Fig. 1From: Magnetic resonance imaging with upconversion nanoprobes capable of crossing the blood-cerebrospinal fluid barrierTransmission electron microscopy (TEM) images of (a) core upconversion nanoparticles (UCNP, NaYF4:Yb/Tm), (b) core-shell UCNP (NaYF4:Yb/Tm@NaGdF4), and (c) Angiopep-2/polyethylene glycol-UCNP (ANG-PEG-UCNP). (d-i) Element mappings of basic chemical elements (Yb, F, Y, Gd, and Na) of ANG-PEG-UCNP.Back to article page