Method for detecting escherichia coli based on magnetic graphene oxide composite gold star @ gold-silver alloy nanoparticles

A nanoparticle and Escherichia coli technology, applied in Raman scattering, material excitation analysis, etc., can solve problems such as poor stability and repeatability, increased time cost, false positives, etc., and achieve the effect of improving specificity and avoiding influence

Active Publication Date: 2019-02-26
NANJING AGRICULTURAL UNIVERSITY
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Such as enzyme-linked immunoassay, generally need to enrich the sample for culture, plus 1-2 hours of detection process, seriously increase the time cost is not conducive to rapid detection
Although the PCR method does not require bacterial enrichment culture, the serious problems

Method used

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  • Method for detecting escherichia coli based on magnetic graphene oxide composite gold star @ gold-silver alloy nanoparticles
  • Method for detecting escherichia coli based on magnetic graphene oxide composite gold star @ gold-silver alloy nanoparticles
  • Method for detecting escherichia coli based on magnetic graphene oxide composite gold star @ gold-silver alloy nanoparticles

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0058] The magnetic graphene oxide nanomaterial preparation of embodiment 1:

[0059] 1) Preparation of magnetic graphene oxide nanomaterials: take 1.736g of NH 4 Fe(SO 4 ) 2 12H 2 O, 0.784g of (NH 4 ) 2 Fe(SO 4 ) 2 ·6H 2 O, in N 2 Under the protection condition of , add it into 180mL ultrapure water at 70℃, and stir well. Add 1MNH 4 OH to adjust the pH to 3, then add 40 mL of 0.9 mg / mL graphene oxide solution, and stir for 30 min. Adjust the pH to 9 and continue stirring for 1 h. Cool to room temperature, alternately wash twice with absolute ethanol and ultrapure water, and obtain magnetic graphene oxide nanomaterials after freeze-drying;

[0060] Among them, the TEM characterization of magnetic graphene oxide is shown in figure 1 As shown, it can be observed from the TEM image that a large number of magnetic nanoparticles are attached to the sheet surface of the magnetic graphene oxide, and the distribution is relatively uniform, wherein the diameter of the magn...

Embodiment 2

[0061] The magnetic graphene oxide nanomaterial preparation of embodiment 2:

[0062] 1) Preparation of magnetic graphene oxide nanomaterials: take 1.736g of NH 4 Fe(SO 4 ) 2 12H 2 O, 0.784g of (NH 4 ) 2 Fe(SO 4 ) 2 ·6H 2 O, in N 2 Under the protection condition of , add it into 200mL ultrapure water at 70℃, and stir evenly. Add 1MNH 4 OH to adjust the pH value to 4, then add 40 mL of 1.150 mg / mL graphene oxide solution, and stir for 30 min. Adjust the pH to 10 and continue stirring for 1 h. Cool to room temperature, alternately wash twice with absolute ethanol and ultrapure water, and obtain magnetic graphene oxide nanomaterials after freeze-drying;

Embodiment 3

[0063] The magnetic graphene oxide nanomaterial preparation of embodiment 3:

[0064] 1) Preparation of magnetic graphene oxide nanomaterials: take 1.736g of NH 4 Fe(SO 4 ) 2 12H 2 O, 0.784g of (NH 4 ) 2 Fe(SO 4 ) 2 ·6H 2 O, in N 2 Under the protection condition of , add it into 220mL ultrapure water at 70℃, and stir well. Add 1MNH 4 OH to adjust the pH to 5, then add 40 mL of 1.40 mg / mL graphene oxide solution, and stir for 30 min. Adjust the pH to 11 and continue stirring for 1 h. Cool to room temperature, alternately wash twice with absolute ethanol and ultrapure water, and obtain magnetic graphene oxide nanomaterials after freeze-drying;

[0065] Step 2: Preparation of Venus@gold-silver alloy nanoparticle solution:

[0066] The preparation method is as follows:

[0067] Preparation of Venus nanoparticles solution:

[0068]1) Synthesis of gold species

[0069] Take a clean Erlenmeyer flask, add 50mL 1mM chloroauric acid solution, heat and stir until boiling;...

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Abstract

The invention discloses a method for detecting escherichia coli based on magnetic graphene oxide composite gold star @ gold-silver alloy nanoparticles, and belongs to the technical field of food safety detection. The method comprises the following steps: respectively preparing a magnetic graphene oxide nano material and a 4-ATP-labeled gold star @ gold-silver alloy Raman substrate material, respectively modifying a nucleic acid aptamer of target bacterium on the surface of the magnetic graphene oxide nano material and the 4-ATP-labeled gold star @ gold-silver alloy Raman substrate material, and when the target bacterium exists, gold star @ gold-silver alloy nano-particles are fixed on the magnetic graphene oxide nano-material through the combination of a surface nucleic acid aptamer and atarget bacterium. Unfixed gold star @ gold-silver alloy nano-particles are removed through magnetic separation. A Raman spectrometer is used for scanning, and a linear relation between the concentration of pathogenic bacteria and the intensity of 4-ATP Raman signals is established, and the quantitative detection of the escherichia coli is realized. According to the invention, rapid and high-sensitivity detection of pathogenic microorganisms is realized. The invention provides an effective method for rapid detection of harmful microorganisms in food and environment.

Description

technical field [0001] The invention relates to a method for detecting Escherichia coli based on magnetic graphene oxide composite Venus@gold-silver alloy nanoparticles, which belongs to the technical field of food safety detection. Background technique [0002] Foodborne pathogenic bacteria such as Escherichia coli can contaminate food during food processing and production, causing food to deteriorate and secrete toxic substances, causing hemorrhagic enteritis, hemolytic uremic syndrome, sepsis and other diseases, especially for those with weaker resistance Weak children can even lead to death. Because this infection has the characteristics of short incubation period, ferocious onset, and simultaneous onset of multiple people in a short period of time, it can easily lead to large-scale outbreaks of foodborne diseases. Establishing and researching rapid detection methods for foodborne pathogens is of great significance for ensuring food safety and human health. [0003] In...

Claims

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Application Information

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IPC IPC(8): G01N21/65
CPCG01N21/65
Inventor 严文静章建浩王红霞戈永慧李艾潼李芮
Owner NANJING AGRICULTURAL UNIVERSITY
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