Novel chemiluminescence immunoassay for the determination of zearalenone in food samples using gold nanoparticles labeled with streptavidin-horseradish peroxidase.

A novel highly sensitive chemiluminescence immunoassay (CLIA) was developed to detect zearalenone in food samples by using both biotinylated zearalenone conjugates and gold (Au) nanoparticles labeled with streptavidin-horseradish peroxidase for signal amplification. Biotinylated zearalenone-ovalbumin conjugates and Au nanoparticles labeled with streptavidin-horseradish peroxidase were synthesized separately. The concentrations of immunoreagents and the reaction times of these immunoreagents were optimized to improve the performances of analytical methods. For the CLIA based on biotinylated zearalenone conjugates and Au nanoparticles labeled with streptavidin-horseradish peroxidase, the limit of detection was 0.008 ng/mL and the IC50 was 0.11 ng/mL. The linear working range was 0.02-0.51 ng/mL. The cross-reactivities with the zearalenone analogues (α-zearalanol, zearalanone, α-zearalenol, β-zearalanol, and β-zearalenol) were 32, 17, 12, 0.3, and 0.1%, respectively. The recovery rates in spiked food samples were 97-117%, and the intraday and interday relative standard deviations were both <10%. Parallel analysis of natural food samples showed a good correlation between this novel CLIA and liquid chromatography-tandem mass spectrometry. This method provides a rapid, accurate, and highly sensitive method to determine levels of zearalenone in food samples.