A study of the binding of colloidal Fe3O4 with bovine hemoglobin using optical spectroscopy

The interaction between bovine hemoglobin (BHb) and Fe3O4 colloid was investigated by UV/vis absorption, FT-IR, fluorescence, resonance light scattering spectra, CD, synchronous fluorescence, and three-dimensional fluorescence spectra techniques under physiological pH 7.40. Fe3O4 effectively quenched the intrinsic fluorescence of BHb via static quenching. The process of binding Fe3O4 on BHb was a spontaneous molecular interaction procedure. The thermodynamic parameters indicate that van der Waals and hydrogen bonds, electrostatic interactions played a major role in stabilizing the Fe3O4–BHb complex. The effect of Fe3O4 on the conformation of BHb was analyzed using CD and synchronous fluorescence spectroscopy.