Najiminaini Mohamadreza, Ertorer Erden, Kaminska Bozena, Mittler Silvia, Carson Jeffrey J L
Imaging Program, Lawson Health Research Institute, St. Joseph's Health Care, London, ON, Canada.
Analyst. 2014 Apr 21;139(8):1876-82. doi: 10.1039/c3an02332j.
Molecular surface plasmon resonance (SPR) sensing is one of the most common applications of an array of periodic nanoholes in a metal film. However, metallic nanohole arrays (NHAs) with low-hole count have lower resolution and SPR sensing performance compared to NHAs with high-hole count. In this paper, we present a compact three-dimensional (3D) plasmonic nanostructure with extraordinary optical transmission properties benefiting from surface plasmon matching and enhanced localized surface plasmon coupling. The 3D nanostructure consisted of a gold film containing a NHA with an underlying cavity and a gold nanocone array (NCA) at the bottom of the cavity. Each nanocone was aligned with the nanohole above and the truncated apex of each nanocone was in close proximity (100 nm) to the gold film. The NHA-NCA structures outperformed conventional NHA structures in terms of bulk sensitivity and Figure of Merit (FOM). Furthermore, the NHA-NCA structure with 525 nm periodicity was capable of sensing streptavidin down to 2 nM exhibiting a 10-fold increase in streptavidin sensitivity compared to conventional NHA structures. The sensitivity and performance of the 3D nanostructure can be further improved by exploiting multiplexing methods in combination with stable light sources and detection systems.
分子表面等离子体共振（SPR）传感是金属薄膜中周期性纳米孔阵列最常见的应用之一。然而，与高孔数的金属纳米孔阵列（NHA）相比，低孔数的金属纳米孔阵列具有较低的分辨率和SPR传感性能。在本文中，我们提出了一种紧凑的三维（3D）等离子体纳米结构，它具有非凡的光传输特性，这得益于表面等离子体匹配和增强的局域表面等离子体耦合。该3D纳米结构由一层含有纳米孔阵列的金膜组成，金膜下方有一个空腔，空腔底部有一个金纳米锥阵列（NCA）。每个纳米锥与上方的纳米孔对齐，每个纳米锥的截顶与金膜紧密相邻（100纳米）。在体灵敏度和品质因数（FOM）方面，NHA-NCA结构优于传统的NHA结构。此外，周期为525纳米的NHA-NCA结构能够检测低至2纳摩尔的链霉亲和素，与传统NHA结构相比，链霉亲和素灵敏度提高了10倍。通过将复用方法与稳定的光源和检测系统相结合，可以进一步提高3D纳米结构的灵敏度和性能。
