Couture Maxime, Brulé Thibault, Laing Stacey, Cui Wenli, Sarkar Mitradeep, Charron Benjamin, Faulds Karen, Peng Wei, Canva Michael, Masson Jean-Francois
Département de chimie, Université de Montréal, CP. 6128, Succ. Centre-Ville, Montréal, QC, H3C 3J7, Canada.
Bionanotechnologies, Department of Pure and Applied Chemistry, Technology Innovation Centre, University of Strathclyde, 99 George Street, Glasgow, G1 1RD, UK.
Small. 2017 Oct;13(38). doi: 10.1002/smll.201700908. Epub 2017 Aug 21.
Gold-coated nanodisk arrays of nearly micron periodicity are reported that have high figure of merit (FOM) and sensitivity necessary for plasmonic refractometric sensing, with the added benefit of suitability for surface-enhanced Raman scattering (SERS), large-scale microfabrication using standard photolithographic techniques and a simple instrumental setup. Gold nanodisk arrays are covered with a gold layer to excite the Bragg modes (BM), which are the propagative surface plasmons localized by the diffraction from the disk array. This generates surface-guided modes, localized as standing waves, leading to highly confined fields confirmed by a mapping of the SERS intensity and numerical simulations with 3D finite element method. The optimal gold-coated nanodisk arrays are applied for refractometric sensing in transmission spectroscopy with better performance than nanohole arrays and they are integrated to a 96-well plate reader for detection of IgY proteins in the nanometer range in PBS. The potential for sensing in biofluids is assessed with IgG detection in 1:1 diluted urine. The structure exhibits a high FOM of up to 46, exceeding the FOM of structures supporting surface plasmon polaritons and comparable to more complex nanostructures, demonstrating that subwavelength features are not necessary for high-performance plasmonic sensing.
据报道，具有近微米周期性的金涂层纳米盘阵列具有等离子体折射传感所需的高品质因数（FOM）和灵敏度，还具有适用于表面增强拉曼散射（SERS）、使用标准光刻技术进行大规模微加工以及仪器设置简单等优点。金纳米盘阵列覆盖有一层金以激发布拉格模式（BM），布拉格模式是由盘阵列的衍射局域化的传播表面等离子体。这会产生表面引导模式，以驻波形式局域化，通过SERS强度映射和三维有限元方法的数值模拟证实了其产生了高度受限的场。优化后的金涂层纳米盘阵列应用于透射光谱中的折射传感，其性能优于纳米孔阵列，并且被集成到一个96孔板读数器中，用于检测磷酸盐缓冲盐溶液（PBS）中纳米级别的卵黄免疫球蛋白（IgY）蛋白。通过检测1:1稀释尿液中的免疫球蛋白G（IgG）来评估该结构在生物流体中的传感潜力。该结构展现出高达46的高FOM，超过了支持表面等离子体激元的结构的FOM，并且与更复杂的纳米结构相当，这表明亚波长特征对于高性能等离子体传感并非必要。
