Research In Electrochemical Sensor Based On Polymer Coated Multiwalled Carbon Nanotube Film And The Determination Of Hydroquinone And Catechol

Carbon nanotubes have attraeted tremendous interest owing to their uniquemechanical, optical, electrical and chemical properties, espeeially their eleetriealproperties such as electrocatalytie activity and excellent resistance to surface fouling.Carbon nanotobes have been added into polymers to improve their electricalconductivity and mechanieal properties. In the preparation of these materials, theeffeetive utilization of MWCNTs depends strongly on the ability to disperse nanotubeshornogeneously throughout the matrix and to achieve strong interfacial bondingbetween MWCNTs and the matrix in order to ensure load translation. However, thedevelopment of polymers/CNTs composites has been impeded by the inability todisperse CNTs in the polymer matrix.In this thesis, we have done some work in this field and the main results areexpressed as follows:①Construction and research of HQ and CT electrochemical sensor base onPLM/MWCNTsA PLM/MWCNTs modified electrode was prepared by electrochemicalpolymerization method, showed enhanced electron transfer properties and favorableelectrocatalytic performance to the HQ and CT.The result showed that the electrochemical signal response of HQ and CT on thesensor was obvious. The oxidative peak current of HQ and CT are linear to theconcentration ranging from8.00×10-7to2.00×10-4M with detection limit of1×10-7mol/L and8×10-7mol/L, respectively. At the same time, the HQ+CT content in realsamples was detected accurately. The sensor has advantages of good stability, goodselectivity and high sensitivity.②Construction and application of HQ and CT sensor usingCu2+-PLL/MWCNTsA novel electrochemical sensor for HQ and CT was constructed based onCu-PLL/MWCNTs. The result showed that the oxidation current was linearly related tothe concentration form8.0×10-7to2.5×10-4mol/L with a detection limit of1.0×10-7mol/L，8×10-8mol/L for HQ and CT, respectively. The electrochemical sensor hasadvantages of simple manufacture, convenient operation and good stability.③The catalytic oxidation of HQ and CT on Cu2+-PLLmodified GCE A glassy carbon electrode modified with copper doped poly (methyl red) coatedhydroxyl multiwalled carbon nanotube film (Cu2+-PMR/MWCNTs), was developed toserve as a sensor for simultaneous determination of HQ and CT in this paper. Theresponse peak currents of the modified electrodes were linear over ranges of8.0×10-7~4.0×10-4M (R2=0.999) for CT and5.0×10-7~2.0×10-4M (R2=0.993) for HQ.The sensor also exhibited good sensitivity with the detection limit of1.0×10-8mol/L and5.0×10-8mol/L for HQ and CT, respectively. This study provides a new kind ofcomposite modified electrode for electrochemical sensors with good selectivity andstrong anti-interference. It has been applied to simultaneous determination of HQ andCT in water sample with high selectivity.④Preparation and application of HQ and CT sensor based onPLAB/MWCNTs modified GCEPAB/MWCNTs electrochemical sensor was prepared using electrochemicalmethod. HQ and CT on the sensor was studied and a sensitive peak current appeared anabout+0.1V and+0.2V. The peak current was linearly related to the concentration of8.0×10-7~4.0×10-4M (R2=0.999) for CT and5.0×10-7~2.0×10-4M (R2=0.993) for HQ.The sensor also exhibited good sensitivity with the detection limit of1.0×10-8mol/L and5.0×10-8mol/L for HQ and CT, respectively. So this modified electrode can bedeveloped as a rapid, accurate detection method for HQ and CT.