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 matrices 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 84.0-103.9%, inter-assay recoveries of 76.1-105% for the crucian matrix and intra-assay recoveries of 78.5-93.0%, inter-assay recoveries of 74.8-85.7% for the clam matrix. The results obtained using the immunosensor and LC-MS/MS were in good agreement. The immunosensor test could be completed within 10 min, offering a convenient option or complementarity to the traditional methods of TTX detection.