LAUSR

The study reports the development of a nanostructured mixed-valence Fe(II)Fe(III)BTC metal-organic framework (BTC = 1,3,5-benzenetricarboxylate) modified carbon paste electrode as a novel sensor for the amoxicillin detection in aqueous solutions using square wave voltammetry. The physicochemical properties of FeBTC were characterized using X-ray diffraction spectroscopy, Fourier-transform infrared spectroscopy, Brunauer-Emmett-Teller analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy. These techniques revealed that FeBTC has a surface area of 1211 m2/g, a total pore volume of 1.46 cm3/g, particle sizes ranging from 10 to 20 nm, and a mixed-valence structure. Furthermore, SEM, TEM, and energy-dispersive X-ray spectroscopy showed homogeneous distribution of FeBTC throughout the modified electrode. The electrochemical study showed that the mixed-valence FeBTC improved the electron transfer capabilities of the electrode. Under optimal conditions, the modified electrode exhibited a significant increase in peak height compared to the unmodified electrode (4.6 times higher), with an acceptable reproducibility of 4.88% relative standard deviation. The linear range of the sensor was 1-100 µM with a good coefficient of determination of 0.9985, and a detection limit of 0.107 µM. Additionally, the sensor demonstrated excellent performance with the satisfactory recoveries and a good correlation with LC-MS/MS analysis.