Fabrication of a Branch-Like Ni-Doped ZnO/Graphene Nanoplatelet Composite for Enhanced Electrochemical Determination of 17β-Estradiol and Acetaminophen

Efficient sensing materials are required to achieve sensitive, selective, and reproductive detection of different targets by means of electrochemical approaches. In this study, a sensing material of a Ni-doped ZnO/graphene nanoplatelet (Ni-ZnO/GNP) composite is constructed through a simple hydrothermal method and further utilized for electrochemical determination of frequently used drugs, acetaminophen and estradiol. The characterization of this Ni-ZnO/GNP hybrid using scanning electron microscopy (SEM), transmission electron microscopy (TEM), x-ray photoelectron spectroscopy (XPS), x-ray powder diffraction (XRD), Raman spectroscopy, and electrochemical techniques reveals that in this composite the highly conductive GNP provides abundant active sites for the growth of Ni-ZnO, while the introduction of Ni-ZnO weakens the accumulation of the GNP. In comparison to either Ni-ZnO or the GNP, the Ni-ZnO/GNP composite exhibits a much larger electrochemically active area and enhanced catalytic activity. In this regard, the electrochemical response of both acetaminophen and estradiol is improved, resulting in their sensitive and reproductive determination with detection limits of as low as 0.0072 and 0.00056 µM, respectively. This study offers a new approach to design high-performance sensing materials as well as to explore their applications for the determination of trace-leveled drugs. Graphical Abstract