Glucose oxidase (GOx) was immobilized on acid activated-bentonite. The activation of bentonite was carried out by adding 1-3 M of hydrochloric acid, and the immobilized GOx enzymes were examined for the oxidation of glucose solution under certain conditions. Besides, the effect of pH and working temperature were also investigated. The result showed that the immobilized GOx increased the rate of catalytic reaction. The optimalcatalytic activityof immobilized GOxwas at 30oC and pH 7. The values achieved for the Michaelis-Menten constant (Km) andand maximum reaction rate (Vmax) were 48.01 mM and 5.41 x 10-3mM.min-1, respectively.The result also showed that effectiveness factor was0.68. Immobilization of GOx on acid activated-bentonite also provides a stable matrix shown by the ability to reuse it up to seven times before its activity decreases to a level of 68%. Keywords: bentonite, glucose oxidase, immobilized enzymes, oxidation, glucose.1. IntroductionEnzymes are protein molecules that reduce the activation energy to accelerate chemical reactions in living cells. However, some of these uses require immobilization of molecules. The enzyme molecule is often used without losing its activity and might be used repeatedly and continuously [1,2]. The immobilization development has increased where they are used as biocatalysts in textile industries and other applications [3-6]. The use of immobilized enzymes is preferred because of their repeated use, the ease of harvesting products, and their greater stability. Glucose oxidase enzyme (GOx) is used as a reagent in the glucose determination in blood, though it is always costly [7, 8]. The development of immobilized enzyme technology has always received attention [8]. For instance, explorations relating to immobilized GOxhave been carried out many times in recent years. The process ofimmobilizing biomolecules using insoluble support materials is critical in the fabrication of various functional materials [9]
