Implantable fiber-optic SPR sensor modified with LPFG and PAA-ran-PAAPBA for continuous glucose monitoring

As the implantable enzyme electrode glucose sensor is unable to overcome the influence of bioelectricity intrinsically, a novel implantable fiber-optic surface plasmon resonance (SPR) sensor which can detect the glucose concentration in interstitial fluid (ISF) to satisfy the clinical demand of continuous blood glucose monitoring is proposed. Because the SPR sensor is sensitive to temperature and the body temperature drift which has a great effect on measurement results when the sensor is implanted, long period fiber grating (LPFG) is integrated into the SPR sensor for temperature compensation. The glucose-specific boronic acid polymer PAA-ran-PAAPBA which is stable and easy to synthetize is immobilized on the SPR sensor using nano layer-by-layer technique to eliminate the interference of other chemical substances in ISF and realize the specific detection of glucose molecules.