A Glucose Sensor for Enhanced Sensitivity and Accuracy via In Situ Temperature Monitoring

This study aims to develop an advanced glucose sensor based on single-mode fiber-no-core fiber-single-mode fiber (SMF-NCF-SMF) microfibers modified with glucose oxidase (GOD) for accurate and simultaneous measurement of glucose concentration and temperature, which could significantly enhance diagnostic capabilities in medical and biological applications. The sensor utilizes the evanescent wave principle to detect glucose concentration and the thermal optical effect to measure temperature. Experimental results demonstrate a concentration sensitivity of 2.07 nm/(mg/mL) within the range of 0–3 mg/mL and a temperature sensitivity of −0.35 nm/°C within the range of 25 °C–50 °C. These findings highlight the distinct impacts of concentration and temperature on the interference wavelength. By establishing a demodulation matrix, the sensitivities for both concentration and temperature can be separately determined. In situ temperature monitoring not only eliminates temperature interference but also ensures that GOD remains at its optimal temperature for maximum activity, thereby enhancing the sensitivity and accuracy of glucose concentration detection. Given its high sensitivity, accuracy, and simplicity, this sensor shows promising potential for widespread use in disease diagnosis and biological detection, paving the way for more advanced diagnostic technologies.