Quantum-dot-based sandwich lateral flow immunoassay for the rapid detection of shrimp major allergen tropomyosin

Abstract

Tropomyosin (TM) has long been reckoned as the major allergen in shrimp is known to cause both food safety and public health concern all over the globe. In the present study, a simple, rapid, specific and accurate quantum-dot-based sandwich fluorescent lateral flow Immunoassay (LFIA) was developed for the detection of TM in processed foods. Fluorescent probes were prepared by EDC/NHS reaction of rabbit anti-TM polyclonal IgG with carboxylated quantum dots. Obtained results indicated that the visual detection limit (VDL) and the instrumental detection limit (IDL) of were 0.05 μg mL-1 and 0.01 μg mL-1, respectively. In addition, the detection time could be controlled within ten min. Furthermore, the established method showed no cross-reactivity with other species except shrimp. Moreover, the intra- and inter-assay coefficients of variation of the spiked samples were 8.87 %− 11.9 % and 7.75 %− 21.12 %. Besides, LFIA could detect 8 of 9 real food samples which were identified as TM-positive by the validated ELISA method. Additionally, 0.045 μg g-1 of incurred TM in model processed foods (roast fish fillet, boiled meatball and steamed meatball) also could be detected by the developed assay. These findings indicated that the LFIA developed in this research possess a great significance on the rapid and accurate detection of allergens in shrimp foodstuffs, related products and their production lines.