SERS-based detection and adsorption mechanism of deoxynivalenol (DON) assisted by density functional theory

Deoxynivalenol (DON) is a secondary metabolite produced by fungi that contaminates food during the process of production and storage, and can potentially cause acute or chronic poisoning upon ingestion. This study employs surface-enhanced Raman spectroscopy (SERS) combined with density functional theory (DFT) to detect the pure DON sample. The investigation focuses on the adsorption mechanism of DON molecules on gold nanoparticles (AuNPs) and indicates that the O6 atoms in the DON molecule act as sensitive sites for nucleophilic reactions by using DFT calculations. Experimental results demonstrate that pure DON molecules exhibit a strong SERS response, displaying excellent linear and non-linear relationships across concentration ranges of 0.01-0.2 μg/mL (R² = 0.992) and 0.2-1 μg/mL (R² = 0.997), respectively. The limit of detection (LOD) and quantification (LOQ) are 0.0085 μg/mL and 0.0256 μg/mL, respectively, which show excellent detection sensitivity. These findings can provide a theoretical foundation for monitoring DON toxins in foodstuffs.