A novel glucose biosensor constructed by glucose oxidase immobilized with methylene blue intercalated layered lanthanum niobic acid nanocomposite.

Cationic methylene blue (MB) was intercalated into layered semiconductor KLaNb 2 O 7 for the first time by the ion-exchange method. MB + forms an inclined monolayer between LaNb 2 O 7 − nanosheets and the nanocomposite exhibited a pair of characteristic redox peaks of MB + cation. The nanocomposite was proved to be capable of immobilizing glucose oxidase (GOD) and facilitate catalytic activities of GOD. The MB + –LaNb 2 O 7 /GOD/CTS/GCE biosensor we constructed showed high electrochemical catalytic activities towards oxidation of glucose with the existence of oxygen. The biosensor had a linear range on detection of glucose from 2.5×10 −5 M to 2.83×10 −3 M and a detection limit of 2.0×10 −5 M. [ABSTRACT FROM AUTHOR]