# Physicochemical and Multimodal Imaging Properties of Core–Shell Ln2O3@Carbon Nanoparticles (Ln = Tb and Ho)

## TL;DR

Researchers created new core-shell nanoparticles with potential for MRI and fluorescence imaging due to their magnetic and light-emitting properties.

## Contribution

First synthesis of Ln2O3@carbon nanoparticles with dual T2 MRI contrast and fluorescence imaging capabilities.

## Key findings

- Nanoparticles showed low toxicity and good colloidal stability.
- Paramagnetic properties suitable for T2 MRI contrast at high fields.
- Carbon shell emitted photoluminescence at 460 nm for fluorescence imaging.

## Abstract

In this study, core–shell Ln2O3@carbon nanoparticles (core = Ln2O3 and shell = carbon; Ln = Tb and Ho) were synthesized for the first time by preparing Ln2O3 nanoparticles through a polyol method, followed by carbon coating using D-glucose as a carbon precursor in aqueous media. The synthesized Ln2O3@carbon nanoparticles exhibited good colloidal stability in solution and very low toxicity in in vitro cellular cytotoxicity tests. They exhibited paramagnetic magnetization values that increased with increasing applied field strength, resulting from spin–orbit magnetic moments of 4f-electrons; hence, they yielded negligible r1 (<0.1 s−1mM−1) and appreciable r2 values (3.446 and 3.677 s−1mM−1 for Ln = Tb and Ho, respectively) at 3 T, highlighting their potential as T2 MRI contrast agents, particularly at high MR fields. In addition, the carbon coating shell exhibited photoluminescence at 460 nm, suitable for applications in fluorescence imaging probes.