Photothermal stability of biologically and chemically synthesized gold nanoprisms.

We report here the influence of the irradiation with femtosecond laser pulses on the gold nanoprisms synthesized using biological and chemical methods. For the bio-mediated growth, we used plant extract as a source of reducing, structure-directing, and stabilizing agents, while for the chemical method, we applied three-step protocol, involving chemicals commonly used in the synthesis of nanostructures. Exposition of the nanostructures to the laser beam causes morphological changes, which affect their extinction spectra.

Bio-mediated synthesis, characterization and cytotoxicity of gold nanoparticles.

We report here a "green" approach for the synthesis of gold nanoparticles (GNPs) in which the Mentha piperita extract was applied for the bioreduction of chloroauric acid and the stabilization of the formed nanostructures. The obtained GNPs were characterized by UV-Vis absorption spectroscopy and transmission electron microscopy (TEM). The reduction of gold ions with the plant extract leads to the production of nanoparticles with various shapes (spherical, triangular and hexagonal) and sizes (from 10 to 300 nm).

Weighing polyelectrolytes packaged in viruslike particles.

This Letter reports on the remarkable selectivity of capsid proteins for packaging synthetic polyelectrolytes in viruslike particles. By applying the contrast variation method in small-angle neutron scattering, we accurately estimated the mean mass of packaged polyelectrolytes ⟨Mp⟩ and that of the surrounding capsid ⟨Mcap⟩. Remarkably, the mass ratio ⟨Mp⟩/⟨Mcap⟩ was invariant for polyelectrolyte molecular weights spanning more than 2 orders of magnitude.