A simple and benign protocol for the synthesis of a deep eutectic solvent-based hydrophilic molecularly imprinted resin in water for excellent selective molecular recognition in aqueous phase

Abstract

Molecularly imprinted polymers (MIPs) are conventionally synthesized in organic solvents, resulting in poor compatibility with water and weak molecular recognition of targets in aqueous environments; hence, developing a green process to synthesize such MIPs would make the procedure more sustainable and the production more environmentally scalable. To achieve these objectives, a new deep eutectic solvent-based hydrophilic molecularly imprinted resin (DES-HMIR) was synthesized in water with excellent selective molecular recognition in aqueous phase; thus, the process pre-empts the consumption of large amounts of organic solvents. During the synthesis, the DES was simultaneously used as a porogen and cosolvent for the template, in order to improve the imprinting factor and increase the specific surface area of the DES-HMIR. Owing to its specific recognition performance and water phase compatibility, the DES-HMIR can specifically recognize and extract targets from aqueous matrices. The obtained DES-HMIR showed excellent specificity towards analytes compared to commercial adsorbents such as HLB, C₁₈, silica and SCX. The DES-HMIR could be easily regenerated with only 0.1 mL of 50% acetonitrile–water at room temperature and reused 26 times without a significant decrease in the adsorption capacity at pH 7. The DES-HMIR demonstrated excellent and specific recognition properties toward its target molecules in aqueous matrices, thereby allowing its use in a variety of promising applications, including environmental, biological, and clinical applications. Finally, the synthesis strategy proposed in this work provides a simple, efficient and green protocol for the preparation of water-compatible MIPs.