Tiny nanosheets, big leap: A new sensor detects ethanol at ultra-low levels

Aerospace Information Research Institute, Chinese Academy of Sciences

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Real-time monitoring of exhaled breath ethanol concentration using the sensor. a Schematic illustration of the experimental setup. The subject consumed 200 mL of beer every 10 min, with BrAC measurements taken prior to each intake. Breath ethanol concentration was measured using two devices: a commercial breathalyzer (Alcoscan AL8800, Sentech Korea Corp.) as a reference, and the developed ethanol sensor integrated with a measurement system. b BrAC response recorded over time. The developed ethanol sensor demonstrated a strong correlation with the reference breathalyzer, effectively tracking changes in breath ethanol concentration. The sensor successfully captured transient ethanol spikes and exhibited a rapid response to alcohol intake, confirming its potential for real-time breath alcohol monitoring applications.

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Credit: Microsystems & Nanoengineering

Accurate detection of ethanol at extremely low concentrations is essential for applications ranging from industrial safety to health monitoring, yet existing sensors often struggle to balance sensitivity, selectivity, and power efficiency. In this study, researchers developed a chemiresistive gas sensor that dramatically improves ethanol detection by integrating ultrathin catalytic nanosheets onto a conventional metal-oxide sensing film. The resulting device responds strongly to ethanol at concentrations spanning from parts per million down to a few parts per billion, representing a substantial performance gain over unmodified sensors. By combining enhanced surface reactions with amplified electronic signal transduction, the new sensor achieves exceptional sensitivity while maintaining stable, low-power operation, opening new opportunities for compact and reliable ethanol monitoring technologies.

Ethanol is widely used in industrial processing, food production, medical diagnostics, and transportation, but its volatility and potential health risks demand reliable monitoring at low concentrations. Conventional metal-oxide gas sensors are attractive because of their simplicity and low cost, yet they typically require high operating temperatures and show limited sensitivity or poor selectivity at trace ethanol levels. Environmental humidity and signal instability further complicate real-world deployment. Improving sensor performance therefore requires new material strategies that can accelerate surface reactions while amplifying electrical responses without increasing power consumption. Based on these challenges, it is necessary to conduct in-depth research into advanced functional materials that can fundamentally enhance ethanol gas sensing performance.

Researchers from Yonsei University and collaborating institutions reported (DOI: 10.1038/s41378-025-01055-6) this advance on November 7, 2025, in Microsystems & Nanoengineering. The team designed a microheater-integrated gas sensor in which ultrathin ruthenium dioxide nanosheets were deposited onto a tin dioxide thin film. This hybrid structure enabled ultra-sensitive ethanol detection across a wide concentration range, including parts-per-billion levels, while operating at low power. Beyond laboratory testing, the sensor also demonstrated real-time tracking of breath alcohol concentration, highlighting its potential for practical safety and health-related applications.

The core innovation lies in functionalizing a traditional tin-oxide sensing layer with monolayer-scale ruthenium dioxide nanosheets. These nanosheets provide an exceptionally high surface-to-volume ratio and strong catalytic activity, which together accelerate ethanol oxidation reactions on the sensor surface. At the same time, electronic interactions at the interface between the two materials create an expanded electron depletion layer, amplifying resistance changes when ethanol is present. As a result, the sensor’s response to ethanol increased by more than threefold compared with an unmodified device.

The sensor was fabricated on a suspended membrane platform incorporating a microheater, minimizing heat loss and enabling continuous operation below 30 milliwatts. Systematic testing showed reliable detection from 10 parts per million down to approximately 5 parts per billion, placing the device among the most sensitive chemiresistive ethanol sensors reported to date. The sensor also exhibited improved selectivity against common interfering gases, stable operation over nearly a month, and reproducible performance across repeated sensing cycles. Importantly, controlled experiments demonstrated that the device could track dynamic changes in breath alcohol concentration in real time, closely matching readings from a commercial breathalyzer.

“This work shows how nanoscale material engineering can fundamentally change the performance limits of conventional gas sensors,” the researchers noted. By leveraging both catalytic and electronic sensitization effects, the design achieves a rare combination of ultra-high sensitivity, low power consumption, and operational stability. They emphasized that the integration of nanosheets onto a scalable thin-film platform makes the approach compatible with existing microfabrication technologies, which is essential for translating laboratory advances into practical sensing devices.

The ultra-sensitive ethanol sensor has implications well beyond laboratory demonstrations. In industrial environments, it could provide early warnings of ethanol leaks or vapor buildup, improving fire prevention and worker safety. In healthcare and transportation, compact and low-power sensors could enable next-generation breath analyzers for real-time alcohol monitoring, supporting medical diagnostics and drunk-driving prevention systems. More broadly, the nanosheet-functionalization strategy can be extended to other target gases, offering a versatile pathway for developing high-performance sensors for environmental monitoring, smart infrastructure, and wearable health technologies.

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References

DOI

10.1038/s41378-025-01055-6

Original Source URL

https://doi.org/10.1038/s41378-025-01055-6

Funding information

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea Government (MSIT) (Nos. RS-2023-00208355, RS-2023-00222166, RS-2024-00348205, RS-2024-00457040).

About Microsystems & Nanoengineering

Microsystems & Nanoengineering is an online-only, open access international journal devoted to publishing original research results and reviews on all aspects of Micro and Nano Electro Mechanical Systems from fundamental to applied research. The journal is published by Springer Nature in partnership with the Aerospace Information Research Institute, Chinese Academy of Sciences, supported by the State Key Laboratory of Transducer Technology.

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Journal

Microsystems & Nanoengineering

DOI

10.1038/s41378-025-01055-6 

Subject of Research

Not applicable

Article Title

Ultra-sensitive ethanol detection using a chemiresistive SnO2 thin-film gas sensor functionalized with RuO2 nanosheets

 

Pros and cons of pesticides and fertilizers in real-world mandarin orange farms

RIKEN

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A photo from a mandarin orange farm in Japan. Fruit and soil samples from similar orchards across Japan were analyzed in this study to determine the effects of varying pesticides and fertilizers.

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Credit: RIKEN

Researchers led by Yasunori Ichihashi at the RIKEN Center for Sustainable Resource Science (CSRS) in Japan recently examined how different kinds of pesticides and fertilizers affect mandarin oranges across Japan. Advanced statistical analysis showed that while reducing pesticides enhanced the diversity of microbes in the soil, it also led to an increase in fruit disease caused by leaf pathogens. The real-world data from commercial farms thus indicate a trade-off above ground with potential ecological benefits below ground. The study offers important insights for the advancement of sustainable agricultural technologies and future policy development.

Typical agricultural research is done in controlled conditions in laboratories or in test fields. This leads to a gap between experimental findings and what happens in real-world farms. In an effort to bridge this gap, Ichihashi and his team collected fruit and soil samples from mandarin orange orchards across 12 prefectures in Japan. Unlike in a controlled experiment, farmers choose the type of pesticides and fertilizers that they want to use. These biases, along with variable environmental factors, make it difficult to discern the real effects.

To overcome this problem, the researchers turned to a statistical method that is often used in academic fields such as economics, where controlled experiments are impractical or unethical. There are many variables that affect fruit and soil, such as the cultivar category, tree age, annual temperature, amount of rain, duration of sunshine, and soil type. The statistical method adjusts these co-varying factors using a technique called inverse probability weighting. After the adjustment, the researchers were able to control for these factors and see how pesticide and fertilizer types affect soil properties, microbial communities, and fruit quality.

Farmers in Japan vary in their use of pesticides and fertilizers. The study showed that the most common practice is to use chemical pesticides with chemical and organic fertilizers. However, some farms used organic pesticides, and some used only organic fertilizer. The frequency of use also varied, with some farms applying pesticides and fertilizer less often than the standard frequency. Complicating the situation, the researchers found that factors such as climate and tree age varied across these different cultivation methods. “These data indicate that simple comparisons between methods can lead to biased conclusions,” says first author Fuki Fujiwara. “This underscores the necessity of using advanced statistical techniques, as was done in this study, to accurately evaluate the effects of cultivation practices.”

Analysis showed that reducing chemical pesticides led to more fruit diseases caused by leaf pathogens. At the same time, it enhanced soil microbial diversity and reduced the number of soil pathogens. Carbon content in the soil was improved by reducing chemical input, not by the use of organic fertilizers. This challenges the common assumption that adding organic fertilizers directly increases carbon storage. Instead, it indicates that reducing fertilizers—nitrogen input—may be more important.

“In the short-term,” explains Fujiwara, “this study offers immediate feedback to the agricultural community by scientifically demonstrating how the types of pesticides and fertilizers affect fruit quality and soil conditions.” Farmers can use these insights to improve their cultivation methods and make informed decisions that balance sustainability with productivity. For policymakers and agricultural extension services, the findings provide valuable evidence for designing support programs that align with real-world farming practices.

“In the long-term this study lays the foundation for more evidence-based decision-making in agriculture by utilizing real-world data and robust statistical methods,” says Fujiwara. The next steps for the laboratory will include applying their methods to other crops and regions, as well as feedback to farmers.

Ichihashi says that by collaborating closely with agricultural producers, they aim to return their scientific findings to the field and strengthen the link between research and practice. “We hope to enhance partnerships with farmers, private companies, and local governments to improve data collection and practical implementation of research findings.”

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Journal

Plant Biotechnology

DOI

10.5511/plantbiotechnology.25.0605a 

 

Land-intensive carbon removal requires better siting to protect biodiversity

Potsdam Institute for Climate Impact Research (PIK)

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The study, published in Nature Climate Change and led by scientists at the Potsdam Institute for Climate Impact Research (PIK) analysed future projections across five large-scale modelling projects, as well as considering 135,000 species and 70 biodiversity hotspots, to produce spatial mapping of where land-based carbon removal may be sited in the future.

The authors’ approach allows for a risk–risk assessment, not only focusing on overlaps between biodiversity areas and land allocated to carbon dioxide removal (CDR), but also showing the positive impacts of CDR in avoiding climate impacts on biodiversity. The work on the biodiversity importance was led by the Wallace Initiative under Dr. Jeff Price, with researchers from the Tyndall Centre for Climate Change Research at the University of East Anglia and James Cook University, Australia.

In ambitious emissions reductions scenarios, where global warming returns to 1.5°C by 2100 after temporarily overshooting this limit, up to 13 percent of areas allocated to CDR would overlap with important biodiversity sites. The authors emphasise that this would not necessarily mean the loss of these areas, depending on the specific implementation of removals. Nevertheless, given how sensitive some species are to human intervention, this remains a concern.

Careful site selection for carbon removal is critical

“As the world warms, we should be responding by cutting emissions as quickly as possible, but we are also going to need to be scaling carbon removal,” said Ruben Prütz, a PIK researcher and lead author of the study. “We can see from our maps that CDR has the potential to encroach on the areas that shelter biodiversity from harm in a warmer world. Careful site selection for carbon removal is thus critical to preventing negative biodiversity outcomes.”

Increased land use change for carbon removal could also conflict with internationally agreed targets for biodiversity conservation. The 2022 Kunming-Montreal Global Biodiversity Framework aims to “bring the loss of areas of high biodiversity importance, including ecosystems of high ecological integrity, close to zero by 2030”.

Other carbon dioxide removal technologies, such as direct air carbon capture and storage, could supplement land-based options and reduce spatial competition , but these are in earlier phases of technological development and much more expensive.

Benefits for biodiversity through carbon dioxide removal

However, the risk–risk analysis also reveals that the effects of carbon removal on temperatures could have positive outcomes for biodiversity. The study shows that effective implementation of reforestation and BECCS could reduce the long-term loss of biodiversity due to climate factors by up to 25 percent, producing net benefits. But the authors stress that positive outcomes depend on the ability of these ecosystems to recover from higher peak temperatures, which is extremely uncertain.

“We have to recognise that our continued use of fossil fuels is both punishing us, as we suffer from extreme events and other climate impacts, and reducing the tools we have to implement solutions,” Prütz concluded.

Equity and land-based CDR

Land use change for carbon removal is also unequally distributed across different regions of the world. The models allocate up to 15 percent of biodiversity-relevant land in low and middle-income countries to forest-based carbon removal, compared to just 7 percent in wealthy countries.

“This puts a greater burden on the countries who have historically contributed less to emissions,” said Sabine Fuss, PIK researcher and a co-author of the paper. “It also stresses the need for international finance to flow from wealthier countries to those that need it for biodiversity protection, to safeguard a common good.”

Article: Prütz, R., Rogelj, J., Ganti, G., Price, J., Warren, R., Forstenhäusler, N., Wu, Y., Augustynczik, A. L. D., Wögerer, M., Krisztin, T., Havlík, P., Kraxner, F., Frank, S., Hasegawa, M., Doelman, J., Daioglou, V., Humpenöder, F., Popp, A., Fuss, S., (2026): Biodiversity implications of land-intensive carbon dioxide removal. – Nature Climate Change. [DOI: 10.1038/s41558-026-02557-5]

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Journal

Nature Climate Change

DOI

10.1038/s41558-026-02557-5 

Method of Research

Computational simulation/modeling

Subject of Research

Not applicable

Article Title

Biodiversity implications of land-intensive carbon dioxide removal

 

Major IPCC workshops bring diverse climate voices to Reading

University of Reading

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University of Reading Whiteknights Campus

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Credit: University of Reading

The Intergovernmental Panel on Climate Change (IPCC) will host two major international workshops at the University of Reading in February 2026. 

The closed workshops, held at the University of Reading in collaboration with the Department for Energy Security and Net Zero and the Met Office, will run from 10 to 12 February and will help to make IPCC reports more inclusive and robust. 

 The first workshop will examine how to better include diverse knowledge systems in IPCC work. This means exploring how indigenous, local, and practitioner knowledge can work alongside scientific research to create more complete climate assessments. 

The second workshop will focus on improving assessment methods. This includes exploring how artificial intelligence and machine learning can help climate scientists review huge amounts of research more efficiently, as well as better techniques for evaluating climate action and policies. 

The workshops will produce recommendations for consideration by authors working on the entire set of IPCC reports planned for the seventh assessment cycle. 

Prof Sir Jim Skea, Chair of the IPCC said: “The outcomes and recommendations of the two scientific workshops will provide critical guidance for the IPCC leadership and authors working on the next IPCC assessment. The guidance will help them assess the ever-growing body of climate literature and engage with wider forms of knowledge, including that by Indigenous Peoples and local communities. The University of Reading has been a generous host and a genuine partner in this effort.”  

Professor Robert Van de Noort, Vice-Chancellor of the University of Reading, said: "The University of Reading has one of the largest clusters of climate scientists in the world and a global reputation for excellence in climate research. Hosting these IPCC workshops reflects our expertise and our commitment to advancing climate knowledge. We're bringing together diverse voices from across the planet to strengthen how we understand and respond to the climate challenge. This collaboration is exactly what's needed to make real progress." 

Minister for Climate, Katie White, said:“These workshops bring together world‑leading scientists to strengthen the IPCC’s assessments - the foundation for climate action over the next decade. 

"The University of Reading, the Met Office and the UK Government are proud to host this work, demonstrating the UK’s scientific leadership in action as we tackle the climate challenge head-on.” 

Professor Rowan Sutton, Director of Met Office Hadley Centre and Professor of Climate Science, University of Reading said: “The Met Office is proud to be supporting Reading University to bring together these important workshops on indigenous knowledge and artificial intelligence. Effective climate action must be based on robust and up to date scientific evidence. The IPCC plays the central role in ensuring this evidence is gathered, assessed and made available to policy makers around the world. The Met Office is proud to have six lead authors in the current assessment cycle, highlighting our role as a global leader in climate science and our commitment to the IPCC process.” 

Pre-workshop events  

On Monday 9 February, the University of Reading will host three events offering a rare opportunity to understand how the world's leading climate science body works. 

An afternoon introduction (2:00pm - 3:00pm) will inform invited guests, including many early career researchers, about pathways to getting involved in the IPCC.  Business owners and decision-makers invited to a subsequent session, running from 4:00pm-5:30pm, will be informed how they can make use of IPCC reports and findings. 

The day concludes with a high-level public lecture and panel discussion (6:30-8:00pm) led by IPCC Chair Professor Sir Jim Skea, which will explain what the IPCC does and how it functions. The session will also highlight the key scientific questions in the current report cycle and the objectives of the two workshops. 

Members of the public can register to attend the evening lecture in person or online: The Science Behind the Climate Headlines: An Introduction to the Intergovernmental Panel on Climate Change