Fig. 2

(a) UV-vis absorption and fluorescence spectra of Gd/Ru-CDs solutions. (b) T1WI and T1 Map images of Gd/Ru-CDs (Gd³⁺ concentration: mM); (c) and longitudinal MR relaxation curve of Gd/Ru-CDs. (d) Cell viability of Gd/Ru-CDs towards L929 and 4T1 cells; (e) The hemolytic percentage of Gd/Ru-CDs to human red blood cells (PBS as a negative control and TX-100 as a positive control); (f) The fluorescence stability of Gd/Ru-CDs in 30 days. (g) Fluorescence images of the cellular uptake of Gd/Ru-CDs (200 μg mL^− 1) by 4 T1 cells in 6 h, scale bar = 20 μm