A novel method to detect Listeria monocytogenes via superparamagnetic lateral flow immunoassay

Lei Shi, Feng Wu, Yiming Wen, Fang Zhao, Junjian Xiang, Lan Ma

Research output: Contribution to journalArticlepeer-review

68 Scopus citations

Abstract

A novel strip test system combining immunomagnetic separation with lateral flow immunoassay (LFIA) was established for the accurate detection of Listeria monocytogenes. In this system, a pair of matched monoclonal antibodies was used to construct a sandwich immunoassay, in which superparamagnetic particles were coupled with one of the antibodies as a labeled antibody to capture the target bacteria, while the other antibody was immobilized on the detection zone. After a 20-min reaction, the strips were analyzed by a novel instrument which could detect the magnetic signal of the immunocomplex in a magnetic field. Sensitivity evaluation showed that the limit of detection (LOD) of the superparamagnetic LFIA system for L. monocytogenes was 104 CFU/mL, which was at least one log lower than conventional LFIA. No cross-reaction was observed when Salmonella, Escherichia coli O157:H7, or three types of harmless Listeria strains were tested. Further evaluation with actual food samples indicated that the superparamagnetic LFIA system showed 100 % concordance with real-time PCR. Therefore, this novel superparamagnetic LFIA system could be used as a rapid, sensitive, and specific method for the detection of L. monocytogenes. [Figure not available: see fulltext.]

Original languageEnglish (US)
Pages (from-to)529-535
Number of pages7
JournalAnalytical and Bioanalytical Chemistry
Volume407
Issue number2
DOIs
StatePublished - Jan 21 2015

Keywords

  • Lateral flow immunoassay
  • Listeria monocytogenes
  • Sandwich immunoassay
  • Superparamagnetic

ASJC Scopus subject areas

  • Analytical Chemistry
  • Biochemistry

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