Synthesis Of Iron Family Metal Oxide Nanocomposite For Electrochemical Sensor

The determination of the glucose and hydrogen peroxide is closely related to human health.The electrochemical biosensors exhibit excellent features such as high sensitivity,good selectivity,low detection limit,low cost,good stability.Besides,it also can realize the real-time,fast and on-site detection of those substances.The electrochemical biosensor is based on the relationship between the change of electrical signal and the concentration of the detection materials.The high sensitivity and high stability of electrochemical biosensors can be achieved by the improvement of electrochemical catalytic activity and the improvement of stability.Therefore,research on sensing materials has become important content in the study of electrochemical biosensors recently.Moreover,the rapid development of nanotechnology provides a very good opportunity for the new development of electrochemical biosensors.Among the nanomaterial,iron,cobalt,nickel as a member of the iron element has great potential applications in the field of the electrochemical biosensor because of their excellent electrical,optical and chemical properties.Metal oxide nanocomposite materials combine metal oxide nanoparticles with other components by physical or chemical method.The composite is a kind of composite material which has special properties of each component and has synergistic effect.Therefore,Metal oxide nanocomposites have wide applications in many fields.The main research contents of this paper are as follows:1 The Fe₂O₃/graphene nanocomposite is prepared by hydrothermal process for the determination of ascorbic acid in the presence of uric acid.In contrast to the glassy carbon electrode and graphite electrode,the Fe₂O₃/graphene nanocomposite modified glassy carbon electrode has excellent catalytic performance towards ascorbic acid in the presence of uric acid.The reason may due to the synergistic effect of graphene and Fe₂O₃ nanoparticles.In addition,the Fe₂O₃/graphene nanocomposite has other good sensing properties,such as high sensitivity,good stability and reproducibility.2 In this study,we have demonstrated a facile method to prepare the NiO/graphene nanocomposites for the determination of H2O2.Due to the synergistic effect of graphene and NiO nanoparticles,Electrochemical experiment results show that the NiO/graphene composite demonstrate s a high peak current towards the oxidation of H2O2.Moreover,high electrocatalytic activity toward H2O2 is observed with a low detection limit of 0.7664 ?M,high sensitivity of 591 ?A mM-1 cm-2,a wide linear range of 0.25-4.75 mM?R2=0.9971?.In addition,the NiO/graphene nanocomposite has other excellent features,such as high stability and repeatability.3 In this article,the core-shell structure of NiCo₂O₄@polyaniline is prepared by the in-situ polymerization process after a simple hydrothermal method.The core-shell structure of NiCo₂O₄@polyaniline can combine the excellent structure and effective diffusion distance,which greatly improve the catalytic performance of the catalyst.Under the optimum condition,the glucose biosensor exhibits excellent sensing properties,such as high sensitivity?4.55 mA mM-1 cm-2?,low detection limit?0.3833 ?M?and wide detection range?0.015-4.735 mM?.