Polyvinyl butyral/graphene oxide nanocomposite modified electrode for the integrate determination of terminal metabolites of catecholamines in human urine

Abstract

We for the first time reported the development of an electrochemical sensor with polyvinyl butyral/graphene oxide (PVB/GO) nanocomposite film for the integrate determination of major terminal metabolites of catecholamines. The PVB/GO nanocomposite modified electrode was characterized by ATR-FTIR spectroscopy, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), scanning probe microscopy (SPM) and electrochemical impedance spectroscopy (EIS). The PVB/GO-modified glassy carbon electrode exhibits a good affinity and electrocatalytic activity to the oxidation of homovanillic acid (HVA) and vanillylmandelic acid (VMA), and the two terminal metabolites showed nearly consistent peak potentials at the modified electrode by differential pulse voltammetry (DPV). The performance of the developed sensor was evaluated in terms of linearity, precision, stability, repeatability and recovery for the determination of HVA/VMA. The electrode enables the ‘equivalent’ determination over the ranges of 0.549–120μM with a detection limit (LOD) of 0.18μM for HVA and 0.75–120μM with a detection limit of 0.25μM for VMA, respectively. The proposed sensor has the advantages of low cost, well stability, and high sensitivity. It was successfully applied to the integrate determination of the terminal metabolites of catecholamines in human urine.