Highly sensitive Au-Fe_2O_3-Au and Fe_2O_3-Au-Fe_2O_3 biosensors utilizing strong surface plasmon resonance

摘要

In this paper, two SPR biosensor configurations utilizing Fe2O3 layer coupled with Au thin film in the angular interrogation mode have been proposed and analyzed theoretically. The proposed configurations are prism-Au-Fe2O3-Au-sensing medium and prism-Fe2O3-Au-Fe2O3-sensing medium. The reflectivity was calculated as a function of incident angle based on Fresnel coefficients for transverse magnetic polarized light. The thicknesses of Au and Fe2O3 layers have been optimized to achieve the best performance of the sensor. The optimized sensitivities are 171.3 deg RIU-1 and 205.4 deg RIU-1 for the two configurations, respectively. The optimized two sensor configurations can be easily fabricated with high sensitivity than the many previously reported in the literature. Therefore, the proposed structures will find a broad range of applications in biomedical, label-free chemical and environmental protection.