Side-polished fiber SPR sensor with tempetrature self-compensation for continuous glucose monitoring

Abstract

A side-polished fiber surface plasmon resonance (SPR) sensor modified by graphene and borate polymer was proposed for implantable continuous glucose monitoring with temperature self-compensation in situ by long period fiber grating (LPFG). The cladding layer of one side of the cylindrical fiber was polished off to construct SPR sensor for easy surface modification. Single-layer graphene was transferred onto the Au film in the polished area to enhance the sensitivity of the sensor. A LPFG was engraved into the core of the fiber to measure the temperature fluctuation to compensate the resonance wavelength shift of SPR spectrogram. The biocompatible borate polymer, PAA-ran-PAAPBA, was bound onto the graphene to specifically absorb glucose molecules. The SPR sensor enabled the detection of hypoglycemia which is still a big challenge for continuous glucose monitoring in clinic.