Tropomyosin (TM) is the main allergen in shellfish. Developing a novel, simple and accurate method to track and detect TM in food products is necessary. In this work, a label-free fluorescent aptasensor based on polythymidine (poly(T))-templated copper nanoclusters (CuNCs) was designed for sensitive detection of TM in processed shrimp products. Magnetic beads (MBs), aptamer and cDNA were used to construct an MBs-aptamer@cDNA complex as a detection probe, and with the presence of TM, the poly(T)-templated CuNCs attached at the end of the cDNA as the fluorescent signal was released from the complex to turn on the fluorescence. Under optimal conditions, the poly(T)-templated CuNCs aptasensor achieved a linear range from 0.1 to 50 μg/mL (R 2 = 0.9980), a low limit of detection of 0.0489 μg/mL and an excellent recovery percentage of 105.29%-108.91% in the complex food matrix, providing a new approach for food safety assurance.
Tropomyosin (TM), the major allergen in shellfish, is a common protein cause of allergenic diseases, hence a sensitive, efficient method for TM detection is urgently needed to protect allergy sufferers in food products. In this work, a novel fluorescent aptasensor for TM-sensitive detection based on DNA-templated silver nanoclusters (AgNCs) and catalytic hairpin assembly (CHA) was designed. With the rapid separation and enrichment of magnetic beads, the detection of TM was converted to the detection of cDNA (complementary DNA). Then the cDNA was utilized as the initiator to successfully trigger the CHA amplification technique, which ultimately formed double-stranded to induce high fluorescence signals by AgNCs. Specifically, the cDNA could trigger repeated cycles, which enabled signal amplification and enhanced aptasensor performance with an excellent linear relationship in a wide linear range from 0.1 to 50 μg/mL (R 2 = 0.9967) and a desirable low detection limit of 0.0179 μg/mL. It is worth noting that the method was successfully validated with high specificity and stability for detecting processed shrimp products, implying great potential in the field of allergen assay.
危险品化学品经营许可证（带存储）