Raman spectroscopy of albumin interaction with nanodiamond films

This study is focused on finding the possible structural changes of molecules of one of the principal proteins of blood plasma (albumin) that occur upon their interaction with nanodiamonds. The interaction between nanodiamond films and protein films that form after solutions dry up is analyzed. A possibility of spontaneous protein crystallization after the solution dries up on the surface of a nanodiamond film is demonstrated. It is found by means Raman spectroscopy that the secondary structure, the structure of disulfide bridges, and the structure of the tyrosine doublet of the protein do not change (with respect to the corresponding structures in the lyophilized state) upon the interaction of the protein with a nanodiamond film, at least in the bulk of a protein film with a thickness of 1 μm. However, conformational changes may occur in a fairly thin (about 20 nm) near-surface layer of the protein film.