An effect of silver arsenic sulfide and gallium sulfide dielectric materials in SPR refractive sensor: a numerical study.

In this article, we present a highly sensitive surface plasmon resonance (SPR) sensor to detect the cancer biomarker Carcinoembryonic antigen (CEA). The sensor is designed using the Kretschmann configuration and incorporates an FK51A prism along with layered materials such as silver (Ag), silver arsenic sulfide (Ag3AsS3), and gallium sulfide (GaS) and selected (2D) materials like black phosphorus and Graphene. These 2D materials are chosen for their excellent optical properties and their ability to increase electric field confinement in sensing interfaces. The simulation results show that the proposed multilayer sensor provides considerable improvements in the sensing performances including high sensitivity, sharp resonance curves, and increased figure of merit (FoM). Results confirms that the proposed sensor with WS2 is gained a maximum sensitivity of 350.61°/RIU and an extraordinary quality factor (QF) of 106.650 RIU-1. Compared to existing sensors, this sensor shows better results with a simple construction process. The use of customized 2D materials also improves signal-to-nosie ratio (SNR) of 1.57 and combined sensitivity factor (CSF) of 68.20, which is highly suitable for detecting the initial stage CEA. This task indicates that integrating 2D materials in SPR platforms can greatly extend biosensor technologies for cancer diagnosis.