One Dual Stimulus Response Molecular Imprinted Hydrogel for Specific Recognition and Enrichment of Doxorubicin

In this study, dual stimulus-response molecularly imprinted hydrogels (MIHs) with water-soluble doxorubicin (DOX) as the imprinted molecule were developed for improving the selective specific recognition capacity. By using N-isopropylacrylamide (NIPAM) as a temperature-sensitive monomer, and N-[3-(dimethylamino)propyl]methacrylamide (DMAPMA) as a pH-responsive functional monomer, a series of MIHs with different concentration ratios of dual functional monomers and cross-linker were prepared to study the influencing factors of selective recognition. The results show the prepared MIHs have different rigidity and flexibility under different synthesis conditions. The MIH7 with good adsorption performance and specific recognition ability was selected with its molar ratio of NIPAM/DMAPMA/cross-linker (200/10/100). Its imprinting factor of DOX was as high as 2.26. Adsorption kinetic and adsorption thermodynamic studies showed that MIH7 and DOX had high affinity, and its affinity constant K_D was as high as 9.11 × 10⁻⁶ mol/L. For selectivity adsorption, the MIH7 had excellent selectivity at pH 5, with a selectivity factor as high as 1.97 for epirubicin, which is extremely similar in structure, and selectivity factors as high as 6 and 7.68 for idarubicin and oxytetracycline, respectively. The prepared MIH7 was well separated with good specific recognition of DOX in the serum samples, which provided a potential strategy based on the dual stimulus-response and cross-linker for the efficient recognition of water-soluble molecules.