In this article sensor with improved measurement technique for the detection of milk allergens was developed. β-lactoglobulin (BLG) protein was used as the biomarker for cow milk detection. The structure of the sensor with nanocrystalline cerium oxide is proposed with an advanced measurement method, which consists of using a micro-flow system to provide a constant volume of the substance to be tested for the dynamic analysis of the beta-lactoglobulin protein, the major milk allergen. The influence of illumination on the experiment and the degree of cleaning of the sensor surface between each measurement are analyzed. Because the existing ELISA method is too long (1.5 hours), and the proposed method allows to identify the presence of beta-lactoglobulin in a few minutes. U gs = µA