The following work describes theoretical background for antibody immobilization and exemplifies solutions, which can be applied when designing a test for the presence of food allergens in groceries. Symptoms of an allergy occur as a consequence of ingestion of foods whose components show antigenic properties. Detection of allergenic proteins is being done mainly with the use of immunometric assays). First biosensor systems were composed of specific antibodies immobilized on polystyrene plate. Further steps were taken release functional groups of the matrix polymer so that the antibody binding is less random (nitrocellulose) and remains more stable. Then, there were complex matrices capable of binding an antibody with higher density and reduced denaturating effect (polycaprolactam) as well as elaborate chemical structures, known as "Self-assembled layers". Physical distance between both elements is favorable and allows to minimize disturbance from steric effects. Due to the use of a messenger coupled to the antibody results can be obtained.