[Development of colloidal gold immunochromatographic strip for rapid detection of domoic acid]

The colloidal gold immunochromatographic test strip was developed in order to establish a rapid detection assay of Domoic acid (DA) content in marine shellfish. The colloidal gold with particle diameter 20 nm was obtained by reducing gold chloride with sodium citrate. After identification by electron micrograph, optimum conditions for labeling were determined and colloidal gold was labeled by DA monoclonal antibody. The gold-labeled antibody was coated on some chosen glass fiber and dried. The coating antigen (DA-BSA) and Goat anti Mouse IgG were spotted respectively on a piece of nitrate fiber membrane as test line and control line. Finally the test strips were constructed and the detection sensitivity was measured. The results showed that, the detection limit of colloidal gold immunochromatographic test strip was 20 ng/mL and the whole analysis process could be completed within 15 min. The method established is sensitive and the procedure of determination is simple and quick without special equipment. The colloidal gold immunochromatographic test strip could be widely used for batch detection of domoic acid in shellfish on site and has great prospect for commercial development.