A sulfonamide based glucose-responsive hydrogel with covalently immobilized glucose oxidase and catalase

A new glucose-sensitive hydrogel, based on sulfonamide chemistry with covalently conjugated glucose oxidase and catalase, was synthesized and tested. The pH-induced full swelling transition of the gel occurred in the range of pH 6.5 approximately 7.5. In a glucose concentration range of 0-300 mg/dl in an isotonic phosphate buffered saline solution (pH 7.4), the pH inside the gel varied from pH 7.4 to 7.2. At the same glucose concentration range, the gel showed reversible glucose dependent swelling without hysteresis from 12 to 8, expressed in water (g)/polymer (g).