A green and sustainable synthesis of polydopamine molecularly imprinted resin for selective recognition emodin in Rumex acetosa L.: experiments and simulation

The typical phytochemical emodin (ED) found in Rumex acetosa L. is extensively utilized in traditional medicine and demonstrates substantial pharmacological effects. However, Rumex acetosa L. is frequently regarded as a weed and discarded, leading to the underutilization of this valuable resource. In this work, a polydopamine molecularly imprinted resin (PDA@MIR) was successfully synthesized for the selective recognition and isolation of ED. The PDA@MIR is fabricated using macroporous resin X-5 as the carrier, dopamine as the green functional monomer, and emodin as the template molecule. The PDA@MIR displays excellent adsorption capacity (41.55 mg⋅g −1 ) for ED and adsorption affinity (IF = 3.19). Meanwhile, even after going through 10 cycles of adsorption-desorption tests, it demonstrates consistent adsorption efficacy and reusability. Moreover, the PDA@MIR can serve as the innovative column filler in solid-phase extraction (SPE) for applying to the separation of ED from Rumex acetosa L. roots extracts. The adsorption recovery rate of ED reaches 90.95%, while the effective adsorption recovery rate is 85.33%. The DFT simulation and NMR analysis reveales that the recognition mechanism of PDA@MIR is attributed to interactions involving hydrogen bonds and Van der Waals forces. Furthermore, this study provides valuable insights into the design of molecularly imprinted resin materials, which possess superior recognition capabilities and exceptional selectivity for the specific separation and recognition of phytochemicals from plant extracts.