The Use of SPR Technology for the Detection of Food Allergens

Ingrid Malmheden Yman

National Food Administration, Uppsala, Sweden

We have evaluated the potential of a surface plasmon resonance (SPR)-based sensor system for food allergen analysis and developed direct and sandwich immunoassays for the detection of milk, egg, hazelnut, peanut, shellfish and sesame seeds in food samples. Affinity-purified polyclonal antibodies against the proteins were immobilized on the biosensor chip. Food samples were injected and the proteins that bound to the antibodies on the surface were detected by a shift in the resonance angle. By adding a second antibody in a sandwich assay, matrix effects could be eliminated and the sensitivity and selectivity enhanced. Detection of allergen levels down to 1-12.5 µg/g in food samples were demonstrated for the various assays. Good agreement was also obtained with other types of immunoassays like rocket immunoelectrophoresis, enzyme immunoassay and immunoblotting.

Advantages of the biosensor immunoassays are the short analysis time, the high degree of automation allowing loading of a great number of samples at the same time and the possibility of simultaneous detection of several analytes in the same extract by parallel analysis in different flow channels.