Magnetic nanoprobe-enabled lateral flow assays in the applications of food safety and in vitro diagnostic

Abstract

Early-stage disease and food contamination identification can enable timely medical care and avert possible food poisoning incidents. With their remarkable benefits of affordability, speed, portability, real sample applicability, and reliability, lateral flow assays (LFAs) are common point-of-care instruments that have been extensively investigated in the fields of food safety, in vitro diagnostics, and environmental monitoring. Nanoprobes are the essential components of LFAs that produce sensitive, specific, and reliable signals for determining trace levels of analytes in food and clinical samples. Magnetic nanocomposites have become impressive signal probes for LFAs thanks to the magnetic enrichment capability of magnetic nanocomponents, which significantly reduces the matrix effect and improves the signal-to-noise ratio. This review systematically presents recent advancements in key aspects of magnetic LFA preparation and application, including 1) describing different magnetic nanoprobes that simultaneously integrate the properties of magnetic and secondary nanoparticles (plasmonic, fluorescent, and photothermal features) and their corresponding signal readout mode, as well as 2) highlighting protocols and strategies for the preparation of magnetic nanocomposites with distinct analytical characteristics, and 3) introducing the utilization of magnetic LFA in food safety (pathogens, pesticide and antibiotic residues, mycotoxins, and allergens) and in vitro diagnostic applications (respiratory bacteria and biomarkers). Potential strategies for converting magnetic LFAs from laboratory to practical applications are also explored. This review paves the way for the broader implementation of magnetic LFA in food safety and in vitro diagnostics by systematically covering the current applications, challenges, opportunities, and potential prospects for magnetic LFA.