1 research outputs found
Adsorption of Amino Acids, Aspartic Acid, and Lysine onto Iron-Oxide Nanoparticles
Understanding
the adsorption of amino acids (AAs) onto magnetic
iron-oxide nanoparticles (SPIONs) is important not only for the preparation
of the aqueous suspensions, but also for understanding the interactions
at the bionano interface. In this investigation the adsorption of
aspartic acid (Asp) and lysine (Lys) onto SPIONs was studied, based
on a characterization of the suspension properties, i.e., measurements
of the ξ-potential, the hydrodynamic size, and the osmolality,
and by direct HPLC analysis of the AA in the supernatants and at the
nanoparticles of the ultracentrifuged suspensions. The results show
that the AAs adsorb onto the SPIONs in the form of large molecular
associates, which decisively influence the nanoparticles’ surface
properties. A measurement of the freezing-point depression using a
Knauer osmometer proved that the molecular associates are already
formed in the AA aqueous solutions