Solventless mechanochemical preparation of novel magnetic bioconjugates

A solventless mechanochemical approach was employed to obtain a bioconjugate (BSA-DA-Fe₂O₃) based on bovine serum albumin (BSA) and dopamine (DA) coated iron oxide magnetic nanoparticles. UV-vis measurements of the obtained material showed a distinctive peak at 280 nm which, together with the presence of N on the surface of the nanomaterial (a band at 400 eV in the XPS spectrum) and zeta potential measurements, confirmed the successful immobilization of the protein. Additionally, the presence of two bands at 1652 and 1545 cm^-1 in the FT-IR spectra of both BSA and BSA-DA-Fe₂O₃ and steady-state fluorescence analysis validated that the protein preserved its native-like structure after the mechanochemical milling process. Also the functionalized MNPs preserved their magnetic properties as have been demonstrated by their magnetic susceptibility value.