In this research, it reported a novel three-dimensional (3D) metallic hybrid system by introducing single-layer graphene (SLG) between silver nanoparticles (NPs) and silver nano-discs (NDs) arrays (Ag NPs/SLG/Ag NDs). By combining the plasmonic metallic nanostructures and the unique physical/chemical properties of graphene, Ag NPs/SLG/Ag NDs hybrid substrate was fabricated, and it exhibited extremely high surface-enhanced Raman scattering (SERS) performance. By tuning the diameter of Ag NDs, the SERS performance of Ag NPs/SLG/Ag NDs hybrid substrate has been systematically studied. The detection limit for rhodamine 6g (R6G) could reach the concentrations as low as 1 × 10⁻¹² mol/L, and the average enhancement factor (EF) of the Ag NPs/SLG/Ag NDs substrate could reach 5.65 × 10⁸. These advantages indicated that the Ag NPs/SLG/Ag NDs hybrid substrate could be regarded as a candidate for organic molecules detection under extremely low concentration. Besides, spatial Raman mapping of Ag NPs/SLG/Ag NDs with 2.5 μm diameter NDs showed the larger SERE signal existed around the rim of Ag NDs which was related to the localized surface plasmons. This phenomenon was contributed by a larger electromagnetic field which was tuned by Ag NPs and the edge of Ag NDs. This mechanism also has been confirmed by the electromagnetic simulation result.

中文翻译：

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与局部表面等离子体激元相关的SERS性能的空间拉曼作图研究

在这项研究中，它报道了一种新颖的三维（3D）金属混合系统，方法是在银纳米颗粒（NPs）和银纳米光盘（NDs）阵列（Ag NPs / SLG / Ag NDs）之间引入单层石墨烯（SLG） 。通过结合等离子体金属纳米结构和石墨烯独特的物理/化学性质，制备了Ag NPs / SLG / Ag NDs杂化衬底，并表现出极高的表面增强拉曼散射（SERS）性能。通过调节Ag NDs的直径，系统地研究了Ag NPs / SLG / Ag NDs杂化底物的SERS性能。罗丹明6g（R6G）的检出限可低至1×10 ^-12 mol / L，Ag NPs / SLG / Ag NDs底物的平均增强因子（EF）可达5.65×10 ⁸。这些优点表明，Ag NPs / SLG / Ag NDs杂化底物可被视为在极低浓度下检测有机分子的候选物。此外，直径为2.5μm的NDs的Ag NPs / SLG / Ag NDs的空间拉曼作图表明，较大的SERE信号存在于Ag NDs的边缘周围，这与局部表面等离子体激元有关。这种现象是由较大的电磁场引起的，该较大的电磁场由Ag NP和Ag ND的边缘调整。电磁仿真结果也证实了这一机理。