The detection of shrimp allergenicity in food based on recombinant tropomyosin by LFIA method

Tropomyosin (TM), a major shrimp allergen, poses a significant challenge to food safety. This study aimed to develop a biosynthetic recombinant tropomyosin (rTM) as a standardized alternative to the natural tropomyosin (nTM) and to establish a sensitive detection method. Structural analyses using ultraviolet, fluorescence, and circular dichroism spectroscopies confirmed high similarity between rTM and nTM. Comparable allergenicity was further validated in a murine model. A novel lateral flow immunoassay (LFIA) employing Prussian blue nanoparticles (PBNPs) as probes was subsequently developed. This assay exhibited a wide linear range of 0.1–50 μg/mL and a low detection limit of 0.051 μg/mL, and excellent specificity, accuracy, and precision in spiked food matrices. This work establishes a foundation for developing nTM alternatives and provides a reliable, portable platform for sensitively detecting macromolecular food allergens.