Static and Dynamic Plasmon-Enhanced Light Scattering from Dispersions of Polymer-Grafted Silver Nanoprisms in the Bulk and Near Solid Surfaces

Polarized (VV) and depolarized (VH) static (SLS) and dynamic light scattering (DLS) experiments were conducted in dispersions of sterically stabilized silver nanoprisms in three different solvents where strong plasmon-enhanced scattering was observed. In the dilute regime, hydrodynamic sizes obtained from VV and VH were in good agreement with TEM data. VV correlation functions revealed two relaxation modes, reflecting the translational and rotational diffusions unambiguously. Increasing the concentration, the bimodal nature of the correlation functions was retained, and it appeared that the VH correlation function was more strongly influenced. Evanescent-wave DLS was shown to probe rotational and translational diffusion in the vicinity of a hard wall. It is suggested that DLS methodologies can be successfully applied to this type of metallic nanoparticles for characterization and exploration of their dynamics

Incorporation of Nanoparticles into Polymersomes: Size and Concentration Effects

Because of the rapidly growing field of nanoparticles in therapeutic applications, understanding and controlling the interaction between nanoparticles and membranes is of great importance. While a membrane is exposed to nanoparticles its behavior is mediated by both their biological and physical properties. Constant interplay of these biological and physicochemical factors makes selective studies of nanoparticles uptake demanding. Artificial model membranes can serve as a platform to investigate physical parameters of the process in the absence of any biofunctional molecules and/or supplementary energy. Here we report on photon- and fluorescence-correlation spectroscopic studies of the uptake of nanosized SiO₂ nanoparticles by poly(dimethylsiloxane)-<i>block</i>-poly(2-methyloxazoline) vesicles allowing species selectivity. Analogous to the cell membrane, polymeric membrane incorporates particles using membrane fission and particles wrapping as suggested by cryo-TEM imaging. It is revealed that the incorporation process can be controlled to a significant extent by changing nanoparticles size and concentration. Conditions for nanoparticle uptake and controlled filling of polymersomes are presented