Gadolinium and Ytterbium-Doped carbon dots for Fluorescence/Magnetic Resonance/Computed tomography multimodal imaging

Multimodal imaging is a potent technique that integrates complementary information from various imaging modalities, offering comprehensive insights into disease diagnosis. However, the development of biocompatible multimodal probes remains a challenge. In this study, we present the synthesis, characterization, and application of gadolinium and ytterbium co-doped carbon dots (Yb/Gd-CDs) for triple-modal fluorescence (FL)/magnetic resonance (MR)/computed tomography (CT) imaging. Notably, Yb and Gd were successfully incorporated into the lattice of CDs using a facile one‐pot hydrothermal approach to obtain Yb/Gd-CDs. The Yb/Gd-CDs demonstrated an ultra-small size, excellent colloidal stability, and low toxicity, making them suitable for further in vivo applications. Moreover, the Yb/Gd-CDs exhibited excellent fluorescence, high X-ray attenuation (40.17 HU/g/L), and high T 1 relaxivity (11.16 mM -1 s −1 ) with an ultra-low r 2 /r 1 ratio of 1.08, showcasing remarkable performance in in vivo fluorescence, T 1 -weighted MR, and CT imaging of mice. Yb/Gd-CDs show great promise for in vivo multimodal imaging, and this work provides a highly biocompatible CDs-based theranostic platform with multiple functions for disease diagnosis.