A D-shaped fiber SPR sensor with a composite nanostructure of MoS2-graphene for glucose detection

Fiber-based techniques make it possible to implant a miniaturized and flexible surface plasmon resonance (SPR) sensor into the human body for glucose detection. However, the miniaturization of fiber SPR sensors results in low sensitivity compared with traditional prism-type SPR sensors due to limited sensing area. In this paper, we proposed a D-shaped fiber SPR sensor with a composite nanostructure of molybdenum disulfide (MoS2)-graphene to improve the sensor sensitivity. Compared with the traditional cylindrical fiber, the planar sensing area on the side-polished fiber makes it easier to modify two-dimensional materials. Chemical vapor deposition (CVD) graphene and CVD MoS2 were modified on the sensor surface to obtain the MoS2-graphene composite nanostructure. π-π stacking interactions were used to modify pyrene-1-boronic acid (PBA) on the graphene. The excellent photoelectric properties of the MoS2-graphene composite nanostructure and the ability of PBA to specifically bind glucose molecules improved the glucose detection performance of the SPR sensor. The results show that specific detection of glucose was realized and that the highest sensitivity was achieved with three-layer MoS2 and monolayer graphene. A D-shaped fiber SPR sensor with MoS2-graphene composite nanostructure and PBA, and the sensitivity of up to 6708.87 nm/RIU was achieved in glucose detection. [Display omitted] •A D-shaped fiber SPR glucose biosensor with MoS2-graphene is fabricated.•Composite nanostructure is built by liquid phase transfer for excellent photoelectric properties.•The sensor sensitivity is enhanced to about 4 times by modifying MoS2-graphene.•PBA modified on the sensor surface shows good selectivity for glucose detection.