| Because of the novel and unique physicochemical properties, such as insoluble and infusible, chemical stability and mechanical stability, conducting polymer has emerged as a kind of exciting materials. And it has been widely used for electrochemical sensing and biosensing based on its fascinating poperties. However, many conducting polymers still has some defects, which will restrict their application in electrochemical sensors, so there is still an urgent need to prepare conducting polymers with high stability, large surface area, and good conductivity. Poly-(3,4-ethylenedioxythiophene)(PEDOT) successfully overcomes most of the short comings of conducting polymers, and it has became a kind of most stable and promising conducting polymer. It has been extensively studied because of its good stability, high conductivity, large visible light transmittance and good processing performance. However, most PEDOT based sensors are based on two-dimensional PEDOT film, which has relative small surface area, low loading amout for other materials, and large resitance for mass tranport. To further elevate the performance of PEDOT based electrochemical sensor, a new three dimensional porous PEDOT(shorten as 3D-P-PEDOT) was prepared. Several electrochemical sensors with high sensitivity and low detection limit based on 3D-P-PEDOT and its hybrid with Cux O or PB were constructed. The main contents of this thesis are as following:1. Poly-(3,4-ethylenedioxythiophene)(PEDOT) with a unique three dimensional(3D), porous structure(3D-P-PEDOT) was prepared by a facile electrodeposited approach. We found that the morphology can be changed through changing the electrodeposited conditions, so the mechanism of its growth could be explored based on the different morphlogy obtained from the SEM figures. Finally, the electrochemical and electrocatalytic behaviors of the 3D-P-PEDOT/GCE towards nitrite and ascorbic acid oxidation were evaluated by cyclic voltammograms, chronoamperometry and amperometric method, and the result showed that the sensitivity, linear range and over-potential obtained was better than those of previously reported PEDOT based sensors. The nitrite concentration in the range of 0.5 to 9200 ?M linearly depended on the catalytic current, the sensitivity was 64.31 ?A cm-2 m M-1, and the detection limit was 0.2 ?M(S/N=3). The ascorbic acid concentration in the range of 0.5 to 11200 ?M linearly depended on the catalytic current, the sensitivity was 55.21 ?A·cm-2·m M-1, and the detection limit was 0.1 ?M(S/N=3).2. 3D-P-PEDOT-Cux O hybrid was prepared through a facile electrochemical deposition and cyclic voltammetry treatment process. The hybrid material was characterized by scanning microscopy(SEM), X-ray energy dispersive spectrum(EDS), Raman, and electrochemical methods. When the PEDOT and the hybrid material was used to detect hydrazine, it is found that 3D-P-PEDOT not only as matrix to increase the loading amount of Cux O and can enhance the conductivity, but also directly contributed to the catalytic oxidation of hydrazine. The electrochemical and electrocatalytic behaviors of the 3D-P-PEDOT-Cux O/GCE towards hydrazine oxidation were evaluated by cyclic voltammograms, chronoamperometry and amperometric method. The hydrazine concentration in the range of 0.5 to 600 ?M, and 600 to 53000 ?M linearly depended on the catalytic current, the sensitivity was 414 ?A·cm-2·m M-1, 157 ?A·cm-2·m M-1, and the detection limit was 0.2 ?M(S/N=3).3. Three dimensional poly(3,4-ethylene-dioxythiophene)(3D-P-PEDOT) film was prepared through a potentiostatic deposition, and then Prussian Blue nanoparticles(PBNPs) was grown on 3D-P-PEDOT film using a very simple and environmental friendly method-soaking. The hybrid film showed good performance in the detection of H2O2, which was owning to the synergistic interaction between the 3D-P-PEDOT and the PBNPs. The sensor has excellent catalytical performance and antinterference capability for H2O2 detection. The H2O2 concentration in the range of 0.17 to 5667 ?M linearly depended on the catalytic current ? The sensitivity was 1.15 ?A·cm-2·m M-1, and the detection limit was 0.08 ?M(S/N=3). |
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