Fast and efficient adsorption/desorption of protein by a novel magnetic nano-adsorbent

A novel magnetic nano-adsorbent was prepared by covalently binding polyacrylic acid (PAA) on Fe3O4 superparamagnetic nanoparticles (13.2 nm) via carbodiimide activation. The maximum weight ratio of PAA to Fe3O4 was 0.12 (i.e., average of two PAA molecules on a magnetic nanoparticle). The magnetic nano-adsorbent possessed a high ionic exchange capacity of 1.64 meq g−1 and was efficient for the recovery of lysozyme. The lysozyme could be completely adsorbed in 0.1 M phosphate buffer at pH 3–5 and completely desorbed in NaSCN solution (>1 M) within 1 min, and retained 95% activity after adsorption/desorption. In addition, the adsorption behavior followed the Langmuir adsorption isotherm with a maximum adsorption amount of 0.224 mg mg−1 and a Langmuir adsorption equilibrium constant of 10 ml mg−1 at 25 °C. The change of enthalpy at 15–35 °C was −4.2 kJ ml mol−1 mg−1.

[1]  M. Wahlgren,et al.  The Adsorption from Solutions of β-Lactoglobulin Mixed with Lactoferrin or Lysozyme onto Silica and Methylated Silica Surfaces , 1993 .

[2]  E. Vulfson,et al.  The synthesis of sub-micron magnetic particles and their use for preparative purification of proteins. , 1998, Biotechnology and bioengineering.

[3]  Yan Sun,et al.  Fabrication and characterization of a rigid magnetic matrix for protein adsorption. , 2002, Journal of chromatography. A.

[4]  Robert C. Cammarata,et al.  Nanomaterials : synthesis, properties, and applications , 1996 .

[5]  C. Harland.  Ion exchange : theory and practice , 1994 .

[6]  A. Bajpai.  Adsorption of bovine serum albumin onto glass powder surfaces coated with polyvinyl alcohol , 2000 .

[7]  Nathan Kohler,et al.  Surface modification of superparamagnetic magnetite nanoparticles and their intracellular uptake. , 2002, Biomaterials.

[8]  W. Ngah,et al.  Removal of copper(II) ions from aqueous solution onto chitosan and cross-linked chitosan beads , 2002 .

[9]  Szu-Han Wu,et al.  Synthesis of Nickel Nanoparticles in Water-in-Oil Microemulsions , 2000 .

[10]  Younan Xia,et al.  Modifying the Surface Properties of Superparamagnetic Iron Oxide Nanoparticles through A Sol−Gel Approach , 2002 .

[11]  J. G. Zadow,et al.  The precipitation of proteins by carboxymethyl cellulose , 1975, Journal of Dairy Research.

[12]  I. Safarik,et al.  Use of magnetic techniques for the isolation of cells. , 1999, Journal of chromatography. B, Biomedical sciences and applications.

[13]  H. Shirahama,et al.  Adsorption of plasma proteins onto polymer latices. , 1991, Advances in colloid and interface science.

[14]  Dong-Hwang Chen,et al.  Immobilization of yeast alcohol dehydrogenase on magnetic nanoparticles for improving its stability , 2001, Biotechnology Letters.