Photonic cavity enhanced high-performance surface plasmon resonance biosensor
Gui‐Shi Liu, Xin Xiong, Shiqi Hu, Weicheng Shi, Yaofei Chen, Wenguo Zhu, Huadan Zheng, Jianhui Yu, Nur Hidayah Azeman, Yunhan Luo, Zhe Chen
Abstract
Herein we propose a novel strategy to enhance surface plasmon resonance (SPR) by introducing a photonic cavity into a total-internal-reflection architecture. The photonic cavity, which is comprised of a highly reflective photonic crystal (PC), defect layers, and a gold (Au) film, enables Fabry–Perot (FP) resonances in the defect layers and therefore narrows the SPR resonance width in the metallic surface as well as increases the electric field intensity and penetration depth in the evanescent region. The fabricated sensor exhibits a 5.7-fold increase in the figure of merit and a higher linear coefficient as compared with the conventional Au-SPR sensor. The demonstrated PC/FP cavity/metal structure presents a new design philosophy for SPR performance enhancement.