Optimus, Centre for Opto-Electronics and Bio-photonics School of Electronic and Electrical Engineering, Nanyang Technological University, Singapore.
Nanotechnology. 2017 Jun 9;28(23):235302. doi: 10.1088/1361-6528/aa6f00.
Well-ordered periodic nanostructures are excellent substrates for many surface-enhanced Raman spectroscopy (SERS) applications. Conventional fabrication approaches such as high precision electron beam lithography or focused ion beam produce high resolution nano-features with great reproducibility at the expense of low throughput. In this work, a highly sensitive and scalable AAO-nano-fibre (ANF) SERS substrate is demonstrated by optimising the second anodisation time of the standard two-step anodisation of aluminium and performing an additional wet etching step on the resulting AAO substrate. The optimised ANF substrate exhibits SERS sensitivity that surpasses the AAO nanoholes and the metal-film-on-nanoparticles substrates. A detection limit of 0.1 nM is achieved with a signal-to-noise ratio of 2.6-3 using a low excitation power of 0.1 mW. The ANF substrate exhibits an enhancement factor of 9.28 × 106 and a standard deviation of no more than 8%. The results indicate that the highly sensitive and scalable ANF substrate is a promising substrate for commercial SERS application.
有序的周期性纳米结构是许多表面增强拉曼光谱（SERS）应用的优秀基底。传统的制造方法，如高精度电子束光刻或聚焦离子束，以低产量为代价，具有很高的分辨率和很好的重现性。在这项工作中，通过优化铝的标准两步阳极氧化的第二次阳极氧化时间，并对所得的 AAO 基底进行额外的湿蚀刻步骤，展示了一种高灵敏度和可扩展的 AAO 纳米纤维（ANF）SERS 基底。优化后的 ANF 基底表现出的 SERS 灵敏度超过了 AAO 纳米孔和金属薄膜纳米粒子基底。使用低激发功率 0.1 mW，通过信噪比为 2.6-3，实现了 0.1 nM 的检测限。ANF 基底的增强因子为 9.28×106，标准偏差不超过 8%。结果表明，高灵敏度和可扩展的 ANF 基底是商业 SERS 应用的有前途的基底。
