Fig. 2From: Passage of Magnetic Tat-Conjugated Fe3O4@SiO2 Nanoparticles Across In Vitro Blood-Brain Barrier a XPS survey scan spectra; b Fe2p, c Si2p, and d N1s of Fe3O4, Fe3O4@SiO2, and Fe3O4@SiO2-Amino NPsBack to article page