Three-dimensional (3D) crumpled graphene-silver hybrid nanostructures on shape memory polymers for surface-enhanced Raman scattering

Compare with the two-dimensional (2D) structure of graphene, introducing three-dimensionality to graphene can provide more molecular adsorption sites by fully using the three-dimensional volume of laser. Here, we describe the fabrication of 3D wrinkled Ag NPs-graphene hybrid film which rarely contains two classes of wrinkles, micro wrinkles and nano wrinkles. We obtain a new 3D wrinkled Ag NPs-graphene hybrid structure by the buckling and crumpling of graphene to produce nano wrinkles with the formation of the micro wrinkles of the polystyrene (PS) polymer. We also have carefully examined evolution of crumpling and optimized the size and spacing of deposited Ag NPs on graphene for higher SERS intensity. The 3D Ag NPs-graphene hybrid film shows at least 1 order of magnitude lower detection limit than that of the flat one by SERS detection of triphenyl phosphine (PPh3). We believe that this wrinkled Ag NPs-graphene hybrid structure could be applied as a great potential platform for highly sensitive SERS substrate.