Voltammetric detection of caffeine content in different tea stuffs by using Co3O4/GCE-Nafion electrode

Abstract

In this study, we synthesized Caffeine assisted Co3O4 nanostructures via a low-temperature hydrothermal method. After structural and surface characterization, prepared Co3O4 nanostructures were deposited on the surface of GCE through the drop-casting process with resulting electrode represented as Co3O4/GCE-Nafion. The modified electrode was used as a working electrode for oxidation of Caffeine (CAF). A square wave voltammetry technique used to examine the performance of the modified electrode offers the limit of detection (0.23 µM). In comparison, amperometry shows more sensitive responses such as the limit of detection (0.097 µM) and demonstrates good agreement in results at a wide range scale. The modified electrode exhibits good reproducibility with no significant interference in results. We compared these analytical results with other reported analytical techniques, but we obtain better results as compared to previous reports. Furthermore, Co3O4/GCE-Nafion was used to determine the concentration of CAF in tea samples, and the excellent recoveries were obtained at different concentrations of CAF. These results offer good reusability of the modified electrode in real-sample analysis and suggest the electrode feasibility for quality assurance of food and drug regularity authority applications.