Optical fiber SPR biosensor with a solid-phase enzymatic reaction device for glucose detection

A portable and user-friendly optical fiber sensing platform for rapid glucose detection based on surface plasmon resonance (SPR) sensing and enzymatic reaction is proposed. We designed a simple and easy-to-use miniaturized device for the specific decomposition of glucose; the device can fully react with glucose samples and produce glucose-free samples. The optical fiber SPR biosensor was prepared for detecting glucose samples before and after enzymatic reaction through the device, and to obtain an SPR differential signal that corresponds specifically to glucose concentration. Different levels of urine glucose concentrations in a broad range of 0–400 mg/dL were distinguished by the proposed method with a sensitivity of 3.10 pm/(mg/dL). Our novel method has the following advantages: (1) the sensor and enzymatic reaction device can be reused with low cost; (2) the interference of the background solution can be eliminated for more specific glucose detection; (3) the operation is simple and fast without requiring professional operation skills, and the test samples can be directly loaded/released for detecting; (4) the platform is also suitable for the specific detection of other enzymatic reactions by changing the reaction enzyme. The platform provides a new pathway for the detection of food additives and medical immunoassays.