| Carbon nanotubes exhibit many extraordinarily attractive physical and chemical properties, such as the large surface area, the good ability to promote electro-transfer reactions, remarkable catalysis towards biomolecules, good biocompatibility, and etc. Room temperature ionic liquids can be used as electrolyte as well as solvent. They also have attracted considerable attention due to their unique physical and chemical properties, such as high thermal and chemical stability, high conductivity, the ability to dissolve a wide range of organic and inorganic molecules, wide electrochemical potential window, ability to facilitate direct electron-transfer reactions, good biocompatibility and etc. Since the introduction specially, carbon nanotubes and room temperature ionic liquids have received enormous attention in the fields of electrochemistry. Moreover, it's attractive that the combined application of them has more promising prospects in many fields of electrochemistry, for example, the fabrication of chemical modified electrode.A novel modified electrode (MWNTs-IL-Gel/GCE) was prepared with multi-walled carbon nanotubes (MWNTs) and ionic liquid, 1-butyl-3- Methylimidazolium hexafluorophosphate, to modify glassy carbon electrode. First of all, we investigate the electrochemical behaviors of rutin at the MWNTs-IL-Gel/glassy carbon electrode (GCE). Then, we present the preparation of rutin functionalized carbon nanotubes and ionic liquid compound (MWNTs-Rutin-IL). The MWNTs-Rutin-IL composite film was characterized by different methods, and was modified glass carbon electrode. Next, we investigate the electrocatalysis behaviors of the MWNTs-Rutin-IL/GCE for tryptophane, and discuss the electrocatalytic mechanism。The main research work was as follows:1. Electrochemical behavior of rutin on a multi-walled carbon nanotube and ionic liquid composite film modified electrodeIn this paper, the electrochemical behaviors of rutin at the MWNTs-IL-Gel/glassy carbon electrode (GCE) were investigated. Good electrocatalysis behavior towards the oxidation of rutin with enhancement of the redox peak current and decrease of the peak-to-peak separation was demonstrated. The electrochemical parameters of rutin were calculated giving values of the charge-transfer coefficient (α) and the electrode reaction standard rate constant (ks) as 0.47 and 0.2 s-1, respectively. In addition, the MWNTs-IL-Gel/GCE was characterized by different methods including electrochemical impedance spectroscopy (EIS), scanning electron microscope (SEM), clay film thickness, and UV–vis spectra. The oxidation peak currents of rutin in such modified electrode increased linearly with the concentration of rutin in the range from 7.2×10-8 to 6.0×10-6 molL-1 with a detection limit of 2.0×10-8 molL-1. These results suggest that the proposed electrode can be used for sensitive, simple and rapid determination of rutin.2. Study on Biomolecules-functionalized Carbon Nanotube and Ionic Liquid Composite Modified ElectrodeThe combination of biomolecules-functionalized multiwalled carbon nanotube (MWNTs) and ionic liquid (IL) yields nanostructured biointerfaces, formed a novel kinds of structurally uniform and bioelectrocatalytic activity materials. Rutin was chosen as a model biomolecules to investigate the composite system. The MWNTs-Rutin-IL composite film was Characterized by different methods including thermogravimetric analysis (TGA), UV–vis spectra, electrochemical impedance spectroscopy (EIS) and scanning electrochemical microscope (SECM). A pair of well-defined quasi reversible redox peaks of rutin were obtained at the MWNTs-Rutin-IL composite film modified glassy carbon electrode (GCE) by direct electron transfer between the rutin and the GCE electrode. Dramatically enhanced biocatalytic and electrocatalytic activity was exemplified at the MWNTs-Rutin-IL/GCE electrode by the oxidized of tryptophane. The oxidation peak currents of tryptophane in such modified electrode increased linearly with the concentrations of tryptophane in the range from 8×10-8 to 2×10-5 molL-1 with a detection limit of 3.0×10-8 molL-1. The unique composite material based on biomolecules-functionalized carbon nanotube and ionic liquid have wide potential applications in direct electrochemistry, biosensors, and biocatalysis.
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