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

- A novel magnetic ultra-thin (∼10 nm) molecularly imprinted polymer (MMIP) for morphine (MO) was prepared by surface imprinting.
- The type and ratio to template of function monomer is screening by semi-flexible docking.
- Screening dummy template by computer simulation semi-flexible docking method.
- Study the adsorption mechanism by changing the pH.
- Detect the trace morphine by MISPE-HPLC in complex samples with a simple way.

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 Fe3O4 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 R2 = 0.9937), precision (1.07%-3.72%) and accuracy (83.62%-100.37%).