State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, People's Republic of China.
Nanotechnology. 2017 May 5;28(18):185301. doi: 10.1088/1361-6528/aa6952. Epub 2017 Mar 27.
The plasmonic cavity arrays are ideal substrates for surface enhanced Raman scattering analysis because they can provide hot spots with large volume for analyte molecules. The large area increases the probability to make more analyte molecules on hot spots and leads to a high reproducibility. Therefore, to develop a simple method for creating cavity arrays is important. Herein, we demonstrate how to fabricate a V and W shape cavity arrays by a simple method based on self-assembly. Briefly, the V and W shape cavity arrays are respectively fabricated by taking KOH etching on a nanohole and a nanoring array patterned silicon (Si) slides. The nanohole array is generated by taking a reactive ion etching on a Si slide assembled with monolayer of polystyrene (PS) spheres. The nanoring array is generated by taking a reactive ion etching on a Si slide covered with a monolayer of octadecyltrichlorosilane before self-assembling PS spheres. Both plasmonic V and W cavity arrays can provide large hot area, which increases the probability for analyte molecules to deposit on the hot spots. Taking 4-Mercaptopyridine as analyte probe, the enhancement factor can reach 2.99 × 10 and 9.97 × 10 for plasmonic V cavity and W cavity array, respectively. The relative standard deviations of the plasmonic V and W cavity arrays are 6.5% and 10.2% respectively according to the spectra collected on 20 random spots.
等离子体激元腔阵列是表面增强拉曼散射分析的理想基底，因为它们可以为分析物分子提供具有大体积的热点。大面积增加了在热点上产生更多分析物分子的可能性，从而实现了高重现性。因此，开发一种简单的方法来创建腔阵列非常重要。本文展示了如何通过基于自组装的简单方法来制造 V 和 W 形状的腔阵列。简而言之，通过在纳米孔和纳米环阵列图案化硅（Si）片上进行 KOH 蚀刻，分别制造出 V 和 W 形状的腔阵列。纳米孔阵列是通过对组装有单分子层聚苯乙烯（PS）球的 Si 片进行反应离子蚀刻而产生的。纳米环阵列是通过在 Si 片上进行反应离子蚀刻来产生的，该 Si 片在自组装 PS 球之前用十八烷基三氯硅烷进行了单层覆盖。等离子体激元 V 和 W 腔阵列都可以提供大的热点区域，从而增加了分析物分子沉积在热点上的可能性。以 4-巯基吡啶作为分析物探针，等离子体激元 V 腔和 W 腔阵列的增强因子分别达到 2.99×10 和 9.97×10。根据在 20 个随机点上采集的光谱，等离子体激元 V 腔和 W 腔阵列的相对标准偏差分别为 6.5%和 10.2%。
