An SPR based sensor for allergens detection

Area of Science:

• Food Science
• Analytical Chemistry
• Biosensing Technology

Background:

• Food manufacturers require sensitive methods to detect milk allergens like α-casein in cleaning-in-place (CIP) rinse samples.
• Existing methods like ELISA may lack the sensitivity or real-time capabilities needed for rapid quality control.
• Accurate allergen detection is crucial for food safety and regulatory compliance.

Purpose of the Study:

• To develop a simple, sensitive, and label-free optical sensor for detecting α-casein, a biomarker for cow's milk allergens.
• To enable direct analysis of α-casein in final rinse samples from CIP systems in food manufacturing.
• To provide a tool for validating cleaning procedures and enhancing food allergen risk management.

Main Methods:

• Development of a Surface Plasmon Resonance (SPR) sensor chip with four sensing arrays.
• Immobilization of α-casein-specific polyclonal antibodies onto a gold sensor chip using EDC/NHS coupling.
• Optimization and characterization of the SPR assay in buffer and real-world CIP rinse samples.

Main Results:

• Achieved a detection limit of 58 ng/mL for α-casein in direct binding assays, exceeding the required 2 µg/mL for α-S1-casein.
• Demonstrated good selectivity for α-casein and adequate recovery rates from CIP final rinse samples.
• The SPR sensor provides label-free, real-time detection with superior sensitivity compared to ELISA.

Conclusions:

• The developed SPR sensor is a viable tool for monitoring milk allergen levels in food manufacturing environments.
• This technology can effectively validate cleaning processes and improve overall food allergen risk management strategies.
• The sensor offers a sensitive and efficient alternative for routine quality control of cleaning procedures.