Development and application of time-resolved fluorescent immunochromatography test strip for okadaic acid and dinophysis toxins

Diarrhetic shellfish poisoning (DSP) are mainly composed of okadaic acid (OA), dinophysis toxin-1 (DTX-1) and dinophysis toxin-2 (DTX-2), which are seriously harmful for human consuming seafood. OA has been often found, while DTX-1 and DTX-2 been occasionally detected at the coastal waters of China. This paper mainly introduced the principle of immunochromatographic assay, and used nitrocellulose membrane as carrier. Fluorescent immunobeads were adopted to label monoclonal antibodies against okadaic acid. The time-resolved fluorescent immunochromatography strip for rapid and accurate detection of OA, DTX-1 and DTX-2 was developed by using bovine serum albumin (BSA) to synthesize high coupling ratio coated antigen. The time-resolved fluorescent immunochromatography strip limits of quantitation for OA, DTX-1 and DTX-2 were 90.6 μg/kg, 115.4 μg/kg and 69.8 μg/kg, respectively. The experimental results show that the time-resolved fluorescent immunochromatography strip developed in this paper has a good correlation with the results of LC-MS/MS for the detection of toxin samples containing one, two or three components of OA, DTX-1 and DTX-2. The time-resolved fluorescent immunochromatographic strip is sensitive, accurate, easy to operate and low cost. It has a good application prospect in marine environmental monitoring and seafood food safety detection in China.