A high-sensitivity fiber-optic photoacoustic (PA) gas microsensor is demonstrated with dual enhancement based on acoustics and detection. Due to the characteristic of small size, a Helmholtz resonator is integrated into a miniature PA sensor. The acoustically amplified PA signal is detected by a high-sensitivity fiber Fabry-Perot (F-P) interferometric cantilever. The first-order resonant frequencies of the interferometric cantilever and Helmholtz resonator are matched by subtle adjustments. The weak PA signal is significantly enhanced in a volume of only 0.35 mL, which breaks the volume limitation of the resonance modes in traditional PA sensing systems. To improve the resolution of the microsensor, a white light interferometry (WLI)-based spectral demodulation algorithm is utilized. The experimental results indicate that the minimum detection limit of acetylene (CH) drops to about 15 ppb with an averaging time of 100 s, corresponding to the normalized noise equivalent absorption (NNEA) coefficient of 2.7 × 10 W·cm·Hz. The dual resonance enhanced fiber-optic PA gas microsensor has the merits of high sensitivity, intrinsic safety, and compact structure.
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http://dx.doi.org/10.1021/acs.analchem.4c00532 | DOI Listing |
Talanta
December 2024
Engineering Research Center of Smart Microsensors and Microsystems, Ministry of Education, College of Electronics and Information, Hangzhou Dianzi University, Hangzhou, Zhejiang, 310018, China; China-Israel Polypeptide Device and Application Technology Joint Research Center, Hangzhou, 310027, China. Electronic address:
Nitrogen dioxide (NO) is an important contaminant that poses a severe threat to environmental sustainability. Traditional inorganic NO gas detectors are generally used under harsh operating conditions and employ environmentally unfriendly resources, thus preventing widespread practical applications. Herein, self-assembled peptide microtubes (SPMTs) are combined with SnO nanoparticles (NPs) to develop a bioinspired NO gas sensor.
View Article and Find Full Text PDFSensors (Basel)
November 2024
Department of Materials Science, Institute for Experimental Condensed Matter Physics, Heinrich Heine University of Düsseldorf, 40225 Düsseldorf, Germany.
We report the results of a zinc oxide (ZnO) low-power microsensor for sub-ppm detection of NO and HS in air at 200 °C. NO emission is predominantly produced by the combustion processes of fossil fuels, while coal-fired power plants are the main emitter of HS. Fossil fuels (oil, natural gas, and coal) combined contained 74% of USA energy production in 2023.
View Article and Find Full Text PDFMicromachines (Basel)
October 2024
Department of Plant Sciences, University of Cambridge, Downing St., Cambridge CB2 3EA, UK.
The development of low-cost tools for rapid soil assessment has become a crucial field due to the increasing demands in food production and carbon storage. However, current methods for soil evaluation are costly and cannot provide enough information about the quality of samples. This work reports for the first time a low-cost 3D printed device that can be used for soil classification as well as the study of biological activity.
View Article and Find Full Text PDFMar Pollut Bull
December 2024
Marine Biological Section, Department of Biology, University of Copenhagen, Strandpromenaden 5, 3000 Helsingør, Denmark; Environmental Dynamics Section, Department of Science and Environment, Roskilde University, Universitetsvej 1, 4000 Roskilde, Denmark. Electronic address:
Epiphytes on seagrass leaves can render parts of the leaf phyllosphere anoxic in darkness owing to leaf/epiphyte respiration and O diffusion constraints. In such anoxic microenvironments, anaerobic microbes can potentially produce phytotoxins and greenhouse gases, but the actual occurrence of such processes in seagrass epiphytic biofilms remain uncertain. We used microsensors to measure O, NO, NO and HS concentration gradients, as well as NO and O dynamics within epiphytic biofilms on seagrass (Zostera marina) leaves under changing environmental conditions.
View Article and Find Full Text PDFJ Environ Qual
September 2024
Department of Biological and Chemical Engineering, Aarhus University, Aarhus, Denmark.
Greenhouse gas emissions from liquid livestock manure storage significantly contribute to global warming. Accurate farm-scale models are essential for predicting these emissions and evaluating manure management strategies, but they rely on multiple parameters describing carbon loss dynamics. Surface respiration may significantly influence carbon loss and methane emission, yet it is not explicitly included in current models.
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