Effect of Various Deep Eutectic Solvents on the Sustainable Synthesis of MgFe2O4 Nanoparticles for Simultaneous Electrochemical Determination of Nitrofurantoin and 4-Nitrophenol

The innovations in the field of green chemistry have expedited the pace of advances in varied research areas ranging from the development of diverse routes for the material synthesis to designer solvents. Deep eutectic solvents (DESs) integrating the metrics and principles of sustainability substitute the traditional hazardous and volatile reagents, which is significantly attracting the attention of research and industrial sectors. In view of that, we introduce deep eutectic-mediated solid-state synthesis of phase-pure magnesium ferrite nanoparticles at a temperature of 500 °C for the simultaneous detection of nitrofurantoin and 4-nitrophenol. The influence of five different DESs on the effectual formation, structure, and composition of magnesium ferrite nanoparticles was investigated through various techniques such as field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), Fourier-transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and electrochemical impedance spectroscopy (EIS). Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques are employed to evaluate the electrochemical behavior of as-synthesized samples toward the electrochemical detection of nitrofurantoin and 4-nitrophenol. Comparatively, the choline chloride and fructose DES-assisted nanometric magnesium ferrite (MgFe2O4)-modified electrode exhibits a higher sensitivity, lower detection limits (NFT = 33 nM and 4-NP = 7 nM), a linear range (0–342.6 μM), an excellent selectivity, and a good reproducibility. The practical applicability of the fabricated sensor was studied in water and fruit samples and thus affords satisfactory results for NFT and 4-NP detection.