Simultaneous Voltammetric Measurement of Dopamine, Acetaminophene and Xanthine at a Glassy Carbon Electrode Modified with reduced graphene oxide

In current work highly sensitive and stable electrochemical sensor for simultaneous detection of dopamine (DA), acetaminophene (AC) and xanthine (XA) is constructedbased on the modified GCE with reduced graphene oxide (rGO).[1] A facile electrochemical method was applied to prepare electrochemically reduced graphene oxide(rGO). The morphology and structure of rGO were characterized by Fieldemission Scanning Electron Microscope (FESEM), and X-ray diffraction (XRD). Cyclic voltammetry (CV), different pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) were used to study the electrochemical properties of the modified electrode. The results indicate that the rGO has excellent electrocatalytic activity for the oxidation ofdopamine (DA), acetaminophene (AC) and xanthine (XA).[2] Com-pared with the bare glassy carbon electrode (GCE), rGO modified GCE (rGO/GCE) exhibits much higherelectrocatalytic activities toward the oxidation of dopamine (DA), acetaminophene (AC) and xanthine (XA) with increasing of peak currents and decreasing of oxidation overpotentials. Differential pulse voltammetry results show that, two concentration ranges of 0.1-4.9 and 4.9-150.0 μM for DA, two concentration ranges of 0.4-7 and 7-150.0 μM for AC and two concentration ranges of 0.1-12 and 12-150.0 for XN. The calculated detection limits of the analytes were calculated as 20, 44 and 43 nM for DA, AC and XN, respectively. The proposed modified electrode was successfully used for simultaneous determination of in DA, AC and XN in the human serum and urine samples. This work provides a simple and green route to construct graphenebasedelectrochemicalsensor, which is promising for the simultaneous determination of DA, AC and XA