Rapid detection of <i>Listeria monocytogenes</i> using fluorescence immunochromatographic assay combined with immunomagnetic separation technique

Abstract

Summary To ensure the safety and quality of food ingredients, especially meat and dairy products, a high‐throughput, rapid and sensitive method to detect Listeria monocytogenes ( LM ) is always on a high demand. In this work, a specific induction method to enrich and detect LM based on fluorescence immunochromatographic assay ( FICA ) combined with immunomagnetic separation ( IMS ) techniques has been developed. The immunomagnetic‐beads ( IM ) beads were obtained through functionalised magnetic microspheres and the conjugated reaction between the carboxyl on beads surface and amino groups of antibody. The prepared IM ‐beads could be used for rapidly enriching pathogenic bacteria with fewer steps, resulting in a high specificity for four pathogenic serotypes and about a 40‐fold improvement of detection limit compared with FICA only. In addition, this method was successfully applied in LM detection in sausage, pork and milk samples with a potential for further application in rapid on‐site detection of pathogenic bacteria.