This review summarizes progress in understanding electron transfer from photoexcited nanocrystals to redox enzymes. The combination of the light-harvesting properties of nanocrystals and the catalytic properties of redox enzymes has emerged as a versatile platform to drive a variety of enzyme-catalyzed reactions with light. Transfer of a photoexcited charge from a nanocrystal to an enzyme is a critical first step for these reactions. This process has been studied in depth in systems that combine Cd-chalcogenide nanocrystals with hydrogenases. The two components can be assembled in close proximity to enable direct interfacial electron transfer or integrated with redox mediators to transport charges. Time-resolved spectroscopy and kinetic modeling have been used to measure the rates and efficiencies of the electron transfer. Electron transfer has been described within the framework of Marcus theory, providing insights into the factors that can be used to control the photochemical activity of these biohybrid systems. The range of potential applications and reactions that can be achieved using nanocrystal–enzyme systems is expanding, and numerous fundamental and practical questions remain to be addressed.

With the ongoing flexibilization of work, new trends concerning work outside the company’s premises such as coworking spaces are on the rise. Coworking spaces are designed to offer collaboration and community in furnished and equipped workspaces on a rental base. There is a growing body of scientific literature on coworking spaces with empirical results of qualitative and quantitative research. The present study adds to the latter by examining psychosocial demands experienced by coworkers in Germany based on a quantitative survey (n = 112). Among coworkers the home office was or still is another frequently used workplace. However, can the coworking space be seen as a better alternative to the home office in terms of work- and performance-related, social, environmental and health-related aspects? Results showed moderate to low psychosocial demands regarding quantitative workloads. Compared to the home office, the coworking space proved to be the preferred work arrangement. Results are discussed with regard to current literature and workplace design. In conclusion, coworking spaces can be seen as an alternative to the home office that was highly valued in the present sample. It is recommended to further emphasize aspects of work environment and ergonomics in order to create health-promoting and satisfying workplaces.

The generation of reduced semiconductor nanocrystals is of interest for a variety of optoelectronic applications. In comparison to other nanocrystalline materials, little work has been reported on reduction of CdS nanocrystals, which are particularly interesting for solar photochemistry applications. Most nanocrystal reduction strategies require electron donors that reduce ground state or photoexcited nanocrystals. In this work, we report the discovery of photocharging of CdS nanocrystals under continuous wave illumination with no added reductants. The long-lived reduced states form under illumination, saturate at high concentrations, and recover over time scales of minutes when illumination stops. This process occurs in CdS nanocrystals of different sizes, morphologies, organic surface capping ligands, and multiple solvents but not in CdSe nanocrystals. We propose a charging mechanism in which the photoexcited holes oxidize surface-capping ligands, which then dissociate from the nanocrystal surface. We contrast this ligand-mediated process with solvent-mediated photoreduction that occurs in CdS nanocrystals with polar ligands, which requires hole scavengers.

Redox enzymes are capable of catalyzing a vast array of useful reactions, but they require redox partners that donate or accept electrons. Semiconductor nanocrystals provide a mechanism to convert absorbed photon energy into redox equivalents for enzyme catalysis. Here, we describe a system for photochemical carbon−carbon bond formation to make 2-oxoglutarate by coupling CO2with a succinyl group. Photoexcited electrons from cadmium sulfide nanorods (CdS NRs) transfer to 2-oxoglutarate:ferredoxin oxidoreductase fromMagnetococcus marinusMC-1 (MmOGOR), which catalyzes a carbon−carbon bond formation reaction. We thereby decouple MmOGOR from its native role in the reductive tricarboxylic acid cycle and drive it directly with light. We examine the dependence of 2-oxoglutarate formation on a variety of factors and, using ultrafast transient absorption spectroscopy, elucidate the critical role of electron transfer (ET) from CdS NRs to MmOGOR. We find that the efficiency of this ET depends strongly on whether the succinyl CoA (SCoA) cosubstrate is bound at the MmOGOR active site. We hypothesize that the conformational changes due to SCoA binding impact the CdS NR−MmOGOR interaction in a manner that decreases ET efficiency compared to the enzyme with no cosubstrate bound. Our work reveals structural considerations for the nano−bio interfaces involved in light-driven enzyme catalysis and points to the competing factors of enzyme catalysis and ET efficiency that may arise when complex enzyme reactions are driven by artificial light absorbers.

In 2020, many in-person scientific events were canceled due to the COVID-19 pandemic, creating a vacuum in networking and knowledge exchange between scientists. To fill this void in scientific communication, a group of early career nanocrystal enthusiasts launched the virtual seminar series, News in Nanocrystals, in the summer of 2020. By the end of the year, the series had attracted over 850 participants from 46 countries. In this Nano Focus, we describe the process of organizing the News in Nanocrystals seminar series; discuss its growth, emphasizing what the organizers have learned in terms of diversity and accessibility; and provide an outlook for the next steps and future opportunities. This summary and analysis of experiences and learned lessons are intended to inform the broader scientific community, especially those who are looking for avenues to continue fostering discussion and scientific engagement virtually, both during the pandemic and after.

German engineering services are perceived worldwide as „Made in Germany“. This stands for the quality and safety of industrial products from Germany. The markets of the world expect: Innovative technology, adequate service life, unrestricted usability, reliability, economic availability and technical safety in operation. On the one hand, market expectations demand a targeted application of engineering and on the other hand emphasize that the state must not limit itself to rulemaking and the threat of punishment. It should set standards and structures as required and at the same time ensure their fulfillment and compliance through active action. Giving more of this governmental task to the private sector or the economy is a political will, but the necessary balance between state implementation and guarantee responsibility must be maintained. Spectacular major accidents, as well as recurring incidents and accidents, always require a critical review of safety practices and methods. Unfortunately, safety technology itself does not constitute an independent specialist discipline. Rather, security issues are addressed specifically and sometimes differently in the legal areas and the associated disciplines such as construction, electrical engineering or mesh construction. The high degree of differentiation that has occurred in specialist disciplines and the contradictory increase in the complexity of innovative systems due to IT elements or hybrid construction methods make it difficult to gain general knowledge from the investigations into the events that have occurred. A closed safety-methodical concept as a valid framework for all disciplines provides the base here and can remedy this situation. For German-speaking countries, the base for this is now „Das Qualitätsmerkmal Technische Sicherheit – Denkansatz und Leitfaden 1)“ – since 2016, for extended space „Technical Safety – An Attribute of Quality – An Interdisciplinary Approach and Guideline2)“ describes this base.   Deutsche Ingenieurleistungen werden weltweit unter dem Begriff „Made in Germany“ wahrgenommen. Dieser steht für Qualität und Sicherheit der industriellen Erzeugnisse aus Deutschland. Die Märkte der Welt erwarten: Innovative Technologie, angemessene Lebensdauer, uneingeschränkte Gebrauchstauglichkeit, Zuverlässigkeit, wirtschaftliche Verfügbarkeit und technische Sicherheit im Betrieb. Die Markterwartungen erfordern einerseits eine gezielte Anwendung der Ingenieurwissenschaften und betonen andererseits, dass sich der Staat nicht nur auf die Regelsetzung und die Strafandrohung beschränken darf. Er soll im erforderlichen Maß Normen und Strukturen vorgeben und über aktives Handeln gleichzeitig deren Erfüllung und Einhaltung sicherstellen. Diese staatlichen Aufgaben vermehrt in die Hände privater Einrichtungen bzw. der Wirtschaft zu geben ist zwar politischer Wille, dennoch muss die erforderliche Balance zwischen Durchführungs- und Gewährleistungsverantwortung des Staates eingehalten werden.   Spektakuläre Störfälle mit großer öffentlicher Wirkung verlangen genauso wie die immer wieder auftretenden Zwischenfälle und Unfälle stets eine kritische Überprüfung der Vorgehensweisen und Methoden zur Erzeugung von Sicherheit. Leider bildet die Sicherheitstechnik selbst keine eigenständige Fachdisziplin. Vielmehr werden sicherheitstechnische Belange jeweils spezifisch und zum Teil unterschiedlich in den Rechtsbereichen und den zugeordneten Fachdisziplinen wie Bauwesen, Elektrotechnik oder Maschenbau angesprochen. Der hohe Grad der eingetretenen Differenzierung in Fachdisziplinen und die gegenläufige Zunahme der Komplexität innovativer Systeme durch IT-Elemente oder hybride Bauweisen erschwert eine allgemein nutzbare Erkenntnis aus den Untersuchungen zu den aufgetretenen Ereignissen.   Ein geschlossenes sicherheitsmethodisches Konzept als gültiger Rahmen für alle Fachdisziplinen liefert hier die Grundlage und kann hier Abhilfe schaffen. Für den deutschsprachigen Raum liegt nun als Grundlage „Das Qualitätsmerkmal Technische Sicherheit – Denkansatz und Leitfaden 1)“ – seit 2016 vor, für den erweiterten Raum beschreibt “Technical Safety – An Attribute of Quality – An Interdisciplinary Approach and Guideline 2)” diese Basis.