This paper reports on a portable selective chemical sensor for hazardous vapors at trace levels, which combines a two-stage purge and trap vapor pre-concentration system, a Micro-Electro-Mechanical-System (MEMS) based fast gas-chromatographic (FAST-GC) separation column and a miniaturized quartz-enhanced photoacoustic spectroscopy (QEPAS) detector. The integrated sensing system provides two-dimensional selectivity combining GC retention time and QEPAS spectral information, and was specifically designed to be rugged and suitable to be deployed on unmanned robotic ground vehicles. This is the first demonstration of a miniaturized QEPAS device used as spectroscopic detector downstream of a FAST-GC separation column, enabling real-world analyses in dirty environments with response time of a few minutes. The main modules of the GC/QEPAS sensor device will be described in detail together with the system integration, and successful test results will be reported and discussed.
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http://dx.doi.org/10.3390/s20010120 | DOI Listing |
ACS Nano
January 2025
Institute of Photonics and of Nanotechnologies- National Researcher Council (IFN-CNR), LNESS Laboratory, Piazza Leonardo Da Vinci 32, 20133 Milano, Italy.
Manipulating the optical landscape of single quantum dots (QDs) is essential to increase the emitted photon output, enhancing their performance as chemical sensors and single-photon sources. Micro-optical structures are typically used for this task, with the drawback of a large size compared to the embedded single emitters. Nanophotonic architectures hold the promise to modify dramatically the emission properties of QDs, boosting light-matter interactions at the nanoscale, in ultracompact devices.
View Article and Find Full Text PDFLuminescence
January 2025
Faculty of Materials Science and Chemistry, China University of Geosciences, Wuhan, China.
Currently, the development of red Mn-activated fluoride luminescent materials attracts a lot of attention in optical thermometry sensors, solid lighting, display, and plant growth areas. Nevertheless, the thermal stability of Mn-activated fluoride luminescent materials is still a crucial issue. Herein, a new red RbNaVF:Mn luminescent material with outstanding thermal stability was successfully synthesized through the facial coprecipitation method.
View Article and Find Full Text PDFSmall Methods
January 2025
Dept. Chemical Engineering and Biotechnology, University of Cambridge, Cambridge, CB3 0AS, UK.
The integration of Machine Learning (ML) with super-resolution microscopy represents a transformative advancement in biomedical research. Recent advances in ML, particularly deep learning (DL), have significantly enhanced image processing tasks, such as denoising and reconstruction. This review explores the growing potential of automation in super-resolution microscopy, focusing on how DL can enable autonomous imaging tasks.
View Article and Find Full Text PDFSensors (Basel)
January 2025
Department of Structures for Engineering and Architecture, University of Naples Federico II, Via Claudio 21, 80125 Naples, Italy.
The growing importance of state assessments in civil engineering has led to intensive research into the development of damage identification methods based on vibrations. Natural frequencies and modal shapes have garnered great interest because modal parameters are invariant of structure. Moreover, thanks to the global nature of modal parameters, their variations are not limited to the location of the damage.
View Article and Find Full Text PDFSensors (Basel)
January 2025
State Key Laboratory of Materials Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
This study has investigated the effects of different annealing temperatures on the microstructure, chemical composition, phase structure, and piezoelectric properties of ZnO films. The analysis focuses on how annealing temperature influences the oxygen content and the preferred c-axis (002) orientation of the films. It was found that annealing significantly increases the grain size and optimizes the columnar crystal structure, though excessive high-temperature annealing leads to structural degradation.
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