Gadolinium-doped carbon dots with high quantum yield as an effective fluorescence and magnetic resonance bimodal imaging probe

Gd-CDs with maximum quantum yield of 69.86% and improved longitudinal relaxivity of 14.33 mM−1 s−1 were synthesized via a convenient one-step hydrothermal method. Excellent water solubility, good biocompatibility, and negligible cytotoxicity make Gd-CDs an ideal dual-modal fluorescence/MR imaging nanoprobe in practical biological and clinic applications in the future.156