Elaboration of a novel nanosensor using nanoparticles of α-Fe2O3 magnetic cores for the detection of metronidazole drug. Urine human and tap water

Metronidazole (MTZ) is a widely used antibiotic to treat infections caused by anaerobic bacteria, protozoa, and bacteroids such as trichromonosis and vaginosis. In this study, we present a simple strategy for constructing an electroanalysis platform for metronidazole in real samples. We prepared a modified carbon paste with α-Fe₂O₃ magnetic core nanoparticles to construct an α-Fe₂O₃@CPE electrochemical sensor. The surface morphology and composition of the sensor were evaluated using several methods, such as X-ray diffraction and scanning electron microscope. The average size of the α-Fe₂O₃ magnetic core nanoparticles was around 34.30 ​nm. Cyclic voltammetry, electrochemical impedance spectroscopy and chrono-coulometry were performed for the understanding of the electron transfer behavior on the electrocatalytic surface of α-Fe₂O₃@CPE and the unmodified electrode CPE. The resulting sensor demonstrates a very good shift of the Metronidazole reduction peak to a more positive potential (−0.57v vs Ag/AgCl) compared to the unmodified CPE electrode (−0.71v .vs Ag/AgCl). The Metronidazole peak reduction current Ipc varies linearly with metronidazole concentration in the range of 10^-4 ​M to 0.8x10^-6 ​M with a limit of detection and limit of quantification of 2.852x10^-7 ​M and 9.509x10^-7 ​M respectively. Exceeding the detection limits of several existing analytical methods. The proposed procedure has been successfully demonstrated on pharmaceutical tablets and real tap water and urine samples.