FePt@CoS(2) yolk-shell nanocrystals as a potent agent to kill HeLa cells

Spherical CoS(2)@carbon core-shell nanoparticles: one-pot synthesis and Li storage property

Well-defined spherical CoS(2)@carbon core-shell nanoparticles, with an average diameter of 40 nm and thin graphite shell of 4 nm, were synthesized by the one-pot method in the presence of NaN(3) in supercritical CS(2) at 600 °C using cobaltocene as the cobalt source. The obtained product was characterized by XRD, Raman, FESEM, TEM and HRTEM and the possible formation mechanism was proposed here. Due to the good electronic conductivity and buffering matrix effect of graphitic carbon shells, the CoS(2)@carbon core-shell nanocomposite exhibited highly reversible capacity, good cycle performance and high Coulombic efficiency in lithium ion storage and retrieval, which makes it promising as an attractive anode material candidate for lithium ion batteries.

Novel nanocrystals as a platinum-delivery vehicle for chemotherapy

Evaluation of: Gao J, Liang G, Zhang B et al.: FePt@CoS2Yolk-shell nanocrystals as a potent agent to kill HeLa cells. J. Am. Chem. Soc. 129(5), 1428–1433 (2007) [1] . Here, a recent paper describing the synthesis and cytotoxicity of Pt-containing yolk-shell nanocrystals is evaluated. The authors synthesized FePt nanocrystals and encapsulated them in CoS2 shells. Cervical cancer cells (HeLa) were then exposed to these nanoparticles and examined for cell viability. The nanocrystals exhibited cytotoxicity at Pt concentrations lower than that of the well-established organoplatinum chemotherapy drug, cisplatin. The nanocrystal synthesis, the potential of these nanocrystals for chemotherapy and the implications of this study on the future development of a new class of ‘nanochemotherapeutics’ are discussed.

Formation of nanotubes and hollow nanoparticles based on Kirkendall and diffusion processes: a review

The Kirkendall effect is a consequence of the different diffusivities of atoms in a diffusion couple causing a supersaturation of lattice vacancies. This supersaturation may lead to a condensation of extra vacancies in the form of so-called "Kirkendall voids" close to the interface. On the macroscopic and micrometer scale these Kirkendall voids are generally considered as a nuisance because they deteriorate the properties of the interface. In contrast, in the nanoworld the Kirkendall effect has been positively used as a new fabrication route to designed hollow nano-objects. In this Review we summarize and discuss the demonstrated examples of hollow nanoparticles and nanotubes induced by the Kirkendall effect. Merits of this route are compared with other general methods for nanotube fabrication. Theories of the kinetics and thermodynamics are also reviewed and evaluated in terms of their relevance to experiments. Moreover, nanotube fabrication by solid-state reactions and non-Kirkendall type diffusion processes are covered.

Fluorescent magnetic nanocrystals by sequential addition of reagents in a one-pot reaction: a simple preparation for multifunctional nanostructures

Core-shell nanostructures consisting of FePt magnetic nanoparticles as the core and semiconducting chalcogenides as the shell were synthesized by a series of reactions in a one-pot procedure. Adding Cd(acac)2 as the cadmium precursor to a reaction mixture containing FePt nanoparticles afforded FePt@CdO core-shell intermediates. The subsequent addition of chalcogens yielded FePt@CdX core-shell nanocrystals (where X was S or Se). The reverse sequence of addition, i.e., adding X before Cd, resulted in spongelike nanostructures because the chalcogens readily formed nanowires in the solution. Transmission electron microscopy, energy-dispersive X-ray spectrometry, selected area electron diffraction, fluorescence spectroscopy, and SQUID were used to characterize the nanostructures. These core-shell nanostructures displayed superparamagnetism at room temperature and exhibited fluorescence with quantum yields of 2.3-9.7%. The flexibility in the sequence of addition of reagents, combined with the compatibility of the lattices of the different materials, provides a powerful yet convenient strategy for generating sophisticated, multifunctional nanostructures.