Reshaping the imprinting strategy through the thermo-responsive moiety-derived “deep eutectic solvents” effect

As a new concept having emerged in last few years, the “deep eutectic solvents” (DESs) effect integrated into the imprinting technology inevitably exposes design limitations of stimuli-responsive molecularly imprinted polymers (MIPs), as well as inadequate analysis of the adsorption performance of MIPs. Herein, a simple yet defined N-isopropylacrylamide/(3-acrylamidopropyl) trimethylammonium chloride (NIPAM/APTMAC) binary DESs system was proposed to prepare intelligent MIPs with thermo-sensitivity. Accordingly, magnetic and thermo-responsive MIPs based on functional monomers-derived DESs (TM-DESs-MIPs1) were synthesized, revealing DESs effect-regulated affinity/kinetics for the enhanced adsorption capability, eco-friendly thermo-regulated elution for high release efficiency, and simple magnetic separation, along with superior selectivity to rhein (RH) and good regeneration ability. TM-DESs-MIPs1 were utilized to extract RH from Cassiae semen samples coupled with high performance liquid chromatography (HPLC), yielding satisfactory recoveries (79.47%−110.82%) and low limits of detection (LOD) (16.67 µg/L). Another two kinds of MIPs adopting the thermo-responsive moiety-derived DESs effect strategy further demonstrated great applicability of such intelligent MIPs for analyses of complicated samples.