Highly Sensitive and Strongly Fluorescent Gum Tragacanth Based Superabsorbent Hydrogel as a new Biosensor for Glucose Optical Detection
In this study, a superabsorbent biosensor hydrogel of highly sensitive blood glucose was prepared based on the gum tragacanth (GT) nanoparticles, acrylic acid (AA) monomer, N, N'-methylenebisacrylamide (MBA) and fluorescein O,O′-diacrylate (FlA-DA) as cross-linkers. Then CdTe quantum dots (QDs) and glucose oxidize (GOx) enzyme bioreceptor were immobilized within the cross-linked network of hydrogel. The prepared biosensor was highly fluorescent due to the synergism process between QDs and FlA-DA. The biosensor was able to perform enzyme-catalyzed oxidation of glucose to produce H2O2, a product which subsequently quenched the fluorescence emission. The quenching rate was a function of the glucose concentration. The detection limit and the Michaelis–Menten constant (KM) of the present system was found to be an excellent value of 0.1 and 1.35 mM, respectively, which were much lower than those of conventional gel materials. This new device has also shown satisfactory reproducibility and accuracy with real blood samples without pretreatment. The results indicate that this new highly fluorescent biosensor with simple and sophisticated fabrication offers high immobilization for the fluorescent reporters and bioreceptors, and this can be a suitable diagnostic device for biomedical applications.