Fig. 9. (a) Intensity of the T1-weighted magnetic resonance (MR) imaging signal (the bright field and the color mapping images) as a function of concentration of Gd3+ in UCNP–BPNS nanocomposite, and (b) graph of relaxation rate (1/T1) versus concentration of the Gd3+ in UCNP–BPNS nanocomposite with the corresponding linear fit.
