An immediate and antibody protected carboxyl quantum dot immunochromatographic analysis hierarchical signal amplification test strip based on biotin-streptavidin system for the detection of aflatoxin B1 in peanuts

As a relatively mature detection method, the test strip can quickly and sensitively detect the target. We designed an immunochromatographic strip based on biotin-streptavidin system to protect antibody (Ab) activity and achieve signal amplification. The coupling condition of biotin (B) and antibody is relatively mild, which protects the activity of antibody. The high affinity between biotin and streptavidin (SA) and the one-to-many binding mode can connect multiple quantum dots (QDs) together to achieve a certain signal amplification effect. The coupling conditions of biotin and antibody (B-Ab), the working volume of QDs-SA and the volume of B-Ab were optimized. Under the optimal conditions, aflatoxin B1 in peanut was detected. The detection range obtained by the experimental method was 1–10 μg/Kg, compared with the traditional quantum dot test strip method under the same conditions in this experiment, the amount of detection antibody is reduced and the detection range is increased. Compared with other immunochromatographic methods based on quantum dots to detect aflatoxin B1 (AFB1), the detection limit can reach the same order of magnitude, and the detection time is less.