In situ immobilization of glucose oxidase in chitosan–gold nanoparticle hybrid film on Prussian Blue modified electrode for high-sensitivity glucose detection

An improved amperometric glucose biosensor was constructed by in situ incorporating glucose oxidase (GOD) within the electrodeposited chitosan–gold nanoparticle (chitosan–AuNP) hybrid film on a Prussian Blue (PB) modified electrode. The method is simple and controllable. It combined the merits of in situ immobilizing biomolecules in the chitosan–AuNP hybrid film by electrochemical method and the synergic catalysis effects of PB and GOD molecule. Scanning electron microscopy showed that the chitosan–AuNP hybrid film was homogeneous with small pores, which improved the stability and sensitivity of the biosensor. The biosensor prepared under optimal conditions showed fast response time (3 s), high sensitivity (69.26 μA mM−1 cm2), long-term operational stability, good suppression of interference and low detection limit (6.9 × 10−7 M). A linear calibration plot was obtained in the wide concentration range from 1.0 × 10−6 to 1.6 × 10−3 M. The biosensor was successfully applied to determine the glucose concentration in human serum samples.