Dissertation > Excellent graduate degree dissertation topics show

Study on Novel Chemically Modified Electrode and Its Applications for Life Science and Environmental Science

Author: DiYunYun
Tutor: ShiGuoYue；JinLiTong
School: East China Normal University
Course: Analytical Chemistry
Keywords: Chemically modified electrode Electro-catalytic
CLC: O657.1
Type: Master's thesis
Year: 2009
Downloads: 289
Quote: 0
Read: Download Dissertation

Abstract

Chemically modified electrode is the mid-1970s developed a new, is currently the most active electrochemical and electro analytical chemistry frontier has been applied in many aspects of life sciences, environmental science, analytical science and materials science . Chemically Modified Electrode most prominent feature is then coated with a thin film having selective chemical group (on the electrode surface from monomolecular to several microns), endowed with a particular electrode of the chemical, electrochemical, optical , electrical and transmission properties such electrode thereby selectively desired reaction. Because of its easy automation, easy to carry, sensitivity and accuracy, good selectivity, in Electroanalytical Chemistry with a wide range of uses. Four scientific fields of the 21st century, namely: life sciences, information science, materials science and environmental science, life science and environmental science development to analytical chemistry higher, more severe challenges. In these research areas, trace and ultra-trace biologically active substances in situ, real-time, in the body and on-line analysis, high sensitivity, high selectivity related to environmental substances analysis and detection, and green chemistry analysis of test problems has become a constraint one of the main problems related to development of the subject. Chemically modified electrode based on a variety of electrochemical sensing technology with its high sensitivity, high selectivity, a variety of analytical tools and easy to implement automation, miniaturization and other features to meet the requirements of the above subject areas, and thus in these areas has been extensive research and application. However, as a basis for the chemical modification of the electrode itself, there are a lot of problems, has been plagued by the problem of the stability and reproducibility of the people, the service life issues, recycling and regeneration issues, in this regard, there are a lot of basic work to be in we went to study and solve. This paper concentrates on the new modified electrode, and strive to improve the speed of the electron transfer between the electro-active material and electrode, thereby preparing a high sensitivity, low detection limit and stability, good chemical and biological sensors and modified electrode was used for glutathione glutathione, glucose and nitrobenzene compounds. The study focused on the selection and Built materials each having excellent characteristics, the chemical modification of the functional design of the electrode and on this basis. Try a variety of materials to carbon nanotubes, mesoporous silica, chitosan as a reaction platform, by dispensing electrostatic adsorption layer assembly and electrochemical polymerization method to build a modified electrode; SEM, TEM characterization used to study the surface morphology of the sensor; AC impedance, current - time curve, cyclic voltammetry method to explore the electroactive species on the modified electrode electrochemical properties and catalytic response mechanism. The thesis work will strive to achieve chemically modified electrodes, life science, environmental science and electrical analysis of the organic combination of the chemical. Text of a total of four sections: an introduction (Chapter I) the main part of the contents Overview of chemically modified electrodes, used to build a chemically modified electrode material as well as the application of chemically modified electrodes. The paper briefly introduces the principle and classification of chemically modified electrodes; briefly nanomaterials modified electrode and polynuclear metal ferricyanide modified electrode development, preparation and related applications; chemically modified electrode in the analysis of environmental pollution and the life sciences . Based the MWCNTs-mv RuO / RuCN modified electrode build its electro-catalytic properties of glutathione (Chapter II) of the paper, the carbon nanotubes (MWCNTs), RuCl _{3 K ₄ Ru (CN) ₆ successfully build a the MWCNTs-mv RuO / RuCN modified electrode and its electrochemical properties of. First, by dispensing carboxyl carbon nanotube modified glassy carbon electrode surface; Then, containing 1 mmol / L RuCl ₃ and 1mmol/LK ₄ Ru (CN ) the ₆ of 25mmol/LH ₂ SO ₄ solution electrochemical polymerization cycle-0.2V ~ 1.2V range scanning system have to the MWCNTs-mv RuO / RuCN modified electrode. On the MWCNTs-mv RuO / RuCN modified electrode surface by scanning electron microscopy (SEM) were used to characterize physical and study the electrochemical properties of the modified electrode by electrochemical methods to calculate the carbon nanotube modified before and after MV RuO / RuCN modified volume changes. It was found that the modified electrodes have good electro-catalytic oxidation of glutathione oxidation peak current size and the concentration of glutathione in 1.0 × 10 ^{-6 mol / L ~ 2.0 × 10 ^{-3 mol / L range showed a good linear relationship. The paper further discussed the MWCNTs-mv RuO / RuCN modified electrode electro-catalytic oxidation mechanism of glutathione. Finally, we RuO the MWCNTs-mv is the / RuCN modified electrode for capillary electrophoresis - electrochemical detection of glutathione (oxidized and reduced), The results showed that the modified electrode can effectively improve the sensitivity of capillary electrophoresis glutathione. Research in the life sciences, clinical medicine and pharmacokinetics is expected to have a good prospect. New glucose biosensor based the Amplex UltraRed and HRP study (Chapter III) chitosan biocompatible, have a good affinity for the enzyme, and can effectively prevent the leakage of the enzyme, the paper will shell oligosaccharides and glucose oxidase enzyme is immobilized on the electrode surface. Glucose oxidase solution of glucose oxidation reaction generate H ₂ O ₂, the solution of horseradish peroxidase (HRP) catalyzes the formation of H ₂ O ₂ is decomposed into hydroxyl radicals, hydroxyl radicals irreversible oxidation of the non-electrically active the Amplex UltraRed generate water and having electrical activity of resorufin (7 - hydroxy-3H-phenoxazine -3 - triazone). -Resorufin In about-0.1V (vs. SCE) occurs a reversible 2-electron reduction of the chemical reaction to generate the dihydroresorufin be detected, so as to achieve the purpose of indirect detection of glucose. By electrochemical methods to study the electrochemical properties of the modified electrode H ₂ O ₂, at the same time found that the modified electrode has good electrical catalytic oxidation of glucose oxidation the size of the peak current and the concentration of glucose showed a good linear relationship, the linear range is 0.8μmol / L ~ 324μmol / L, the lowest detection limit 0.4μmol / L (S / N = 3), and the Michaelis constant 21.78μmol / L . The method is sensitive, low detection limit, good reproducibility, no significant effect of common interfering substances such as ascorbic acid, dopamine sensor detection. 4 for the detection of trace nitrobenzene compounds {MSU / PDDA} n / GC nano-modified electrode (Chapter IV) In this paper, the mesoporous silica (MSU) and chlorinated poly diallyl dimethyl ammonium base (PDDA) on a glassy carbon electrode layer Assembly, was constructed for the solution in the detection of TNT and nitrobenzene compounds {MSU / PDDA} _n / GC nano-modified electrode. The MSU material as the precursor to zeolite Y, the ionic liquid 1 - 16 alkyl-3 - methyl bromide substituting imidazole for the template synthesis of TEM characterization results show that the material having a larger pore diameter and specific surface area. By AC impedance characterization of the {MSU / PDDA} n Electrochemical Properties of Films, differential pulse voltammetry (DPV) as a means and according to TNT, TNB, DNT and DNB nitrobenzene compounds on the electrode changes in the catalytic reduction current nitrobenzene compounds rapid detection of the electrode reaction and sensing mechanism. The results showed that the modified electrode response speed is fast, high sensitivity, good stability, the electrode response current and nitrobenzene compounds concentration of 4.4 × 10 ^{-9 mol / L to 1.1 × 10 ^{- 7 mol / L range showed a good linear relationship. This study to provide a new method for rapid analysis and monitoring of environmental pollution, and trace amounts of explosives.}}}}}

Related Dissertations

CLC: > Mathematical sciences and chemical > Chemistry > Analytical Chemistry > Instrument analysis ( physics and physical chemistry ) > Electrochemical analysis
© 2012 www.DissertationTopic.Net Mobile