Core-shell Au@4-MBA@Ag enhanced SERS immunochromatography for rapid and on-site detection of deoxynivalenol in animal feeds.

Abstract

Deoxynivalenol (DON), a highly stable and globally prevalent mycotoxin, has become a critical food safety concern due to its widespread contamination in animal feed, particularly in corn, wheat, and other cereal-based ingredients. As one of the most frequently detected mycotoxins in feedstuffs, DON contamination not only causes significant economic losses in livestock production but also poses severe health risks to animals, including vomiting, immunosuppression, and growth retardation, which may ultimately affect human health through the food chain. Existing detection methods for DON are often limited by time-consuming procedures or analytical complexity. Here, we report a novel surface-enhanced Raman scattering-based lateral flow immunoassay (SERS-LFIA) for rapid, sensitive, and specific detection of DON residues in animal feeds. The biosensor employs core-shell Au@4-MBA@Ag nanoparticles functionalized with 4-mercaptobenzoic acid (4-MBA) as a Raman reporter and DON-specific antibodies for target recognition. After systematic optimization, the SERS-LFIA platform achieved both qualitative and quantitative detection within 16 min, with an exceptionally low limit of detection (LOD) of 0.01 µg/kg. The assay demonstrated excellent specificity, showing no cross-reactivity with other major mycotoxins, including aflatoxin B₁, zearalenone, and ochratoxin A. Remarkable reproducibility was evidenced by intra- and inter-batch coefficients of variation (CV) of 3.51% and 2.19%, respectively. The test strips maintained stability for at least 3 months at 4 ± 0.5 °C and for 2 months at 25 ± 0.5 °C, making them particularly suitable for routine monitoring in feed mills and farms. This innovative SERS-LFIA system represents a significant advancement in mycotoxin detection technology, offering a robust, field-deployable solution for monitoring DON contamination in animal feed, which is crucial for ensuring feed safety and animal health.