Magnetic molecular imprinting sensor for detecting Gram-negative bacterium signal molecule

Abstract

The invention discloses a magnetic molecular imprinting sensor for detecting a Gram-negative bacterium signal molecule, belonging to the technical field of rapid detection of pathogenic bacteria. The novel magnetic molecular imprinting sensor is constructed by combining a surface molecular imprinting technology, a magnetic separation technology and an electrochemical sensing technology; and meanwhile, the magnetic molecular imprinting sensor has the specificity of the molecular imprinting technology, the renewability and rapid separation property of the magnetic separation technology, and the rapidness and sensitivity of electrochemical analysis, so that low-content Gram-negative bacterium signal molecules can be accurately detected. The invention further discloses a preparation method and application of the magnetic molecular imprinting sensor; the indirect detection on partial Gram-negative bacteria can be realized; and the magnetic molecular imprinting sensor has the advantages of sensitivity, rapidness and high specificity and the like, is low cost and is suitable for detecting the Gram-negative bacteria in the fields of food industries, medical treatment industries and the like.

Description

technical field [0001] The invention relates to a magnetic molecular imprint sensor for detecting signal molecules of Gram-negative bacteria, belonging to the technical field of rapid detection of pathogenic bacteria. Background technique [0002] Enteropathogenic bacteria in food is one of the main causes of human foodborne diseases and a major killer of human health. Cooked meat, bread and cakes are very easy to directly cause food-borne diseases, while aquatic products are also a major hidden danger of human food-borne diseases due to the pollution and invasion of various microorganisms in the water. Most of the intestinal bacteria in food belong to Gram-negative bacteria (Gram-negative), the most common ones are Salmonella, Shigella, diarrhea-causing Escherichia coli, Clostridium aerogenes and Vibrio parahaemolyticus, etc. . Gram-negative bacteria, generally refers to bacteria that are red in the Gram stain reaction. They produce endotoxins, which make people sick by ...

AI Technical Summary

Problems solved by technology

Traditional detection methods include enrichment culture screening and subsequent counting detection, biochemical reaction identification or serological identification, etc. These traditional methods are mature in technology, high in accuracy, and require simple equipment, but the experimental operation is cumbersome and the detection cycle is long. Preparation and Heavy finishing work, insufficient specificity, low sensitivity, and the need for professional operators, etc.

ELISA requires special equipment, the detection steps are cumbersome, expensive, long detection time, and prone to false positives

Although the development of molecular-level detection methods of multiplex PCR and real-time fluorescence quantitative PCR has advantages over traditional methods, the equipment required is expensive, the detection process is complicated, the cost is high, and the detection environment and operators have high requirements for professional skills. The reagents used are very harmful to the human body and the environment, and the specificity of this method is not good due to the complexity of the toxin-producing genes

DNA probe technology is fast and highly sensitive, but this technology has certain limitations: First, the DNA of bacteria that have died or sublethal bacteria after food processing may still exist and be detected, but this does not mean that there must be Live pathogenic microorganisms are in; second, food poisoning caused by some pathogenic bacteria is caused by the ingestion of toxins produced by bacteria, so the positive results obtained by DNA probes or PCR methods for toxin genes only mean that there are The existence of pathogenic microorganisms with these gene sequences has the potential to produce toxins, but it does not necessarily mean that there are living cells, or that the genes have been expressed, or that toxins have been produced

However, different bacterial biosensors have different sensitivities to AHLs with different acyl side chain lengths. For example, Agrobacterium tumefaciens is most sensitive to AHLs substituted by the C-3 carbonyl of acyl side chains, while Chromobacterium violaceum ) is more sensitive to short-chain C-3 AHL without substituents, which shows that a bacterial biosensor cannot detect all AHL molecules

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