Biomimetic dandelion-like magnetic nanoparticles for capture and detection of S. aureus and L. monocytogenes

Foodborne pathogenic microorganism pose a serious threat to public health security; thus, constructing quick and sensitive methods for early screening foodborne pathogenic microorganism is necessary for human health. Teicoplanin (Teic) is a broad-spectrum biometric molecule, which can recognize Gram-positive (G(+)) bacteria. In this study, using bovine serum albumin (BSA) and PEG(2k) as carrier and linker, respectively. Teic was wired to magnetic beads (MBs) to form the biomimetic dandelion-like magnetic nanoparticles (MBs-PEG-BSA-Teic) to capture Staphylococcus aureus (S. aureus) and Listeria monocytogenes (L. monocytogenes ). The MBs-PEG-BSA-Teic displayed excellent capture ability of S. aureus (> 93%) and L. monocytogenes (> 86%). After separation, the fluorescence probes were added, forming a sandwich structural compounds, namely, MBs-PEG-BSA-Teic similar to bacteria similar to fluorescence probes. The fluorescence intensity of the probes was measured by a multimode microplate reader. Consequently, this novel method showed high detection sensitivity to target model bacteria, and the detection limit of S. aureus and L. monocytogenes in PBS buffer solution and juice were achieved 10(1) CFU/mL, spinach and ground beef samples were achieved 10(2) CFU/g. The method has easy operation and high sensitivity, and it is less interfered by food matrix or negative bacteria; thus, this method is suitable for early screening G(+) pathogen in suspected food samples.

Automated summary

In this study, a novel method was developed to capture foodborne pathogenic bacteria using biomimetic magnetic nanoparticles. The method showed high detection sensitivity and capture ability, making it suitable for early screening of pathogenic bacteria in food samples.