Preparation of perovskite-type composite oxide LaNi0.5Ti0.5O3–NiFe2O4 and its application in glucose biosensor

A novel nanostructured perovskite-type composite oxide LaNi0.5Ti0.5O3–NiFe2O4 (LNT–NFO) was synthesized by sol–gel method and characterized by X-ray diffractometer (XRD) and transmission electron microscopy (TEM). Amperometric glucose biosensors based on the carbon paste electrode (CPE) were constructed by immobilizing glucose oxidase (GOD) with LNT–NFO and the experimental conditions such as the amount of GOD, pH value, and applied potential were investigated. Under the optimum conditions, the electrochemical performances of the LNT–NFO with different ratios of LNT-NFO (10:1, 20:1, 30:1) modified CPE have been researched on the oxidation of glucose. The results show that LNT–NFO (20:1) can immobilize GOD more effectively. The biosensor based on LNT–NFO/CS/GOD modified CPE exhibits good reproducibility, stability and selectivity in glucose determination with linear signal-to-glucose concentration range of 0.5–10 mM and a detection limit (S/N = 3) of 0.04 mM.