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 (10 s), high sensitivity (26.6 mA cm À2 M À1), 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 mM for the detection of glucose. In addition, the biosensor was successfully applied to determine glucose in human serum samples.

An improved amperometric glucose biosensor was constructed by immobilizing glucose oxidase (GOD) in a titania sol-gel film, which was prepared by a vapor deposition method, on a Prussian Blue (PB)-modified electrode. The method combined the merits of immobilizing biomolecules in the titania sol-gel film by vapor deposition method and the synergic catalysis effects of PB and GOD molecules. Results showed that the fabricated titania sol-gel/PB membrane possessed high surface area, good mechanical stability, and good hydrophilicity, which provided a biocompatible microenvironment for maintaining the bioactivity of the immobilized enzyme and prevented the enzyme from leaking out of the film. Therefore, the present biosensor exhibited fast response time (10 s), high sensitivity (12.74 mA cm -2 mM -1 ), long-term operational stability, good suppression of interference, and a wide linear range from 0.02 to 15 mM with a low detection limit of 5 mM for the detection of glucose. In addition, this simple and controllable method could fabricate biosensors in batches with a very small amount of enzyme.