A detection method for Listeria monocytogenes

Abstract

The invention discloses a detection method for Listeria monocytogenes. The present invention utilizes the nano-silver cage as the substrate, mixes it with the standard sample solution of Listeria monocytogenes of known concentration, and performs Raman detection after hatching to establish a standard curve of Listeria monocytogenes concentration-Raman signal intensity, and then The nano-silver cage substrate is mixed with the actual sample to be tested, and the Raman signal intensity obtained by Raman detection after incubation is compared with the standard curve, so as to obtain the content of Listeria monocytogenes in the actual sample to be tested. The invention combines the spatial limitation effect and the Raman fingerprint spectrum to realize rapid and specific detection of Listeria monocytogenes. The method is simple, does not need to prepare a template, is environmentally friendly and pollution-free, and the prepared nano-silver cage base shell and inner wall are rough, which greatly increases the contact area between Listeria monocytogenes and the base, thereby significantly improving the SERS detection effect.

Description

technical field [0001] The invention belongs to the field of spectrum detection, and in particular relates to a detection method for Listeria monocytogenes. Background technique [0002] Listeria monocytogenes (Listeria monocytogenes), referred to as Listeria monocytogenes, facultative anaerobic, Gram-positive bacteria, the size of (0.4-0.5) μm × (0.5-2) μm, widely exists in in nature. Bacterial food poisoning caused by Listeria monocytogenes mainly occurs through consumption of contaminated food, such as dairy products, ready-to-eat meat and seafood, and vegetables and fruits, and the contamination mainly occurs during processing. Listeria monocytogenes infection can cause gastrointestinal disease, brain and blood infection in immunocompromised patients, or fetal complications in pregnant women. Listeria monocytogenes is a psychrophilic biofilm-forming bacterium that is resistant to most disinfectants. Therefore, timely and accurate identification of the presence of L. m...

AI Technical Summary

Problems solved by technology

This type of SERS tag can specifically bind to microorganisms, so it has the advantages of ultra-sensitivity, high quantitative ability, etc., but the substrate preparation steps are complicated, requiring complex chemical modification processes, antibodies and aptamers are expensive and unstable, and also increase the cost and the risk of developing antibiotic resistance

For example, in the patent application CN 106645090 A, a layer of SiO was synthesized on the surface of gold nanoparticles modified with Raman reporter molecules. 2 layer, and then modified the antibody of pathogenic bacteria on its surface as a Raman signal probe. The magnetic nanoparticles modified with pathogenic bacteria antibody are used for magnetic separation, which requires complicated preparation steps and long substrate preparation time, resulting in a longer total analysis time and requiring the use of antibodies

In the patent application CN 110702662 A, boronic acid-functionalized polydopamine-coated Au@Ag nanoparticles were used as SERS tags to modify the Fe of IgG 3 o 4 Magnetic nanoparticles are used for magnetic separation, which can achieve sensitive detection of bacteria, however, the substrate preparation steps are cumbersome, time-consuming and labor-intensive, and still require the use of antibodies

Therefore, it is still a big challenge to seek a new detection idea to realize the rapid and specific detection of L. monocytogenes.

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