A Layered Nano-structured Perovskite-type Oxide LaNiTiO_3 for Nonenzymatic Catalytic Detection of Hydrogen Peroxide

摘要

A nonenzymatic biosensor for hydrogen peroxide (H_2O_2) is developed based on a glassy carbon electrode loaded with layered nano-structured perovskite-type oxide LaNiTiO_3 by sol-gel method. Characterizations of as-synthesized LaNiTiO_3 are conducted using powder X-ray diffraction, transmission electron microscopy, scanning electron microscopy and low temperature N_2 adsorption and desorption isotherms techniques. Electrochemical properties of the fabricated biosensor are studied by cyclic voltammetry and current-time curves. Experimental results show the electrochemical biosensor has high activity to the oxidation of H_2O_2 with a fast response time of ～2 s in 0.1 M NaOH solution. A wide linearity is obtained from 0.05 μM to 10.0 mM with a low detection limit of 0.01 μM (S/N = 3) and a high sensitivity of 854 μA mM~(-1) cm~(-2) under optimal conditions: the content of LaNiTiO_3 modifier (5.0 μL, 0.5 mg/mL) and applied potential (0.55 V). The biosensor also exhibits good stability, reproducibility and anti-interference ability, suggesting potential practical application of LaNiTiO_3 in biological analysis and environmental detection.