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Heavy metal pollutants in the environment of modern society, especially lead pollution problem, increasingly a cause for concern, the environment and the human body in lead detection method for extensive. Lead is widely present in the environment and has strong toxicity of heavy metal ions, with the rapid development of modern industrial and transportation, environmental lead pollution has become increasingly serious, has become an important social issues that affect humans, especially children's health. The study confirmed that: blood lead levels exceed 100μg / L will affect the growth and development of children, especially damage to the neurological development of children, and affect a child's intelligence and behavior. The blood lead determination methods including the dithizone complex colorimetry, atomic absorption spectrometry, atomic emission spectrometry. All of these methods are the analysis of the cost of expensive, cumbersome steps, long time analysis shortcomings. Compared with this electrochemical method, and its advantages of low cost and high sensitivity, as the advantages of methods for the detection of heavy metal ions, including lead. Chemically modified electrodes prepared by the various channels, the molecular tailoring of the surface of the electrode by a controllable method, according to the intention to the predetermined function of the electrode on which to selectively carry out a desired reaction, at the molecular level to achieve the electrode The features of the design. Chemically modified electrode electrochemistry, electroanalytical chemistry is very active field of research. Such modified electrode comprises a chemical change of the electrode interface area, and therefore it presents the nature of the electrode material itself on any surface, the nature of the different. Since the 1975 advent of chemically modified electrodes for chemical and related interdisciplinary pioneering an innovative and promising a broad field of research. Analysis that is required in order to improve the detection sensitivity of the analysis, to meet the real-time live, to reduce the cost of analysis and sample requirements, how to implement the detection means of the entire analysis miniaturization then get efficient chemical biosensor analytical chemistry has become of miniaturization and integration of the study important to the development of cutting-edge one. The sensor system has been built based on chemically modified electrodes widely used in the natural and life sciences, become a common research an effective tool to solve scientific research and practical problems. And integration, miniaturization has become a hot research. By the miniaturization of the analysis system, can effectively reduce the required amount of sample and reagent, to reduce analysis costs and energy consumption, but also can improve the detection sensitivity of the analysis, and to increase the detected flux. Attracted the attention of the majority of research workers. This paper is based on the above background, around how will be based on a new type of chemical modification of the electrode system to establish the chemical and biological sensors used in the actual sample analysis, laboratory research to finally be able to in real life with the public requirement standards this goal , to carry out the work. Focus on the establishment of a more sensitive, simple, accurate and heavy metal Pb (Ⅱ) quantitative analysis method to the analysis method can create actual promotion to the detection of blood lead and environmental lead ions. Therefore, the subject of great theoretical and practical significance. The thesis is divided into six sections: The first chapter describes the toxicity of lead and its harm to the human body, summed up the lead ion detection means. Again introduced the overview of chemically modified electrodes, cited its main preparation methods and applications in the electric field of analytical chemistry. Finally, experimental ideas, this paper provides an overview of this thesis research ideas and innovation. The subject of theoretical and practical significance. Chapter II, was constructed which can be used blood lead testing an integrated-type thin film electrode. CAD technology to design integrated three-electrode system template. Use of the method of deposition, electrochemical sensor technology, modern printing technology and micro-machining technology combined, developed the mass production of integrated three-electrode system. Were investigated Ag / AgCl electrode conductive silver plastic with silver chloride powder mixed coated with gold film substrate plating production Ag / AgCl reference electrode, and ultimately in the gold film surface system got stable Ag / AgCl reference electrode . Development has been the gold film electrode, Ag / AgCl reference electrode, carbon printing ink electrode integrated in one three-electrode integrated system. For blood lead testing of integration and miniaturization possible. Followed by co-deposition of mercury plating deposition time, deposition potential impact of experimental results, after the dissolution time detection of Pb (Ⅱ) in the standard sample, were investigated, and optimize their experimental conditions were investigated electrode stability and reliability. The third chapter in the second chapter of the work on the basis of further to build rapid blood lead analysis system based on proven technology prepared film electrodes. Differential pulse anodic stripping voltammetry situ plated mercury mL level electrolytic cell system under reaction to a 50μL trace system, in the 3min time, can be measured μg / dL level trace blood lead. Reduced blood volume and system error caused by the large proportion of diluted blood samples; disposable electrode that is also used to avoid the the traditional electrodes repeated cleaning caused additional workload, but also avoid the repeated use may cause blood samples between electrodes cross pollution. In the solution of the system of the pH = 1.1, the detection limit of 1.2μg/dL, showed a good linear relationship between the lead ions in the concentration range of 1.2 ~ 70μg/dL. Through the analysis of a large number of experimental data collation, preparation conditions under strict control integrated three-electrode system for blood lead fast analysis system has universal applicability of the empirical formula Y = 9.726E-8 X * 9.959E-8 (line The correlation coefficient was 0.998). The rapid blood lead analysis system with fast, accurate, low cost, to achieve the requirements of real-time detection. Further work caused by the defects of the vapor-deposited gold film electrodes themselves high screening rate, the three-electrode system to be improved, and to carbon printing ink, as a working electrode. Experimental results show that the electrode system also has a good stability and reliability. Chapter IV synthesis of mercapto-modified β-cyclodextrin (6 - (2-mercaptoethylamino)-6-deoxy-β-cyclodextrin, MEA-β-CD), was constructed in the surface of the gold electrode layer of stable performance of the mercapto compound from assembled monolayers (self-assembled monolayer, SAM). Self-assembled electrode surface were characterized by electrochemical means, then get a used mercury-free detection of Pb (Ⅱ) new film modified electrode. Through optimization of the experimental conditions and found that by increasing the positive potential of the dissolution process, it is possible to achieve a good regeneration of the electrode. The modified electrode relative to the other interfering ions: Cu (II), Cd (II), Co (II), Ni (II), Zn (II) and Cr (Ⅱ) showed high Pb (Ⅱ) sex. Experiments in order to the acidic solution HClO 4 as the media, the use of differential pulse stripping voltammetry. Detection limit of 0.71 × 10 -8 M (three times the signal-to-noise ratio), which is very close with the traditional mercury-based lead ion detection means, and it is not on the health and environmental hazard. 1.7 × 10 -8 M to 9.3 x 10 -7 M range of concentrations to maintain a linear relationship, greatly superior to that reported in the literature to the coating method, etc. Preparation cyclodextrin modified glassy carbon electrode results. The modified electrode for the creation of a High Sensitive and Selective mercury-free measurement of lead sensor has proposed a new way. This electrode applied to the detection of the actual blood sample, consistent with the results with the results of the ICP-AES method. Chapter 5, heterocyclic compounds modified electrode detection of lead ions were discussed. In this chapter, we discuss the heterocyclic compounds thiophene, pyrrole copolymer, and Morin polymerization on the electrode surface to detect trace amounts of lead ions of several new film modified electrode. The article is divided into two. Discuss the detection of the lead ion in the pyrrole, thiophene the monomers copolymerizable measured lead and morin system. Heterocyclic compounds polymerizable modified electrode in the mercury-free conditions, the electrochemical response signals of each of the lead ion, and showing a linear relationship. Is presumed to be the presence of a heterocyclic polymer in nitrogen, sulfur, oxygen atom, with Pb (Ⅱ) in solution in the presence of certain chelating effect, but the specific mechanism of action remains to be discussed. Chapter VI first comprehensive summary of the thesis work, objective evaluation of the research results achieved, and also pointed out some shortcomings in the study. And work on the basis of the previous chapters, the methodology proposed further direction, goals and route of the proposed follow-up work.
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