The Preparation And Applications Of Hydrogen Peroxide Electrochemical Sensor Based On Graphene

Because of its simple preparation, low cost and sensitive response, the hydrogen peroxide electrochemical sensor has potential application in medicine, health care, environmental monitoring, industrial production and other fields. How to prepare a hydrogen peroxide electrochemical sensor of fast response, strong anti-interference ability and high stability has been an issue of concern to many electrochemical workers. Moreover, graphene shows a broad prospect in the preparation and application of electrochemical sensors due to its excellent biocompatibility and electronic conductivity. Focusing on the electrochemical detection of hydrogen peroxide, this paper explored the application of graphene and its composite materials in the detection. The following three aspects were included in the research contents:1. Preparation and characterization of graphite oxidesGraphite oxides were synthesized by the modified Hummers method with flake graphite as raw materials. We designed two kinds of solutions and got the simples. Transmission electron microscopy and infrared spectrometer were used to characterize the shape and structure of these simples. It was shown that, after ultrasonic dispersion, the two simples of graphite oxides present good layered structure. The surface of the graphite oxides had-OH,-C=O,-COOH,-C-O-C- functional groups, and the second solution of the graphite oxides obtained stronger hydrophilic.2. Electrochemical characteristics of hemoglobin on graphene modified electrode and electrocatalysis to hydrogen peroxideHb-DMF/ERGO/GC electrode was prepared by dropping Hb on the surface of electro-deposited grapheme electrode. The electrode was characterized by cyclic voltammetry, and the electrocatalytic behavior of H2O2 was also studied. The results showed that Hb-DMF/ERGO/GC electrode had sensitive response to H2O2 in phosphate buffer(p H 7.0) with a detection limit of 2.20×10-6 mol/L, and the linear range was 3.26×10-5~1.96×10-3 mol/L. Moreover, because of the high selectivity, good stability and reproducibility, Hb-DMF/ERGO/GC electrode could be applied in the development of H2O2 volt-ampere sensor.3. The preparation of nano Cu O/ERGO/GC electrode and the detection of H2O2 under alkaline conditionThe nano Cu O/ERGO/GC electrode was generated by electroplating graphene and copper oxide nanoparticles on the surface of glassy carbon electrode successively. The electrochemical workstation was chosen to optimize the related conditions, and scanning electron microscopy was used to characterize the structure of these nanoparticles. Then the electrode was used to detect H2O2 under alkaline conditions. The results showed that, under the optimum conditions, these copper oxide nanoparticles were spheres, and the concentration of H2O2 revealed good liner relationships with the catalytic currents in range of 2.30×10-5 to 2.99×10-3 mol/L and 2.99×10-3 to 8.33×10-3 mol/L. The linear correlation coefficients were 0.9943 and 0.9972 respectively, and the detection limit was 6.96×10-6 mol/L.