| Due to carbon nanotubes have unique spatial structure and excellent electricalproperties, carbon nanomaterials have received much attention by many researchers.According to different fabrication methods, various kinds of carbon nanomaterialswhich were suitable for applications in chemistry, physics and material science weregained. Electrochemical detection has many outstanding advantages such asspeediness, high sensitivity, convenience, innocuity, low cost, online testing and so on.Therefore they have been aroused attention and concern of chemists and biologists inClinical medical, environmental monitoring, drug analysis field and so on. In thispaper, signal-walled carbon nanotubes modified glassy carbon electrode and thenanocomposites of SWCNTs modified electrode were prepared. The electrochemicalbehaviors of the nanocomposite materials were studied. Additionally, the carbonnanomaterials based on electrodes were applied as electrochemical sensors withsatisfied results. The main points of this thesis were summarized as follows:1. A novel nanocomposites sensor for epinephrine detection in the presence ofUric Acids and Ascorbic Acids. A novel nanocomposites film of conducting polymersincluding Single-walled Carbon Nanotubes （SWCNTs）, polypyrrole （PPy） and goldnanoparticles （AuNPs） modified electrode has been applied in voltammetric sensorsto detect epinephrine （EP） sensitively when ascorbic acids （AA） and uric acids （UA）exist. The nanocomposites film of conducting polymers which shows an excellentelectrocatalystic activity for the oxidation of EP and UA was characterized byscanning electron microscopy （SEM） and electrochemical methods. The catalyticpeak currents obtained from differential pulse voltammetry （DPV） increased linearlywith increasing EP concentrations in the range of4.0×10-9to1.0×10-7M with adetection limit of2.0×10-9M （S/N=3）, respectively.2. Electrocatalytic detection of dopamine in the presence of ascorbic acid anduric acid using single-walled carbon nanotubes modified electrode. Single-walledcarbon nanotubes （SWCNTs） fabricated by sodium dodecyl sulfate （SDS）（f-SWCNTs）modified glassy carbon electrodes （f-SWCNTs/GCE） for the simultaneousdetermination of ascorbic acid （AA）, dopamine （DA） and uric acid （UA）. The f-SWCNTs/GCE displayed very good in electrochemical catalytic activities withrespect to GCE. The oxidation over-potentials of DA and UA decreased dramatically,and their oxidation peak currents increased significantly at f-SWCNTs/GCE comparedto those obtained at the bare GCE. Simultaneously, the oxidation peak currents of AAdecreased accordingly. The f-SWCNTs/GCE not only divide the overlappingvoltammetric responses of them into individual voltammetric peaks, but also totallyeliminate the interference from AA and distinguish DA from UA. The catalytic peakcurrents obtained from Square wave voltammetry increased linearly with increasingDA concentrations in the range of5.0×10-6to1.0×10-4M with a detection limit of2.0×10-8M （S/N=3）. The method was also successfully applied for determination ofDA and showed good recovery in some biological fluids.3. The electrochemical behaviors and determination of morin onf-SWCNTs/AuNPs modified glassy carbon electrodes. The gold nanoparticles （AuNPs）and functional Single-walled carbon nanotubes （f-SWCNTs） composite film-modifiedglassy carbon electrode （GCE） was fabricated simply by the electrostatic interactionbetween the positively charged AuNPs and the negatively charged SWCNTs. And thef-SWCNTs/AuNPs/GCE electrode was used for the selective and sensitivedetermination of Morin. It was found that the f-SWCNTs/AuNPs/GCE electrode hadhigher catalytic activity towards the oxidation of Morin. The f-SWCNTs/AuNPs/GCEcan totally eliminate the interference from Rutin and distinguish Morin from Rutin.The catalytic peak currents obtained from differential pulse voltammetry （DPV）increased linearly with increasing Morin concentrations in the range of1.0×10-8to5.0×10-7M with a detection limit of4.0×10-8M （S/N=3）, respectively. |
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