| Nanomaterials have unique nature (such as volume effect, surface effect, quantum size effect and macroscopic tunnel effect), different from bulk material and single-molecule material. They had been widely used as modifer with chemically modified electrode. Similarly, because of their peculiar molecular structure, CD and its derivatives could have molecular recognition. At present, they had been widely used in various fields, especially in the analysis and separation area. The main research work is described as follows:1. Review on chemically modified electrode in analytical chemistryIn chapter one, the types, preparation methods, modifer and applicable value of chemically modified electrode had been described briefly. Especially, CD and CNTS modified electrodes, were used in the field of analytical chemistry, described in detail.2. Detemination of CBs by HP-β-CD sensitized electrochemical signal with Rh6G as a electrochemical probeThe additon of CBs could change the electrochemical signal of the system (Rh6G-HP-β-CD). Simultaneously, it had a linear relationship between the concertration of the CBs and the electrochemical signal attenuation. So we developed a new method for determining CBs, using Rh6G as a electrochemical probe, which based on competitive inclusion. This method showed excellent reproducibility, reversibility and sensitivity. The linear range was obtained over the range from 1.0×10-6-1.5×10-5 mol/L for CB and 5.0×10"7-6.0×10"6 mol/L for 4,4'-PCB, and the detection limit was respectively 5.0×10-7mol/L and 2.5×10-7mol/L. It has been applied to the determination of CB and 4,4'-PCB in waste water samples with satisfactory results.3. Determination of PCP at carbon nanotubes modified electrode incorporated withβ-CDA facile and reliable electrochemical technique atβ-cyclodextrin incorporated carbon nanotubes modified glassy carbon electrode (β-CD/CNTs/GCE) was proposed for quantification of pentachlorophenol (PCP). Theβ-CD/CNTs/GCE showed well analytical performance characteristics in electrocatalytic oxidation of PCP, compared with the simple carbon nanotube modified electrode (CNTs/GCE) and bare glassy carbon electrode (GCE). After accumulation for 5 min onβ-CD/CNTs/GCE, the peak current increased linearly with the concentration of PCP in the range of 8.0×10-7 to 1.04×10-5 mol/L. The detection limit was 4.0×10-8 mol/L at 3σlevel. The proposed electrode presented a good repeatability for the quantification of PCP in artificial wastewater, and the recovery was 97%-103%. This modified electrode combined the advantages of carbon nanotubes and supramolecular cyclodextrin, leading to new capabilities for electrochemical detection of PCP.4. Direct determination of 4-chlorophenol with a carbon nanotubes andα-CD modified electrodeThe three chlorophenol isomers couldn't be simultaneously determined without any pretreatment on GCE. The modified electrode had strong catalytic effect towards the electrochemical oxidation of chlorophenol isomers and preferentially selective adsorbed 4-CP. The electrochemical sensor had good selectivity and high sensitivity to detect trace amounts of chlorophenol isomers. The linear relationships between the peak current and the concentration were obtained in the range of 5.0x10-7-5.0x10-5 mol/L for 4-CP, with the detection limit of 2.0×10-7 mol/L for 4-CP. It was found that all the studied coexisting substances, except structure and size similar with 4-CP, could be tolerated in considerable amounts. This proposed method was successfully used for direct determining trace amounts of 4-CP in artificial wastewater samples with satisfactory results.
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