Study And Application Of Nano-materials In The Rapid Detection Of Food Contaminants

Food safety has attracted high attention at home and abroad, it is one of the focal point of concern and attention of people in the daily life, and the biological pollution and chemical pollution is the main factor which causes the food safety incidents.In recent years, nanotechnology has become one of the hot topics that have being talked about and searched around the world, unique physical and chemical properties of nano-materials, the nanotechnology is widely used in food testing in the field, including the detection of food borne pathogens, pesticide residue detection and detection of heavy metals and so on.This thesis is based on the principle of immunology, biological functional nanoparticles were constructed to detect biological pollutants-Enterobacter sakazakii and chemical pollutants-heavy metal lead, setting up two kinds of high sensitivity, fast, convenient detection method. Firstly immune functional nanoparticles combined with fluorescence quantum point set up a method for detecting Enterobacter sakazakii visualization.Synthesized by the hydrothermal method using Fe3O4as the core of the superparamagnetic beads, silica coating, modified Fe3O4nano-magnetic beads, coupled with specific antibody detection, combined with food-borne pathogens Enterobacter sakazakii fluorescent quantum dots. Experiments show that, this method can specifically detect Enterobacter sakazakii, and the detection sensitivity of103cfu/mL, and Enterobacter sakazakii magnetic beads enrichment combined with fluorescent quantum dots under fluorescent microscopy and its concentration has a certain proportion with fluorescence intensity. The method can be used in rapid detection.It has rapid, high sensitivity, high specificity, convenience etc. characteristics, and can be used for rapid detection of visualization. Next, this thesis constructs a using gold nanoparticles rapid detection method of heavy metal lead. The gold nanoparticles were prepared by citric acid three sodium reduction, combined with the specific antibody, assembled into a strip for detection of heavy metal lead, and measured by T/C immuno chromatographic analyzer than semi quantitative detection. Experiments show that, this method can lead to detect specific, and the sensitivity is50ng, with a good stability, repeatability, within a certain range, the linear relationship between the lead concentration and T/C ratio exhibits good, and the food samples. Experiments show that, this method has high sensitivity, convenience in rapid detection of.Methods this paper constructs the rapid detection of foodborne pathogens Enterobacter sakazakii and heavy metal lead, provides a theoretical and experimental approach for the rapid detection of future food detection in biological contamination and chemical contaminants.