Fabrication of free-standing and flexible silver nanoparticle-graphene films and their surface-enhanced Raman scattering activity

A free-standing and flexible silver nanoparticle-graphene (Ag NP-GE) film with high surface-enhanced Raman scattering (SERS) sensitivity has been synthesized. Firstly, the highly stable and dispersive Ag NP-GE nanocomposite was fabricated by an in situ reduction method using graphene oxide sheets as substrates and ethylene glycol as a reduction agent in a solvothermal environment. Secondly, the Ag NP-GE films can be fabricated through vacuum filtration of the Ag NP-GE suspension. The highly SERS-active Ag nanoparticles and Ag nanoparticle aggregates make a significant contribution to the high sensitivity of SERS to rhodamine 6G molecules with an enhancement factor of 5.6 x 10(7).