Nanopore arrays with TMOKE-enhanced high performance sensing

Abstract

Magneto-plasmon sensing structure based on surface plasmon resonance (SPR) and magneto-optical (MO) effect has become a hot research topic in recent years. In this work, we propose a magneto-plasmon crystal consisting of an Au/Co double-layer nanoporous structure with optically thick Au film as a substrate. Due to the excitation of high-quality SPR, a Fano-like transverse magneto-optical Kerr (TMOKE) spectrum with subnanometer bandwidth is realized. A sensitivity of up to 677 nm RIU−1 is detected under subtle refractive index changes in air, and all the calculated figure of merits (FOM) are higher than 104 RIU−1. In addition, in order to highlight the superiority of the sensing performance of the MO plasmon (MOSPR) sensor, we compare the MOSPR sensor with the SPR sensor and calculate their FOM in different refractive index environments. The results show that the FOM of the MOSPR sensor is two orders of magnitude higher than that of the SPR sensor, which proves that the performance of the MOSPR sensor is significantly better than that of the SPR sensor and provides a theoretical basis for biosensing and gas detection based on magneto plasmon.