LAUSR

Listeria monocytogenes is one of the most common pathogenic bacteria. After infection, the main symptoms of listeriosis are sepsis, meningitis and mononucleosis. A G-quadruplex DNAzyme-based LAMP biosensing platform was developed for the colorimetric detection of L. monocytogenes. Four primers were designed to hybridize against six distinct sequences in the target DNA making the highly specific amplification in the step of LAMP. The G-quadruplex sequence amplified simultaneously in LAMP could form DNAzyme with the addition of hemin. The catalytic horseradish peroxidase-mimicking DNAzymes allowed the colorimetric responses of the target DNA from L. monocytogenes. The response surface methodology was used to screen and optimize the crucial factors affecting the response. This assay could detect L. monocytogenes specifically with as low as 47.5 CFU per reaction by the naked eye. Furthermore, this colorimetric detection assay was successfully applied to detect L. monocytogenes in spiked pork samples. Therefore, the rapid, specific and visual detection of L. monocytogenes has demonstrated potentially broad applicability in food safety.