Electrodeposited Cerium Oxide Nanoparticles as Sensor for Caffeine

In this research, a glassy carbon electrode modified with cerium oxide nanoparticles was used to study the electrochemical behavior and determination of caffeine. For this purpose, the surface of the electrode was modified by electrochemical precipitation of cerium oxide at a temperature of 60 °C. The effect of different parameters, such as temperature, electrodeposition potential, pH, buffer type, and concentration of cerium in the preparation of the electrochemical sensor were investigated. Cerium oxide (CeO₂) nanoparticles were also characterized by different techniques such as scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD) analysis. Increasing the current and minimizing the over potential of caffeine on the glassy carbon electrode modified with cerium oxide nanoparticles are the main advantage of the designed sensor. Under optimal conditions, the oxidation peak currents were proportional to caffeine concentration in the range of 10–368 µM with a low detection limit of 2.9 µM. The modified CeO₂/GC electrode has high sensitivity, selectivity, stability, reproducibility, and a larger active surface area than a bare glassy carbon electrode and fast response. Finally, the analytical efficiency of the proposed modified electrode was evaluated for the determination of caffeine in some real samples.