Aflatoxin Extraction From Different Samples And Lateral-flow Immunoassay Methods For Aflatoxin B1Using Magnetic Composite Particles As Carriers

Aflatoxins is a kind of compound which extremely toxic, mutagenic, teratogenic, and carcinogenic. According to the regulations, The maximum allowable limit for aflatoxins in food and feeds have been reported in different countries. Therefore, the extraction method from sample and the determination method for aflatoxins became a hot spot in the field of research and applications. Herein, A method based on immunoaffinity magnetic particles, which could extract aflatoxin B1and total aflatoxins from food, were established respectively. In addition, an immunochromatographic strip based on GoldMag nanoparticles for rapid detection of aflatoxin B1was also developed.1. Two kinds of immunoaffinity magnetic particles were prepared for extraction of aflatoxin B1and total aflatoxins (B1+B2+G1+G2).10μg anti-AFB1mAb or anti-AFT mAb could be coupled on1mg functional magnetic particles in one step.17.5ng of AFB1in peanuts could be extracted by using1mg conjugation of magnetic particles and anti-AFBl mAb, and18ng of AFT could be extracted by lmg conjugation of magnetic particles and anti-AFT mAb.2. The extraction capacities of two immunoaffinity magnetic particles for maize and wheat are higher than the ones for peanuts and walnut. For immunoaffinity magnetic particles conjugated with anti-AFB1mAb, a significant result was obtained, the recovery is more than98%and relative standard deviation (RSD) less than8.5%. The results for immunoaffinity magnetic particles conjugated with anti-AFT were different. For AFB1and AFG1, the recovery was more than98%(>100%for maize and wheat) and the range of RSD was3.99%-8.29%. For AFB1and AFG2, the ranges of the recovery and RSD were84%-91%and6.02%-7.86%respectively. 3. The complex of anti-AFBl and GoldMag nanoparticles was prepared and the conjugation conditions is optimized.117.2μg of anti-AFB1mAb was labeled to lmg of GoldMag nanoparticles at25℃for1.5h.4. By visual observation, the detection limit was found to be around4ppb (ng/ml). For quantitative analysis by using the instrument of MagnaBioscience, the detection limit was found to be around0.1-0.3ppb and the detection range was0.3ng/ml-4ng/ml.