Gold Nanoparticle-Embedded Porous Graphene Thin Films Fabricated via Layer-by-Layer Self-Assembly and Subsequent Thermal Annealing for Electrochemical Sensing

A uniform three-dimensional (3D) gold nanoparticle (AuNP)-embedded porous graphene (AuEPG) thin film has been fabricated by electrostatic layer-by-layer assembly of AuNPs and graphene nanosheets functionalized with bovine serum albumin and subsequent thermal annealing in air at 340 degrees C for 2 h. Scanning electron microscopy (SEM) investigations for the AuEPG film indicate that an AuNP was embedded in every pore of the porous graphene film, something that was difficult to achieve with previously reported methods. The mechanism of formation of the AuEPG film was initially explored. Application of the AuEPG film in electrochemical sensing was further demonstrated by use of H2O2 as a model analyte. The AuEPG film-modified electrode showed improved electrochemical performance in H2O2 detection compared with nonporous graphene AuNP composite film-modified electrodes, which is mainly attributed to the porous structure of the AuEPG film. This work opens up a new and facile way for direct preparation of metal or metal oxide nanoparticle embedded porous graphene composite films, which will enable exciting opportunities in highly sensitive electrochemical sensors and other advanced applications based on graphene metal composites.