A Method for Simultaneous Detection of Three Foodborne Pathogenic Bacteria Based on Multicolor Upconversion Fluorescent Labeling

Abstract

The invention provides a method used for simultaneous detection of three food-borne pathogenic bacteria based on multicolor upconversion fluorescence labeling. According to the method, three upconversion materials with differentiable fluorescence spectrums are used for forming multicolor upconversion fluorescent nanoprobes via respective connection with aptamers of staphylococcus aureus, vibrio parahaemolyticus, and salmonella, and complementary oligonucleotide single chains of the aptamers are connected with magnetic nanoparticles so as to form nano-composites. When bacteria to be tested are in a detection system, double chain unwinding is realized because of specific binding of the pathogenic bacteria with corresponding aptamers; it is possible to realize simultaneous quantitative determination of staphylococcus aureus, vibrio parahaemolyticus, and salmonella by monitoring upconversion fluorescence signal strength at 477nm, 550nm, and 660nm, detection linear range ranges from 50 to 1000000cfu / ml, and detection limits are 25cfu / ml, 10cfu / ml, and 15cfu / ml respectively. The method is used for detection of pathogenic bacteria, is high in sensitivity, is rapid and convenient, and can be used for detection of the three pathogenic bacteria in food such as milk and shrimp meat; and results are accurate and reliable.

Description

technical field [0001] A method for simultaneous detection of three food-borne pathogens based on multicolor up-conversion fluorescent labels, involving the technical fields of nanomaterials and analytical chemistry, for the detection of Staphylococcus aureus, Vibrio parahaemolyticus and Salmonella in food . Background technique [0002] Food-borne pathogenic bacteria are one of the important food hazard substances. They have strong survival and reproduction ability and are easy to spread, which greatly endanger human life, health and safety. Such as Escherichia coli, Salmonella, Staphylococcus aureus, etc. can infect the human body through food and cause diseases. More importantly, there are often a variety of foodborne pathogenic bacteria in food at the same time. Although the respective levels are not high, they can also cause foodborne diseases. Therefore, it is necessary to develop a detection method with high sensitivity and good specificity that can simultaneously d...

AI Technical Summary

Problems solved by technology

However, most fluorescent dyes are unstable and easy to be photobleached, which affects the detection sensitivity. Although quantum dots and other fluorescent nanomaterials have improved the fluorescence quenching phenomenon, their excitation light is still in the ultraviolet-visible region, so the biological samples tested It will also be excited, the fluorescence background value is high, and the detection sensitivity is still affected

Moreover, due to the broad emission peaks, the emission peaks overlap each other, which restricts the application prospects of these materials in the simultaneous labeling and detection of multiple pathogenic bacteria.

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