提出了一种用化学气相沉积法(CVD)直接在贵金属表面生长石墨烯，得到石墨烯覆盖金属纳米颗粒的表面增强拉曼基底的方法，并对得到的基底进行了形貌表征、拉曼光谱表征和探针分子表征，从而分析讨论了基底结构的稳定性和增强因子。实验结果表明：制备得到的基底均匀，稳定性好，并且增强因子能够达到107。主要是石墨烯在拉曼基底中起到了保护贵金属而不被氧化的作用，并且能够有效抑制荧光，其化学增强对增强因子也有贡献。

A method of obtaining graphene coated bimetallic nanoparticles used as surface enhanced Raman scattering (SERS) substrates is put forward, by which graphene grows on two-layer metal films in-situ by chemical vapor deposition (CVD) method. The morphology, Raman spectra and probe moleculars of substrate are characterized, and the stability and enhancement factor are analyzed. The experiment results indicate that the substrate shows a well-distributed morphology characteristic and remains SERS-active with a long lifetime. The enhanced factor is estimated to be 107. Graphene plays a role in preventing the surface oxidation of Ag and Cu nanoparticles after exposured to ambient air and dramatically suppress fluorescence of the probe molecules. The chemical enhancement of graphene can also help to improve the enhanced factor of substrate.