Raman spectroscopy of the interaction of carbon-coated iron nanoparticles with proteins

In this work, using Raman spectroscopy, the interaction of graphene-coated iron nanoparticles (G-Fe NPs) with the proteins lysozyme and immunoglobulin G (IgG) is studied. Two additional peaks in the Raman spectrum in the region of
$655-730\ \text{cm}^{-1}$
reflecting the interaction of G-Fe NPs with IgG were found for their solution. The amplitude of the found peaks decreases significantly with a change in pH to 4, which is below the isoelectric point of the IgG. In the spectrum of solution of G-Fe NPs and lysozyme, at pH values below the lysozyme isoelectric point, no additional peaks reflecting the interaction of nanoparticles with protein were observed.