School of Electronic Science and Engineering, Southeast University, Nanjing 210096, People's Republic of China.
Nanoscale Res Lett. 2014 Mar 13;9(1):114. doi: 10.1186/1556-276X-9-114.
Surface-enhanced Raman scattering is an effective analytical method that has been intensively applied in the field of identification of organic molecules from Raman spectra at very low concentrations. The Raman signal enhancement that makes this method attractive is usually ascribed to the noble metal nanoparticle (NMNP) arrays which can extremely amplify the electromagnetic field near NMNP surface when localized surface plasmon resonance (LSPR) mode is excited. In this work, we report a simple, facile, and room-temperature method to fabricate large-scale, uniform gold nanoparticle (GNP) arrays on ITO/glass as SERS substrates using a promoted self-assembly deposition technique. The results show that the deposition density of GNPs on ITO/glass surface increases with prolonging deposition time, and nanochain-like aggregates appear for a relatively longer deposition time. It is also shown that these films with relatively higher deposition density have tremendous potential for wideband absorption in the visible range and exhibit two LSPR peaks in the extinction spectra because the electrons simultaneously oscillate along the nanochain at the transverse and the longitudinal directions. The SERS enhancement activity of these GNP arrays was determined using 10-6 M Rhodamine 6G as the Raman probe molecules. A SERS enhancement factor as large as approximately 6.76 × 106 can be obtained at 1,363 cm-1 Raman shift for the highest deposition density film due to the strong plasmon coupling effect between neighboring particles.
表面增强拉曼散射是一种有效的分析方法，已被广泛应用于极低浓度下从拉曼光谱中识别有机分子的领域。这种方法之所以具有吸引力，是因为当局域表面等离子体激元共振（LSPR）模式被激发时，贵金属纳米粒子（NMNP）阵列可以极大地增强 NMNP 表面附近的电磁场。在这项工作中，我们报告了一种简单、方便且在室温下的方法，使用促进的自组装沉积技术在 ITO/玻璃上制备大规模、均匀的金纳米粒子（GNP）阵列作为 SERS 基底。结果表明，随着沉积时间的延长，ITO/玻璃表面上 GNP 的沉积密度增加，而对于较长的沉积时间，会出现纳米链状聚集体。还表明，这些具有较高沉积密度的薄膜在可见光范围内具有宽带吸收的巨大潜力，并在消光谱中表现出两个 LSPR 峰，因为电子同时沿纳米链在横向和纵向方向振荡。使用 10-6 M 罗丹明 6G 作为拉曼探针分子，确定了这些 GNP 阵列的 SERS 增强活性。由于相邻颗粒之间的强等离子体耦合效应，在最高沉积密度的薄膜上，在 1,363 cm-1 拉曼位移处可以获得约 6.76×106 的大 SERS 增强因子。
