“…One-pot approach such as hydrothermal treatment of citrate acid (CA), ethanediamine, and GdCl 3 at 200 °C [21], or microwave-assisted polyol method using sucrose, concentrated H 2 SO 4 , and GdCl 3 [22], have also been successfully demonstrated to prepare Gd-doped CQDs. Recently, Gd-doped CQDs are also prepared by simple calcination of gadopentetic acid (Gd-DTPA) [23]. Nevertheless, exploration of CQDs as multimodal imaging nanoprobes for biological processes monitoring still remains in the early stage.…”