High sensitivity and Figure of Merit Achieved in a WS ₂ /Au-SPR Microfluidic Sensing Chip for Glucose Detection

A high-performance surface plasmon resonance (SPR) biosensor for glucose detection was developed based on a planar waveguide. The deposition of tungsten disulfide (WS₂) nanoparticles onto a gold film significantly enhanced the refractive index sensitivity, reaching 2530.1 nm/RIU, while the figure of merit (FoM) was remarkably improved from 34.3 to 53.3 RIU⁻¹ by enhancing the evanescent field intensity in the sensing region through precise modulation of the waveguide thickness. A biorecognition interface was constructed via self-assembly of 11-mercaptoundecanoic acid (11-MUA) to enable stable and efficient immobilization of glucose oxidase, facilitating highly sensitive glucose detection. The resonance wavelength exhibited excellent linear correlation with glucose concentration, achieving a sensitivity of 91.1 pm/(μg/mL) within the concentration range of 0-150 μg/mL. The sensor demonstrated high specificity and operational stability for glucose detection, as confirmed by analytical validation.