Fabrication and characterisation of a glucose-sensitive hydrogel.
Mac Kenna, Nicky and Calvert, Paul and Morrin, Aoife (2013) Fabrication and characterisation of a glucose-sensitive hydrogel. In: EUROanalysis 2013, 25-29 Aug 2013, Warsaw, Poland .
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Stimuli-responsive hydrogels are an attractive material for biosensing applications due to their biocompatibility, ability to incorporate a wide variety of biorecognition molecules and tuneable mechanical properties. In this study, a glucose-sensitive hydrogel has been developed based on the immobilization of glucose oxidase (GOx) within an ionisable polymer network. The catalysis of glucose to gluconic acid produces an acidic environment, thereby ionizing pendant basic groups of the network and generating charge along the polymer backbone. Electrostatic repulsion forces between adjacent ionized groups creates a large osmotic swelling force altering the hydrodynamic volume and permeability of the gel.
The sensitivity and response time of the hydrogel were optimized via weight-based swelling studies. A linear increase in swelling was observed from 1 - 20 mM glucose (r2 = 0.9946), encompassing the physiological range of blood glucose levels. Additionally, novel electrochemical strategies to track the swelling response of these glucose
-sensitive hydrogels were explored, including both using voltammetry of a bulk solution redox probe and non-faradaic electrochemical impedance spectroscopy (EIS).
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