Lanthanide-labeled fluorescent-nanoparticle immunochromatographic strips enable rapid and quantitative detection of Escherichia coli O157:H7 in food samples
| Autor: | Quan Wang, SiPei Xin, Caiyun Lv, MengYao Long, Wei Jiang, Xiangan Han |
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| Rok vydání: | 2020 |
| Předmět: |
Detection limit
Lanthanide Chromatography Chemistry medicine.drug_class 010401 analytical chemistry Pathogenic bacteria 04 agricultural and veterinary sciences Monoclonal antibody medicine.disease_cause 040401 food science 01 natural sciences Fluorescence 0104 chemical sciences 0404 agricultural biotechnology Ultraviolet light medicine Quantitative analysis (chemistry) Escherichia coli Food Science Biotechnology |
| Zdroj: | Food Control. 109:106894 |
| ISSN: | 0956-7135 |
| DOI: | 10.1016/j.foodcont.2019.106894 |
| Popis: | A simple, rapid, highly sensitive, and quantitative fluorescence-based immunochromatographic test (ICT) was successfully developed for the determination of Escherichia coli O157:H7 in food samples. Europium (III) chelated nanoparticles (EuNPs) conjugated to monoclonal antibodies specific to the O-specific polysaccharide fractions of E. coli O157:H7 were used as the fluorescence reporter. The fluorescence was visually observable within 15 min under dark conditions with an ultraviolet light source, and a test-strip reader was used for quantitative analysis. Under optimal conditions, the visual limit of detection (LOD) of the strip was 104 CFU/mL, and the LOD for quantitative detection was as low as 5 × 102 CFU/mL with the test-strip reader. No cross-reaction was observed in six E. coli strains with different somatic (O) antigens and five other major foodborne pathogenic strains, thus indicating the good specificity of this method. Additionally, the detection sensitivity of E. coli O157:H7 was improved to 1 CFU/mL of the original bacterial content by pre-incubation for 8 h in meat (beef, pork, and chicken) and 6 h in milk samples. The average recovery of E. coli O157:H7 spiked in pork was 84.5–103%, thus indicating the accuracy and reliability of the novel test strips. The developed EuNP-ICT strip assay is highly sensitive, specific, and replicable. This detection system provides a tool that can potentially be used to detect E. coli O157:H7 and other pathogenic bacteria in food samples. |
| Databáze: | OpenAIRE |
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