Synthesis, Characterization and Toxic Metal-Binding Ability of Poly(y-glutamic acid)-Coated Superparamagnetic Nanoparticles

摘要

Poly(γ-glutamic acid)-coated superparamagnetic iron oxide nanoparticles (PGA-SPIONs) were synthesized by co-precipitation method, characterized and evaluated for toxic metal-binding ability in detoxification therapy. Characterization of bare- and PGA-SPIONs by FTIR, VSM and TGA revealed the coating of PGA on SPIONs and by XRD the magnetite nature, with the respective mean particle size by TEM being 11.8 and 14 nm and saturation magnetization value by VSM being 71.2 and 61.7 emu/g. In vitro binding of lead and cadmium by PGA-SPIONs was rapid attaining >90% binding within 1 min. A maximum binding occurred at pH 4-7, corresponding to gastrointestinal pH values except for the stomach (pH 1-2.5). Binding isotherms predicted by the Langmuir isotherm showed a maximum binding capacity of 98.70 mg/g for lead and 31.13 mg/g for cadmium. Incorporation of essential metals (K, Ca, Mg, Zn, Fe and Cu) did not show marked influence on lead binding, but significantly reduced the binding of cadmium.