Functionalization of silica surfaces using organo-silanes is highly sensitive to reaction conditions. Silica-coated nanoparticles were functionalized with propyl-sulfonic acid groups (PS) under different synthesis conditions including, various solvents (Ethanol, methanol, acetonitrile, and toluene), water content in the reaction media (0% to 50%), 3-mercaptopropyl-trimethoxysilane concentration...

In this paper we describe the preparation of fluorescent mesoporous silica nanoparticles (MSNs) for traceable drug delivery systems. The nanoparticles were prepared following a sol-gel procedure, incorporating a modified perylenediimide dye in the silica structure. Transmission electron microscopy and scanning electron microscopy show that the nanoparticles are monodispersed, with a spheroid sh...

A facile one-pot microemulsion method has been developed for the synthesis of spherical silver core-silica shell (Ag@SiO2) nanoparticles with europium chelates doped in the shell through a silane agent. The method is significantly more straightforward than other extant methods. Measurements of the luminescent emissions from the Ag@SiO2 nanoparticles, in comparison with control silica nanopartic...

The cytotoxicity of 15-nm and 46-nm silica nanoparticles was investigated by using crystalline silica (Min-U-Sil 5) as a positive control in cultured human bronchoalveolar carcinoma-derived cells. Exposure to 15-nm or 46-nm SiO(2) nanoparticles for 48 h at dosage levels between 10 and 100 microg/ml decreased cell viability in a dose-dependent manner. Both SiO(2) nanoparticles were more cytotoxi...

Fluorescent-labeled molecules have been used extensively for a wide range of applications in biological detection and diagnosis. A new form of highly luminescent and photostable nanoparticles was generated by doping the fluorescent dye tris(2'2-bipyridyl)dichlororuthenium(II)hexahydrate (Rubpy) inside silica material. Because thousands of fluorescent dye molecules are encapsulated in the silica...

we have used lithium aluminum hydroxide reducing method of silver nitrate to prepare heterogeneous silver-silica nanocomposite particles with thiol and amino groups serving to bind the ag nanoparticles to the surfaces of the sio2 nanoparticles. we examined products of these reductions using ftir, sem, xrd and uv-vis. spectroscopy. the sio2 nanoparticles had diameters ranging from 70 to 90 nm; t...

Drug molecules with lack of specificity and solubility lead patients to take high doses of the drug to achieve sufficient therapeutic effects. This is a leading cause of adverse drug reactions, particularly for drugs with narrow therapeutic window or cytotoxic chemotherapeutics. To address these problems, there are various functional biocompatible drug carriers available in the market, which ca...

Charge-driven bridging of nanoparticles by macromolecules represents a promising route for engineering functional structures, but the strong electrostatic interactions involved when using conventional polyelectrolytes impart irreversible complexation and ill-defined structures. Recently it was found that the electrostatic interaction of silica nanoparticles with small globular proteins leads to...

Metal nanoshells consists of a dielectric core surrounded by a thin noble metal shell, possess unique optical properties, which render nanoshells attractive for use in different technologies. This paper reports a facile method for growth of small gold nanoparticles on the functionalized surface of larger silica nanoparticles. Mono-dispersed silica particles and gold nanoparticles were prepared ...

Amorphous silica is a particularly interesting material because of its inertness and chemical stability. Silica nanoparticles have been recently developed for biomedical purposes but their innocuousness must be carefully investigated before clinical use. The relationship between nanoparticles physicochemical features, their uptake by cells and their biological activity represents a crucial issu...