Enhanced Urine Glucose Sensing Using Two-Dimensional TMDCs-Based SPR Biosensor

While surface plasmon resonance (SPR) sensing technology has been extensively applied in various biomedical applications, traditional SPR sensors often suffer from limited sensitivity. In this study, a bi-metallic/Two-Dimensional (2D) transition metal dichalcogenides (TMDCs)-based SPR biosensor has been proposed to achieve improved performance in urine glucose detection. The design incorporates different TMDC materials, including WS ₂ , WSe ₂ , MoS ₂ , and MoSe _2, to enhance the sensor’s sensitivity. The Lumerical Finite-Difference Time-Domain (FDTD) simulation platform is utilized to design and assess the sensor’s performance. Among the tested sensing materials, the MoS ₂ -based SPR biosensor demonstrated superior sensitivity compared to WS ₂ , WSe ₂ , and MoSe ₂ . The optimized CaF ₂ –Ag–Al–MoS ₂ sensor has effectively detected glucose concentrations in urine ranging from 0 to 0.015 g/dL in non-diabetic persons and from 0.625 to 10 g/dL in diabetic persons, corresponding to a refractive index (RI) range from 1.335 to 1.347. The sensor reveals a broad linear response to urine glucose, indicating accurate and reliable detection. Moreover, the monolayer MoS ₂ -based SPR sensor has achieved outstanding performance, with a high sensitivity of 455.83°/RIU, a detection accuracy of 1.32, and a quality factor of 110.10 RIU ^− 1 for urine glucose monitoring. Additionally, the electric field distribution of the proposed configuration has been studied, revealing that the integration of TMDCs significantly enhances the sensor’s sensitivity. Furthermore, the observed penetration depth is approximately 190 nm, indicating the sensor’s effectiveness in detecting target molecules. This improved sensing capability is mainly achieved due to the strong light absorption and large surface-to-volume ratio of TMDCs. Among them, MoS ₂ stands out with the highest refractive index, which strengthens the confinement of the evanescent field and increases its interaction with biomolecules, thereby boosting the sensitivity. Consequently, the developed SPR biosensor shows promise as a cost-effective, label-free refractive index sensor for non-invasive tracking of glucose levels in the human body.