A glucose biosensor with temperature and pH compensation based on mode resonance coupling in hole-assisted multi-core fiber

External temperature and pH variations inevitably affect the measurement accuracy of the enzymatic biosensors. In order to solve this problem, a glucose biosensor with temperature and pH compensation was proposed and experimentally demonstrated. The biosensor is composed of a segment of hole-assisted three-core fiber (HATCF) and a segment of hole-assisted dual-core fiber (HADCF) in series and achieve three-parameter detection of glucose concentration, temperature and pH based on mode resonance coupling. One suspended core of the HATCF is functionalized with graphene oxide (GO)/glucose oxidase (GOD) for glucose concentration detection, and the other suspended core is utilized for temperature monitoring. The HADCF filled with polyacrylamide hydrogel is used to monitor pH change. This biosensor exhibits a linear response with a sensitivity of 6.82 nm/(mg/mL) under optimal reaction condition (T = 35 °C, pH = 7.0), enabling simultaneous glucose detection and monitoring of the reaction environment temperature and pH. The advantages of stable response, high selectivity, compact size, and three-parameter simultaneous detection make the proposed biosensor a significant candidate for its applications in multi-parameter sensing, environmental biomonitoring and real-time interference compensation detection.