Carbon-coated (Eu/Dy-Enabled) erbium hydroxide nanostructures for biomedical imaging

Abstract

Lanthanides possess versatile optical and magnetic properties, making them an excellent candidate for multimodal imaging. This study focuses on carbon-coated Erbium Hydroxide Nanoparticles (Er(OH)3 NPs), their cytotoxicity, and their potential for biomedical imaging. Er(OH)3 NPs were synthesized via a simple solvothermal method with the incorporation of different lanthanide dopants (Eu, Dy) to enhance the optical and magnetic properties. The spherical morphology, monodispersity, elemental composition, and effective carbon coating were demonstrated using characterizations such as SEM, EDS, and DLS. These monodisperse NPs were further evaluated for their cytotoxicity in Hep2c cervical cancer cells via colorimetric assays, thus proving carbon coating effectively reduces the cytotoxicity. Photoluminescence data of these NPs show multiple emission peaks with a maximum peak at 433 nm when excited at 253 nm. Magnetic resonance imaging (MRI), and computed tomography (CT) scans of these NPs were carried out to evaluate the multimodal imaging potential as contrast agents. The CT contrast shows comparable results to those of iodine-based contrast agents while the MRI scans of the carbon-coated samples show T2-weighted contrast. These findings provide insights into the potential use of Lanthanide-Enabled Er(OH)3 NPs (LEENs) as multimodal contrast agents.