John Chasse

Articles

Recording the Raman Spectrum of a Single Molecule

July 23, 2021

Analytical chemists are continually striving to advance techniques to make it possible to observe and measure matter and processes at smaller and smaller scales. Professor Vartkess Ara Apkarian and his team at the University of California, Irvine have made a significant breakthrough in this quest: They have recorded the Raman spectrum of a single azobenzene thiol molecule. The approach, which breaks common tenets about surface-enhanced Raman scattering/spectroscopy (SERS) and tip-enhanced Raman spectroscopy (TERS), involved imaging an isolated azobenzene thiol molecule on an atomically flat gold surface, then picking it up and recording its Raman spectrum using an electrochemically etched silver tip, in an ultrahigh vacuum cryogenic scanning tunneling microscope. For the resulting paper detailing the effort [1], Apkarian and his associates are the 2021 recipients of the William F. Meggers Award, given annually by the Society for Applied Spectroscopy to the authors of the outstanding paper appearing in the journal Applied Spectroscopy. We spoke to Apkarian about this research, and what being awarded this honor means to him and his team. This interview is part of an ongoing series with the winners of awards that are presented at the annual SciX conference. The award will be presented to Apkarian at this fall’s event, which will be held in person in Providence, Rhode Island, September 28–October 1.

Investigating Lanthanide Deposition Patterns in Tissue Using LA-ICP-MS Imaging

May 07, 2021

In recent years, concerns have arisen about the potential accumulation of lanthanides, like lanthanum and gadolinium, in the human body as a result of their use in clinical treatments or imaging contrast agents, or from exposure through drinking water contaminated with contrast agents. Laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) imaging, which can provide spatially resolved quantification of trace elements in biological samples, is a powerful tool to investigate these questions. Uwe Karst, of the University of Münster in Germany, has been conducting research in this area, and he recently spoke to us about this work. Karst is the 2021 recipient of the Lester W. Strock Award from the New England Chapter of the Society for Applied Spectroscopy (SAS). This interview is part of an ongoing series of interviews with the winners of awards that are presented at the annual SciX conference, which will be held this year from September 26 through October 1, in Providence, Rhode Island.

Quantitative Methods for Multielemental Analysis in Low-Volume Biofluids

February 01, 2021

In precious samples, effective methods for multielemental analysis could provide a deeper understanding of the essential role of elements as cofactors in biological and pathological processes. Tobias Konz of Nestlé Research explains.

Quantitative Methods for Multielemental Analysis in Low Volume Biofluids

September 21, 2020

Tobias Konz of Nestlé Research, Lausanne, Switzerland and various associates have developed and validated what they describe as a reliable, robust, and easy-to-implement quantitative method for multielemental analysis of low-volume samples. The ICP-MS-based method comprises the analysis of 20 elements (Mg, P, S, K, Ca, V, Cr, Mn, Fe, Co, Cu, Zn, Se, Br, Rb, Sr, Mo, I, Cs, and Ba) in 10 μL of serum and 12 elements (Mg, S, Mn, Fe, Co, Cu, Zn Se, Br, Rb, Mo, and Cs) in less than 250,000 cells, and involved the analysis of elemental profiles of serum and sorted immune T cells derived from naıv̈e and tumor-bearing mice. The results indicate a tumor systemic effect on the elemental profiles of both serum and T cells. Konz and his colleagues believe their approach highlights promising applications of multielemental analysis in precious samples such as rare cell populations or limited volumes of biofluids that could provide a deeper understanding of the essential role of elements as cofactors in biological and pathological processes. Konz spoke to us about this work.

The 2020 ASMS Conference Moved On-line in the Face of the Covid-19 Pandemic

May 01, 2020

A preview of this year’s ASMS conference, in its new on-line format.

Detecting and Identifying Food Colorants with SERS

October 01, 2019

SERS is a method that is receiving new attention in the detection, analysis, and identification of both natural and artificial food colorants. Lili He, at the University of Massachusetts, Amherst, recently spoke to Spectroscopy about this important analytical work.

Developing Spectroscopy Instruments for Use in Extreme Environments

September 13, 2019

Spectroscopy can be difficult to carry out outside a controlled laboratory environment. Imagine, then, the hurdles that would accompany performing spectroscopy in the extreme conditions of deep space or the ocean floor. Mike Angel, a professor of chemistry at the University of South Carolina, has taken on those challenges, working on new types of instruments for remote and in- situ laser spectroscopy, with a focus on deep-ocean, planetary, and homeland security applications of deep ultraviolet Raman, and laser-induced breakdown spectroscopy to develop the tools necessary to work within these extreme environments.