ABSTRACT
Based on the Au nanoparticles-ZnO nanocone arrays/graphene foam electrode, a novel dopamine biosensor was successfully developed. Graphene foam was synthesized by chemical vapor deposition, ZnO nanocone arrays were grown on its surface by a hydrothermal method and Au nanoparticles with carboxyl groups were self-assembled onto the ZnO nanocone arrays to obtain Au nanoparticles-ZnO nanocone arrays/graphene foam electrode. The result indicates that the prepared electrode has a high sensitivity (4.36 µA µM-1) and low limit of detection (0.04 µM, S/N = 3) for the detection of dopamine. The prepared electrode also exhibits an excellent selectivity under the interference of uric acid, good repeatability and stability. The prepared sensor has been successfully applied in real samples and has a great potential to be used in the field of medical and health.
Subject(s)
Biosensing Techniques/instrumentation , Dopamine/analysis , Electrodes , Gold/chemistry , Graphite/chemistry , Metal Nanoparticles/chemistry , Zinc Oxide/chemistry , Electrochemical Techniques/methods , Humans , Hydrogen-Ion Concentration , Limit of Detection , Microscopy, Electron, Scanning , Porosity , Reproducibility of Results , Sensitivity and Specificity , Spectrum Analysis, RamanABSTRACT
An electrochemical sensor is described for simultaneous voltammetric determination of dopamine (DA) and uric acid (UA). It is based on the use of a nanomaterial composed of gold nanoparticles and 3-dimensional graphene (Au NP@3D GR). The 3D GR was prepared by chemical vapor deposition using nickel nanoparticles as the template at a temperature of around 900 °C. The surface of 3D GR contains oxygen-functional groups after treatment with acid. Carboxylated Au NP were self-assembled and anchored onto the surface of 3D GR. The nanomaterial was placed on a ITO electrode. The few-layer graphene on the ITO glass has a porous structure and the distribution of Au NP is uniform. The electrode shows a high sensitivity and a low detection limit for DA and UA. Figures of merit include detection limits of 0.1 M for DA and of 0.1 µM for UA, and well separated peaks at potentials of 0.18 and 0.30 V (vs. Ag/AgCl), respectively, at pH 7.0. The electrode has good repeatability and stability. Graphical abstract Carboxylated gold nanoparticles were self-assembled and immobilized on 3-dimensional graphene by chemical vapor deposition for simultaneous determination of dopamine (DA) and uric acid (UA).