High sensitive immunoassay for multiplex mycotoxin detection with photonic crystal microsphere suspension array.

Area of Science:

• Analytical Chemistry
• Food Science
• Biotechnology

Background:

• Mycotoxin contamination in cereals poses significant risks to human and animal health.
• Accurate and rapid detection methods are crucial for food safety and quality control.
• Existing methods for multiplex mycotoxin detection can be time-consuming and reagent-intensive.

Purpose of the Study:

• To develop a novel, sensitive, and high-throughput competitive immunoassay for the simultaneous detection of multiple mycotoxins.
• To establish a method for encoding silica photonic crystal microspheres (SPCMs) for multiplexing.
• To validate the assay's performance in detecting aflatoxin B1 (AFB1), fumonisin B1 (FB1), and citrinin (CIT) in cereal samples.

Main Methods:

• Artificial antigens (Ags) of mycotoxins were immobilized on SPCMs encoded by reflectance peaks.
• A competitive immunoassay format was employed using fluorescein isothiocyanate (FITC)-labeled antibodies (Abs).
• Analyte extraction from spiked cereal samples followed by incubation with SPCMs and labeled Abs, with fluorescence detection.

Main Results:

• The assay achieved low limits of detection (LOD) as low as 0.5 pg/mL for AFB1, 1 pg/mL for FB1, and 0.8 pg/mL for CIT.
• Wide linear detection ranges were observed: 0.001–10 ng/mL for AFB1 and FB1, and 0.001–1 ng/mL for CIT.
• Mean recovery rates ranged from 74.7% to 127.9%, and results for naturally contaminated samples correlated well with ELISA.

Conclusions:

• The developed SPCM-based competitive immunoassay is a sensitive, rapid, and high-throughput method for multiplex mycotoxin detection.
• The assay demonstrates excellent performance characteristics, including low LOD and wide linear range.
• This method offers significant advantages in terms of reagent and time savings for mycotoxin analysis in food safety applications.