Aggregation triggered aflatoxin B1 determination in foodstuff employing 5-aminotetramethylrhodamine decorated gold–silver core–shell nanoparticles in surface enhanced Raman scattering

Abstract

The current study examines aflatoxin B1 (AFB1) as the indicator of the total aflatoxins in wheat with a 5-aminotetramethylrhodamine (NH2-Rh)-decorated gold–silver core–shell nanoparticles (Au@Ag CSNPs) sensor based surface enhanced Raman scattering (SERS) strategy, using Hg(II) as the media. The principle of the work was based on the selective interaction of Hg(Ⅱ) media with AFB1 via carbonyl oxygen atoms to inhibit the aggregation of NH2-Rh-Au@Ag CSNPs sensor. Due to the nanogap effect induced by sensors aggregation, the quenching in SERS intensity was an indication for AFB1 selective quantification. Under the optimized experimental conditions, a detection limit of 0.03 ng·mL−1 was obtained with a correlation coefficient R2 = 0.9895 within the dynamic range of 0.1–5.0 ng·mL−1. This quantification of AFB1 was further coupled with solid-phase extraction in real wheat, hazelnut, and peanut oil samples. The strategy was validated by standard HPLC-FLD approach and was in a good agreement. The proposed detective system offers a promising platform for the rapid determination of traces AFB1 residue in foodstuff with high selectivity and economical efficiency.