A TiO2-Sol-Gel Derived Prussian Blue Nanoparticles-Based Glucose Biosensor

A highly sensitive and selective glucose biosensor was designed by immobilizing glucose oxidase (GOD) on a Prussian blue nanoparticles (nanoPBs) modified glassy carbon electrode using a novel titanic dioxide Solution-Gelation (TiO₂-Sol-Gel) technique. Glucose measurement was based on the level of hydrogen peroxide (H₂O₂) produced concomitantly with the reaction of glucose and oxygen mediated by GOD. NanoPBs catalyze this reaction efficiently by reducing the reaction potential and improving GOD activity. The biosensor showed voltaic response to H₂O₂ in a linear range of 5.0 times 10^-7 to 4.0 times 10^-4 mol/L and amperometric response to glucose in a linear range of 1.0 times 10^-4 to 2.4 times 10^-2 mmol/L with fine reproducibility (relative standard deviation varied from 3.6% to 4.2%). This nanoPBs-based biosensor also exhibits high recovery (97% ~ 101.5%) for measuring blood glucose levels and the developed method is applicable for large-scaled manufacturing of disposable biosensors.