Mechanochemical Synthesis of Graphene Oxide/UiO-66-NH₂ Nanocomposites: Characterization and Fabrication of an Electrochemical Sensor for the Determination of Tetracycline Residues in Milk Samples

Abstract

High Resolution Image Download MS PowerPoint Slide This paper describes a green mechanochemical approach for the synthesis of a graphene oxide-based UiO-66-NH 2 metal organic framework composite (GO/UiO-66-NH 2 ) for the fabrication of a sensitive electrochemical sensor for the determination of tetracycline (TC) residues in milk samples. The structural and electrochemical characteristics of the GO/UiO-66-NH 2 nanocomposite were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), FT-IR spectroscopy, and cyclic voltammetry (CV). Incorporation of UiO-66-NH 2 onto the GO surface can increase the number of effective reaction sites and improve the electrochemical performance of the fabricated sensor. The sensor was simply prepared through drop-casting a GO/UiO-66-NH 2 suspension onto the glassy carbon electrode surface and used for TC determination by differential pulse voltammetry (DPV) as a sensitive analytical method. The fabricated sensor provided a linear calibration over the concentration ranges of 0.02–1.00 μg mL –1 ( R 2 = 0.9921) and 1.00–40 μg mL –1 ( R 2 = 0.9932) with a limit of detection of 0.003 μg mL –1 using DPV. The proposed sensor was successfully applied to measure the TC residues in different milk samples with satisfying recovery from 94.0 to 105.0%.