M13 bacteriophage based fluorescence immunoassay against food allergens of Ara h 3 and Mac i 1

Food allergy is increasingly prevalent and poses notable health risks, which underscores the urgent need to develop reliable and sensitive detection methods for effective identification of food allergens. This study aims to address the limitations of existing methods by developing an immunoassay utilizing bacteriophage/carbon dots (CDs)@silica core-shell nanospheres. Two CDs with different emission wavelengths (513 nm for Green CDs, 645 nm for Red CDs) were synthesized for signal development and amplification. The nanobodies (Nbs) displayed on M13 bacteriophage were employed for the rapid fluorescence quantification of peanut allergen Ara h 3 and macadamia allergen Mac i 1 through magnetic separation. Generally, the method was established with detection limits of 9.5 and 10.2 ng/mL for Ara h 3 and Mac i 1, respectively, demonstrating a sensitivity of 2-5 times greater than traditional methods. Collectively, this multiplexed testing offers a potential analytical strategy based on bacteriophage for effective screening of food allergens.