title: UV/ozone-oxidized large-scale graphene platform with large chemical enhancement in surface-enhanced Raman scattering.
abstract: We fabricated a highly oxidized large-scale graphene platform using chemical vapor deposition (CVD) and UV/ozone-based oxidation methods. This platform offers a large-scale surface-enhanced Raman scattering (SERS) substrate with large chemical enhancement in SERS and reproducible SERS signals over a centimeter-scale graphene surface. After UV-induced ozone generation, ozone molecules were reacted with graphene to produce oxygen-containing groups on graphene and induced the p-type doping of the graphene. These modifications introduced the structural disorder and defects on the graphene surface and resulted in a large chemical mechanism-based signal enhancement from Raman dye molecules [rhodamine B (RhB), rhodamine 6G (R6G), and crystal violet (CV) in this case] on graphene. Importantly, the enhancement factors were increased from ∼10(3) before ozone treatment to ∼10(4), which is the largest chemical enhancement factor ever on graphene, after 5 min ozone treatment due to both high oxidation and p-doping effects on graphene surface. Over a centimeter-scale area of this UV/ozone-oxidized graphene substrate, strong SERS signals were repeatedly and reproducibly detected. In a UV/ozone-based micropattern, UV/ozone-treated areas were highly Raman-active while nontreated areas displayed very weak Raman signals.
authors: Department of Chemistry, Seoul National University, Seoul 151-742, Korea.
authors: Sung
authors: S
authors: Huh
authors: Jaesung
authors: J
authors: Park
authors: Young Soo
authors: YS
authors: Kim
authors: Kwang S
authors: KS
authors: Kim
authors: Byung Hee
authors: BH
authors: Hong
authors: Jwa-Min
authors: JM
authors: Nam
mesh_terms: D006108:Graphite / Q000737:chemistry*; D008027:Light; D008422:Materials Testing; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010084:Oxidation-Reduction; D010126:Ozone / Q000737:chemistry*; D010316:Particle Size; D012542:Scattering, Radiation; D020349:Surface Plasmon Resonance / Q000379:methods*; D013499:Surface Properties; D014466:Ultraviolet Rays
chemical_list: D010126:Ozone; D006108:Graphite