Zr-MOF Nanospheres on Zn-MOF Nanorods on Ni Foam for the Electrochemical Detection of Ivermectin in Urine Samples

Ivermectin (IVM) is a broad-spectrum antiparasitic drug widely used in human medicine with established uses in treating various parasitic infections. This study introduces Zr (zirconium)-metal–organic framework (MOF) nanospheres on Zn (zinc)-metal–organic framework (MOF) nanorods on nickel foam (NF) as an advanced electrochemical sensor for detecting IVM in simulated urine samples. We synthesized Zr-MOF nanospheres and Zn-MOF nanorods and then coated the spheres with rods using ultrasonication to form Zr-MOF on Zn-MOF. This approach enhances the electrochemical properties by leveraging the distinct characteristics of each MOF component. These nanostructures are meticulously characterized using transmission electron microscopy (TEM) to determine the morphology of the sensor. The valence states of Zr-MOF on Zn-MOF are investigated utilizing XPS (X-ray photoelectron spectroscopy), and X-ray diffraction (XRD) has validated the material's crystalline nature. The resulting Zr-MOF on Zn-MOF/NF sensor demonstrates a wide linear range of detection (1 nM to 5 μM) with a sensitivity of 0.075 mA/nM.cm–2 and a lower detection limit (LOD) of 1.75 nM (= 3s/m). This sensor is highly selective over other interfering species such as urea, uric acid (UA), glucose, sucrose, and ions such as Na+, K+, Cl–, SO42–, and Ca2+. The differential pulse voltammetry (DPV) technique reveals effective real-time detection capabilities in simulated urine samples. The Zr-MOF on Zn-MOF nanostructures offer a significant advancement in electrochemical sensing due to their enhanced conductivity and expanded active surface area, making them a promising material for sensitive and selective analyte detection. This sphere and rod configuration demonstrates a superior electrochemical performance, highlighting its potential for applications in advanced sensing technologies. Future research could further explore its capabilities in detecting a wider range of biomolecules and its integration into clinical diagnostics and biomedical applications.