Green and eco-friendly porous imprinted hydrogels with cellulose nanocrystals-based precise-designed hyperbranched sites for high-accuracy separation and purification of naringin

Hyperbranched sorbents has attracted extensive concern from scholars at home and abroad owing to its rich surface termination recognition units and hyperbranched crosslinking structure. In this work, a new kind of porous hyperbranched boronate affinity molecularly imprinted hydrogel (PHs@CNCs@Y-Br-MIPs) were prepared via Pickering emulsion template method for selective separation and purification of flavonoids in complex agricultural wastewater. The novel multi-response hyperbranched Pickering particles based on cellulose nanocrystals (CNCs) can effectively enhanced the biocompatibility, hydrophilic, and interface stability of the emulsion system. Meanwhile, the introduction of dipentaerythritol hexyl (3-mercaptopropionic acid) (DH) in CNCs@SH@Y-Br could provide abundant hyperbranched anchor groups for immobilizing template molecules, resulting in the formation of more specific binding sites. In addition, the 4-formyl-1,2 phenylbis (2-bromo-2-methyl protocarbamate) (Y-shaped initiator) can precisely regulate the distribution of imprinted site and imprinted efficiency via atomic radical polymerization (ATRP). As expected, the resulting PHs@CNCs@Y-Br-MIPs showed fast adsorption kinetics (360 min) for NRG under pH = 7.4 and the excellent NRG adsorption capacity (Qmax = 42.28 μmol g−1). Compared to non-imprinted polymer, the PHs@CNCs@Y-Br-MIPs exhibited the promising imprinting factors (IF = 2.74) owing to the abundant boronate affinity sites numbers of 46.81 μmol g−1 and the high-affnity binding site density of 0.56 μmol/m2 on PHs@CNCs@Y-Br-MIPs. The adsorption–desorption cycles proved excellent regenerability (only 6.79 % loss) after six adsorption–desorption cycles. Furthermore, the NRG extraction rate of PHs@CNCs@Y-Br-MIPs increased to 93.61 %. The purified NRG had good antibacterial properties against Staphylococcus aureus (13.17 mm of antibacterial bands). As such, the ability to hyperbranched imprinted polymers-regulate the recognition site density and selectivity highlights their significance in functioning as smart porous imprinted sorbents for separation and purification of targeted flavonoid molecules.