Highly Dispersed Hemoglobin-Layered Double Hydroxides Hybrid Materials

In this work, we prepare hemoglobin-Layered double hydroxides hybrid materials, which dispersed state is different, by self-assembly of exfoliated LDH nanosheets with hemoglobin (Hb). XRD, SEM, TEM, and FT-IR are employed to systematically analyze the resulting composite in detail. The Hb intercalated LDH and highly dispersed Hb-LDH nanohydrid materials can be synthesized by controlling the reactive conditions. The TG-DTA curves indicate the thermal stability of Hb which is assembled with LDH are improved. The ATR-FTIR spectra indicates the second structure of Hb is not changed after assembling. The fluorescence spectra indicates the environmental polarity around the Trp- and Tyr- residues are enhanced, and the changes are diminishing by the increasing of dispersed state.The catalytic activity of Hb was studied using H₂O₂ oxidation of o-phenylenediamine (OPD) to phenazine as a model reaction. Though the catalytic activiy of immobilized Hb are lower than free Hb in water at 25℃, the catalytic activity of immobilized Hb are higher than free Hb both in water at 90℃and in tolene at 25℃, and the residual acivity are higher than free Hb, too. The catalytic activiy of highly dispersed Hb-LDH is higher than Hb intercalated LDH both in water at 25℃, 90℃and in tolene at 25℃.The residual activity of unaged highly dispersed Hb-LDH is 18.57 times that of free enzyme in water at 90℃, and 5.75 times that of free enzyme in tolene at 25℃.