1.A.N. Bach Institute of Biochemistry, Russian Academy of Sciences, Leninsky prospect 33, 119071, Moscow, Russia ;
Abstract:
We describe a sensitive method for the immunochromatographic determination of aflatoxin B1. It is based on the following steps: 1) Competitive interaction between non-labeled specific primary antibodies and target antigens in a sample and in the test zone of a membrane; 2) detection of the immune complexes on the membrane by using a secondary antibodies labeled with gold nanoparticles. The method enables precise adjustment of the required quantities of specific antibodies and the colloidal (gold) marker. It was applied in a lateral flow format to the detection of aflatoxin B1 and exhibits a limit of detection (LOD) of 160 pg?·?mL?1 if detected visually, and of 30 pg?·?mL?1 via instrumental detection. This is significantly lower than the LOD of 2 ng?·?mL?1 achieved by conventional lateral flow analysis using the same reagents.
Immunochromatography with secondary labeled antibodies caused 10-fold decrease of detection limit