Gold nanoparticle-based paper sensor for multiple detection of 12 Listeria spp. by P60-mediated monoclonal antibody.

The genus ofListeriaconsists of heterologous species and its presence in the food chain is an indicator of poor hygiene. However, a portable and simple paper sensor for detection of listeria spp. with high accuracy was still unknown. In this study, we prepared a pair of monoclonal antibodies (mAbs) that specifically recognize the P60 protein on the cell surface ofListeriaspp. The selected pair was found to be sensitive to both the P60 protein and cell body of the genusListeria. On this basis, a rapid paper sensor was established for sensitiveListeriaspp. detection. The developed paper sensor broadly cross-reacted with the 12 tested strains ofListeriaand the sensitivity in PBS buffer was 103–104colony-forming units (CFU) judged by the gray values of the test line. No cross-reaction with any other gram-positive or gram-negative strains tested was observed. A study using milk samples showed that this paper sensor could detect samples contaminated with low levels of the testedListeriaspp. (1–9 CFU/mL) after 8 h of enrichment and further concentrate for approximately 10 times by centrifugation. The results were in accordance with those obtained using the polymerase chain reaction method. [ABSTRACT FROM AUTHOR]