Affinity based glucose measurement using fiber optic surface plasmon resonance sensor with surface modification by borate polymer

• An affinity based method of glucose detection based on fiber optic surface plasmon resonance (FO-SPR) sensor with surface modification by borate polymer is presented.
• The bioelectricity would cause significant drift to the measuring signal of implantable enzyme electrode biosensors that currently used in clinical treatment of diabetics. The FO-SPR sensor proposed here is able to detect the glucose by measuring the optical surface refractive index, thus, it avoids the impact of bioelectricity when applied for implantable measurement of glucose, making the measuring result more stable and reliable.
• Affinitive modification of the sensor by biocompatible borate polymer realized non-consumption measurement of glucose and it overcomes the defect of the enzyme electrode biosensors, which consumes the glucose irreversibly in measurement due to the oxidation of glucose. The modified FO-SPR sensor here provided a higher sensitivity, especially for the application of treating diabetics in hypoglycemic state.

An affinity based method of glucose measurement using a fiber optic surface plasmon resonance (FO-SPR) sensor with surface modification by a borate polymer was proposed. In this method, the sensor is able to obtain the glucose concentration by detecting the surface refractive index of the sensor, which could avoid the impact of bioelectricity from viable tissues when applied for implantable measurement. A biocompatible borate polymer, PAA-ran-PAAPBA, which is capable of associating and dissociating with glucose molecules dynamically, performed non-consumption measurement of glucose, thereby enabling the possibility of glucose detection in hypoglycemic situations. Numerical simulation was performed based on the FO-SPR theory, and an online-transmission FO-SPR sensor with optimized structural parameters was fabricated. PAA-ran-PAAPBA was synthesized and immobilized onto the surface of the FO-SPR sensor using layer-by-layer self-assembly technique. An experimental system was built, and contrast-measurement experiment for 1–10 and 10–300 mg/dL glucose solutions was performed; the FO-SPR sensor bonded with the borate polymer exhibited higher accuracy, especially for low-concentration detection. This study laid a technical foundation for further exploration of implantable measurement systems for blood glucose.