Polydopamine surface-imprinted and chitosan-polyethyleneimine-scaffolded COF aerogel for efficient aflatoxins removal from infant foods

Aflatoxin contamination poses a serious threat to infant health, yet selective enrichment and separation of trace aflatoxins from complex food matrices remains challenging. Herein, we report a polydopamine surface-imprinted chitosan-polyethyleneimine-scaffolded COF aerogel (Fe₃O₄@COF@MIP-AG) featuring large pores, specific binding sites, and a unique medium-blocking effect that enhances resistance to matrix macromolecules and competing molecules. Adsorption follows pseudo-second-order kinetics and Freundlich isotherms, indicating chemisorption-dominated, heterogeneous multilayer adsorption. Notably, the material combines robust mechanical stability with ultrafast kinetics, making it highly suitable for solid-phase extraction (SPE). Density functional theory (DFT) confirmed the thermodynamic stability of the aflatoxin-adsorbent complex and directly links the gel's adsorption configuration to its high selectivity for target analytes. This work establishes a generalizable design strategy for adjustable-performance aerogels and offers mechanistic insights that support the development of highly specific aflatoxin enrichment technologies.