FOOD SCIENCE ›› 2021, Vol. 42 ›› Issue (18): 314-320.doi: 10.7506/spkx1002-6630-20200615-196

• Safety Detection • Previous Articles     Next Articles

Detection of Escherichia coli O157:H7 by Cascade Signal Transduction System Combined with Immunochromatography

SHAN Shan, HUANG Yanmei, ZHAO Xuelong, CHEN Wenyao, LIU Chengwei, LONG Zhong’er, LIU Daofeng   

  1. (1. Nanchang Key Laboratory of Microbial Resources Exploitation & Utilization from Poyang Lake Wetland, College of Life Sciences, Jiangxi Normal University, Nanchang 330022, China; 2. Jiangxi Yeli Medical Device Co. Ltd., Nanchang 330008, China;3. State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China; 4. Jiangxi Province Key Laboratory of Diagnosing and Tracing of Foodborne Disease, Jiangxi Provincial Center for Disease Control and Prevention, Nanchang 330029, China)
  • Published:2021-09-29

Abstract: For ultrasensitive detection of Escherichia coli O157:H7, the target bacteria were enriched effectively by immunomagnetic separation. Then, colloidal gold nanoprobes simultaneously with a large amount of antibodies and β-lactamase were used as the mediators. β-Lactamase was employed to hydrolyze penicillin efficiently for the transduction and amplification of detection signals. Immunochromatography was applied for detecting the variation in penicillin concentration. The sensitivity of the developed method was 2 × 102 CFU/mL, which was 570 folds higher than that of traditional immunochromatography. In addition, this method avoided the Hook effect in sandwich immunochromatography, which provides a new tool for immunochromatographic detection of macromolecular analytes with high sensitivity and accuracy.

Key words: signal transduction; immunochromatography; ultrasensitive detection; Escherichia coli O157:H7

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