Preparation Of Cu-Doped Mg-Al Hydrotalcites For The Selective Isolation Of Hemoglobin

Hydrotalcites or layered double hydroxides(LDHs)are a large class of 2D anionic clays material.The wide tunability of the species of metal cations,M2+/M3+ molar ratios and ion-exchangeable properties of interlayer compensating anions allow the LDH to be tailored to manufacture materials according to particular requirements in a wide variety of areas,including catalysts or catalyst supports,adsorbents,electroactive and photoactive materials,and drug delivery.The Cu-doped Mg-Al hydrotalcites,occupied the interlayer space of LDHs by carbonate,can be synthesized by coprecipitation method under constant pH and low supersaturation and characterized by X-ray diffraction,fourier transform infrared spectroscopy,scanning electron microscopy,elemental analysis and thermogravimetric analysis.The as-synthesized materials are in the form of roughly hexagonal plates of hydrotalcite resulting in a Cu2+ content of 23.17%(wt%)in the final product.It can be used for the efficient isolation of hemoglobin since the Cu-doped Mg-Al hydrotalcite provides abundant binding sites for Hb via metal-affinity interaction between metal-ions Cu2+and histidine residues of protein.The binding capacity can reach 3028 mg g-1 provided by Langmuir adsorption model.The adsorbed hemoglobin can be readily stripped by using 0.1%CTAB(pH 4.0),giving rise to a recovery of 74.9%.The Cu-doped Mg-Al hydrotalcite can be applied in the practical pretreatment of biological samples,namely human whole blood,obtaining high-purity hemoglobin as proved by SDS-PAGE(sodium dodecyl sulfate polyacrylamide gel electrophoresis assay)assays.