▎ 摘　　要

Herein, we report the simultaneous voltammetric determination of serotonin (5-HT) and melatonin (MET) using a reduced graphene oxide/ruthenium oxide (RGO/RuO2) modified glassy carbon electrode (GCE) for the first time. The as-synthesized RGO/RuO2 composites were characterized by using a variety of techniques, such as scanning electron microscopy (SEM), infrared spectroscopy (IR), X-ray diffraction (XRD), Raman spectroscopy and energy dispersive X-ray spectroscopy (EDX). An enhanced voltammetric oxidation peak was observed for serotonin (5-HT) and melatonin (MET) at RGO/RuO2 modified GCE. Notably, a sufficient voltammetric peak to peak separation (Delta E-p) of 290 mV was found between the two species by using differential pulse voltammetry (DPV) analysis. The lower limit of detection (LOD) was calculated as 0.02 mu M for 5-HT and 0.18 mu M for MET. Moreover, the fabricated sensor was found to exhibit excellent sensitivity, reliability, and durability, surpassing those achievable with other modified electrodes, which may find use in practical industrial applications.