S-shaped long period fiber grating glucose concentration biosensor based on immobilized glucose oxidase

In this study, we fabricated an S-shaped long period fiber grating (S-shaped LPFG) using the lithography process and then used alkylation technology to immobilize glucose oxidase for glucose concentration measurements. The principles of the associated experiment suggest that this phenomenon is caused by the use of glucose oxidase and glucose-specific binding characteristics for testing. The combination of glucose oxidase with glucose alters the external refractive index of the optical fiber, changing the refractive index and thereby changing the transmission loss. The experimental results show that the transmission varied in a linear manner with differing glucose concentrations. The best sensitivity of the S-shaped LPFG glucose concentration sensor was 6.229 dB/wt% from 0 similar to 1 wt%, and the linearity (R-2) was 0.949. The results demonstrate that the proposed S-shaped LPFG has good potential for high-sensitivity glucose concentration sensor applications.