The Research Of Immunofluorescence And Infrared Spectroscopy In Food-brone Pathogen Detection

Food-borne pathogenic bacteria are a broad spectrum of microbial pathogens and widely responsible for many food-borne diseases. Food-borne pathogenic bacteria are one of the important parts in food testing. With the development of technology and the requirements of food testing, food testing technology is constantly improved in the direction of accuracy, efficiency, and diversification.Nanotechnology is a new cross-disciplinary from the 1980s , which have a wide range of applications in the biology, medical science, chemistry, environment and so on. Nanotechnology always has been focused on the development and usage of nano-materials, especially in recent years, nano-biotechnology which are combined nanotechnology and biotechnology has become one of the focal points.This paper mainly studies a new rapid detection method of Salmonella via a combined approach of magnetic microparticles for enrichment and antibody-conjugated semiconductor quantum dots (QDs) as fluorescence markers. At the same time, food-borne pathogens were studied by means of infrared spectroscopy combined with statistical analysis in this paper.(1) With the water-in-oil reverse microemulsions method, theγ-Fe2O3 magnetic nanoparticles were coated with silica to empower the particles with high dispersion and compatibility to biomacromolecule. The magnetic beads were designed by modifying with the amino silane so as to possess biocompatibility. And the magnetic nanoparticles are possessed with biological specificity by immobilizing antibody. EDAC used as a cross-linker, NHSS as a protective agent, functionalized quantum dots (QDs) are prepared by cross-linking reaction of QDs and polyclonal antibody. The results of experiment show that immune-magnetic particles have good characteristics of dispersion and biological specificity; And the fluorescent Immune QDs have better fluorescence and biological specificity.(2) Immunofluorescence technology is one of important way to detect food-borne pathogens. A new rapid detection method of Salmonella via a combined approach of magnetic nanoparticles for enrichment and antibody-conjugated semiconductor quantum dots (QDs) as fluorescence markers was studied in this paper. The immune magnetic beads and pathogenic bacteria formed"bead-cell"complexes in the enrichment procedure. And the antibody-conjugated QDs would be marked on the"bead-cell"complexes to form the"sandwich"complexes based on antigen-antibody reaction. Fluorescence microscope were be used to examine the fluorescence of sample to determine it's microorganism polluting condition. The results show that this method can quickly detect pathogens in the contaminated samples.(3) The usage of infrared spectroscopy (FTIR) analysis to biological macromolecules is one of the hot spots in chemical analysis in recent years, and the technique combined with statistical analysis methods are used to study food-borne pathogens in this article, the results of our experiments show that a large number of pathogenic bacteria can be classified rapidly and accurately by means of this method. If a large number of bacteria can be analyzed by this method, we can establish artificial neural network (the database) to quickly identify the unknown strain of the bacteria, as well as serotypes (about several minutes).