Novel Synthesis of Ca²⁺-Doped MgAl₂O₃-G-SiO₂ Mesoporous Nanospheres toward Sensing Effects for Selective Electrochemical Performance of Azithromycin

Abstract

Azithromycin is one of the most concentrated antibiotics in wastewater, as conventional wastewater treatment facilities cannot eliminate this antibiotic from the environment. In this study, we proposed using a graphene-based mesoporous electrochemical sensor to take simultaneous voltammetric measurements of azithromycin. Because of its homogeneous pore structure, large surface area, quick electron transfer rate, and superior biocompatibility, magnesium-containing mesoporous silica is a promising resource for the immobilization of biomolecule matrix. Ca²⁺-doped MgAl₂O₃-G-SiO₂ was used to build an amperometric biosensor through a self-assembly process. At room temperature in a buffer solution with a pH of 7.0, the modified electrode under ideal circumstances displayed good azithromycin sensing activity, a linear range of 1 to 5 µmolL⁻¹, a detection limit of 0.5 µmolL⁻¹, and a reaction time of less than 2 sec. An array of morphological analysis methods—including X-ray diffraction methos, scanning electron microscopy, Brunauer-Emmett-Teller method, high resolution tunneling electron microscopy, Raman, diffuse reflectance spectroscopy, and X-ray photoelectron spectroscopy—was used to examine the nanocomposite’s crystalline structure. Cyclic voltammetry was used to determine the sensing effects in the mesoporous active nanomaterials. Finally, it was found that the electrochemical sensor performed as an ideal biosensor that was able to detect azithromycin in the presence of several interfering species with high stability, selectivity, and repeatability.