Gold core @ platinum shell nanozyme-mediated magnetic relaxation switching DNA sensor for the detection of Listeria monocytogenes in chicken samples

Herein, an [email protected] nanozyme-mediated magnetic relaxation switching (MRS) DNA biosensor has been developed for the rapid detection of Listeria monocytogenes. [email protected] nanoparticle was with enhanced stability and high peroxidase activity for decomposing the hydrogen peroxide. After DNA hybridization and magnetic separation, the conjugates of MNP180-probe1-L. monocytogenes DNA-probe2[email protected] could adjust the hydrogen peroxide-mediated Mn(VII)/Mn(II) conversion, and thus leading to the change of the transverse relaxation time. The amount of [email protected] was directly proportional to the concentration of L. monocytogenes. The [email protected] nanozyme and the hydrogen peroxide-mediated Mn(VII)/Mn(II) signal conversion system contributed to the sensitivity and stability of this sensor. This sensor enabled the detection of L. monocytogenes with a LOD of 30 CFU/mL, which was 33-folds enhancement compared with that of enzyme-linked immunosorbent assay, providing a promising platform to trace the foodborne pathogen in the complex food matrix.