Fabrication of Nanostructure Electrochemical Sensor Based on the Carbon Paste Electrode (CPE) Modified With Ionic Liquid and Fe3O4/ZIF-67 for Electrocatalytic Sulfamethoxazole Detection

The detection of sulfamethoxazole, an antibacterial sulfonamide drug, is a very effective with antibiotic properties, and commonly used in the treatment of a variety of infections. Due to the importance in diseases treatment of humans and also of animals, the development of techniques for its quantification in body fluids is highly desirable. A voltammetric sensor is described for the determination of the antibiotic sulfamethoxazole. It is based on the use of a carbon paste electrode modified with a Fe3O4/ZIF-67 nanocomposite and ionic liquid (IL) 1-Butyl-3-methylimidazolium hexafluorophosphate (Fe3O4/ZIF-67/ILCPE). The morphology and structure of the nanocomposite were characterized by Fourier-transform infrared spectroscopy (FT-IR), x-ray diffraction (XRD), transmission electron microscopy(TEM) and field emission scanning electron microscopy (FESEM). Under the optimal conditions, the response of the electrode, typically measured between 0.74 and 1.1 V (vs. Ag/AgCl), increases linearly in the 0.01−520.0 µM sulfamethoxazole concentration range, and the lower detection limit is 5.0 nM. Moreover, this electrode could substantially be applied for the analysis of sulfamethoxazole in the real samples (e.g., urine, tap water and river water).