Zhang Chentao, Lin Kun, Huang Yuanqing, Zhang Jianhuan
Department of Instrumental and Electrical Engineering, Xiamen University, Xiamen 361005, China.
Xiamen Key Laboratory of Optoelectronic Transducer Technology, Xiamen 361005, China.
Sensors (Basel). 2017 Jun 22;17(7):1462. doi: 10.3390/s17071462.
Surface-enhanced Raman scattering (SERS) has been extensively investigated as an effective approach for trace species detection. Silver nanostructures are high-sensitivity SERS substrates in common use, but their poor chemical stability impedes practical applications. Herein, a stable and sensitive SERS substrate based on the hybrid structures of graphene/silver film/laser-textured Si (G/Ag/LTSi) was developed, and a simple, rapid, and low-cost fabrication approach was explored. Abundant nanoparticles were directly created and deposited on the Si surface via laser ablation. These aggregated nanoparticles functioned as hotspots after a 30 nm Ag film coating. A monolayer graphene was transferred to the Ag film surface to prevent the Ag from oxidation. The SERS behavior was investigated by detecting R6G and 4-MBT molecules. The experimental results indicate that the maximum enhancement factor achieved by the G/Ag/LTSi substrate is over 10⁷ and less than 23% SERS signals lost when the substrate was exposed to ambient conditions for 50 days. The covering graphene layer played crucial roles in both the Raman signals enhancement and the Ag nanostructure protection. The stable and sensitive SERS performance of G/Ag/LTSi substrate evince that the present strategy is a useful and convenient route to fabricate large-area graphene-silver plasmonic hybrids for SERS applications.
表面增强拉曼散射（SERS）作为一种痕量物质检测的有效方法已得到广泛研究。银纳米结构是常用的高灵敏度SERS基底，但其较差的化学稳定性阻碍了实际应用。在此，开发了一种基于石墨烯/银膜/激光刻蚀硅（G/Ag/LTSi）混合结构的稳定且灵敏的SERS基底，并探索了一种简单、快速且低成本的制备方法。通过激光烧蚀在硅表面直接产生并沉积了大量纳米颗粒。在涂覆30 nm银膜后，这些聚集的纳米颗粒起到了热点的作用。将单层石墨烯转移到银膜表面以防止银氧化。通过检测R6G和4-MBT分子研究了SERS行为。实验结果表明，G/Ag/LTSi基底实现的最大增强因子超过10⁷ ，并且当基底在环境条件下暴露50天时，SERS信号损失小于23%。覆盖的石墨烯层在拉曼信号增强和银纳米结构保护方面都发挥了关键作用。G/Ag/LTSi基底稳定且灵敏的SERS性能表明，本策略是制备用于SERS应用的大面积石墨烯-银等离子体杂化材料的一种有用且便捷的途径。
