A non-enzymatic sensor for hydrogen peroxide based on the use of α-Fe2O3 nanoparticles deposited on the surface of NiO nanosheets

This work reports on the synthesis of nanocomposites from NiO and α-Fe2O3 by a hydrothermal route. The material was characterized in terms of structural and morphological features by X-ray diffraction and scanning electron microscopy. The nanocomposites were synthesized by growing α-Fe2O3 nanoparticles on the surface of flower-like NiO nanosheets, and then characterized by cyclic voltammetry and amperometric techniques. A glassy carbon electrode (GCE) modified with the nanocomposite displayed distinctly improved response to H2O2 compared to a GCE modified with bare NiO. The H2O2 sensor, best operated at a voltage of 0.4 V (vs. Ag/AgCl) has a sensitivity of 146.98 μA·μM−1·cm−2, a 0.05 mM lower detection limit, and a linear working range that extends from 0.5 to 3 mM of H2O2. The sensor is reproducible and long-term stable even in the presence of various interfering molecules such as ascorbic acid and uric acid.