Immobilization of glucose oxidase in poly(2-hydroxyethyl methacrylate) membranes

Glucose oxidase (GOD) was immobilized in a poly(2-hydroxyethyl methacrylate) (HEMA) membrane through matrix entrapment in order to investigate the effect of various parameters (e.g. concentration of ingredients, temperature, repeated interaction with glucose and shelf storage) on the activity of the enzyme. Permeability of the membrane to a model permeant was tested and SEMs were obtained. It was observed that upon immobilization the affinity of GOD towards glucose was substantially decreased, and increasing the GOD content of the membrane adversely affected the activity. Membranes with the highest enzyme activity were also found to be the most permeable. Changes were detected in the pH and temperature where GOD is most active. Membrane permeability was observed to increase when crosslinker, and/or HEMA concentrations were low. The same parameters were also found to alter the morphology of the membrane as observed under SEM.