High Figure of Merit (FOM) of Bragg Modes in Au‐Coated Nanodisk Arrays for Plasmonic Sensing |
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| Authors: | Maxime Couture Thibault Brulé Stacey Laing Wenli Cui Mitradeep Sarkar Benjamin Charron Karen Faulds Wei Peng Michael Canva Jean‐Francois Masson |
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| Affiliation: | 1. Département de chimie, Université de Montréal, Montréal, QC, Canada;2. Bionanotechnologies, Department of Pure and Applied Chemistry, Technology Innovation Centre, University of Strathclyde, Glasgow, UK;3. College of Physics and Optoelectronics Engineering, Dalian University of Technology, Dalian, China;4. Laboratoire Charles Fabry Institut d'Optique Graduate School, Université Paris Sud, CNRS, Palaiseau, France;5. Laboratoire Nanotechnologies Nanosystèmes LN2 – CNRS, Université de Sherbrooke, Institut Interdisciplinaire d'Innovation Technologique, Sherbrooke, QC, Canada;6. Centre Québécois sur les Matériaux Fonctionnels (CQMF) |
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| Abstract: | 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. |
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| Keywords: | Bragg mode gold‐coated nanodisk array high FOM multiwell plate reader plasmonic sensing SERS |
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