Gallium nanoparticles as novel inhibitors of Aß40 aggregation.

Alzheimer's disease (AD) has been consistently related to the formation of senile amyloid plaques mainly composed of amyloid ß (Aß) peptides. The toxicity of Aß aggregates has been indicated to be responsible for AD pathology. One scenario to decrease Aß toxicity is the development of effective inhibitors against Aß amyloid formation. In this study, we investigate the effect of gallium nitride nanoparticles (GaN NPs) as inhibitors of Aß40 amyloid formation using a combination of biophysical approaches. Our results show that the lag phase of Aß40 aggregation kinetics is significantly retarded by GaN NPs in a concentration dependent manner, implying the activity of GaN NPs in interfering with the formation of the crucial nucleus during Aß aggregation. Our results also show that GaN NPs can reduce the amyloid fibril elongation rate in the course of the aggregation kinetics. It is speculated that the high polarization characteristics of GaN NPs may provoke a strong interaction between the particles and Aß40 peptide and in this way decrease self-association of the peptide monomers to form amyloids.

Field effect devices and sensors based on electrospun polymer assisted tin oxide nanoribbons.

Electrospinning is presented as a facile method of preparing relatively long tin oxide (SnO2) nanofibers that are robust and stable in air. Upon heat treatment, the fibers collapse into a ribbon-like structure with surfaces that are not smooth, rather, are marked with several interconnected pathways. These nanoribbons were electrically characterized in a field effect transistor configuration in vacuum, with and without ultra violet (UV) light exposure. The resultant variable resistor device exhibits n-type behavior having an on/off ratio of approximately 6000. The devices show a direct response to UV with faster response times upon exposure to longer wavelength light. In the presence of UV, the device conductance and mobility increases, reaching a value approximately 2 cm2/-s for the 364 nm UV light source, comparable to amorphous Si.