Graphene oxide-rare earth metal-organic framework composites for the selective isolation of hemoglobin

ACS Appl Mater Interfaces. 2014 Jul 9;6(13):10196-204. doi: 10.1021/am503298v. Epub 2014 Jun 27.

Abstract

Graphene oxide-La(BTC)(H2O)6 (H3BTC=1,3,5-benzenetricarboxylic acid) metal organic framework composites (LaMOF-GOn, n = 1-6, corresponding to the percentage of GO at 1, 2, 3, 4, 5, and 10%) are prepared through a simple and large-scale method at room temperature. The obtained composites are characterized by ATR-FTIR spectra, SEM, XRD, TGA, and N2 adsorption-desorption isotherm. The presence of GO significantly changes the morphologies of the composites from spindly rectangular rods to irregular thick blocks and increases their surface area from 14.8 cm(2) g(-1) (LaMOFs) to 26.6 cm(2) g(-1) (LaMOF-GO3), whereas at the same time, the crystalline structure of La(BTC)(H2O)6 is maintained. As a novel solid-phase adsorbent the LaMOF-GO composite exhibits outstanding adsorption properties for proteins. The strong hydrophobic interaction, especially π-π interaction between protein and the composite, is the main driving force for protein adsorption. In particular, highly selective isolation of hemoglobin (Hb) is achieved by using LaMOF-GO3 composite as sorbent in 4 mM B-R buffer containing 0.05 mol L(-1) NaCl at pH 8. The retained Hb could be effectively recovered with a 1 mM B-R buffer at pH 10, giving rise to a recovery of 63%. The practical applicability of the LaMOF-GO3 composite is demonstrated by the selective adsorption of Hb from human whole blood, and SDS-PAGE assays indicate that Hb could be selectively isolated with high purity from biological samples of complex matrixes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adsorption
  • Electrophoresis, Polyacrylamide Gel
  • Graphite / chemistry*
  • Hemoglobins / isolation & purification*
  • Metals, Rare Earth / chemistry*
  • Organic Chemicals / chemistry*
  • Oxides / chemistry

Substances

  • Hemoglobins
  • Metals, Rare Earth
  • Organic Chemicals
  • Oxides
  • Graphite