Gum arabic coated magnetic nanoparticles with affinity ligands specific for antibodies

Research output: Contribution to journalArticlepeer-review

56 Citations (Scopus)


A novel magnetic support based on gum Arabic (GA) coated iron oxide magnetic nanoparticles (MNP) has been endowed with affinity properties towards immunoglobulin G (IgG) molecules. The success of the in situ triazine ligand synthesis was confirmed by fluorescence assays. Two synthetic ligands previously developed for binding to IgG, named as ligand 22/8 (artificial Protein A) and ligand 8/7 (artificial Protein L) were immobilized on to MNPs coated with GA (MNP_GA). The dimension of the particles core was not affected by the surface functionalization with GA and triazine ligands. The hydrodynamic diameters of the magnetic supports indicate that the coupling of GA leads to the formation of larger agglomerates of particles with about 1μm, but the introduction of the triazine ligands leads to a decrease on MNPs size. The non-functionalized MNP_GA bound 28mg IgG/g, two times less than bare MNP (60mg IgG/g). MNP_GA modified with ligand 22/8 bound 133mg IgG/g support, twice higher than the value obtained for ligand 8/7 magnetic adsorbents (65 mg/g). Supports modified with ligand 22/8 were selected to study the adsorption and the elution of IgG. The adsorption of human IgG on this support followed a Langmuir behavior with a Qmáx of 344mg IgG/g support and Ka of 1.5×10,5 M. The studies on different elution conditions indicated that although the 0.05M citrate buffer (pH 3) presented good recovery yields (elution 64% of bound protein), there was occurrence of iron leaching at this acidic pH. Therefore, a potential alternative would be to elute bound protein with a 0.05M glycine-NaOH (pH 11) buffer.

Original languageEnglish
Pages (from-to)462-471
Number of pages10
JournalJournal of Molecular Recognition
Issue number5
Publication statusPublished - 1 Sep 2010


  • Affinity ligands
  • Antibodies
  • Gum arabic
  • Magnetic nanoparticles
  • Purification


Dive into the research topics of 'Gum arabic coated magnetic nanoparticles with affinity ligands specific for antibodies'. Together they form a unique fingerprint.

Cite this