Preparation Of Graphene/Ferrocene Composite And Its Electrochemical Sensor

Electrochemical sensor is one of an important part and hotspot in the electrochemical research. It has lots of advantages, such as high sensitivity, good stability, low cost, simple operation and so on, and it was widely used in environmental pollution detection, life sciences, food and clinical diagnosis, etc.Graphene is a two-dimensional material, which consists of carbon atoms. It has many excellent physical and chemical properties, such as large surface area,excellent mechanical properties, good thermal conductivity properties and other electrocatalytic properties. It has a large number of applications in the technical revolution since it was found in 2004. However the graphene surface went into a state of inertia, which is easy to reunite, and limite its further application in various fields. In practical applications, graphene composite is more used, that is, combining graphene with different materials to improve its electrochemical performance.Ferrocene has a structure of sandwich and containe REDOX centers and it is easy to be modified. If introducing ferrocene into the graphene through covalent bond to get a new composite, not only can enhance the activity of ferrocene in electronic sensors,but also expand the applications of graphene and its composites in the electrochemical field.In this article, we synthesized a compound of grapheme/ferrocene by covalent bond. Firstly, we use the improved Hummers method to get graphene oxide with good water dispersibility, and then the graphene oxide/ferrocene composite was prepared through covalent function with ferrocene. Infrared spectrum, transmission electron microscopy and XRD were used to characterize its morphology and structure. Then it was restored under constant potential, and dropped on different electrodes to detect dopamine. The results showed that the composite film modified glass carbon electrode performs excellent electrocatalysis in redox behaviors of DA.The oxidation peak current was linearly related to the concentration of DA in the range from 0.4~300μmol·L-1, with a correlation coefficient of 8×10-8 mol/L. It wasalso available to detect UA. The oxidation peak current was linearly related to the concentration of UA in the range from 5×10-6~1×10-4mol/L, with a correlation coefficient of 0.898μmol/L. In addition, we also constructed the HRP-GR-Fc-Nafion sensor to measure H2O2. The result showed that the synergy of ferrocene with graphene improved electron transfer rate, which improve the performance of sensor effectively. The reductive peak current was linearly related to the concentration of UA in the range from 4 to 5000μmol/L, with a correlation coefficient of 0.85μmol/L.