ABSTRACT
Here we report the simple and rapid synthesis of three-dimension Pt flower-like nanostructures (PtNFs) on a polypyrrole nanowires (PPyNWs) matrix. Both PtNFs and PPyNWs are prepared by an electrochemical approach without using any seed, template or surfactant. The morphology and chemical composition of the resulting PtNF/PPyNWs hybrids are characterized by scanning electron microscopy and by X-ray photoelectron spectroscopy, respectively. Taking methanol oxidation as a model catalysis reaction, the electrocatalytic performance of the as-prepared PtNF/PPyNWs system has been evaluated by cyclic voltammetry and chronoamperometry, evidencing that these 3D materials exhibit excellent electrocatalytic activity and high level of poisoning tolerance to the carbonaceous oxidative intermediates. Such electrocatalytic performances can be ascribed to the combined effect of the flower-like structure promoting the exposure of more sites and the polymer nanowires matrix endorsing high dispersion of PtNF on a high electrochemically active surface area, besides the removal of sub-products from electrocatalytic sites.
ABSTRACT
Superparamagnetic magnetite nanoparticles were synthetized and capped by a SiO2 shell in order to avoid oxidation and aggregation of the iron oxide nanostructures. The inorganic capping was then further decorated by folic acid molecules, by using a very simple procedure exploiting supramolecular interactions among the organic moieties and the inorganic nanoparticles. The supramolecular nanoadduct thanks to folic acid molecules could act as a "Trojan horse" for the cancer cells and due to its superparamagnetic properties could induce local heat generation upon an appropriate magnetic field application. In fact, temperature was increased up to 42 °C when a 18 mT magnetic field was applied to the nanoparticles and the hybrid nanostructures were verified to be selectively internalized by HeLa cells, a human cervical cancer line known to overexpress the folic acid receptor.
