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LPS (endotoxin) is a cell wall component of Gram-negative bacteria, which is located in the outermost layer of the cell wall, the cell wall covering the sticky peptide. Surviving bacteria in the state of not release endotoxin, in the bacterial cell death or lysis of bacterial cells using artificial methods destroy the case released. The chemical composition of endotoxin are lipopolysaccharides, proteins and phospholipids, lipopolysaccharide composed mainly of its toxicity. And different species of gram-negative bacteria are the bacterial lipopolysaccharide molecule specific polysaccharide, non-specific polysaccharide and lipid A core composed of three parts. Lipid A is a major toxic component of endotoxin. Gram-negative bacteria of different lipid A structure similar. Endotoxin widely present with air, soil, water and other closely related to human life and the environment, the human body is extremely sensitive to endotoxin, a trace amount (1-5ng / kg body weight) of endotoxin can lead to body temperature. In addition to outside of pyrogenic reactions, endotoxin also cause reduced number of white blood cells, Shwartzman reaction, endotoxin shock, microcirculation, sowing intravascular coagulation, etc., adversely affect human health. Closely associated with drinking water and human health. Carried out in foreign countries, many of source water, drinking water endotoxin contamination survey, the domestic basically a blank. Understand the various stages of the production process of drinking water endotoxin levels, help in evaluating the effects of endotoxin purification for the development of relevant standards provide a scientific basis. Currently the main endotoxin detection methods are: rabbit method, Limulus test, immunoassay, biosensors France. Now the majority of domestic and endotoxin detection is Limulus test, endotoxin detection is the current \LAL method for rapid, sensitive (0.01-1ng/ml), easy to operate and easy to promote. But there is not easy to distinguish between weak positive and negative, you need to kill a lot of horseshoe crabs on the edge of the sample and reagents are consumed in large quantities is not easy to judge other shortcomings. Other methods, such as rabbit pyrogen test low sensitivity, time-consuming, has gradually been eliminated; ELISA less time-consuming, high sensitivity and specificity, repeatability, simple but there are large and reagent consumption, high requirements for instruments inadequate . Biosensor developed rapidly in recent years, the rapid detection of virulence factors of a new technology. Such detection method has less time-consuming, the sensitivity and specificity advantages. The sensor as the enzyme immunoassay technology, a biosensor, an electrochemical electrode, amplification and immune specific binding, it not only has high sensitivity of electrochemical analysis, but also has a high specificity of immune recognition. And enzyme immunoassay electrode construction method is flexible and easily integrated miniaturized systems, enzyme immunoassay sensor detection equipment is relatively simple, easy to use, reduce manual operations, more intelligent. The study Wuhan source water, water treatment process stages of the endotoxin content was determined, a clear endotoxin contamination levels and purification treatment process; electrodeposition method using the rapid detection of endotoxin create novel enzyme immune sensors, and its optimal detection conditions as well as its performance characteristics have been studied and discussed. The first part of the water treatment process, Wuhan endotoxin detection Objective: Wuhan, Hubei Province mainly endotoxin contamination in drinking water situation and conventional water treatment processes endotoxin removal. Methods: in March 2008, collecting the Yangtze River as water waterworks Pinghu door to the Han River water for the water purification treatment Zongguan various aspects of water samples for investigation. The use of \Results: Pinghu door water: Yangtze River water endotoxin content ranges from 98.08 ~ 104.08EU/ml, peripheral water endotoxin content ranges from 18.03 ~ 22.58EU/ml; Zongguan water: Han River source water content range of endotoxin was 84.33 ~ 86.94EU/ml, peripheral water endotoxin content ranges 40.20 ~ 44.44EU/ml; two water endotoxin removal rates were 76.98 ~ 82.68% and 47.30 ~ 53.76%. Conclusion: There are water treatment process endotoxin removal, but finished water endotoxin levels are still higher than abroad. The second part of endotoxin enzyme immunoassay sensor preliminary study Objective: To establish a modified gold nanoparticles-based enzyme immunoassay endotoxin sensor. Methods: electrodeposition and electrostatic adsorption and antigen-antibody binding reaction endotoxin monoclonal mouse anti-horseradish peroxidase fixed (HRP)-labeled rabbit anti-mouse IgG / gold nanoparticles modified glassy carbon electrode surface , prepared for the detection of endotoxin enzyme immunoassay sensors. Then by cyclic voltammetry (CV) and constant potential method (CPE) was measured endotoxin is fixed at a glassy carbon electrode surface changes caused by electrical signals, which were quantitatively analyzed. Results: 0.1mol/LPBS (pH7.0), dimethylaminomethyl ferrocene concentration of 1mmol / L, H2O2 concentration of 0.2mmol / L, the measurement temperature is 37 ℃ conditions appropriate test conditions; this condition The enzyme immune sensor detection limit of 0.01Eu/mL, linear range 0.01-100Eu/mL, correlation coefficient R = 0.930, sensor response signals two weeks after the initial 70%. Conclusion: The sensor preparation method is simple and sensitive.
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