Surface Functionalization of Graphene Oxide with Polystyrene Sulfonic Acid Brushes to Fabricate Hierarchical Ag and Au Microstructures as SERS Substrates

Abstract In this work, we reported the spontaneous growth of Ag and Au microstructures on the surface of the graphene oxide‐grafted‐polystyrene sulfonic acid brushes (GO‐g‐PSSA) in Ag(NH 3 ) 2 OH solution and HAuCl 4 solution, respectively. The influences of reaction time and temperature on the morphology and size of Ag (Au) particles were investigated. By optimizing reaction conditions, Ag nanosheet‐assembled microstructures and sea urchin‐like Au microspheres were obtained. These hierarchical Ag (Au) microstructures with highly nanotextured topographies could provide many “hot spots” for surface‐enhanced Raman spectroscopy (SERS). The as‐prepared GO‐g‐PSSA/Ag (Au) composites exhibited excellent SERS performances using Rhodamine 6G (R6G) as the probe molecules and the detection limit of R6G was up to 10 −12 m.