Aptamer-modified magnetic nano material and application thereof in separating ochratoxin A

The invention provides an aptamer-magnetic nanoparticle compound, which comprises an inner nuclear layer formed by paramagnetic Fe3O4 magnetic nanoparticles, a silanization layer and an aptamer modification layer located at the outer side of the silanization layer, so that the aptamer-magnetic nanoparticle compound not only has a characteristic of being quickly separated from a complex sample solution under an externally applied magnetic field, but also has a characteristic of carrying out specificity recognition capture on a detected substance by using an aptamer. Therefore, the detected substance can be separated from the complex sample solution quickly and effectively by using the aptamer-magnetic nanoparticle compound provided by the invention, the selectivity is good, and the separation efficiency is high. Data shows that the separation efficiency and the recovery rate of the aptamer-magnetic nanoparticle compound reach up to 80-92%. Furthermore, the separated detected substance is gathered and then applied to detection again, thereby being capable of effectively improving the accuracy.