Hong Koh Yiin, Brolo Alexandre G
Department of Chemistry, University of Victoria, Victoria, BC V8P 5C2, Canada.
Department of Chemistry, University of Victoria, Victoria, BC V8P 5C2, Canada.
Anal Chim Acta. 2017 Jun 15;972:73-80. doi: 10.1016/j.aca.2017.04.003. Epub 2017 Apr 10.
The convergence between nanometric sensing (e.g. surface-enhanced Raman scattering - SERS) and lab-on-chip technologies has emerged as a potential revolutionary approach for a variety of "real-world" applications. Surface plasmons (SPs) can be excited on metal interfaces through light coupling to metallic surface gratings. The generation of SPs is a fundamental requirement for SERS. The work reported in this paper demonstrates a versatile procedure to prepare both large area (i.e. one inch) and microarrays (μarrays) metallic gratings structures capable of supporting SP excitation (and SERS). Laser interference lithography (LIL), either alone or combined with traditional laser photolithography (LPL), was used to generate the periodic patterns. The fabrication procedure was simple, high-throughput, and reproducible, with array-to-array variations in geometrical parameters of less than 5%. Since the basic pattern of the nanostructures was a one-dimensional grating, the polarization anisotropy nature of the substrates was also explored. The use of these polarization-dependent properties to eliminate non-polarization sensitive interferences (e.g. spurious spectral background) was demonstrated. Lastly, the nanostructured gold μarrays were integrated on a chip for SERS detection of ppm-levels of 8-quinolinol, an emerging pharmaceutical contaminant in aquatic systems. A low-cost structure for fluid handling was realized by simply using perforated epoxy membranes. The results demonstrated that the procedure described here is suitable for the generation of simple integrated μarrays for SERS applications in environmental analysis.
纳米传感技术（如表面增强拉曼散射 - SERS）与芯片实验室技术的融合，已成为一种适用于各种“实际应用”的潜在革命性方法。表面等离子体激元（SPs）可通过光与金属表面光栅耦合在金属界面上被激发。SPs的产生是SERS的基本要求。本文报道的工作展示了一种通用方法，可制备能够支持SP激发（以及SERS）的大面积（即一英寸）和微阵列（μ阵列）金属光栅结构。单独使用激光干涉光刻（LIL）或与传统激光光刻（LPL）相结合，用于生成周期性图案。制造过程简单、高通量且可重复，阵列之间几何参数的变化小于5%。由于纳米结构的基本图案是一维光栅，还对基底的偏振各向异性性质进行了探索。展示了利用这些偏振相关特性消除非偏振敏感干扰（如杂散光谱背景）。最后，将纳米结构化金μ阵列集成在芯片上，用于SERS检测水生系统中一种新兴的药物污染物——ppm级别的8 - 喹啉醇。通过简单地使用穿孔环氧膜实现了一种低成本的流体处理结构。结果表明，本文所述方法适用于生成用于环境分析中SERS应用的简单集成μ阵列。
