Preparation, Characterization and Electroanalytical Application of Multi-walled Carbon Nanotubes with Enzyme and Dye Film Modified Electrodes
| Autor: | Sing-Ying Yang, 楊欣穎 |
|---|---|
| Rok vydání: | 2011 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 99 Part I：MWCNTs/GR modified electrode which contains multi-walled carbon nanotubes (MWCNTs) and glutathione reductase (GR) has been synthesized on gold electrode. The presence of MWCNTs enhances the surface coverage concentration (Γ) and stability. The modified electrode also exhibits a promising enhanced electrocatalytic activity towards the reduction of glutathione disulfide (GSSG). The cyclic voltammetry has been used for the measurement of electroanalytical properties of analytes by means of modified electrodes. The sensitivity values of MWCNTs/GR modified gold electrode are higher than the values which are obtained for only GR modified electrode. We have studied the surface morphology of the modified electrode using scanning electron microscopy (SEM) and atomic force microscopy (AFM), which revealed that GR is coated on MWCNTs. Finally, the flow injection analysis (FIA) has been used for the amperometric detection of analytes at MWCNTs/GR film modified SPCE. Part II： In this work, we report the direct electrochemistry of horseradish peroxidase (HRP) at bismuth oxide (Bi2O3) nanoparticles coated multiwalled carbon nanotubes (MWCNTs) film modified glassy carbon electrode (GCE). In order to improve the stability of the modified electrode and to avoid the interference effect a thin layer of nafion was formed over the modified electrode. The prepared Bi2O3 nanoparticles, Bi2O3 nanoparticles coated MWCNT (Bi2O3-MWCNT), and NF/HRP/Bi2O3-MWCNT films have been characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), atomic force microscopy (AFM), and powder X-ray diffraction (XRD) studies. The electrochemical behavior of the various film modified electrodes has also been probed via electrochemical impedance spectroscopy (EIS) technique. The prepared NF/HRP/Bi2O3-MWCNT film modified GCE has been employed for H2O2 quantification at physiological pH conditions. The NF/HRP/Bi2O3-MWCNT film showed excellent amperometric i–t response towards H2O2 in the linear concentration range between 13.12 mM-36.95 mM. The developed NF/HRP/Bi2O3-MWCNT biosensor was highly selective towards H2O2 and it detects H2O2 present in the contact lens cleaning solution. Part III： f-MWCNTs/BR9 modified electrode which contains functionalized multi-walled carbon nanotubes (f-MWCNTs) and Basic Red 9 (BR9) has been synthesized on glassy carbon electrode (GCE) and indium tin oxide (ITO). The presence of f-MWCNTs enhances the surface coverage (Γ) and stability. The modified electrode also exhibits a promising enhanced electrocatalytic activity towards the oxidation of neurotransmitters, serotonin and epinephrine (EP). The cyclic voltammetry has been used for the measurement of electroanalytical properties of analytes by means of modified electrodes. The sensitivity values of f-MWCNTs/BR9 modified glassy carbon electrode are higher than the values which are obtained for only BR9 and f-MWCNTs modified electrode. We have studied the surface morphology of the modified electrode using scanning electron microscopy (SEM) and atomic force microscopy (AFM), which revealed that BR9 is coated on f-MWCNTs. Finally, the Differential pulse voltammetry (DPV) has been used for the detection of mixture analytes at f-MWCNTs/BR9 modified electrode. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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