Abstract:

Specific immunochromatographic strips were prepared for the detection of semicarbazide (SEM) in meat. CPSEM, a derivate of SEM, was conjugated to bovine serum albumin (BSA) by active ester method, and a complete antigen named CPSEM-BSA was obtained. Subsequently, monoclonal antibody against CPSEM purified by ammonium sulfate precipitation was also conjugated to Au nanoparticles prepared by controlled reduction of gold chloride with sodium citrate. After C/T line and working concentration of antibody conjugated to Au nanoparticles were optimized, gold based immunochromatographic strips which allow to specifically detect SEM were obtained. The strips were evaluated for sensitivity, specificity, accuracy and stability in this study. Distinct results could be read by naked eyes 5 min later, and the limit of detection of the strips was 0.72 ng/ml. The strips showed no cross-reactivity with other analogs of SEM except for nitrofurazone, and no effectiveness losing occurred during 7 weeks of storage at room temperature. A good correlation was observed between results of SEM determination by this method and ELISA. This method is rapid, easy, sensitive, specific, accurate and stable and can meet the demands of commercial use on the whole. 

Key words: semicarbazide (SEM), gold immunochromatographic assay (ICA), strip