Rapid detection of Salmonella by low-field NMR biosensor using long-arm functional magnetic nanoprobes

Developing rapid detection tools and methods for foodborne pathogens has always been a research hotspot, which is undoubtedly very important for food safety. In this study, the preparation of functional magnetic nanoprobes and their application to detect target pathogens in a complex matrix by low-field nuclear magnetic resonance (LF-NMR) is demonstrated. The long-arm functional magnetic nanoprobes were constructed by modification with polyethylene glycol (PEG) onto carboxyl-modified magnetic nanoparticles (MNPs) and then reaction with biotin (Bio). Under the optimal conditions, the lower limit that can be detected in the PBS buffer system is 10(0) CFU/mL, and the detection of the actual sample matrix can be achieved 10(2) CFU/g. The practical application of LF-NMR sensors to detect harmful pathogenic bacteria in food provides an efficient way of monitoring dangerous pathogenic diseases.