Strategy of Fusion Covalent Organic Frameworks and Molecularly Imprinted Polymers: A Surprising Effect in Recognition and Loading of Cyanidin-3-O-glucoside

Seven magnetic covalent organic framework molecularly imprinted polymers with magnetic responsiveness, large specific surface area, and molecular recognition ability were successfully synthesized, suitable for the separation of cyanidin-3-O-glucoside from complex samples. Using a room-temperature synthesis strategy, covalent organic frameworks accompanied by imprinted sites were formed in one step on the functionalized magnetic nanoparticles with 1,6-hexanediamine. The composite materials were easy to prepare and showed high adsorption capacity (127 mg g–1) together with favorable adsorption selectivity for cyanidin-3-O-glucoside over other flavonoids and phenolic acids. Magnetic covalent organic framework molecularly imprinted polymers exhibited good stability in 10 adsorption–desorption cycles. This work established a new method of extracting and separating high-purity anthocyanins and even unstable natural compounds.