Determination of Glucose with Biosensor by Immobilization of Glucose Oxidase with Chitosan

A glucose biosensor was fabricated from a glucose oxidase-immobilized by chitosan and oxygen electrode. The effects of concentration of chitosan (0.3%), enzyme loading (0.8 mg), pH 7.0, phosphate buffer concentration (300 mmol/L), and temperature 25 T for the response of the biosensor were investigated. The glucose biosensor has a linear response range of 0.016 - 1.10 mmol/L with a detection limit of 8.0 mu mol/L (S/N = 3). The response time was less than 60 s. The biosensor showed extremely good stability with a shelf-life of at least 3 months. The biosensor exhibited good repeatable response to a 0.25 mmol/L glucose solution with a relative standard deviation of 2.5% (n = 10). The precision of fabrication of the biosensors using four different membranes was good with a RSD of 4.7%. Some common potential components ill sample such as niacinamide, vitamin B-6, vitamin B-12, vitamin E, Ca2+, Mg2+, K+ and Zn2+ showed no interferences oil the response of the glucose biosensor. The biosensor was successfully applied to determine the glucose in commercial beverage samples.