An electrochemical sensor based on MOF-derived NiO@ZnO hollow microspheres for isoniazid determination

The electrocatalytic activity of metal-organic framework (MOF)-derived NiO@ZnO hollow microspheres was studied for its application to an isoniazid sensor. The MOF-derived NiO@ZnO hollow spheres were synthesized by the coordination reaction of terephthalic acid with Zn²⁺ and Ni²⁺ and followed by calcination. Morphology characterization showed that the MOF-derived NiO@ZnO sphere has circular core-shell structure with pores on its surface. Further electrochemical characterization of the prepared sensor by cyclic voltammetry and differential pulse voltammetry proved that the material has good electrical conductivity and strong catalytic ability. Distinct oxidation peaks occur for INZ at potential of 0.22 V (vs. saturated calomel electrode). Under the optimal experimental conditions, the linear range of the sensor for isoniazid determination was 0.8 ~ 800 μM, and the detection limit was 0.25 μM (S/N = 3). In addition, the sensor displayed good stability, repeatability, and reproducibility. The established method was successfully applied for determination of isoniazid in tablets and mouse serum with admirable accuracy and reliability. Graphical abstract Schematic presentation of an electrochemical sensor based on MOF-derived NiO@ZnO hollow microspheres for isoniazid determination.