Synergizing nanozyme-catalyzed signal amplification with magnetic separation for sensitive dual-mode Listeria monocytogenes detection

• Published in: Mikrochimica acta (1966) Vol. 192; no. 11; p. 734
• Main Authors: Wang, Yongqi, Liao, Jiali, Li, Jiajie, Xiao, Zhuqian, Wang, Hongpeng, Huang, Jun, Yu, Linkai
• Format: Journal Article
• Language: English
• Published: Vienna Springer Vienna 13.10.2025; Springer Nature B.V
• Subjects: Analytical Chemistry; Aptamers; Aptamers, Nucleotide - chemistry; Biosensing Techniques - methods; Biosensors; Catalysis; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Colorimetry; Colorimetry - methods; Food; Horseradish peroxidase; Iron oxides; Limit of Detection; Listeria; Listeria monocytogenes; Listeria monocytogenes - isolation & purification; Lysine; Magnetic separation; Magnetite Nanoparticles - chemistry; Microengineering; Milk - microbiology; Monoclonal antibodies; Nanochemistry; Nanoparticles; Nanotechnology; Oxidation; Peptidoglycans; Peroxidase; Silicon dioxide; Silicon Dioxide - chemistry; Target recognition; Vancomycin; Nanozyme; identification; Fluorescence-colorimetric detection; Magnetic nanoparticles; Listeria monocytogenes identification
• ISSN: 0026-3672; 1436-5073; 1436-5073
• DOI: 10.1007/s00604-025-07614-y

A dual-mode biosensing platform for the sensitive detection of Listeria monocytogenes (L. monocytogenes)  is presented. This method integrated vancomycin-modified magnetic nanoparticles (MNPs, 10‒30 nm) for efficient bacterial capture compared to L. monocytogenes monoclonal antibody, and aptamer-conjugated Fe-doped L-lysine-derived nanozyme (Fe@LS) for target recognition and signal amplification. The Fe@LS nanozyme exhibited pronounced peroxidase (POD)-like activity, catalyzing the oxidation of TMB with a Michaelis constant ( K m ) of 0.63 mM and a maximum reaction velocity ( V max ) of 1.89 × 10 −8  M·s −1 . Within this system, vancomycin-functionalized magnetic beads (Fe 3 O 4 @SiO 2 @NH 2 @van) enabled broad-spectrum binding to bacterial peptidoglycan, while the aptamer-modified Fe@LS (apt/Fe@LS) conferred the specific recognition of L. monocytogenes . Both fluorescence and colorimetric modes exhibited linear responses across a concentration range from 1.0 × 10 2 to 1.0 × 10 8  CFU/mL ( R 2  > 0.99), yielding a wider detection range compared to that catalyzed by horseradish peroxidase (HRP). When applied to simulated food samples (lake water, milk, and vegetable), the platform demonstrated satisfactory recoveries (90.0‒109.0%) and low inter-assay variability (< 8.0% RSD). The proposed dual-mode biosensing strategy offers a robust and reliable tool for the detection of L. monocytogenes in complex food environments. Graphical Abstract