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

• Published in: Sensors and actuators. B, Chemical Chemical, 2022-03, Vol.355, p.131289, Article 131289
• Main Authors: Chen, Guanhua, Wang, Zhengzheng, Deng, Mei, Xiao, Fangbin, Bai, Xuekun, Xu, Hengyi
• Format: Article
• Language: English
• Subjects: Bacteria; Beads; Biomimetics; Buffer solutions; Fluorescent indicators; Food; Food irradiation; Listeria monocytogenes; Magnetic nanoparticles; Multimode Microplate Reader; Nanoparticles; Public health; Screening; Sensitivity; Serum albumin; Staphylococcus aureus; Target detection; Teicoplanin
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2021.131289

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 PEG2k 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~bacteria~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 101 CFU/mL, spinach and ground beef samples were achieved 102 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. •BSA and PEG were used to mediate Teic with MBs, introducing multiple binding sites.•MBs-PEG-BSA-Teic with fluorescence method has low LOD and high specificity.•The method can be used for simultaneous detection of multiple G+ bacteria.