Abstract The identification of peptides that can be coupled to magnetic nanoparticles and be directed against specific receptors has been developed and applied intensively in various biomedical applications, such as magnetic resonance imaging (MRI), to diagnose neurodegenerative diseases. This work describes the properties of magnetic zero-valent iron (nZVI) nanoparticles coated with silica and subsequently decorated with a peptide as a biomarker of neuroinflammation. The synthesized nanostructured compounds were systematically characterized by XRD, SEM, AFM, DLS, FTIR and VSM techniques. Biotin-Streptavin-HRP system was carried out to confirm the peptide's anchoring to the surface of the nanoparticles. The results showed that this nanostructured compound is an excellent candidate as a contrast agent capable of being used in magnetic resonance imaging, which would optimize the diagnosis of neuroinflammatory lesions compared to current contrast media.

Rare earth garnets (REE3Fe5O12) have magnetic-electric and optical properties that can be used in transmitters, microwave and data storage devices. These properties depend mainly on partial or total substitution of the cationic sites, as well as by the synthesis method used. Therefore, in this work was studied the influence of the substituting cation on the structural and morphological properties of new garnets with formula Sm3−xREExFe5O12 with x = 0.0 - 1.0; obtained by the solid-state reaction method. Characterization of samples was carried out by XRD, Rieltveld refinement, SEM and Raman spectroscopy. The results showed that the substitution favors system stability and formation of garnets single phase with cubic structure and space group of Ia3d (230) at temperatures lower than reported by other authors. The substitution generated a decrease of the lattice parameters, the crystal size and favored particle formation of the order of micrometers (from 1.3 to 3.6 µm).