Effect of physiological fluid on the photothermal properties of gold nanostructured

https://www.mdpi.com/1422-0067/24/9/833

Effect of Aminosilane Nanoparticle Coating on Structural and Magnetic Properties and Cell Viability in Human Cancer Cell Lines

Magnetic nanoparticle interfaces have aroused great scientific research interest in the biomedical area since the interaction of cells or biomolecules with nanoparticles is determined by the surface properties. Currently, in medical applications, there is a need to study cell interaction and growth, along with changes in structural or magnetic properties, attributed to nanoparticle coatings. In this study the coercive field changes in NixFe3-xO4 nanoparticles (x = 0.0, 0.2, 0.4, 0.6, 0.8, and 1.0) driven by partial or total substitution of Fe2+ content by Ni2+, and by aminosilane coating are evaluated. The nanoparticles are synthesized by the coprecipitation method. The inverse spinel structure is confirmed by X-ray diffraction results and Raman spectra. The aminosilane coating is confirmed by energy-dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy. Dynamic light scattering confirms a mean hydrodynamic size of 10 nm. Scanning electron microscopy micrographs of the uncoated and aminosilane-coated samples show that the particles have a hemispherical shape. The coating increases the coercive field. In addition, uncoated Ni0.2Fe2.8O4 has the highest viability in both MCF7 and HeLa cell lines, and aminosilane coating decreases cell viability. This study contributes to future applications of nanomedicine, such as hyperthermia and drug delivery

Synthesis and characterization of niobium doped bismuth titanate | Síntesis y caracterización del titanato de bismuto dopado con niobio

Pure and niobium doped bismuth titanate ceramics Bi4Ti3−xNbxO12(Nb − BiT) with x ranging from 0% to 2% are prepared by sol–gel method. Pellets are sintered by pressureless sintering (PLS) and spark plasma sintering (SPS). Raman spectroscopy indicates distortion in the structure due to the substitution of titanium by niobium. X-ray photoelectron spectroscopy (XPS) displays the Nb integration to the bismuth titanate ceramic structure. X-ray diffraction shows no secondary phases and offers clues about crystallographic texturing due to the SPS technique. The shape and size of the grains are strongly influenced by the niobium added to the system as reported by scanning electron microscopy. Ferroelectric hysteresis loops exhibit the effect of the niobium and the texturing on the ferroelectric behavior. Higher values of remanent polarization are reported for PLS samples. In comparison with PLS, higher values ofthe relative permittivity are reported for SPS samples due to the non-homogeneous incorporation of N