SERS-lateral flow immunoassay based on AuNR@Ag@SiO₂-AuNP assembly for ultra-sensitive detection of deoxynivalenol in grain

In view of the serious harm and widespread pollution caused by deoxynivalenol (DON), it is crucial to quantify its presence in the food safety assessment process. Here, we designed a core-shell-satellite nano assembly structure as a probe, composed of an anisotropic AuNR@Ag core, an ultra-thin SiO₂ layer and a high surface coverage AuNPs satellites, which showed outstanding SERS activity and high stability. Anti-DON antibodies were modified on the surface of the prepared core-shell-satellite nano-assembly structure as SERS immunoprobe for DON specific detection using SERS-based lateral flow immunoassay (LFIA) with the advantages of simplicity, rapidity, and high sensitivity. Under optimal conditions, the detection limit for detecting DON using the SERS-LFIA method was 0.053 fg/mL, and the linear detection ranged from 0.1 fg/mL to 1 μg/mL. The SERS-LFIA strips based on AuNR@Ag@SiO₂-AuNP nanostructures demonstrated the great potential for quick quantitative DON detection, providing a reference for trace detection of highly toxin mycotoxins.