PEG-based Fluorescent Hydrogel for Glucose Biosensing

Diabetes mellitus is a chronic metabolic disorder caused due to lack of insulin production by pancreatic islet cells (Type I) or underutilization of insulin produced in the pancreas (Type II). Complications arising due to this disease can be minimized by vigilant monitoring of blood glucose levels. In this study, a fluorescent enzymatic hydrogel was designed for rapid glucose detection. The glucose-responsive hydrogel was formed by polymerizing multi-arm poly (ethylene glycol), glucose oxidase and serum albumin with aminomethylcoumarin as fluorophore. The sensing mechanism relies on enzymatic catalysis of glucose, that protonates the pH sensitive aminomethylcoumarin, resulting in a fluorescence “turn-on” response. Thermal and mechanical properties of the hydrogel, with and without sensing elements were characterized. The effect of cross-linking on glass transition temperature of the hydrogels were recorded. The compression analysis of the fluorescent hydrogel shows high elasticity with good mechanical strength. Overall, a random copolymer that can be suitably modified for hydrogel based sensing is designed. At room temperature, upon addition of glucose, hydrogel sensor shows fast response time, good sensitivity and reproducibility at physiological pH. The developed fluorescence hydrogel holds great promise as an injectable glucose biosensor for in-vivo continuous glucose monitoring