Preparation of Superparamagnetic Ribonuclease A Surface-Imprinted Submicrometer Particles for Protein Recognition in Aqueous Media

Abstract

Superparamagnetic ribonuclease A surface-imprinted polymeric particles that can preferentially bind the template protein in an aqueous environment were prepared in this study. Methyl methacrylate and ethylene glycol dimethacrylate were employed as the functional and cross-linker monomers, respectively. Regularly shaped submicrometer (700-800 nm) particles imprinted with ribonuclease A were successfully prepared using redox-initiated miniemulsion polymerization. Nanosized Fe3O4 magnetite was encapsulated in the imprinted particles with good encapsulation efficiency (17.5 wt %) for the incorporation of the superparamagnetic property. Good selectivity toward the template over the control protein in an aqueous environment was demonstrated by the imprinted particles in the batchwise and competitive rebinding tests with the highest template loading, Qmax, of 127.7 mg/g observed in the batch rebinding test. Given the small sizes of the imprinted particles and the presence of the binding sites on the surface, the rebinding process was kinetically favorable despite the sheer bulk of the macromolecules. In the desorption study, it was found that the more hydrophobic solvent was more effective for ribonuclease A desorption from the imprinted particles. This indicated that the hydrophobic effect was probably the main form of interaction responsible for the template rebinding to the imprinted sites in an aqueous media.

Preparation of silica-magnetite nanoparticle mixed hemimicelle sorbents for extraction of several typical phenolic compounds from environmental water samples

“…Both of the magnetic nanoparticles without and with a coating of SiO 2 exhibited typical superparamagnetic behavior due to not exhibiting hysteresis, remanence and coercivity. It is believed that the large saturation magnetization is a measure of the maximum magnetic strength [5]. The SiO 2 shell results in the decrease in the magnetic strength of the core/shell nanoparticles due to the weight contribution from the nonmagnetic SiO 2 .…”

“…Magnetic carrier technology (MCT), first reported by Robinson et al in 1973 [1], has become an increasingly popular tool in bioseparations, environmental and material science [2][3][4][5]. A distinct advantage of this technology is that magnetic materials can be readily isolated from sample solutions by the application of an external magnetic field.…”

Mixed hemimicelles solid-phase extraction based on cetyltrimethylammonium bromide-coated nano-magnets Fe3O4 for the determination of chlorophenols in environmental water samples coupled with liquid chromatography/spectrophotometry detection

“…There is no remanence and coercivity, suggesting that such NPs are superparamagnetic. Another key parameter is the large saturation magnetization, which is a measurement for the maximum magnetic strength [40]. The saturation magnetization is 63.2 emu/g for Fe 3 O 4 NPs and 58.7 emu/g for CTAB-coated very susceptible to magnetic fields and causes solid and liquid phases to separate easily.…”

Recent advances in molecular imprinting technology: current status, challenges and highlighted applications

“…Hydrophobic interaction, together with shape recognition mechanism, can provide satisfactory selectivity toward the template protein as reported by Tan et al 168 …”

“…In recent years, magnetic composite modified MIPs have become a hotspot based on the significant advantages of magnetic separation over conventional methods. 45,85,121,125,133 After binding the target molecule, the black MNPs can be easily separated by using an external magnetic field to replace the centrifugation and filtration step in a convenient and economical way. Compared to silica surface imprinting, the MNPs surface imprinting had the remarkable superiority of magnetic separation besides surface imprinting.…”