Deep eutectic solvent-assisted green synthesis of a TpPa-COF-based surface molecularly imprinted polymer for selective adsorption of Myricetin

This study explores the synthesis and application of a 2D block -shaped covalent organic framework(COF) and its integration into a surface molecularly imprinted polymers(SMIPs) for the selective adsorption of Myricetin(Myr) from food samples. The COF was synthesized using a binary deep eutectic solvent(DES1) composed of choline chloride and glycerol, while the molecularly imprinted polymers(MIPs) were polymerized on the surface of the COF utilizing a ternary deep eutectic solvent(DES2), consisting of choline chloride, acrylamide, and ethylene glycol. After optimizing the proportion of DESs, the resulting 50%-DES applied to COF(DC)-MIP exhibited a high adsorption capacity of 40.04 mg/g within 0.5 h at pH 6.0. The adsorption process, characterized by Langmuir isotherms and pseudo-second-order kinetics, was exothermic. The XPS and UV–Vis spectra confirm the adsorption mechanisms, indicating that Myr adsorption onto the COF-based MIP was predominantly driven by hydrogen bonding and π-π stacking interactions. Due to the COF serving as the matrix material, which enhances the structural stability and solvent resistance of the polymer, the 50%-DC-MIP demonstrated excellent recyclability, maintaining consistent performance over five cycles. Because of excellent selectivity, the 50%-DC-MIP was effectively employed to grape juice, bayberry juice and green tea resulting in satisfactory recoveries of 94.67% to 102.25%, 93.75% to 108.33% and 97.33% to 101.15%, respectively. These findings highlight the potential of COF-based MIPs for the selective extraction and detection of bioactive compounds like Myricetin in complex food samples, aligning with green chemistry principles by utilizing DES as environmentally friendly solvents.