Preparation of GOD/Sol-Gel Silica Film on Prussian Blue Modified Electrode for Glucose Biosensor Application

A novel amperometric glucose biosensor was fabricated by in situ incorporating glucose oxidase (GOD) within the sol-gel silica film on a Prussian blue (PB) modified electrode. The method is simple and controllable, which combined the merits of in situ immobilizing biomolecules in sol-gel silica film by electrochemical method and the synergic catalysis effects of PB and GOD molecules. Scanning electron microscopy (SEM) showed that the GOD/sol-gel silica film was homogeneous with a large number of three-dimensional nanopores, which not only enhanced mass transport, but also maintained the active configuration of the enzyme molecule and prevented the leakage of enzyme, therefore improved the stability and sensitivity of the biosensor. The fabricated biosensor showed fast response time (10s), high sensitivity (26.6 mA cm(-2) M-1), long-term stability, good suppression of interference, and linear range of 0.01 mM - 5.8 mM with a low detection limit of 0.94 mu M for the detection of glucose. In addition, the biosensor was successfully applied to determine glucose in human serum samples.