| Graphene nanosheets, which possess a variety of fascinating properties such as extremely large surface area, good electrical conductivity, and unique optical properties, have attracted considerable attentions in sensors in recent years. Gold nanoparticles(AuNPs), which have small particle size, good biocompatibility and catalytic activity, are widely used in sensors. Using two-dimensional graphene nanosheets as substrates to construct graphene/AuNPs nanocomposite can not only avoid the aggregation of nanomaterials efficiently, but also exploit synergies of graphene and AuNPs in sensing performances. In this paper, a three-dimensional(3D) functionalized graphene nanosheets/AuNPs composite film was fabricated by electrostatic layer-by-layer assembly. Morphologies and sensing performances of the as made and different atmospheres, temperatures annealed3D composite films were investigated. And the main contents of this paper are as follows:1. A well-organized, highly-dispersed3D functionalized graphene nanosheets/AuNPs composite film was fabricated by electrostatic layer-by-layer assembly. UV-vis and SEM characterizations show that the film increased uniformly with growth layers. Electrochemical sensors based on the3D functionalized graphene nanosheets/AuNPs composite film can be used to detect H2O2and glucose, and the detection limit of H2O2is0.5μmol·L-1. Additionally, the film can be used as surface enhanced Raman scattering substrate to detect trace Rh6G.2. An uniform AuNP-embedded porous(AuEPG)3D film, which an AuNP was embedded in every pore of the porous graphene film, was fabricated by annealing the above film in air at340℃for2h. During the thermal annealing in air, the coalescence of close-packed AuNPs in the3D composite film resulted in etching of the neighboring graphene nanosheets giving nanoporous graphene films. AuEPG film modified electrodes showed much better electrochemical performances in H2O2and NO2-detection, and the detection limit of H2O2is0.1μmol·L-1. |
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