Wang Ling, Zhang Yan, Yang Yongqiang, Zhang Jing
School of Material Engineering, Shanghai University of Engineering Science, Shanghai 201620, China.
Jiangsu Graphene Inspection Technology Key Laboratory, Jiangsu Province Special Equipment Safety Supervision and Inspection Institute Branch of Wuxi, Wuxi 214174, China.
Materials (Basel). 2018 Jul 12;11(7):1199. doi: 10.3390/ma11071199.
Graphene and its derivatives have been demonstrated to be good surface-enhanced Raman scattering (SERS) substrates. However, the literature offers some contrasting views on the SERS effect of graphene-based materials. Thus, understanding the mechanism of the SERS enhancement of graphene is essential for exploring its application as a SERS substrate. In this study, graphene oxide (GO) and chemically reduced graphene oxide (CRGO) films with different morphologies and structures were prepared and applied as SERS substrates to detect Raman dye molecules. The observed enhancement factors can be as large as 10~10³. The mechanism of SERS enhancement is discussed. It is shown that the SERS effect was independent of the adsorption of dye molecules and the surface morphologies of graphene-based films. Raman shifts are observed and are almost the same on different graphene-based films, indicating the existence of charge transfer between dye molecules and substrates. The Raman enhancement factors and sensitivities of dye molecules on different films are consistently within the / ratios of graphene-based substrates, indicating that the dramatically enhanced Raman spectra on graphene-based films are strongly dependent on the average size of ² carbon domain.
石墨烯及其衍生物已被证明是良好的表面增强拉曼散射（SERS）基底。然而，文献中对于基于石墨烯的材料的SERS效应存在一些不同观点。因此，了解石墨烯SERS增强机制对于探索其作为SERS基底的应用至关重要。在本研究中，制备了具有不同形态和结构的氧化石墨烯（GO）和化学还原氧化石墨烯（CRGO）薄膜，并将其用作SERS基底来检测拉曼染料分子。观察到的增强因子可达10~10³。讨论了SERS增强机制。结果表明，SERS效应与染料分子的吸附以及基于石墨烯的薄膜的表面形态无关。在不同的基于石墨烯的薄膜上观察到拉曼位移且几乎相同，这表明染料分子与基底之间存在电荷转移。不同薄膜上染料分子的拉曼增强因子和灵敏度始终在基于石墨烯的基底的/比值范围内，这表明基于石墨烯的薄膜上显著增强的拉曼光谱强烈依赖于²碳域的平均尺寸。
