The Key Laboratory of Molecular Engineering of Polymers, Ministry of Education, Department of Macromolecular Science, Fudan University, Shanghai 200433, China.
Phys Chem Chem Phys. 2011 Dec 21;13(47):21116-20. doi: 10.1039/c1cp22727k. Epub 2011 Oct 21.
Herein, noble metal nanoparticle (Au or Ag NP) decorated graphene sheets, fabricated according to a facile one-pot environmentally friendly method, are used as good substrates for the investigation of the combined surface-enhanced Raman scattering (SERS) effect, where both the electromagnetic mechanism and the chemical mechanism effects coexist among the Au or Ag NPs, graphene sheets and the absorbed analytes. Our results show that, in aqueous solution, the SERS effect of both the Au and Ag NPs on the absorbed probe molecules and on graphene is competitive, which varies dependent on the species and the concentration of the absorbed probe molecule. By a detailed comparison of three probe molecules (rhodamine 6G, nile blue A, and 4-aminobenzenethiol) with different coupling abilities to the graphene sheets, we finally attribute this phenomenon to the result of the strong suppressing effect of the macrocyclic probe molecules on the SERS of graphene, induced by charge transfer, as the probe molecules are coupled to the graphene sheets. This competitive effect is a non-ignorable phenomenon when graphene/Au or Ag nanocomposites are used as SERS substrates, and our study may deepen our understanding of the SERS mechanism.
在此，我们使用根据简便的一锅法绿色环保方法制备的贵金属纳米粒子（金或银纳米粒子）修饰的石墨烯片作为研究的良好基底，以研究联合表面增强拉曼散射（SERS）效应，其中金或银纳米粒子、石墨烯片以及被吸附的分析物之间同时存在电磁机制和化学机制效应。我们的结果表明，在水溶液中，金和银纳米粒子对被吸附的探针分子以及对石墨烯的 SERS 效应是竞争的，这取决于被吸附的探针分子的种类和浓度而变化。通过对三种与石墨烯片具有不同结合能力的探针分子（若丹明 6G、尼罗蓝 A 和 4-氨基苯硫酚）的详细比较，我们最终将这种现象归因于大环探针分子通过电荷转移与石墨烯结合时对石墨烯 SERS 的强烈抑制作用的结果。当石墨烯/金或银纳米复合材料用作 SERS 基底时，这种竞争效应是一个不可忽视的现象，我们的研究可能会加深对 SERS 机制的理解。
