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Updated: Jan 31, 2026

IridiumIII Luminescent Probe for Detection of the Malarial Protein Biomarker Histidine Rich Protein-II
Published on: July 7, 2015
Metal affinity-carboxymethyl cellulose functionalized magnetic graphene composite for highly selective isolation of
Yixun Liang1, Jiawei Liu1, Lili Wang1
1Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of the Ministry of Education, Modern Separation Science Key Laboratory of Shaanxi Province, College of Chemistry & Materials Science, Northwest University, Xi'an 710069, PR China.
Abstract:
A metal affinity-carboxymethyl cellulose functionalized magnetic graphene, namely MGCI-Cu composite, was prepared by successive modifications of graphene oxide nanosheets with magnetic nanoparticles, carboxymethyl cellulose (CMC), iminodiacetic acid (IDA) and then chelated with copper ions. The successful modifications of the graphene surface were demonstrated by various characterizations, and a high density of 6.17 μmol m-2 for metal affinity groups was obtained. The composite exhibited high adsorption selectivity toward histidine-rich proteins. The adsorption was governed by strong metal affinity binding force between hisitidine residues of proteins and immobilized Cu2+ ions of MGCI-Cu composite. In particular, highly selective isolation of hemoglobin (Hb) was achieved in 0.2 mol L-1 phosphate buffer at pH 8. The adsorption capacity of Hb significantly increased to 769 mg g-1 in comparison to that of 435 mg g-1 on metal affinity modified magnetic graphene composite (MGI-Cu) without CMC modification. The adsorbed Hb molecules were recovered with a carbonate buffer (0.2 mol L-1 pH 10) containing 0.5 mol L-1 imidazole. MGCI-Cu composite displayed favorable reusability for at least four times after regeneration of the composite by edetic acid (EDTA) and Cu2+ solution. The practical applications demonstrated that MGCI-Cu composite could highly selectively isolate Hb from human whole blood and polyhistidine-tagged recombinant protein from Escherichia coli (E. coli) lysate.
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