A multicolorimetric assay for rapid detection of Listeria monocytogenes based on the etching of gold nanorods

Listeria monocytogenes ( L. monocytogenes ) is one of the most common food-borne pathogens . The authors describe a sensitive and reliable multicolorimetric assay for L. monocytogenes using a sensing system based on TMB 2+ etching of gold nanorods . Apt-MNP was used as the capture probe, and IgY-BSA-MnO 2 NPs was chosen as an oxidase-like nano-artificial enzyme to oxidize TMB to generate TMB 2+ . Under the optimized conditions, the longitudinal shift of localized surface plasmon resonances had a linear correlation with the L. m onoc ytogenes concentration in the range between 10 to 10 6  cfu mL −1 . Meanwhile, the sensing system can generate vivid color responses as colorful as a rainbow, and the limit of detection is as low as 10 cfu mL −1 at a glance. Recoveries ranging from 97.4 to 101.3% are found when analyzing spiked food samples without pre-enrichment. In our perception, it shows promise in rapid instrumental and on-site visual detection of L. monocytogenes .