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February 2020

Archives for February 2020

Musfeldt Group Published in Inorganic Chemistry

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The Musfeldt Group recently published their work “Spin-Lattice Coupling Across the Magnetic Quantum-Phase Transition in Copper-Containing Coordination Polymers” in Inorganic Chemistry.

The group employs a series of copper-containing coordination polymers as a platform for exploring spin−lattice coupling across the magnetic quantum-phase transition. This interaction, which they quantify for the out-of-plane pyrazine bending mode as a function of the magnetic and structural dimensionality, reaches a maximum in ladderlike [Cu(pyz)1.5(4-HOpy)2](ClO4)2 because of the intermediate dimensionality.

They also sought to reveal spin−phonon coupling under compression but instead discovered a pressure-induced transition in the ladder to a state that is likely ferroelectric.

Dadmun Group Published in ACS Applied Nano Materials

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The research in Dadmun Group utilizes a variety of techniques to examine methods by which the properties of polymer mixtures can be optimized by control of dispersion size or by the selective migration of a polymeric additive to the surface.

The group was recently published in ACS Applied Nano Materials for their work “Impact of Substrate Rigidity on the Structure of Multilayer Nanoscale ITO Films: Implications for Flexible Electronic Devices.” 

This research looks into polymeric substrates, which have become increasingly important in the recent drive in technology to produce flexible displays and mechanically adaptable devices. Multi-nanoscale layer coatings are often necessary for specific device applications, and these complex coatings are often fabricated by sputtering onto the substrate.

The work presented here investigates the impact of depositing increasingly thick bilayer films of indium tin oxide (ITO) and tungsten (W) on flexible (poly(ethylene terephthalate) (PET)) and rigid (silicon) substrates by utilizing complementary characterization methods of X-ray and neutron reflectivity to study the nanoscale structures (depth profile and interfacial breadth) between layers. 

This fundamental study defines the influence of substrate properties on coating composition, density, and interfacial structure at the nanoscale—all of which play important roles in the application specific properties and function of the targeted bilayers. The findings from this study have implications on the nanoscale structure in flexible functional thin films used in a wide range of applications such as flexible television and smartphone displays.

 

Sharma Lab Published in Analytical Chemistry and Analyst

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Terence MooreThe Sharma Raman Lab published their work “Direct Surface Enhanced Raman Spectroscopic Detection of Cortisol at Physiological Concentrations” in Analytical Chemistry.

Josh Moore is the first author on this piece and recently earned his PhD in the Chemistry program.

Cortisol is an important steroid hormone in vertebrate physiology and plays a role in acute and chronic stress response. Current methods for determination of cortisol concentrations in biofluids require extensive sample preparation and long run times. Raman spectroscopy is an attractive alternative because analysis is rapid and non-destructive to the sample.

The Sharma Lab has developed a surface-enhanced Raman spectroscopy (SERS)-based method for detection of cortisol in ethanol that shows a sigmoidal concentration response and a limit of detection of 177 nanomolar, which is in the physiologically relevant range. The method can be applied to more complex solvent environments through the use of multivariate analysis techniques, where principal components analysis (PCA) demonstrates a linear separation according to cortisol concentration in a serum mimic. “We are, to our knowledge, the first group to report on the detection of cortisol using label-free SERS, which does not require a Raman reporter molecule to obtain signal,” Moore said.

The Sharma Lab published their work “Surface-enhanced spatially-offset Raman spectroscopy (SESORS) for detection of neurochemicals through the skull at physiologically relevant concentrations” in Analyst. 

Detection techniques for neurotransmitters that are rapid, label-free, and non-invasive are needed to move towards earlier diagnosis of neurological disease. Surface-enhanced Raman spectroscopy (SERS) allows for sensitive and selective detection of target analytes. The combination of SERS with spatially offset Raman spectroscopy (SORS) in a technique termed surface enhanced spatially offset Raman spectroscopy (SESORS) permits a sensitive and selective detection of neurotransmitters through the skull.

In this piece, the group presents the SESORS detection of individual neurotransmitters and mixtures of neurotransmitters at physiologically relevant concentrations, while also establishing limits of detection.