Selective and sensitive determination of serotonin in the presence of ascorbic acid using zinc oxide reduced graphene oxide (ZnO/RGO) composite modified carbon paste electrode sensor

Abstract

The enhanced electrocatalytic activity of zinc oxide/reduced graphene oxide nano composite modified carbon paste electrode (ZnO/RGO-MCPE) towards the oxidation of serotonin (SER) was investigated. Modified Hummers method was used for the synthesis of graphite oxide. ZnO/RGO composite was prepared via coprecipitation method which was simple, fast and cost-effective. The modifier was characterized using Powder Xray Diffraction (PXRD), Fourier Transform Infrared Spectroscopy (FT-IR), and Thermogravimetry (TG). The ZnO/RGO composite modified electrode possesses better electrochemical activity in Cyclic Voltammetry (CV) and Differential Pulse Voltammetry (DPV) towards the SER. The large surface area of the ZnO/RGO composite enhances the electrooxidation properties of the SER and the detection limit of the SER is 46 nM. The developed sensor shows good reproducibility, stability, and linear dynamic range. This sensor can also be used for the detection of SER in the presence of ascorbic acid (AA).