Optical resonance-enhanced absorption-based near-field immunochip biosensor for allergen detection

Area of Science:

• Biosensing and Nanotechnology
• Food Science and Analysis
• Immunochemistry

Background:

• Allergen detection in food is crucial for public health.
• Existing methods can be time-consuming and require complex instrumentation.
• Need for rapid, sensitive, and user-friendly diagnostic tools.

Purpose of the Study:

• To develop and evaluate an optical immunochip biosensor for rapid allergen detection.
• To utilize resonance-enhanced absorption (REA) with gold nanoparticles (Au NPs) for signal transduction.
• To assess the sensor's performance for detecting egg white allergens (ovalbumin, ovomucoid) in food.

Main Methods:

• Development of a planar chip-based colorimetric immunoassay using Au NPs.
• Implementation of direct and sandwich assay formats.
• Utilizing resonance-enhanced absorption (REA) for sensitive detection without external instrumentation.
• Visual readout based on concentration-dependent color development.

Main Results:

• The biosensor demonstrated a detection limit of 1 ng/mL for egg white allergens.
• Color development was concentration-dependent and visible to the naked eye.
• The direct assay format achieved high sensitivity and reproducibility with a short 5-minute coating time.
• The sensor showed selective performance in complex food matrices.

Conclusions:

• The REA-based immunochip is a simple, rapid, and sensitive tool for allergen detection.
• It requires minimal technical expertise and instrumentation, enabling high-throughput screening.
• This technology has potential applications in food safety, diagnostics, and other fields requiring affinity binding analysis.