Bioluminescent detection of zearalenone using recombinant peptidomimetic Gaussia luciferase fusion protein

Abstract

The development of a bioluminescent immunosensor is reported for the determination of zearalenone (ZEA) based on a peptide mimetic identified by phage display. The peptide mimetic GW, with a peptide sequence GWWGPYGEIELL, was used to create recombinant fusion proteins with the bioluminescent Gaussia luciferase (GLuc) that were directly used as tracers for toxin detection in a competitive immunoassay without the need for secondary antibodies or further labeling. The bioluminescent sensor, based on protein G–coupled magnetic beads for antibody immobilization, enabled determination of ZEA with a detection limit of 4.2 ng/mL (corresponding to 420 μg/kg in food samples) and an IC50 value of 11.0 ng/mL. The sensor performance was evaluated in spiked maize and wheat samples, with recoveries ranging from 87 to 106% (RSD < 20%, n = 3). Finally, the developed method was applied to the analysis of a naturally contaminated reference matrix material and good agreement with the reported concentrations was obtained.