Simple, Flexible, and Ultrastable Surface Enhanced Raman Scattering Substrate Based on Plasmonic Nanopaper Decorated with Graphene Oxide

Surface enhanced Raman spectroscopy (SERS) is becoming a paramount analytical mechanism in nanotechnology and biological/chemical detection. However, fabrication of highly sensitive SERS substrates often involves expensive and time-consuming procedures and the resulting materials require careful handling. Herein, a simple-to-manufacture, highly sensitive, and easy-to-handle SERS substrate enabled by plasmonic nanopaper decorated with graphene oxide flakes is reported. Owing to the physicochemical properties gathered by this SERS substrate, the nanocomposite leads to a flexible platform facilitating: a) analysis of the model analyte (Rhodamine 6G) via a high energy laser (457 nm) with negligible fluorescent background, which is important to achieve the maximum excitation of the respective localized surface plasmon resonance; b) a charge transferring phenomenon associated to the graphene derivative that, operating in synergy with the previous phenomenon, enhances the SERS signal and allows an analytical limit of detection of 0.13 x 10(-9) M, which is about 2900-fold lower than that obtained with the counterpart substrate made of silver nanoparticle-decorated nanopaper; c) an ultrastable signal which remains completely constant at least during 50 days. Furthermore, the resulting SERS substrate is amenable to a cost-efficient and large-scale production process, which furthers laboratory and real world applications of SERS.