Preparation of Gd2O3:Er,Yb Nanoparticles by Laser Ablation in Liquid and Their Optical Properties for Biomedical Application

Gd2O3:Er,Yb upconversion nanoparticles were obtained by laser ablation in liquid, and their optical properties were investigated. These nanoparticles are suitable for photodynamic therapy which is a cancer treatment approach. Since the nanoparticles are for medical use, purity is required. Thus, laser ablation in liquid was selected as a suitable production method because it produces no impurities. Nanoparticles were prepared by Nd:YAG (532-nm) laser-irradiation to Gd2O3:Er,Yb target in water. The nanoparticles compositions were analyzed using X-ray diffraction, which showed that the nanoparticles and target raw material have the same peak. The primary particle size was measured using scanning electron microscopy, which revealed the coarse (>100 nm) and fine (