Screening of Food Samples for Zearalenone Toxin Using an Electrochemical Bioassay Based on DNA-Zearalenone Interaction, 367. Neda Roustaee Sadrabadi, Ali A. Ensafi, Esmaeil Heydari-Bafrooei, Mohammad Fazilati, Food Analytical Methods, 2016, 9, 2463-2470.
This study was conducted to design a biosensor as a new, rapid, and sensitive tool for investigation of binding of zearalenone with double tranded DNA (dsDNA). Polydiallyldimethylammonium chloride (PDDA)as a polycation and multiwall carbon nanotubes (MWCNTs) provide a ositively charged surface with a high surface area for the immobilization of dsDNA as a polyanion on the surface of pencil graphite electrode (PGE). Using the dsDNA/MWCNT–PDDAmodified PGE, it was possible to detect the interaction of zearalenone with dsDNA, which allowed us to apply the dsDNAmodified electrode for trace determination of zearalenone. The changes at the oxidation signal of adenine were evaluated before/after each modification/immobilization step. By using dsDNA/PDDA–MWCNT/PGE, zearalenone could be detected as low as 0.005 ng mL . The relative standard deviation of five measurements of 0.5 ng mL zearalenone was found to be 4.2 %. Finally, the highly stable electrochemical biosensor was applied to analyze the zearalenone concentration in milk and wheat samples.