One-Step Core/Multishell Quantum Dots-Based Fluoroimmunoassay for Screening of Deoxynivalenol in Maize

Abstract

Deoxynivalenol (DON) is a protein synthesis inhibitor produced by the Fusarium species, which frequently contaminates grains used for human or animal consumption, thereby necessitating their effective monitoring and control. Antibody-based immunoassays provide efficient and cheap methods for screening this mycotoxin. To achieve high sensitivity and avoid enzymatic reaction, a new highly sensitive monoclonal antibody (MAb) and a fluorescent probe consisting of amino-functionalized core/multishell quantum dots (QDs), CdSe/CdS/Cd0.5Zn0.5S/ZnS, bio conjugated to 3-HS-DON-BSA were prepared; then, a sensitive and reliable direct competitive fluorescent-labeled immunosorbent assay (dcFLISA) was developed. Under optimized conditions, the 50% inhibition concentration (IC50) value of the dcFLISA was 5.6 μg/kg with limit of detection of 12.2 μg/kg in maize samples. The recoveries ranged from 77.3 to 84.3% with coefficients of variation (CV%) values below 10%. Good correlation between the dcFLISA and HPLC-MS/MS results in the naturally contaminated maize demonstrated that the dcFLISA was a rapid and sensitive with high-performance and reliable method for the detection of DON. The potential of this method to function as a simple and efficient strategy for small molecule on-site screening might be applied in the future.