Design of Multifunctional Nanostructure for Ultrafast Extraction and Purification of Aflatoxins in Foodstuffs.

Aflatoxins (AFs) are a class of carcinogens, associated with liver cancers, that exist in foodstuffs. There are extremely low maximum limits of AFs in foodstuffs (0.025-20 μg·kg-1). Quick and sensitive detection of such low concentration of AFs in foodstuffs is dominated by the efficiency and selectivity of the AF enrichment process, which is extremely challenging although substantial efforts have been made in recent decades. Here we design and synthesize a multilayer nanoarchitecture composed of a broad-spectrum aflatoxin monoclonal antibody shell, chitosan middle layer, and magnetic bead core (denoted AF-mAb/CTS/Fe3O4). The efficiency of AF-mAb/CTS/Fe3O4 in extracting AFs has been found to be more than 60 times higher than both conventional immunoaffinity chromatography and solid-phase extraction. Furthermore, the nanocomposite displays excellent selectivity and good reusability as well as outstanding efficiency. When coupled to ultraperformance liquid chromatography-tandem quadrupole mass spectrometry, this new nanoarchitecture enables us to probe six AFs at concentrations as low as 0.003 μg·kg-1 in foodstuffs with free matrix effects, which is nearly 10 times smaller than the regulated maximum tolerated does. It is believed that the new nanoarchitecture will provide an efficient and fast pathway to detect AFs in foodstuffs to protect human being from some critical liver cancers.