Scattering Field Enhanced Biosensing Based on Sub-wavelength Split-ring Plasmonic Cavity With High Q-factor

Jin, X., Xue, L., Xiong, J., Ye, S. , Cheng, W., Hou, L. , Marsh, J. H. , Ni, B., Xu, B. and Liu, X. (2023) Scattering Field Enhanced Biosensing Based on Sub-wavelength Split-ring Plasmonic Cavity With High Q-factor. In: Plasmonics in Biology and Medicine XX, San Francisco, CA, USA, 28 Jan - 03 Feb 2023, pp. 1239607-1. (doi: 10.1117/12.2647937)

Abstract

Plasmonic structures are widely used in modern biosensor design. various plasmonic resonant cavities could efficiently achieve a high Q-factor, improving the local field intensity to enhance photoluminescence or SERS (Surface-Enhanced Raman Scattering) of small molecules. Also, the combination between virus-like particles and plasmonic structures could significantly influence the scattering spectrum and field, which is utilized as a method for biological particle detection. In this paper, we designed one kind of gold plasmonic cavity with the shape of a split-ring. An edge gap and a bonus center bulge are introduced in the split-ring structure. Our simulation is based on Finite Difference Time Domain (FDTD) method. Polarization Indirect Microscopic Imaging (PIMI) technique is used here to detect far-field mode distribution under the resonant wavelength. The simulation results demonstrate resonant peaks in the visible spectrum at about 600 nm with a Q-factor reaches to 74. Localized hot spots are generated by an edge dipole mode and a cavity hexapole mode at resonant wavelength, which is according to dark points in the PIMI sinδ image. Also, the split-ring cavity shows a sensitivity when combined with biological particles. The scattering distribution is evidently changed as a result of energy exchange between particles and split-ring cavity, indicating a promising possibility for biosensing.

• Item Type: Conference Proceedings
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Liu, Professor Xuefeng and Hou, Dr Lianping and Cheng, Weiqing and Marsh, Professor John and Ye, Dr Shengwei
• Authors: Jin, X., Xue, L., Xiong, J., Ye, S., Cheng, W., Hou, L., Marsh, J. H., Ni, B., Xu, B., and Liu, X.
• College/School: College of Science and Engineering > School of Engineering > Electronics and Nanoscale Engineering
• ISSN: 0277-786X
• Copyright Holders: Copyright © 2023 SPIE
• First Published: First published in Proceedings of SPIE 12396: 1239607-1
• Publisher Policy: Reproduced in accordance with the publisher copyright policy