Synthesis And Electrochemistry Of Gold Nanoparticles/Graphene/Polypyrrole Nanocomposits

Nanocomposites have received considerable attention due to their uniquechemical and physical properties. With the fast development of nanocomposites, theelectrochemistry based on nanocomposites has been intensively investigated becausethe nanomaterials, such as metal nanoparticles, and graphene, have their speciallyoptical, catalytical, and electrical properties. The nanocomposites combining two orseveral different nanomaterials can improve the deficient characteristics of onenanomaterial due to the synergistic effects of the components and make broaderapplication in electrochemical catalysis, energy and sensing.The gold nanoparticles （AuNPs）-based nanocomposites have unique optical,electrical, and catalytic properties, which tightly depended on their size, shape, andcomponent. So, a variety of approaches have been developed for controling synthesisof AuNPs-based nanocomposites. For example, the AuNPs/conducting polymernanocomposites have been extensively applied in electrocatalysis and electrochemicalbiosensing because the nanocomposites had the excellent catalytic ability of AuNPsand good mechanical strength and electrical conductivity of conducting polymer.Therefore, the preparation of novel conducting polymers–metal nanocompositeswould provide various interesting characteristics and new features innanotechnological applications.Graphene, as the thinnest known material in our universe, has attractedextensively attention from both experimental and theoretical science. Because of itsunique properties, such as fast electron transportation, excellent thermal conductivity,high specific surface area, and good biocompatibility, graphene and graphene-basednanocomposites has shown potential application in electrochemical biosensors.In this work, we focus on the synthesis and electrochemistry of novel AuNPs-based nanocomposites. Firstly, we reported a facile method for the fabricationof a novel three-dimensional （3D） dendritic AuNPs@PPy nanocomposite by reactionof HAuCl4and pyrrole in the presence of PSS. The PSS acted as both dopant andsurfactant. The resulting dendritic AuNPs@PPy nanocomposites showed excellentelectrocatalytic activity toward H₂O₂.Secondly, we reported the synthesis of AuNPs/PPy/RGO nanocompositesthrough a simply wet-chemical method. The RGO was wrapped uniformly by PPyand AuNPs were dispersed well on the surface of RGO/PPy. The resultingAuNPs/PPy/RGO composites exhibited good electrocatalytical activity toward O2.The good electrocatalytical activity might be attributed to the synergistic effect ofRGO, AuNPs and PPy. With glucose oxidase （GOD） as a model, theAuNPs/PPy/RGO/GOD nanocomposite-modified electrode was constructed andexhibited good amperometric response to glucose, good reproducibility and lowdetection limit.