Bioimprinting for multiplex luminescent detection of deoxynivalenol and zearalenone.

A sensitive tool for simultaneous quantitative determination of two analytes in a single spot with the use of a bioimprinted protein is presented for the first time. BSA is chosen as a scaffold for generation of binding sites specific towards two compounds. A multiplex immunosorbent assay for screening of two cereal-born mycotoxins, deoxynivalenol and zearalenone, in wheat and maize is realized with the use of fluorescent silica coated quantum dots as labels. Water-soluble fluorescent nanostructures consist of core/shell Cd-QDs enrobed in silica shells to ensure their solubility. The mycotoxins are simultaneously detected by scanning the assay outcome at two different wavelengths, since two QD@SiO2 labelled conjugates fluorescent in different parts of the spectrum. The assay is combined with a rapid extraction technique. The limits of detection for the simultaneous determination were 100 and 700 µg kg-1 in both matrices for zearalenone and deoxynivalenol, respectively. Liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) was used to confirm the obtained results.