|HOSSAIN, MD ZAKIR - Orise Fellow|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 11/10/2017
Publication Date: N/A
Technical Abstract: Certain Fusarium species (F. graminearum and F. verticilloides in particular) infest grains and can produce a wide range of fungal (myco)-toxins, causing huge economic losses worldwide. A reproducible and sensitive imaging surface plasmon resonance (iSPR) assay was developed and validated for three important Fusarium mycotoxins, deoxynivalenol (DON), zearalenone (ZEA) and T-2 toxin. The assay was based on a competitive inhibition immunoassay where secondary antibodies conjugated with gold nanoparticles (AuNPs) were used for signal amplification. By using AuNPs, the signal was amplified 12 to 90 fold relative to signal from toxin-specific (primary) antibodies alone. The technique is based on antigen coated sensor chips that were used for more than 40 cycles with minimal reduction of signal (<12%). To determine Fusarium toxins in wheat, matrix matched calibration curves were constructed. In spiking studies mean recoveries ranged from 87% to 103% with relative standard deviations of repeatability of less than 15%. The limits of detection were 15 µg/kg for DON, 24 µg/kg for ZEA and 12 µg/kg for T-2 toxin, providing enough sensitivity to monitor for contamination in wheat. The assay was more sensitive than previously reported immunoassay and multiplexed SPR assays. Cut off levels were successfully validated for all three Fusarium toxins, which allowed separation of blank samples from those spiked at levels regulated by the European Commission (100 µg/kg for ZEA and T-2 toxin, or 400 µg/kg for DON, which was one-third of the EC level). To validate the cut off level, the method was also successfully applied to naturally contaminated wheat. This is the first reported iSPR assay that uses signal amplification with AuNPs in order to detect three agriculturally important Fusarium toxins in wheat.