A Gold Nanoparticle-Based Lateral Flow Immunosensor for Ultrasensitive Detection of Tetrodotoxin
Tetrodotoxin (TTX) is a potent marine neurotoxin. Its frequent detection and widespread distribution pose a substantial health risk to consumers. The work presented herein describes the development of a lateral flow immunosensor based on a gold nanoparticle-labeled monoclonal antibody probe, which allows the affinity reaction of antigen-antibody and amplifies the reaction signal. The immunosensor assay was found to provide a visible limit of detection (vLOD) of 10 μg kg-1 in crucian and clam matrix without time-consuming pretreatment. Spiked samples were analyzed using the immunosensor and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The immunosensor gave average intra-assay recoveries of 84.0 ± 7.2–103.9 ± 5.7%, inter-assay recoveries of 76.1 ± 3.6–105 ± 5.3% for crucian matrix and intra-assay recoveries of 78.5 ± 3.1–93.0 ± 1.9%, inter-assay recoveries of 74.8 ± 4.7–85.7 ± 4.0% for clam matrix. Results obtained by immunosensor and LC-MS/MS were in good agreement. The immunosensor test could be completed within 15 min, offering a convenient option or complementarity to traditional methods of TTX detection.