NEXAFS study of a Pt-containing rod-like organometallic polymer (Pt-DEBP): molecular orientation onto HOPG, Au/Si(111), Cr/Si(111) and Si(111) surfaces

Hydrophobic and Hydrophilic Au and Ag Nanoparticles. Breakthroughs and Perspectives

This review provides a broad look on the recent investigations on the synthesis, characterization and physico-chemical properties of noble metal nanoparticles, mainly gold and silver nanoparticles, stabilized with ligands of different chemical nature. A comprehensive review of the available literature in this field may be far too large and only some selected representative examples will be reported here, together with some recent achievements from our group, that will be discussed in more detail. Many efforts in finding synthetic routes have been performed so far to achieve metal nanoparticles with well-defined size, morphology and stability in different environments, to match the large variety of applications that can be foreseen for these materials. In particular, the synthesis and stabilization of gold and silver nanoparticles together with their properties in different emerging fields of nanomedicine, optics and sensors are reviewed and briefly commented.

Functionalized platinum nanoparticles with surface charge trigged by pH: synthesis, characterization and stability studies

In this work, the synthesis and characterization of functionalized platinum nanoparticles (PtNPs) have been investigated. PtNPs were obtained by a wet redox procedure using 2-diethylaminoethanethiol hydrochloride (DEA) as capping agent. By varying the Pt/thiol molar ratio, monodispersed and stable particles with diameters in the range of 3-40 nm were isolated. The amino functionality allows neutral particles to be obtained in basic water solution and positive charged nanoparticles in neutral or acidic water solution (pH 7-2), as confirmed by DLS and ζ-potential measurements. FTIR spectroscopy, FE-SEM, DLS and ζ-potential measurements confirmed the size and showed long term water stability (up to three months) of the colloidal system.

Electron microscopy reveals a soluble hybrid network of individual nanocrystals self-anchored by bifunctional thiol fluorescent bridges

Today, nanochemistry research of hybrid materials growth in liquid media represents a new challenge for tailoring specific nano-sized materials directly related to the hybrid electron-optical properties. Distinctive assumptions about the origin, the growth, and the functionalization of hybrid nanoparticles have recently been proposed by scientific research to attend the different aspects of observable behaviors. Therefore, appropriate morpho-structural observation of the hybrid nanoparticles is the most important factor for controlling the chemical and physical properties. Here, we report how the gold nanocrystals (Au-NCs) structurally covered by an outer layer material of 9,9-didodecyl-2,7-bisthiofluorene (FL) bifunctional stabilizer evolve into a self-organized 2D-network as a function of different nano-structural features. Detailed morpho-structural investigation of this hybrid material through electron microscopy techniques has been performed from the atomic-scale to hundreds of nanometers. The experimental information gathered allowed us to figure out the evolution growth of the gold-FL nanoparticles (AuFL-NPs) from the early stage of the gold-organic nucleation to the final assembled bi-dimensional network. The reported results represent a valuable background toward the full comprehension of growth mechanisms of organic-inorganic materials responsible for the final chemical and physical properties.

Synthesis of functionalized gold nanoparticles capped with 3-mercapto-1-propansulfonate and 1-thioglucose mixed thiols and "in vitro" bioresponse

The synthesis, characterization and assessment of biological behavior of innovative negatively charged functionalized gold nanoparticles is herein reported, for potential applications in the field of radiotherapy and drug delivery. Gold nanoparticles (AuNPs) functionalized with two capping agents, i.e., the 3-mercapto-1-propansulfonate (3-MPS) and 1-β-thio-D-glucose (TG), have been on purpose synthesized and fully characterized. Advanced characterization techniques including X-Ray Photoelectron Spectroscopy (XPS) were applied to probe the chemical structure of the synthesized nanomaterials. Z-potential and Dynamic Light Scattering measurements allowed assessing the nanodimension, dispersity, surface charge and stability of AuNPs. Transmission Electron Microscopy (TEM) and Flame Atomic Absorption Spectroscopy (FAAS) were applied to the "in vitro" HSG cell model, to investigate the nanoparticles-cells interaction and to evaluate the internalization efficiency, whereas short term cytotoxicity and long term cell killing were evaluated by means of MTT and SRB assays, respectively. In conclusion, in order to increase the amount of gold atoms inside the cell we have optimized the synthesis for a new kind of biocompatible and very stable negatively charged TG-functionalized nanoparticles, with diameters in a range that maximize the uptake in cells (i.e., ∼15nm). Such particles are very promising for radiotherapy and drug delivery application.