Computational-aided design of magnetic ultra-thin dummy molecularly imprinted polymer for selective extraction and determination of morphine from urine by high-performance liquid chromatography

In this work, a novel magnetic ultra-thin dummy molecularly imprinted polymer (MMIP) for morphine (MO) was prepared. In order to obtain highly selective recognition cavities, the MMIP has been designed using semi-flexible docking to screen the optimal monomer and its ratio to morphine from six representative monomers. Furthermore, the dummy template was creatively screened by semi-flexible docking method from opioid drugs. The system of dihydrocodeine (DI) as dummy template, methacrylamide (MAC) as founctional monomer, ethyleneglycol dimethacrylate (EGDMA) as crosslinker was chosen for MO imprinting. The morphological and magnetic properties of MMIP were characterized by FT-IR, TEM and VSM. The results suggested that molecularly imprinted polymer (MIP) was synthesized evenly on Fe 3 O 4 surface. The adsorption experiments revealed that MMIP showed better extraction capacity and selectivity toward MO and its analogues than the non-imprinted polymer (NIP). The MMIP possessed adsorption capacity of 14.71   mg/g for MO and the imprinting factor was 2.10 at separate adsorption and 1.87 at competitive adsorption. A magnetic molecularly imprinted solid phase extraction coupled with HPLC method (M-MISPE-HPLC) has been established for the analysis of MO in urine sample. The developed method was validated for its linearity (0.038–100   mg   L −1 R 2   =   0.9937), precision (1.07%–3.72%) and accuracy (83.62%–100.37%).