A facile fabrication of large-scale reduced graphene oxide-silver nanoparticle hybrid film as a highly active surface-enhanced Raman scattering substrate

We demonstrated here a facile approach to produce a large-scale reduced graphene oxide–silver nanoparticle (RGO–AgNP) hybrid film, and further explored its application as a highly active surface-enhanced Raman scattering (SERS) substrate. The RGO–AgNP nanohybrids were firstly synthesized by reducing graphene oxide (GO) and Ag+ cations with sodium citrate, and the RGO–AgNP hybrid film was then fabricated by evaporating the RGO–AgNP nanohybrids solution and harvesting the film formed at the air–liquid interface with a solid substrate. Two probe molecules, Rhodamine 6G (R6G) and melamine (MA), were chosen to evaluate the enhancement performance of the fabricated SERS-active substrate. Our results indicated that this RGO–AgNP hybrid film-based SERS-active substrate presents outstanding performances for detecting R6G with an enhancement factor of 2.3 × 106 and a detection limit of approximately 1.0 × 10−12 M. In addition, this SERS substrate shows excellent ability to recognize MA molecules with a detection limit of approximately 1.0 × 10−7 M.