Superparamagnetic Bead-Based Microfluidic Fluoroimmunoassay Platform for Rapid Ochratoxin A Detection in Flour

Area of Science:

• Analytical Chemistry
• Biotechnology
• Food Science

Background:

• Onsite diagnostics and food safety require simplified, cost-effective methods.
• Transitioning laboratory techniques to miniaturized devices is crucial for field applications.

Purpose of the Study:

• To develop a modular microfluidic platform for rapid onsite diagnostics.
• To integrate a competitive fluorescence immunoassay using superparamagnetic beads.
• To demonstrate the platform's utility for Ochratoxin A detection in food.

Main Methods:

• Developed a modular microfluidic chip with two modules for reaction and separation.
• Integrated a competitive fluorescence immunoassay on superparamagnetic beads.
• Used fluorescein-labeled Ochratoxin A (OTA) as a competitor for OTA detection.

Main Results:

• Achieved a fast competitive reaction in 5 minutes and particle separation using a magnetic module.
• Demonstrated a direct correlation between OTA concentration and remaining fluorescent competitor.
• Obtained a limit of detection of 1.2 μg L⁻¹ for OTA within a 10-minute assay time.
• Successfully applied the system to determine OTA in spiked wheat flour samples.

Conclusions:

• The microfluidic platform enables rapid, user-friendly, and cost-effective onsite analysis.
• Conventional cytometry immunoassays can be transformed into miniaturized, point-of-need methods.
• The developed system is suitable for accurate Ochratoxin A determination in food matrices.