High sensitivity fiber SPR sensor based on InSe nanosheets and Au nanoparticles

Abstract

Surface Plasmon Resonance (SPR) fiber sensors are widely used in the field of biosensing. However, there are still issues of low sensitivity and poor stability in practical detection processes. This paper proposes a highly sensitive fiber SPR sensor based on InSe nanosheets and Au nanoparticles. This paper investigates the enhancement effects of different thicknesses of InSe films inserted between the Au film and the fiber and the adsorption of Au nanoparticles on the Au film surface of the fiber-InSe-Au sensor. The sensitivity of the fiber-InSe-Au sensor reaches 5534.76 nm/RIU, which is 2.71 times higher than the fiber-Au sensor and a 22% improvement compared to the fiber-Au-InSe sensor. The sensitivity of the fiber-InSe-Au-AuNPs sensor further increases to 5853.75, and the FOM reaches 28.11, a 47% improvement compared to the fiber-InSe-Au sensor. Moreover, the enhancement substance is situated within the Au film, which enhances the sensor's stability. Additionally, due to the low biotoxicity and high biocompatibility of Au nanoparticles, the high-performance sensor designed in this study is exceptionally well-suited for biosensing applications.