Fig. 2. (a) Fluorescence spectra of LRu and NCPs with different Gd/Yb ratios. (b) T 1-weighted MR images and CT images of the NCPs with different Gd/Yb ratios and water. (c) TEM images of PEG@NCPs. (d) Photographs of PEG@NCPs aqueous solutions under sunlight and excitation at 365 nm. (e) UV-Vis absorption and fluorescence spectra of the PEG@NCPs and LRu. (f) r 1 relaxivity curve of the PEG@NCPs and Gd/Yb–Ru NCPs (1 : 2). Inset: T 1-weighted MR images of the PEG@NCPs under different concentrations. (g) CT attenuation plot of the PEG@NCPs. Inset: CT image of the PEG@NCPs under different concentrations.
