The nanoparticles have been synthesized by sol-gel technique
In addition to organic coatings, core-shell structures, such as biocompatible silica- or gold-covered magnetic nanoparticles, have provided an attractive approach to developing stealth nanoparticles. Silica shells serve as protective stable nanoparticle coatings under aqueous conditions. The ability to encapsulate functional molecules within the nanoparticle matrix is a unique feature of these nanostructures. Hyeon and Moon developed Fe3O4 nanocrystal-embedded, core-shell mesoporous silica nanoparticles, and they demonstrated their multifunctional application to simultaneous MR/optical imaging and drug delivery . This study suggested a precise method for controlling the size of the silica nanoparticles smaller than 100 nm. The surfactant cetyltrimethylammonium bromide (CTAB) provided an organic template for the formation of a mesoporous silica shell and stabilized the hydrophobic Fe3O4 nanocrystals in an aqueous solution. The sol-gel process occurred through the template by using tetraethylorthosilicate (TEOS) and rhodamine B isothiocyanate (RITC)-labeled aminopropyltriethoxysilane (APS), and generated amine groups containing silica shell, to which PEG was covalently conjugated via succinimidyl end group to render further biocompatibility. Dox molecules loaded onto the as-synthesized Fe3O4@mSiO2(R)-PEG NPs to convey therapeutic properties. The core-shell structure exhibited magnetic and fluorescent properties, as well as a therapeutic index, suggesting the utility of the nanostructure in biomedical theranostic applications. On the other hand, gold provides several advantages as a coating material due to its inertness and its unique ability to absorb near-IR radiation. Hyeon and Cho described magnetic gold nanoshells (Mag-GNS) consisting of gold nanoshells encapsulating magnetic Fe3O4 nanoparticles as a novel nanomedical platform for simultaneous diagnostic imaging and thermal therapy . Monodisperse 7 nm Fe3O4 nanoparticles stabilized with 2-bromo-2-methylpropionic acid (BMPA) were covalently attached to amino-modified silica spheres through a direct nucleophilic substitution reaction between the bromo groups and the amino groups. Gold seed nanoparticles were then attached to the residual amino groups of the silica spheres. Finally, a complete 15 nm thick gold shell embedded with Fe3O4 nanoparticles formed around the silica spheres to generate Mag-GNS. To target breast cancer, an anti-HER2/neu antibody was conjugated onto the surfaces of the Mag-GNS. SKBR3 breast cancer cells treated with Mag-GNS could be detected using a clinical MRI system, followed by selective destruction by near-IR radiation.
Sol gel synthesis of nanoparticles - SlideShare
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Sol gel synthesis of nanoparticles 1
2) The contest of posters among young scientists of under 35 years old (undergraduate and graduate students, young specialists in sol-gel synthesis of inorganic, hybrid inorganic and disperse systems).
Sol-gel synthesis of amorphous SiOC nanoparticles …
AB - Nanoparticles of CuGaO2delafossite were successfully synthesized from the sol – gel process by controlling the atmospheric conditions at 850 °C. The average size of CuGaO2nanoparticles of ∼40 nm was determined by transmission electron microscopy. Note that the thermodynamically stable conditions for CuGaO2delafossite synthesis are 1100 °C and 1200 °C in nitrogen and air atmosphere, respectively, while our methodology stabilizes the CuGaO2particles in the nano-metric region at low temperature (i.e. 850 °C). Moreover, delafossites CuGaO2nanoparticles show very interesting bifunctional catalytic activity in the electrolysis of water with O2and H2generation at anodic and cathodic potentials respectively. The current densities of CuGaO2nanoparticles as the bifunctional catalysts were found to be 15 mA/cm2and 18 mA/cm2for H2and O2generation, respectively, using 0.5 M KOH solution as an electrolyte versus Ag/AgCl electrode.
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