Chemiluminescence assay forListeria monocytogenesbased on Cu/Co/Ni ternary nanocatalyst coupled with penicillin as generic capturing agent

Bacterial pathogen control is important in seafood production. In this study, a Cu/Co/Ni ternary nanoalloy (Cu/Co/Ni TNA) was synthesized using the oleylamine reducing method. It was found that Cu/Co/Ni TNA greatly enhanced the chemiluminescence (CL) signal of the hydroxylamine-O-sulfonic acid (HOSA)-luminol system. The CL properties of Cu/Co/Ni TNA were investigated systemically. The possible CL mechanism also was intensively investigated. Based on the enhanced CL phenomenon of Cu/Co/Ni TNA, a Cu/Co/Ni TNA, penicillin, and anti-L.monocytogenes(Listeria monocytogenes) antibody-based sandwich complex assay for detection ofL.monocytogeneswas established. In this sandwich CL assay, penicillin was employed to capture and enrich pathogenic bacteria with penicillin-binding proteins (PBPs) while anti-L.monocytogenesantibody was adopted as the specific recognition molecule to recognizeL.monocytogenes.L.monocytogeneswas detected sensitively based on this new Cu/Co/Ni TNA-HOSA-luminol CL system. The CL intensity was proportional to theL.monocytogenesconcentration ranging from 2.0 x 10(2)CFU ml(-1)to 3.0 x 10(7)CFU ml(-1)and the limit of detection wa 70 CFU ml(-1). The reliability and potential applications of our method was verified by comparison with official methods and recovery tests in environment and food samples.

Automated summary

In this study, a Cu/Co/Ni ternary nanoalloy (Cu/Co/Ni TNA) was synthesized and found to greatly enhance the chemiluminescence (CL) signal. A sandwich complex assay for detection of L.monocytogenes was established using Cu/Co/Ni TNA, penicillin, and anti-L.monocytogenes antibody. This new method allows sensitive detection of L.monocytogenes and shows potential for applications in pathogen control.