State Key Laboratory of Precision Measurement Technology and Instrument, Department of Precision Instrument, Tsinghua University, Beijing, China; National Innovation Institute of Defense Technology, Beijing, China.
State Key Laboratory of Precision Measurement Technology and Instrument, Department of Precision Instrument, Tsinghua University, Beijing, China.
Biosens Bioelectron. 2019 Feb 15;127:19-24. doi: 10.1016/j.bios.2018.12.013. Epub 2018 Dec 13.
Single-layered gold nano-hole arrays lead to extraordinary optical transmission (EOT)-modulated surface plasmonic resonance (SPR) and have seen much progress in biochemical sensing. To further improve the sensing performance, the single-layered structure need to be changed. In this paper, a micromachined Fabry-Perot interferometer (µFPI), featuring two parallel and flat gold-coated mirrors, one of which has sub-wavelength nano-hole arrays, was designed, fabricated, and tested experimentally. Its transmission spectrum was confirmed to have EOT-modulated SPR patterns, and its characteristic peak wavelength was found to have a refractive index sensitivity of 593 nm / RIU and a Q factor up to 128.4, which is 10.2 times its EOT counterparts. By applying AC electric signals across the two gold layers, dielectrophoresis (DEP) induced near the nano-holes was proven to enrich particles significantly. To remove the thermal effects on the transmission spectrum, heat was dissipated by flowing sample during measurement. Biochemical sensing experiments were conducted using BSA protein medium of different low concentrations, demonstrating the detection sensitivity enhancement of ~ 6-fold for 1 pM compared to 100 pM. This novel µFPI presents a new paradigm in EOT-based SPR sensing technology by combining the benefits of µFPI interference, EOT near-field measurement and DEP enrichment of molecules.
单层金纳米孔阵列导致了非凡的光传输（EOT）调制表面等离子体共振（SPR），并在生化传感方面取得了很大进展。为了进一步提高传感性能，需要改变单层结构。在本文中，设计、制作并实验测试了一种具有两个平行且平整的镀金反射镜的微机械法布里-珀罗干涉仪（µFPI），其中一个反射镜具有亚波长纳米孔阵列。其透射光谱被证实具有 EOT 调制的 SPR 模式，其特征峰值波长的折射率灵敏度为 593nm/RIU，Q 因子高达 128.4，是其 EOT 对应物的 10.2 倍。通过在两层镀金层之间施加交流信号，证明了近孔的电介质电泳（DEP）可以显著富集粒子。为了消除传输光谱的热效应，在测量过程中通过流动样品来散热。使用不同低浓度的 BSA 蛋白介质进行了生化传感实验，与 100pM 相比，1pM 的检测灵敏度提高了约 6 倍。这种新型µFPI 通过结合µFPI 干涉、EOT 近场测量和分子的 DEP 富集的优点，为基于 EOT 的 SPR 传感技术提供了一种新的范例。
