Synthesis of a stabilized colloidal suspension of PEGylated ceria nanoparticles for biomedical applications

In this study, a simple way to produce pegylated ceria nanoparticles (CNPs) with the use of low-cost and biofriendly starting reagents, such as low molecular Polyethylene Glycol (PEG) and Tris base buffer was attempted. Via this route, a highly stable aqueous suspension of ceria nanocrystals was synthesized. The synthesis of the suspension was performed at room temperature from a cerium nitrate solution. PEG was added as a dispersing agent and aqueous tris(hydroxymethyl)aminomethane (TRIS) solution 20% w/v was poured dropwise in order to achieve ceria precipitation. The CNPs had an average size of 5 nm and were almost monodispersed or formed loose agglomerates with short chainlike patterns of the size of 20 to 25 nm. The CNPs were characterized by TEM, XRD and DLS. PEGylation of the CNPs was confirmed via FT-IR analysis, while their surface chemistry was further investigated by XPS analysis. Finally, the stability of the ceria suspension was characterized with z-potential analysis.