An Electrochemical Sensor Based on Amino Magnetic Nanoparticle-Decorated Graphene for Detection of Cannabidiol

For detection of cannabidiol (CBD)—an important ingredient in Cannabis sativa L.—amino magnetic nanoparticle-decorated graphene (Fe3O4-NH2-GN) was prepared in the form of nanocomposites, and then modified on a glassy carbon electrode (GCE), resulting in a novel electrochemical sensor (Fe3O4-NH2-GN/GCE). The applied Fe3O4-NH2 nanoparticles and GN exhibited typical structures and intended surface groups through characterizations via transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray powder diffraction (XRD), vibrating sample magnetometer (VSM), and Raman spectroscopy. The Fe3O4-NH2-GN/GCE showed the maximum electrochemical signal for CBD during the comparison of fabricated components via the cyclic voltammetry method, and was systematically investigated in the composition and treatment of components, pH, scan rate, and quantitative analysis ability. Under optimal conditions, the Fe3O4-NH2-GN/GCE exhibited a good detection limit (0.04 μmol L−1) with a linear range of 0.1 μmol L−1 to 100 μmol L−1 (r2 = 0.984). In the detection of CBD in the extract of C. sativa leaves, the results of the electrochemical method using the Fe3O4-NH2-GN/GCE were in good agreement with those of the HPLC method. Based on these findings, the proposed sensor could be further developed for the portable and rapid detection of natural active compounds in the food, agricultural, and pharmaceutical fields.