Improving Robustness, Sensitivity and Simplicity of Potentiometric Sensors Through Symmetry and Conceptual Design

 It is an enormous challenge to bring chemical sensing concepts from a controlled laboratory setting into the field while maintaining accuracy. In an environment of uncontrolled, fluctuating temperatures and a lack of repeated calibration, sensor reliability can rapidly deteriorate the accuracy. Today, many sensing concepts are explored for home use or as wearable sensors, and it is paramount to understand and optimize the chemistry for reliable measurements to become possible. This review focuses on the well-established class of potentiometric sensors, mostly known for the measurement of pH, with a range of electrolytes, and how conceptual advances can be used to make them as robust and sensitive as possible. While drawing from recent work of the group at the University of Geneva, the importance of symmetry is stressed to minimize the influence of temperature. The development of self-powered sensing systems that no longer require a battery is explained. This is then connected to protocols in which the sensitivity of these sensors can be reliably improved beyond that dictated by the Nernst equation

Advanced Wastewater Treatment by Ozonation for Abatement of Micropollutants from Municipal Wastewater Effluents

Municipal wastewater treatment plants are important contributors to the discharge of micropollutants to the aquatic environment. Therefore, in Switzerland it has been decided to treat the water at these point sources to reduce the discharge of micropollutants from municipal wastewater effluents. A team of scientists at Eawag has evaluated treatment options, which need to be readily available, easily applicable, and cheap. Based on a rigorous assessment, activated carbon-based processes and ozonation were selected. In this paper the focus is on ozonation, and the different aspects of its application are discussed, including kinetics and mechanisms for ozone reactions with micropollutants and matrix components, formation, and fate of transformation products in biological post-filtration and toxicological aspects. Finally, upgrading of ozonation is described including outreach of this approach to other countries

Overcoming Hydrogen Losses in Fuel Cells: A Membrane-based Approach to Sustainable Energy

Hydrogen (H2) is increasingly recognized as a key candidate to replace fossil fuels due to its high energy density, zero-carbon combustion, and compatibility with fuel cell technologies. Fuel cells offer an efficient means to convert hydrogen into electricity, with only water as a byproduct, making them a cornerstone for the energy transition. However, challenges remain in the widespread adoption of hydrogen, including production methods (green, blue, and grey hydrogen), transportation, and associated losses during fuel cell operation. A critical issue is hydrogen purge losses, where unreacted H2 is vented to maintain fuel cell efficiency and durability. This article explores the fundamentals of H2 fuel cells, purge losses, and the environmental implications. Potential solutions are examined, such as catalytic burning and recirculation systems, to minimize the hydrogen losses in fuel cell strategies. An innovative hydrogen recovery membrane, the SEPARATIC-H2, developed at the University of Fribourg, has been showcased to enhance fuel cell efficiency while reducing H2 waste. By addressing these challenges, hydrogen can reach its potential, accelerating the transition toward a sustainable, low-carbon future

Oligonucleotide-based PROTACs to Degrade RNA- and DNA-Binding Proteins

Proteolysis targeting chimeras (PROTACs) are heterobifunctional molecules that sequester the endogenous protein degradation machinery of cells to induce degradation of targeted proteins. By bringing a target protein and a ubiquitin E3 ligase into close proximity, ubiquitin monomers can be transferred onto surface lysines of the protein, which is subsequently degraded by the proteasome. The functions of RNA- and DNA-binding proteins have been especially hard to modulate with small molecules. However, oligonucleotides that bind RNA- or DNA-binding proteins can be turned into oligonucleotide-based PROTACs to direct ubiquitination and degradation of these proteins. Here we summarize the current state of the field of oligonucleotide-based PROTACs that target RNA- or DNA-binding proteins

When DNA Repair Backfires – Trabectedin Induces DNA Breaks in Active Genes

Many anticancer drugs are ineffective in tumors that have functional DNA repair mechanisms. In contrast, trabectedin, a tetrahydroisoquinoline alkaloid marine natural product, stands out as it is more lethal to cancer cells with active DNA repair, particularly transcription-coupled nucleotide excision repair (TC-NER), making it an intriguing alternative to standard chemotherapeutic agents. To optimize trabectedin’s use in precision oncology, it is essential to understand how its toxicity depends on TC-NER. In this study, we reveal that incomplete TC-NER of trabectedin-DNA adducts generates persistent single-strand breaks (SSBs). These adducts are found to obstruct the second of two sequential NER-mediated DNA incisions. By mapping the 3\u27-hydroxyl groups of SSBs resulting from the first NER incision at trabectedin-DNA adducts, we achieve genome-wide visualization of TC-NER. Our findings show that trabectedin-induced SSBs predominantly occur in the transcribed strands of active genes, accumulating near transcription start sites. This work provides new insights into how trabectedin can be leveraged for targeted cancer therapies and for studying TC-NER and transcription

Metallocene Hydrides: Their Didactic Value for Teaching Organometallic Chemistry: Chemical Education

Metallocene hydrides, Cp2MHn (n=1-3), are complexes known for elements of Groups 3 to 8. Their properties can be understood by the use of a common qualitative MO diagram