Anhui Province Key Laboratory of Optoelectric Materials Science and Technology (OEMST), School of Physics and Electronics Information, Anhui Normal University, Wuhu, 241000, China.
Nanoscale. 2019 Oct 3;11(38):17913-17919. doi: 10.1039/c9nr06561j.
Conical silver nanocavity arrays are fabricated by directly depositing Ag on porous alumina templates with V-shaped nanopores. By controlling the thickness of deposited Ag, complete and cracked cavity arrays are constructed respectively. The cracked cavity arrays with the cavity wall consisting of Ag nanoparticles are demonstrated to exhibit higher surface enhanced Raman scattering (SERS) activity than the complete one. Numerical simulation reveals that an effective coupling of the cavity modes with the surface plasmons of Ag nanoparticles (NPs) generates a significantly enhanced local electric field on the cavity wall responsible for the high SERS activity. The optimized cavity array presents an enhancement factor (EF) of ∼7.4 × 106 and an excellent uniformity with a relative standard deviation (RSD) as small as ∼5% for rhodamine 6G (R6G) molecules. Moreover, a good linear correlation between the logarithmic Raman intensity and the molecular concentration endows the array with quantitative analysis ability. These cavity arrays therefore are of great potential for qualitative and quantitative chemical and biomedical analysis with high sensitivity and reproducibility.
锥形银纳米腔阵列是通过将 Ag 直接沉积在具有 V 形纳米孔的多孔氧化铝模板上来制备的。通过控制沉积的 Ag 的厚度，可以分别构建完整的和有裂缝的腔阵列。已经证明，具有由 Ag 纳米颗粒组成的腔壁的裂缝腔阵列比完整的腔阵列具有更高的表面增强拉曼散射 (SERS) 活性。数值模拟表明，腔模式与 Ag 纳米颗粒 (NPs) 的表面等离激元的有效耦合在腔壁上产生了显著增强的局部电场，这是产生高 SERS 活性的原因。优化后的腔阵列对罗丹明 6G（R6G）分子的增强因子 (EF) 约为 7.4×106，具有很好的均匀性，相对标准偏差 (RSD) 低至约 5%。此外，对数拉曼强度与分子浓度之间的良好线性相关性赋予了该阵列进行定量分析的能力。因此，这些腔阵列具有高灵敏度和可重复性，对于定性和定量化学和生物医学分析具有很大的潜力。
