Sensitive voltammetric sensor based on polyoxometalate/reduced graphene oxide nanomaterial: Application to the simultaneous determination of L-tyrosine and L-tryptophan

In this report, a novel voltammetric sensor based on polyoxometalate (H3PW12040, POM) functionalized reduced graphene oxide (rGO) modified glassy carbon electrode (GCE) was presented for simultaneous determination of L-tyrosine (L-Tyr) and L-tryptophan (L-Trp). The nanocomposites were characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The electrochemical determination of L-Tyr and L-Trp has been studied using square wave voltammetry (SWV) on GCE modified with POM-rGO composite (POM-rGOIGCE). The developed method was also applied successfully for the simultaneous determination of L-Tyr and L-Trp in spiked serum sample and the linearity range of L-Tyr and L-Trp was 1.0 x 10(-11) - 1.0 x 10(-9)M with the detection limit of 2.0 x 10(-12)M. (C) 2016 Elsevier B.V. All rights reserved.