Gold nanoparticles anchored onto three-dimensional graphene: simultaneous voltammetric determination of dopamine and uric acid.

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.

Golf ball-like MoS nanosheet arrays anchored onto carbon nanofibers for electrochemical detection of dopamine.

Arrays of molybdenum(IV) disulfide nanosheets resembling the shape of golf balls (MoS NSBs) were deposited on carbon nanofibers (CNFs), which are shown to enable superior electrochemical detection of dopamine without any interference by uric acid. The MoS NSBs have a diameter of ∼ 2 μm and are made up of numerous bent nanosheets. MoS NSBs are connected by the CNFs through the center of the balls.

Synthesis of ZnO nanowire arrays/3D graphene foam and application for determination of levodopa in the presence of uric acid.

Three-dimensional (3D) graphene foam (GF) was prepared by chemical vapor deposition (CVD) using nickel foam as the template. ZnO nanowire arrays (ZnO NWAs) were vertically grown on the 3D GF by hydrothermal synthesis to prepare ZnO NWAs/GF. This hybrid combines the properties of ZnO NWAs and 3D GF, which has favorable electrocatalysis and outstanding electrical conductivity.

Highly sensitive and selective uric acid biosensor based on a three-dimensional graphene foam/indium tin oxide glass electrode.

A three-dimensional (3D) continuous and interconnected network graphene foam (GF) was synthesized by chemical vapor deposition using nickel foam as a template. The morphologies of the GF were observed by scanning electron microscopy. X-ray diffraction and Raman spectroscopy were used to investigate the structure of GF.

ZnO nanowire arrays on 3D hierachical graphene foam: biomarker detection of Parkinson's disease.

We report that vertically aligned ZnO nanowire arrays (ZnO NWAs) were fabricated on 3D graphene foam (GF) and used to selectively detect uric acid (UA), dopamine (DA), and ascorbic acid (AA) by a differential pulse voltammetry method. The optimized ZnO NWA/GF electrode provided a high surface area and high selectivity with a detection limit of 1 nM for UA and DA. The high selectivity in the oxidation potential was explained by the gap difference between the lowest unoccupied and highest occupied molecular orbitals of a biomolecule for a set of given electrodes.