The Construction And Application Of Sensitive Chemical Sensor For PAHs Determination

At present, the environmental pollution is a serious threat to the environment of humans, animals and plants. As the important member of the environmental pollution, polycyclic aromatic hydrocarbons(PAHs) seriously endenger the atmosphere, water and soil environment. In addition, the PAHs possess three characteristics including carcinogenicity, teratogenicity, and mutagenicity, which especially threaten human’s survival and health. Therefore, to exploit and develop a new method and technology to detect PAHs has become one of scientific research from all countries. However, most of the existing detection technologies of PAHs are complicated and the sensitivity is low. In order to exploit a rapid, simple and sensitive detection method of PAHs, we put forward the following three methods based on the reference to numerous literatures, mainly including electric polymerization, self-assembly and molecular imprinting methods. These methods can rapidly and sensitively determine trace quantity of PAHs in water. The main content of the thesis includes the following aspects:1. We prepared the 2, 6-2 amino anthraquinone modified glassy carbon electrode using self-assembly technology. The modified electrode was characterized by electrochemical methods. Results show that with the increase of self-assembled layer, polarization resistance increased gradually. The peak current increases more obviously at modified electrode compared with the probe in solution, which indicated that the self-assembly technology for inprovement of the electrochemical signal of 2, 6-2 amino anthraquinone was obvious. We investigate the influence of PAHs including naphthalene, anthracene, phenanthrene, pyrene and so on on the electrochemical signal of the modified electrode. As a result, the electrochemical sensor can be used in the determination of trace amounts of naphthalene in solution. Compared with methods such as chromatography, mass spectrometry, and immunity, this method is simpler, rapider and more sensitive.2. Polyurethane molecularly imprinted pyrene modified electrode was prepared with bisphenol A, phloroglucinol and p-toluene isocyanate as the monomer, dimethyl formamide(DMF) as the solvent and pyrene as template molecule. Pyrene and many kinds of PAHs were examined on the influence of electrochemical signals of the modified electrode. The experimental results show that the influence of pyrene on the electrochemical signal of the modified electrodes is the largest.The method can detect pyrene in water with highly sensitivity and specitivity3. We constructed the electrochemical sensor using potentiostatic polymerization method in sulfuric acid solution with emodin as probe and pyrrole as the conductive polymers. We investigate the influence of PAHs including naphthalene, anthracene, phenanthrene, pyrene and so on on the electrochemical signal of the modified electrode. As a result, we established a new method for the determination of naphthalene. In order to check the accuracy of the method, the standard samples were tested and the result was satisfactory.4. Using the excellent physical and chemical properties of graphene, we prepared the polymethylene blue /graphene modified glassy carbon electrode with methylene blue as the electrochemical probe. We investigate the influence phenanthrene on the electrochemical signal of the modified electrode. As a result, we established a new method for the determination of phenanthrene.