The construction of glucose biosensor based on crystalline iridium(III)-containing coordination polymers with fiber-optic detection

This study reports a simple and sensitive method for phosphorescence detection of glucose concentration in beverage samples and human serum. This optical sensor was constructed based on sensing substrate made of crystalline iridium(III)-containing coordination polymers doped in sol–gel matrix and built up under glucose oxidase encapsulated in hydrogel and then immobilized on egg membrane, using the layer-by-layer method. The detection mechanism is based on the depletion of oxygen content upon exposure of glucose solution with a concomitant increase in phosphorescence of coordination polymers. The effects of buffer concentration, pH, interference and temperature have been studied in detail. Under optimum conditions, the luminescence changing rate revealed a good linear relationship from 0.05 mM to 5.0 mM (y = 1.058 [glucose] + 0.6591, R2 = 0.9935) with a detection limit of 0.01 mM. This method has also been successfully applied to the determination of glucose in real samples.