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@SiO 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 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.