| Summary: | <i>Listeria monocytogenes</i> and <i>Listeria ivanovii</i> are important pathogenic <i>Listeria</i> spp. that cause infections in humans and animals. Establishing a rapid and sensitive method for the simultaneous screening of pathogenic <i>Listeria</i> spp. is of great significance for ensuring food safety. Multiplex polymerase chain reaction (mPCR) has been extensively reported to simultaneously detect several pathogens in food with high sensitivity, but a time-consuming pre-enrichment process is necessary. In this study, we report the usage of surface-modified polyethyleneimine-coated positively charged magnetic nanoparticles (PEI-MNPs) for rapid enrichment of pathogenic <i>Listeria</i> spp. through electrostatic interactions. The enrichment process takes only 10 min with high capture efficiency (more than 70%) at a wide pH range and ionic strength. Combined with mPCR analysis, the PEI-MNPs-mPCR strategy can simultaneously, rapidly, and sensitively detect pathogenic <i>Listeria</i> spp. without a time-consuming pre-concentration process. Under the optimal conditions, the detection limits of <i>L. monocytogenes</i> and <i>L. ivanovii</i> in lettuce were both as low as 10<sup>1</sup> CFU/mL, which was a hundred times lower than that without magnetic enrichment. In conclusion, the magnetic enrichment strategy based on charge interaction combined with mPCR analysis has great application potential in shortening the pre-concentration time of foodborne pathogens and improving the detection sensitivity.
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