Last week, a team from the University of Washington unveiled a new ultrafast laser platform capable of generating accurate and reliable ultra-broadband optical frequency comb lines, with a line spacing of just 80 MHz and a resolving power of up to 10 million.
To achieve such high resolution, the team used dual-comb spectroscopy (DCS) to unite two frequency combs onto a single detector to produce interferograms, before performing a Fourier transform to reconstruct the entire spectrum. To demonstrate the power of their system, they measured the narrow reflection system of a volume Bragg grating.
“Broadband, high-resolution UV spectroscopy provides unique insights into electronic transitions in atoms and molecules, making it invaluable for applications such as chemical analysis, photochemistry, atmospheric trace gas sensing and exoplanet exploration, where the simultaneous detection of numerous absorption features is essential,” said lead author Konstantin Vodopyanov in a press release. The team believe they have developed the first example of ultra-wideband DCS performed in the ultraviolet range at such high resolution.
A heads up: we’ll be publishing an article on DCS, featuring the folks at IPG Photonics, who collaborated on this study. So watch this space!
Scientists begin development of a library of basalt-based spectral signatures through analysis of chemical processes of the Earth’s mantle layer, with a goal to determine the presence of surface water on exoplanets. Link
Researchers use broadband optical spectroscopy (BOS) to identify cases of necrotizing enterecolitis, a disease causing ischaemia and necrosis of the colon, in premature infants. Link
A new, highly sensitive detector combines fingerprint infrared and surface-enhanced infrared absorption (SEIRA) spectroscopy to convert incident infrared light into "nanolight" in the form of phonon polaritons. Link
Researchers detect chloronitramide – a toxic compound produced as a decomposition product from inorganic chloramines – in American tap water through use of nuclear magnetic spectroscopy (NMR). Link
A new technique using laser-induced breakdown spectroscopy (LIBS) and three machine learning models effectively detects corrosion in concrete. Link
In Hot Water
TYou may be familiar with Northwest Africa 7034 – a Martian meteorite identified in 2011 that is believed to be the second oldest ever discovered at an estimated 4.43 billion years old. It is colloquially known as the “Black Beauty.”
More recently, using nano-scale imaging and spectroscopic techniques, researchers from Curtin University were able to identify element patterns that suggest the oldest known evidence yet of hot water activity on Mars via analysis of a zircon grain of the meteorite.
Co-author Aaron Cavosie commented that the study "takes us a step further in understanding early Mars, by way of identifying tell-tale signs of water-rich fluids from when the grain formed, providing geochemical markers of water in the oldest known Martian crust," in a recent press release.
PFAS Remediation
Last week we reported on redox-polymer redox-electrodialysis (ED): a new electrochemical system developed to remove per- and polyfluoroalkyl substances (PFAS) – a group of toxic and particularly persistent pollutants – from water.
The development team used Fourier transform infrared (FTIR) spectroscopy and energy-dispersive X-ray spectroscopy (EDS) to show that the technique minimizes membrane fouling. This use of spectroscopic techniques for PFAS identification was one of the topics addressed by Diana Aga (University at Buffalo, USA), when she spoke to us about the current and future landscapes for PFAS remediation.
“[Nuclear Magnetic Resonance spectroscopy] is a powerful tool because it doesn’t require standards to quantify PFAS. It can provide absolute signals for fluorine atoms and help us determine the Total PFAS content in the sample without extensive clean-up steps. However, the limitation of NMR is that we need high concentrations to get reliable signals, so NMR is better suited for analyzing high-concentration samples, like PFAS contaminated biosolids or industrial wastes.”
I’d certainly recommend checking out the full account of her experiences and perspectives on the topic of PFAS, in case you missed it previously.
Divide and Conquer
A team from the University of Osaka, Japan, has developed a new technique for the long-range enhancement of fluorescence and Raman spectroscopy using a random array of silver nanoislands. When testing the device, they observed Raman signal enhancement up to 107 times and fluorescence increases up to 102 times compared with traditional methods.
“The chemical stability and mechanical robustness of our substrates make them suitable for a wide range of applications, including environmental pollutant detection or medical diagnosis,” explained senior author Mitsuo Kawasaki in a press release.
Be sure to read the full story on the team’s findings.
SAM I Am
Methylmercury is a toxic compound formed when bacteria reacts to mercury in water, soil or plants, able to cause severe damage to the central nervous system. To better understand how this occurs, a team from the University of Michigan collaborated with the SLAC National Accelerator Laboratory to identify the methyl donor involved in the biological process that produces it by converting inorganic mercury; namely, S-adenosyl-L-methionine (SAM).
The team used advanced X-ray absorption spectroscopy at the Stanford Synchrotron Radiation Lightsource (SSRL) to study the process. “Nobody knew how mercury is methylated biologically,” said Riti Sarangi, a senior scientist at SSRL and co-author of the study, in a press release. “We need to understand that fundamental process before we can develop an effective methylmercury remediation strategy. This study is a step toward that.”
Click here to read the full story!
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