Computational design, synthesis and utilization of a magnetic molecularly imprinted polymer on graphene oxide nanosheets for highly selective extraction and determination of buprenorphine in biological fluids and tablets

Herein, a novel approach to computational design and preparation of a magnetic molecularly imprinted polymer (MMIP) for the selective extraction of buprenorphine (BUP) from real plasma and urine samples and tablets has been developed. The MMIP was synthesized on graphene oxide (GO) nanosheets after their modification with a silica coating layer and vinyl moieties. Following the sorption and elution of BUP, the analyte determination was conducted by high-performance liquid chromatography. At first, Fe3O4 nanoparticles were immobilized on the GO surface via a chemical co-precipitation process, and then the magnetic GO was functionalized with vinyl moieties, and finally a MIP layer was synthesized on the surface of the modified magnetic GO via a precipitation polymerization process. The prepared polymer was characterized by FT-IR spectroscopy, scanning electron microscopy, transition electron microscopy and X-ray diffraction analysis. Afterwards, the effect of various parameters on the magnetic solid phase extraction of BUP was explored thoroughly via the design of experiments and desirability function. After optimization, equilibrium isotherms were investigated, and the results showed that the sorption phenomenon obeys the Langmuir model. The maximum sorption capacity of the MMIP toward BUP was equal to 76.9 mg g(-1), which was 4.0 times higher than the sorption capacity of the MNIP. The kinetic studies revealed that the sorption process followed a pseudo-second-order model. Ultimately, the analytical applicability of the developed method was confirmed by the successful extraction and determination of BUP in biological fluids and BUP tablets.