Integrating molecular imprinting into flexible covalent organic frameworks for selective recognition and efficient extraction of aflatoxins

Li-Hong Su; Hai-Long Qian; Cheng Yang; Chuanxi Wang; Zhenyu Wang; Xiu-Ping Yan

doi:10.1016/j.jhazmat.2024.133755

Integrating molecular imprinting into flexible covalent organic frameworks for selective recognition and efficient extraction of aflatoxins

J Hazard Mater. 2024 Apr 5:467:133755. doi: 10.1016/j.jhazmat.2024.133755. Epub 2024 Feb 8.

Authors

Li-Hong Su¹, Hai-Long Qian², Cheng Yang¹, Chuanxi Wang³, Zhenyu Wang³, Xiu-Ping Yan⁴

Affiliations

¹ State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, Wuxi 214122, China; Institute of Analytical Food Safety, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
² State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, Wuxi 214122, China; Institute of Analytical Food Safety, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, Jiangnan University, Wuxi 214122, China.
³ Institute of Environmental Processes and Pollution control, and School of Environment and Civil Engineering, Jiangnan University, Wuxi 214122, China.
⁴ State Key Laboratory of Food Science and Resources, Jiangnan University, Wuxi 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, Wuxi 214122, China; Institute of Analytical Food Safety, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China; Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, Jiangnan University, Wuxi 214122, China. Electronic address: xpyan@jiangnan.edu.cn.

PMID: 38359765
DOI: 10.1016/j.jhazmat.2024.133755

Abstract

Covalent organic frameworks (COFs) are promising adsorbents for extraction, but their selectivity for molecular recognition remains a challenging issue due to the very limited structural design with rigid structure. Herein, we report an elegant strategy for the design and synthesis of molecularly imprinted flexible COFs (MI-FCOFs) via one-pot reaction between the flexible building block of 2,4,6-tris(4-formylphenoxy)- 1,3,5-triazine and linear 4-phenylenediamine for selective extraction of aflatoxins. The flexible chain structure enabled the developed MI-FCOF to adjust the shape and conformation of frameworks to suit the template molecule, giving high selectivity for aflatoxins recognition. Moreover, MI-FCOF with abundant imprinted sites and function groups exhibited an exceptional adsorption capacity of 258.4 mg g^-1 for dummy template which is 3 times that of no-imprinted FCOF (NI-FCOF). Coupling MI-FCOF based solid-phase extraction with high-performance liquid chromatography gave low detection limits of 0.003-0.09 ng mL^-1 and good precision with relative standard deviations ≤ 6.7% for the determination of aflatoxins. Recoveries for the spiked rice, corn, wheat and peanut samples were in the range of 85.4%- 105.4%. The high selectivity of the developed MI-FCOF allows matrix-free determination of AFTs in food samples. This work offers a new way to the design of MI-FCOF for selective molecular recognition.

Keywords: Aflatoxins; Flexible covalent organic frameworks; Molecularly imprinted polymers; Selective extraction.

MeSH terms

Adsorption
Aflatoxins*
Arachis
Metal-Organic Frameworks*
Molecular Imprinting*

Substances

Metal-Organic Frameworks
Aflatoxins