability and reproducibility. Furthermore, DFO/S-gCN/GCE was applied to monitor the amount of nitrofurazone present in lake and river water samples with admirable recovery results.