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Updated: Aug 16, 2025
Foodborne Pathogen Screening Using Magneto-fluorescent Nanosensor: Rapid Detection of E. Coli O157:H7
Published on: September 17, 2017
Naked-Eye Detection of Food-Borne Pathogens Using Multiplex Hyperbranched Rolling Circle Amplification and Magnetic
Congli Tang1, Hongna Liu1, Wenjing Pan1
1Hunan Key Laboratory of Biomedical Nanomaterials and Devices, Hunan University of Technology, Zhuzhou 412007, China.
Abstract:
Food safety is a significant public health issue in both developed and developing countries. Previous detection methods struggle to meet the current demands. We have proposed a new way to detect pathogens, allowing detection to be visualized by the naked eye. Using our newly developed assay, when target genes are present in the reaction, corresponding padlock probes form closed-loop molecules. Each reaction tube contains a pair of universal primers for identifying target genes. The ring padlock probes and corresponding universal primers start hyperbranched rolling circle amplification (HRCA) under the action of the polymerase, so as to gain branched chain amplification products, which are irreversibly entangled with magnetic particles to form aggregated magnetic particle clusters, and the detection results are visible to naked eyes. On the contrary, by using linear probes, the clustering of magnetic particles will not be produced. This method was applied to the detection of five food-borne pathogens enterohemorrhagic Escherichia coli (EHEC), enterotoxigenic Escherichia coli (ETEC), enteropathogenic Escherichia coli (EPEC), enteroinvasive Escherichia coli (EIEC) and Escherichia coli (E. coli), with detection limits of 1 × 103, 1 × 104, 1 × 103, 1 × 104 and 1 × 102 CFU/mL, respectively. This method can realize multiplex automatic detection of nucleic acid and shows great development potential in the field of molecular diagnosis.
Insights
A novel assay enables naked-eye detection of foodborne pathogens by visualizing magnetic particle clusters formed through hyperbranched rolling circle amplification. This method offers a sensitive and visual approach for food safety pathogen detection.
Area of Science:
- Food safety
- Molecular diagnostics
- Public health
Background:
- Foodborne pathogens pose significant public health risks globally.
- Existing pathogen detection methods face limitations in meeting current demands for speed and sensitivity.
- There is a need for innovative diagnostic tools for effective food safety monitoring.
Purpose of the Study:
- To develop a novel, visually detectable assay for foodborne pathogens.
- To enable naked-eye visualization of pathogen detection.
- To establish a sensitive and rapid method for molecular diagnosis.
Main Methods:
- Utilized padlock probes that form closed-loop molecules upon target gene binding.
- Employed hyperbranched rolling circle amplification (HRCA) initiated by universal primers and ring padlock probes.
- Integrated magnetic particles for irreversible entanglement with amplification products, forming visible clusters.
Main Results:
- Achieved naked-eye visualization of pathogen detection through magnetic particle aggregation.
- Demonstrated successful application in detecting five foodborne pathogens: EHEC, ETEC, EPEC, EIEC, and E. coli.
- Established sensitive detection limits ranging from 1x10^2 to 1x10^4 CFU/mL for the tested pathogens.
Conclusions:
- The developed assay provides a sensitive and visually intuitive method for foodborne pathogen detection.
- The technique facilitates multiplex automatic nucleic acid detection.
- This approach holds significant potential for advancing molecular diagnostics in food safety applications.
