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 (WS 2 ) 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.