Involving High School Students in Computational Physics University Research: Theory Calculations of Toluene Adsorbed on Graphene.

To increase public awareness of theoretical materials physics, a small group of high school students is invited to participate actively in a current research projects at Chalmers University of Technology. The Chalmers research group explores methods for filtrating hazardous and otherwise unwanted molecules from drinking water, for example by adsorption in active carbon filters. In this project, the students use graphene as an idealized model for active carbon, and estimate the energy of adsorption of the methylbenzene toluene on graphene with the help of the atomic-scale calculational method density functional theory.

Uptake of gold nanoparticles in healthy and tumor cells visualized by nonlinear optical microscopy.

Understanding the mechanism underlying the interactions between inorganic nanostructures and biological systems is crucial for several rapidly growing fields that rely on nano-bio interactions. In particular, the further development of cell-targeted drug delivery using metallic nanoparticles (NP) requires new tools for understanding the mechanisms triggered by the contact of NPs with membranes in different cells at the subcellular level. Here we present a novel concept of multimodal microscopy, enabling three-dimensional imaging of the distribution of gold NPs in living, unlabeled cells.

Corticosteroid solubility and lipid polarity control release from solid lipid nanoparticles.

Solid lipid nanoparticles (SLN) show promise as a drug delivery system for skin administration. The solid state of the lipid particle enables efficient drug encapsulation and controlled drug release. The present study addresses the influence of lipid composition and drug substance lipid solubility on the in vitro release profile of corticosteroids from SLN for topical administration.

High-resolution microspectroscopy of plasmonic nanostructures for miniaturized biosensing.

In this article, we demonstrate how to perform microscale spectroscopy of plasmonic nanostructures in order to minimize the noise when determining the resonance peak wavelength. This is accomplished using an experimental setup containing standard optical components mounted on an ordinary light microscope. We present a detailed comparison between extinction spectroscopy in transmission mode and scattering spectroscopy under dark field illumination, which shows that extinction measurements provide higher signal-to-noise in almost all situations.

Confined plasmons in nanofabricated single silver particle pairs: experimental observations of strong interparticle interactions.

We report on the optical properties of single isolated silver nanodisks and pairs of disks fabricated by electron beam lithography. By systematically varying the disk size and surface separation and recording elastic scattering spectra in different polarization configurations, we found evidence for extremely strong interparticle interactions. The dipolar surface plasmon resonance for polarization parallel to the dimer axis exhibited a red shift as the interdimer separation was decreased; as expected from previous work, an extremely strong shift was observed.

Controlling plasmon line shapes through diffractive coupling in linear arrays of cylindrical nanoparticles fabricated by electron beam lithography.

The effect of diffractive coupling on the collective plasmon line shape of linear arrays of Ag nanoparticles fabricated by electron beam lithography has been investigated using Rayleigh scattering spectroscopy. The array spectra exhibit an intricate multi-peak structure, including a narrow mode that gains strength for interparticle distances that are close to the single particle resonance wavelength. A version of the discrete dipole approximation method provides an excellent qualitative description of the observed behavior.

Experimental design as a tool when evaluating stationary phases for the capillary electrochromatographic separation of basic peptides.

Two different capillary electrochromatography (CEC) stationary phases, Hypersil phenyl and Hypersil C(18), have been characterised with respect to their ability to separate the four basic peptides H-Tyr-(D)Ala-Phe-Phe-NH(2) (TAPP), H-Tyr-(D)Ala-Phe-NH(2) (TAP), H-Phe-Phe-NH(2) (PP) and H-Phe-NH(2) (P). Optimal separation conditions were first established separately for the two phases by applying experimental design in a stepwise procedure. The first step comprised a study to acquire basic knowledge about the variables, their influence on the response and their respective experimental domains for each of the two stationary phases.