Fiber optic sensor modified by graphene oxide–glucose oxidase for glucose detection

A biosensor modified by graphene oxide (GO)–glucose oxidase (GOD) for glucose detection is proposed and demonstrated. Gluconic acid and H 2 O 2 are produced by the reaction between GOD and glucose, and due to the large change of the refractive index (RI) around the sensor, the drift of the interference valleys appears in the transmission spectrum clearly. With this method, a symmetric lateral-offset sensor based on photonic crystal fiber (PCF) is fabricated. Response characteristics of glucose concentration are tested in the range of 10 g/L to 70 g/L. Experimental results show that the sensitivity to glucose concentration can be represented by a quadratic curve, and it has good sensitivity as well as linearity. The temperature sensitivities in the range of 5 °C–30 °C are 0.061 nm/°C and 0.159 nm/°C, which can realize dual-parameter measurement. The biosensor has broad application prospects in the fields of environmental detection and drug research. • The sensor uses PCF based on MZI, which can realize the measurement of glucose concentration and temperature. • The biofilm of GO–GOD is coated on the surface of PCF to improve the sensitivity of glucose concentration of the sensor. • The sensor is simple to fabricate and has good sensitivity and linear relationship with glucose concentration. • The sensor has strong stability in the low temperature range. • The sensor exhibits potential applications in physical, biological and chemical sensing.