Molecularly imprinted superparamagnetic iron oxide nanoparticles for rapid enrichment and separation of cholesterol

Analyst. 2013 Dec 7;138(23):7238-45. doi: 10.1039/c3an01458d. Epub 2013 Oct 17.

Abstract

A general protocol to prepare surface molecularly imprinted polymer core-shell superparamagnetic Fe3O4 nanoparticles (Fe3O4@MIP SPNPs), using a surface-mediated RAFT polymerization approach, is described. Cholesterol-imprinted Fe3O4@MIP SPNPs were obtained by oleic acid-stabilized Fe3O4 nanoparticles with a trithiocarbonate agent and subsequently by polymerizing thin molecularly imprinted layers composed of dimethylacrylamide and N,N'-methylene(bis)acrylamide units. The surface-mediated RAFT polymerization approach allows the synthesis of ∼20 nm hybrid composite particles with a ∼6 nm MIP shell, exhibiting superparamagnetic properties (saturation magnetization = 35.4 emu g(-1)) and specific molecular recognition of cholesterol. The Fe3O4@MIP SPNPs show the capability of rapid enriching and separating cholesterol (∼3.1% in weight) and are renewable and cyclically exploited due to their monodispersive and superparamagnetic features. Moreover, under optimal conditions, the Fe3O4@MIP SPNP recoveries of spiked human serum, milk, yolk and beef were 91.6%, 93.6%, 92.4% and 91.2%, respectively. Finally, the method of molecular imprinting on superparamagnetic particles can be extended to a wide range of applications for cell sorting, biomolecule enrichment and separation, and drug delivery.

MeSH terms

  • Cholesterol / chemistry*
  • Cholesterol / isolation & purification
  • Ferric Compounds / chemistry*
  • Metal Nanoparticles*
  • Microscopy, Electron, Transmission
  • Molecular Imprinting*

Substances

  • Ferric Compounds
  • ferric oxide
  • Cholesterol