Colloidal gold based immunochromatographic strip for the simple and sensitive determination of aflatoxin B1 and B2 in corn and rice

摘要

We have developed a simple and fast immunochromatographic test strip for the simultaneous quantitation of aflatoxin B1 and aflatoxin B2 in com and rice. The strip contains three pads (sample, conjugate, and absorbing pad) and uses the respective polyclonal antibodies immobilized on gold nanoparticles. Matrix interferences were minimized by application of fugacity theory. Clean-up of samples and pre-treatment of strip pads is not required. The visual detection limit is 0.1 ng mL~(-1), and the process can be completed within 5 min. Out of 113 natural samples, 16 rice and 27 corn samples (38% in total) were aflatoxin positive and the test results were confirmed by HPLC. The strip shows, however, high cross reactivity to aflatoxins G1, G2, and M1. We consider this strip to possess wide applicability because of its ease of use, sensitivity, stability, and low cost.