| Many electroactive molecules such as purine, rutin, dopamine are the important candidates of electrochemical analysis due to the importances in the biological process. In electroanalysis ionic liquids (ILs) can be used as the solvent and supporting electrolyte, the binder and the modified film used for electrodes modification, which have exihibited many special chemical and physical properties. Graphene is a new kind of2D carbon material with many unique properties, and the graphene nanocomposites (GRNs) also show many properties such as high spicific surface, high conductivity, moderate biocompatibility and morphology diversification, which makes it to be potential material in the application of electrochemistry.In this thesis a new type of working electrode that mixing N-hexylpyridinium hexafluorophosphate (HPPF6) and graphite powder was contructed and used as substrate electrode and different kinds of GRNs were uesd as modifier to make the modified electrodes. The performance of the working electrodes were investigated by cyclic voltammetry, electrochemical impedance spectra and the topography was scanned by a scanning electron microscopy. The electrochemical behavior of some electroactive substances such as purine, guanosine, adenosine, rutin and dopamine were investigated by cyclic voltammetry, differential pulse voltammetry and chronocoulometry. The results indicated that the GRNs modified CILE showed excellent electrocatalytic activity towards these small molecules. The influence of scan rate to redox current and potential were observed and the related electrochemical parameters were calculated. In the optimal condition, the peak current of analytes had a good linear relationship with the concentration in a certain range. The coexisting substances such as metal ions, small biomolecules and amino acids rarely influence the measured results. These methods are applied in the actual samples determination with satisfactory results. |
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