Controllable synthesis of Gd2O(CO3)2·H2O@silica–FITC nanoparticles with size-dependent optical and magnetic resonance imaging properties

Abstract

Gadolinium carbonate (Gd2O(CO3)2·H2O) nanoparticles (NPs) with different diameters (from 280 nm to 10 nm) were obtained through a simple hydrothermal process by adding different volumes of glycerol. These Gd2O(CO3)2·H2O NPs were further coated with a thin layer of silica containing fluorescent dye (fluorescein isothiocyanate, FITC), and the possibility of using these NPs for optical imaging was demonstrated. In addition, due to the presence of Gd3+ ions on the surface of the NPs, magnetic resonance imaging (MRI) of Gd2O(CO3)2·H2O NPs with different diameters was also reported in detail. Considering the effect of NPs' size on their biocompatibility and MRI properties, our research results indicated that the Gd2O(CO3)2·H2O NPs of 50 nm showed the highest cytotoxicity and the maximum uptake by cells, and the MRI properties of Gd2O(CO3)2·H2O@silica–FITC NPs are also size-dependent. Therefore, these NPs exhibit bifunctionality for both optical imaging and MRI, making them potentially applicable in the biomedical field.