An optical glucose biosensor fabricated by encapsulating glucose oxidase in silica gel via sol-gel method

Abstract

An optical glucose biosensor was fabricated by encapsulating glucose oxidase in TEOS-derived gel film along with Ru(bpy)3Cl2 as an luminescent oxygen transducer, for determining the concentration of glucose in the blood and urine samples. When the oxidation reaction of glucose by glucose oxidase occurred, an increase in the fluorescence intensity of Ru(bpy)3Cl2 was observed due to the oxygen consumption. A good response performance to glucose was exhibited for the biosensor with a wide linear range from 2.0 to 18.0mM, R=0.997. The detection limit of the biosensor was estimated to be 0.368mM, with response time < 50s. There was no apparent interference for the biosensor with fructose, urea and ascorbic acid. In addition, the enzymatic activity and long-term stability were also discussed in details.