Green-Synthesized CuO Nanoparticles from Pomegranate Peel for Dual Electrochemical Detection and Adsorptive Removal of Tetracycline

Green nanomaterials have attracted considerable attention for environmental monitoring due to their sustainability and multifunctional properties. In this study, copper oxide nanoparticles were synthesized using pomegranate peel (pp) extract (CuO@PP) as a reducing and stabilizing agent and investigated for both electrochemical detection and adsorptive removal of tetracycline. The synthesized CuO@PP nanoparticles were characterized by UV–Vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDX), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). CuO@PP nanoparticles were immobilized onto a screen-printed electrode for electrochemical detection of tetracycline. Square wave voltammetry (SWV) showed good analytical performance, with a low detection limit of 3.1 nM, good selectivity, and successful application in real-water samples, including untreated tap water and hospital wastewater. In addition, CuO@PP showed effective tetracycline adsorption, reaching 88% removal within 25 min. The Langmuir model gave an estimated maximum adsorption capacity of 312.77 mg g−1, while the Freundlich model provided a better fit to the experimental data, indicating adsorption on a heterogeneous surface. These results demonstrate the potential of green-synthesized CuO@PP as a multifunctional material for both tetracycline detection and removal, with promising applications in environmental monitoring and water treatment.