Synthesis and characterization of core-shell magnetic molecularly imprinted polymer nanoparticles for selective extraction of tizanidine in human plasma

Abstract

In this study, simple, effective and general processes were used for the synthesis of a new nanomolecularly imprinted polymers (MIPs) layer on magnetic Fe3O4 nanoparticles (NPs) with uniform core-shell structure by combining surface imprinting and nanotechniques. The first step for the synthesis of magnetic NPs was co-precipitation of Fe2+ and Fe3+ in an ammonia solution. Then, an SiO2 shell was coated on the magnetic core with the St'ber method. Subsequently, the C=C groups were grafted onto the silica-modified Fe3O4 surface by 3- (trimethoxysilyl) propyl methacrylate. Finally,MIPs films were formed on the surface of Fe3O4@SiO2 by the copolymerization of C=C end groups with methacrylic acid (functional monomer), ethylene glycol dimethacrylate (crosslinker), 2,2-azobisisobutyronitrile (initiator) and tizanidine (template molecule). The products were characterized using techniques that included Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), thermo gravimetric analysis (TGA), scanning electron microscopy (SEM), UV spectrophotometry, transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). Measurement of tizanidine through use of the core- shell magnetic molecularly imprinted polymers nanoparticles (MMIPs-NPs) in human plasma samples compared to the paracetamol showed that the synthesized nanosized MMIP for tizanidine has acted selectively.