Study On The Colloidal Gold Immunochromatographic Assay For The Determination Of Nitenpyram

In this paper, the colloidal gold immunochromatographic rapid test strip was developed for the determination of insecticide (Nitenpyram) in food and environment, which was effectively applied to identify trace nitenpyram.The polyclonal antibody purification of nitenpyram was completed by protein A-sepharose4B immunoaffinity chromatography. The coating antigen was prepared by conjugating nitenpyram to OVA. Gold chloride was reduced with sodium citrate to make20nm colloidal golds, which was labeled to the anti-nitenpyram polyclonal antibody after identification. The goat anti-rabbit IgG and NI-OVA were dispensed on control line and test line respectively, and the anti-nitenpyram polyclonal antibody was solidified to gold pad.The detection limit of (LOD) nitenpyram colloidal gold immunochromatographic assay was80ng/mL in10min. The cross-reactivity effect of three neonicotinoid insecticides and seven other kinds of insecticides could be ignored with the test stripe.Some fruit juice and vegetables, water and soil in environment were selected to be spiked respectively. The fruit juice and vegetables were analyzed by the stripe and showed a visual detection limit of400ng/mL and800ng/g, respectively. The water and soil were analyzed by the stripe and showed a visual detection limit of160ng/mL and800ng/g, respectively. Either of them was lower than the maximum residue limits. The results obtained by colloidal gold immunochromatographic assay of nitenpyram were coherence with those determined by ELISA.The colloidal gold immunochromatographic assay has advance in rapid, accurate, stable and high specificity. The advantages of the method make it feasible to be the initial detection of nitenpyram in food and environment.