▎ 摘　　要

A novel and sensitive electrochemical method has been developed for the simultaneous determination of dopamine (DA) and 5-hydroxytryptamine (5-HT) using graphene (GR) and poly 4-amino-3-hydroxy-1-naphthalenesulfonic acid modified screen printed carbon sensor. The electrochemical measurements were studied using cyclic voltammetry, square wave voltammetry, whereas the surface morphology of the modified sensor was characterized by Electrochemical Impedance Spectroscopy and Field Emission scanning electron microscopy. The fabricated sensor facilitated the analysis of DA and 5-HT in the concentration range 0.05100 mu M and 0.05150 mu M with the detection limit of 2 nM and 3 nM respectively. The fabricated sensor has been explored for the determination of 5-HT in the plasma samples and the selectivity of the proposed work has been proved by the analysis of DA and 5-HT in the presence of common metabolites present in biological fluids. The analytical applicability of the fabricated sensor has also been successfully demonstrated for the simultaneous detection of DA and 5-HT in the pharmacological formulations, human urine and blood samples. (C) 2016 Elsevier B.V. All rights reserved.