In situ functionalization of gadolinium oxide nanoparticles with polyethylene glycol (PEG) by pulsed laser ablation in a liquid medium (PLAL)

Abstract

Gadolinium oxide (Gd2O3) nanoparticles with paramagnetic properties and biocompatible surfaces are promising materials for bioimaging applications. We synthesizedin situ pegylated Gd2O3(Gd2O3@PEG) nanoparticles by liquid phase pulsed laser ablation (PLAL) of a gadolinium target in a polyethylene glycol (PEG) liquid medium. We characterized their shape and morphology using transmission electron mi-croscopy (TEM), and confirmed their crystalline structure with X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) in combination with energy-dispersive X-ray spectroscopy (EDX) elemental mapping. The magnetic properties of the nanoparticles were characterized by vibrating sample magnetometry (VSM). We have found that the crystalline nanoparticles generated have a spherical shape and a narrow distribution with average diameters of 15.0, 11.6, and 6.0 nm, for PEG concentrations of 0.01, 0.05, and 0.10 mM, respectively. We verified that partially oxidized molecules of PEG are attached to the nanoparticle surface as carboxyl groups. An analysis of the magnetization of Gd2O3@PEG nanoparticles revealed highly paramagnetic properties. Consequently, PLAL forms a green synthesis of Gd2O3@PEG, opening up new opportunities for bioimaging applications