We propose a novel glucose fiber optic sensor combining a thinned cladding fiber Bragg grating (ThFBG) with glucose oxidase (GOD). By immobilizing GOD on the surface of a ThFBG, the fabricated sensor can obtain a high specificity to glucose. Because of the evanescent field, the sensor is very sensitive to the ambient refractive index change arising from the catalytic reaction between glucose and GOD. A four-level fiber model was simulated and verified the precision of the sensing principle. Two methods, glutaraldehyde crosslinking method (GCM) and 3-aminopropyl triethoxysilane covalent coupling method (ATCCM), were experimentally utilized to immobilize GOD. And sensor fabricated with the method ATCCM shows a measurement range of 0-0.82 mg/mL which is better than the sensor fabricated with the method GCM with measurement range of 0-0.67 mg/mL under the same condition. By using ATCCM to immobilize GOD with different concentrations, three sensors were fabricated and used for glucose measurement by monitoring the Bragg wavelength (λ_b) shifts, the results indicate a good linear relationship between wavelength shift and glucose concentration within a specific range, and the measurement range increases as GOD concentration increases. The highest sensitivity of sensor reaches up to 0.0549 nm/(mg.mL^-1). The proposed sensor has distinct advantages in sensing structure, cost and specificity.

Date Published: 19 October 2016
PDF: 6 pages
Proc. SPIE 10155, Optical Measurement Technology and Instrumentation, 101550L (19 October 2016); doi: 10.1117/12.2244494

Published in SPIE Proceedings Vol. 10155:
Optical Measurement Technology and Instrumentation
Sen Han; JiuBin Tan, Editor(s)