Designing of an Ultrasensitive Surface Plasmon Resonance Sensor Based on Strontium Titanate and Transition Metal Dichalcogenide Material for the Detection of Uric Acid

Elevated uric acid (UA) levels are associated with various disorders, making precise and quick detection important for early diagnosis. The dependence of conventional sensors on biorecognition elements, such as enzymes and antibodies, limits their long‐term stability. This study introduces a label‐free multilayer surface plasmon resonance (SPR)‐based sensor design for UA detection across varying concentrations. This sensor is configured as BK7/Ag/WS 2 /SrTiO 3 /Ni, where the combined optical properties of the multilayer stack enhance field confinement and tunability compared to the basic structure. The finite‐difference time‐domain (FDTD) method is used for modeling and analysis. UA concentrations ranging from 100 to 500 ppm are evaluated based on sensitivity, detection accuracy (DA), quality factor (QF), and limit of detection (LOD). A maximum sensitivity and QF of 481.8 deg/RIU and 106.612 RIU −1 , respectively, are achieved at a 400 ppm concentration of UA that reflects 3.54 times increase in sensitivity over the conventional SPR structure. At 400 ppm, this sensor also shows a remarkably low LOD, 2.0756 × 10 −06 , indicating its high sensing capability. The DA value gradually increases with increasing UA concentrations, resulting in a maximum DA at 500 ppm. Overall, the sensor demonstrates high sensitivity and reliability for precise UA detection, highlighting its potential for noninvasive diagnostics.