UV/Ozone-Oxidized Large-Scale Graphene Platform with Large Chemical Enhancement in Surface-Enhanced Raman Scattering

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• 作者：Sung Huh ; Jaesung Park ; Young Soo Kim ; Kwang S. Kim ; Byung Hee Hong ; Jwa-Min Nam
• 刊名：ACS Nano
• 出版年：2011
• 出版时间：December 27, 2011
• 年：2011
• 卷：5
• 期：12
• 页码：9799-9806
• 全文大小：1020K
• 年卷期：0
• ISSN：1936-086X

文摘

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 ∼10³ before ozone treatment to ∼10⁴, 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.