We describe an environmentally friendly, top-down approach to the synthesis of Au 89 Fe 11 nanoparticles (NPs). The plasmonic response of the gold moiety and the magnetism of the iron moiety coexist in the Au 89 Fe 11 nanoalloy with strong modification compared to single element NPs, revealing a non-linear surface plasmon resonance dependence on the iron fraction and a transition from paramagnetic to a spin-glass state at low temperature. These nanoalloys are accessible to conjugation with thiolated molecules and they are promising contrast agents for magnetic resonance imaging.

A frontier topic in nanotechnology is the realization of multifunctional nanoparticles (NPs) via the appropriate combination of different elements of the periodic table. The coexistence of Fe and Ag in the same nanostructure, for instance, is interesting for nanophotonics, nanomedicine, and catalysis. However, alloying of Fe and Ag is inhibited for thermodynamic reasons. Here, we describe the synthesis of Fe-doped Ag NPs via laser ablation in liquid solution, bypassing thermodynamics constraints. These NPs have an innovative structure consisting of a scaffold of face-centered cubic metal Ag alternating with disordered Ag–Fe alloy domains, all arranged in a truffle-like morphology. The Fe–Ag NPs exhibit the plasmonic properties of Ag and the magnetic response of Fe-containing phases, and the surface of the Fe–Ag NPs can be functionalized in one step with thiolated molecules. Taking advantage of the multiple properties of Fe–Ag NPs, the magnetophoretic amplification of plasmonic properties is demonstrated with proof-of-concept surface-enhanced Raman scattering and photothermal heating experiments. The synthetic approach is of general applicability and virtually permits the preparation of a large variety of multi-element NPs in one step.[Figure not available: see fulltext.

Crystalline structure, size and surface coating are the relevant parameters influencing the catalytic and magnetic properties of iron oxide nanoparticles (FeOxNPs). The development of a “green” method for the synthesis of FeOxNPs with good crystallinity, controlled size and uncontaminated surface all at the same time is challenging. Here we show that laser ablation in water can be combined with laser irradiation at 355 nm to obtain FeOxNPs with average size tunable in the 10–30 nm range and a percentage of ferrimagnetic phase up to the 94% of crystalline phases, while maintaining the particles surface free from stabilizers or other chemical by-products and without using harmful or toxic reagents. The final FeOxNPs show good magnetization values and have the typical magnetic behaviour of exchange bias systems, due to their highly polycrystalline structure and small (ca. 3 nm) crystalline domains. The one-step coating with phosphonate ligands conferred long time stability in physiological medium to FeOxNPs

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Magneto-plasmonic nanostructures functionalized with cell targeting units are of great interest for nanobiotechnology applications. Photothermal treatment of cells targeted with antibody functionalized nanostructures and followed by magnetic isolation, allows killing selected cells and hence is one of the applications of great interest. The magneto-plasmonic nanostructures reported herein were synthesized using naked gold and magnetite nanoparticles obtained through a green approach based on laser ablation of bulk materials in water. These particles do not need purifications steps for biocompatibility and are functionalized with a SERRS (surface enhanced resonance Raman scattering) active molecule for detection and with an antibody for targeting prostate tumor cells. Quantitative results for the cell targeting and selection efficiency show an overall accuracy of 94% at picomolar concentrations. The photothermal treatment efficiently kills targeted and magneto-selected cells producing a viability below 5% after 3 min of irradiation, compared with almost 100% viability of incubated and irradiated, but non targeted cells.

a b s t r a c tElectrodeposited porous Ni layers and commercial Ni foams were submitted to spontaneous deposition of Pt, achieved by immersing the Ni substrates in H 2 PtCl 6 solutions, at open circuit, to produce Pt-modified 3D Ni electrodes. When using Ni foams, the immersion was prolonged until the whole amount of H 2 PtCl 6 in the solution had reacted. Such an approach, which granted an easy control of the Pt loading, could not be used for Ni electrodeposits, since they underwent significant corrosion. The true Pt surface area was determined by measuring, for each electrode, the hydrogen desorption charge according to methods described in the literature. The ratios between Pt surface area and Pt loading were higher for Ni foam electrodes than for porous Ni electrodeposits. Both kinds of Pt-modified Ni electrodes were used as cathodes for hydrogen evolution in 1 M KOH. Cathodes with Pt loading below 0.5 mg cm À2 (referred to geometric surface area) evolved hydrogen at À100 mA cm À2 with a À75 mV overpotential. The better activity of foam electrodes as compared to electrodeposits, especially at low Pt loading, was mainly due to their higher Pt surface area per unit Pt mass.

This paper summarizes the main achievements of the RFX fusion science program in the period between the 2008 and 2010 IAEA Fusion Energy Conferences. RFX-mod is the largest reversed field pinch in the world, equipped with a system of 192 coils for active control of MHD stability. The discovery and understanding of helical states with electron internal transport barriers and core electron temperature >1.5 keV significantly advances the perspectives of the configuration. Optimized experiments with plasma current up to 1.8 MA have been realized, confirming positive scaling. The first evidence of edge transport barriers is presented. Progress has been made also in the control of firstwall properties and of density profiles, with initial first-wall lithization experiments. Micro-turbulence mechanisms such as ion temperature gradient and micro-tearing are discussed in the framework of understanding gradient-driven transport in low magnetic chaos helical regimes. Both tearing mode and resistive wall mode active control have been optimized and experimental data have been used to benchmark numerical codes. The RFX programme also provides important results for the fusion community and in particular for tokamaks and stellarators on feedback control of MHD stability and on three-dimensional physics. On the latter topic, the result of the application of stellarator codes to describe three-dimensional reversed field pinch physics will be presented.

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