A novel molecularly imprinted polymer material for the recognition of ochratoxin A

A novel molecularly imprinted polymer composite material (OTA-MIPs) was prepared by the complexation between a metal–organic framework single-crystal ordered macropore ZIF-8 and a novel dummy template for the selective recognition of ochratoxin A (OTA). First, the structural analog of OTA was synthesized as a dummy template molecule. Then, OTA-MIPs were synthesized on the ZIF-8 surface by thermal polymerization. The as-synthesized OTA-MIPs were characterized by infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, and N2 adsorption. The material exhibited a good network structure as well as a high specific surface area and pore size to facilitate the adsorption of target molecules. OTA-MIPs were examined for OTA re-binding properties. The Langmuir model fitted the adsorption data for OTA-MIPs better than the Freundlich model. At the same time, compared to the corresponding non-imprinted (OTA-NIPs) material, OTA-MIPs exhibited a 6.8-fold higher affinity for OTA. The molecular recognition ability of OTA-MIPs was highly specific for OTA compared to structurally similar compounds such as patulin and zearalenone. OTA-MIPs only exhibited a slight downward trend in terms of performance after five times of reuse. These results highlighted their potential for the concentration of OTA from complex food matrices.