Publications by authors named "G Behan"

The development of novel oral drug delivery systems is an expanding area of research and both new approaches for improving their efficacy and the investigation of their potential toxicological effect are crucial and should be performed in parallel. Polystyrene nanoparticles (NPs) have been used for the production of diagnostic and therapeutic nanosystems, are widely used in food packaging, and have also served as models for investigating NPs interactions with biological systems. The mucous gel layer that covers the epithelium of the gastrointestinal system is a complex barrier-exchange system that it is mainly constituted by mucin and it constitutes the first physical barrier encountered after ingestion.

View Article and Find Full Text PDF

Nickel cobalt oxide alloy nanorings have been synthesized using a wet chemistry method. Standard characterization techniques such as transmission electron microscopy (TEM) and scanning electron microscopy (SEM) have been used to characterize the nanorings. We, however, also examined the nanostructures in the helium ion microscope (HIM) and employed backscattered ion spectroscopy to determine thickness and composition of the nanostructure.

View Article and Find Full Text PDF

Self-assembled silver nanoparticle (NP) arrays were produced by deposition at glancing angles on transparent stepped Al2O3 templates. The evolution of the plasmonic resonances has been monitored using reflection anisotropy spectroscopy (RAS) during growth. It is demonstrated that the morphology of the array can be tailored by changing the template structure, resulting in a large tunability of the optical resonances.

View Article and Find Full Text PDF

Due to its low beam current and charge compensation mechanism He-Ion scanning microscopy is a very promising tool for imaging biological cells. However, to obtain relevant information, the method used for sample preparation is also critical. In this work, we have used a Carl Zeiss Orion Plus helium-ion microscope to study the effect of sample gold coating on the morphology of human colorectal adenocarcinoma Caco2 cells.

View Article and Find Full Text PDF

Scanning confocal electron microscopy (SCEM) offers a mechanism for three-dimensional imaging of materials, which makes use of the reduced depth of field in an aberration-corrected transmission electron microscope. The simplest configuration of SCEM is the bright-field mode. In this paper we present experimental data and simulations showing the form of bright-field SCEM images.

View Article and Find Full Text PDF