Chimia最新文献

The detection and identification of the building blocks of life, from amino acids to more complex molecules such as certain lipids, is a crucial but highly challenging task for current and future space exploration missions in our Solar System. To date, Gas Chromatography Mass Spectrometry has been the main technology applied. Although it has shown excellent performance in laboratory research, it has not yet been able to provide a conclusive answer regarding the presence or absence of a signature of life, extinct or extant, in space exploration. In this contribution we present the current measurement capabilities of our space prototype laser-based mass spectrometer for organics detection. The developed mass spectrometer currently allows the detection and identification of small organic molecules, such as amino acids and nucleobases, at sample concentrations at the level of femtomole mm-2, using the same measurement protocol. The latter is highly relevant to space exploration, since with the instrumentation in use so far only one class of organics can be measured with one instrument configuration.

The management of scientific data plays a key role in all research areas and has increased in importance. Providing researchers with customizable data management tools is crucial for effectively managing data according to the FAIR principles. These principles have been defined by Wilkinson et al. in 2016, which describe how scientific data should be managed.[1] To support the specific needs of researchers at Empa, openBIS[2] was chosen as a FAIR compliant data management platform. OpenBIS is an Electronic Laboratory Notebook (ELN) and Laboratory Information Management System (LIMS) developed at ETH. The commissioning of this platform for the case of an analytical chemistry lab presented multiple challenges. In this paper, solutions to adapt openBIS as a digital platform to integrate the laboratory data workflow in chemical analysis and for spectroscopy instruments are presented. Two laboratory projects as case studies are described, consisting of a data pipeline and a complex dashboard for data collection, visualization and interaction. These examples show a successful integration of the data management platform in accordance with the FAIR data guidelines along with maximizing efficiency for laboratory personnel.

Tip-enhanced Raman spectroscopy (TERS) has established itself as a powerful tool in nanoscale chemical analysis, providing unprecedented spatial resolution with high molecular sensitivity and chemical specificity. TERS employs localized surface plasmon resonance at the apex of a sharp scanning probe microscopy tip to overcome the diffraction limit inherent in conventional Raman spectroscopy, achieving spatial resolutions down to the nanometer scale. In this article, we highlight major advancements in TERS over the past five years from our laboratory at ETH Zurich in the following key areas: heterogeneous catalysis, photovoltaic materials, biological membranes, and on-surface molecular assembly. Our recent studies demonstrate the unique capabilities of TERS for in situmonitoring of catalytic reactions, nanoscale mapping of phase behavior in biomembranes, and precise characterization of photovoltaic interfaces. Through these applications, we highlight the potential of TERS for addressing critical challenges across the chemical, biological, and materials sciences. This review serves as a guide for researchers aiming to harness TERS for label-free, non-destructive nanoanalysis to advance understanding of complex molecular materials and processes through ultrahigh sensitivity, specificity, and spatial resolution.

A digital ion trap (DIT) mass spectrometer was developed to extend the mass range in comparison to conventional ion traps. This was achieved by changing the RF voltage from a sinusoidal to a rectangular waveform. In addition to the extended mass range, the size of the instrument was miniaturized. To show the benefits of this development, MALDI applications in MS1, MS2, and MS3 are presented: On one hand, it is possible to analyze intact proteins, on the other hand the instrument enables insights into the structure of antibodies and glycoproteins after enzymatic digestion and collision-induced dissociation (CID).

Biological nanopores have become powerful tools for single-molecule analysis in many fields, including metal ion detection, single-molecule chemistry, polymer size discrimination, nucleic acid sequencing, and protein/peptide/glycan analysis. Among all biological nanopores, aerolysin is considered one of the most promising nanopores for analytical applications. It is a heptameric β-barrel pore-forming toxin (β-PFT) secreted by Aeromonas, featuring a narrow, elongated β-barrel lumen composed of highly charged amino acids. In this review, we summarize the recent advances of biological nanopores in molecular sensing, sequencing, and their applications in solving biophysical questions, with a focus on aerolysin nanopores.

Mössbauer spectroscopy is an effective technique used to examine the iron atom electronic environments in both biomolecular molecules and whole animal studies. Because of its sensitivity to nuclear hyperfine interactions, this technique yields incredibly accurate data regarding the electronic and magnetic states of nuclei, chemical bonds, and the local electronic environment structure around iron atoms. This review demonstrates how Mössbauer spectroscopy contributes to biomedical sciences. The use of Mössbauer spectroscopy in the fields of general biology is discussed, as well as studies that included bacterial analyses, studies related to protein materials, and pharmaceutical studies. In addition, although beyond the scope of this review, the use of Mössbauer spectroscopy to study model compounds to aid in understanding the iron proteins is briefly referred to.

At the extremes, all analytical spectrometric measurements are limited by the resolution of the spectrometer system. Spectral overlaps, isobars in the case of mass spectrometry, can lead to the implementation of complex and time-consuming chemical separations to alleviate those interferences. In the area of elemental/isotopic mass spectrometry, use of sector-field instruments can provide a mass resolution of ~10,000, but still necessitate chemical separations. Described here is the coupling of the liquid sampling-atmospheric pressure glow discharge (LS-APGD) microplasma to ultra-high resolution Orbitrap mass analyzer systems to yield mass resolution values ranging from 70k to 1M. Resolution of this order, with commensurate improvements in precision and accuracy, holds the promise to affect elemental/isotopic determinations without the need for chemical separations.

Demand for lithium is expected to quadruple by the end of the decade. Without new sources of production, the supply-demand curve is expected to invert. Traditional geological reserves will not be able to meet the anticipated gap, thus unconventional sources of lithium will need to be utilized, setting the stage for fierce competition for perhaps the most critical of mineral resources required for the energy transition. Direct Lithium Extraction refers to the umbrella of technologies being developed to access lithium from unconventional sources. Electrochemical extraction offers significant promise for its selectivity and low operating cost when coupled with renewable energy. This review aims to describe materials and process design considerations for electrochemical extraction of lithium from aqueous sources with a specific emphasis on ζ-V2O5 designed in our research group as an insertion host. We point to specific strategies for improving capacity and selectivity for electrochemical lithium extraction based on materials design across length scales. Strategies range from site-selective modification of insertion hosts to controlled tortuosity of ion diffusion pathways in porous electrode architectures. Electrochemical lithium extraction from unconventional sources stands poised to be a linchpin of a sustainable economy when coupled with cleaning of wastewater, hydrogen generation, and recovery of ancillary critical metals.

The stereoregularity of a polymer plays a key role in determining its properties. While stereocontrol can easily be achieved in coordination and ionic polymerization, it remains a challenge with radical polymerization. Considering the ubiquity and versatility of radical polymerization, significant efforts have been made over the past 50 years to address this issue. In this mini review, we highlight some of the strategies that have been developed to enable stereospecific radical polymerization, from the use of Lewis acid additives to the application of high electric fields. We hope that this review will provide the reader with a comprehensive overview of the current state of the art and equip them with the foundational knowledge needed to explore new avenues in this domain.