This paper presents an improved gas sensor based on the dual-excitation of quartz-enhanced photothermal spectroscopy (QEPTS) using a single quartz tuning fork (QTF) for signal detection. The silver coating on one side of the QTF was chemically etched to increase the laser power interacted with QTF for QEPTS signal excitation. By etching the silver coating on one side of QTF, the reflection structure between the silver coating of the other side of QTF and the external flat mirror was established. The device uses an absorption gas cell with an optical range length of 3 m, making the laser beam interact with the gas more completely and posing more gas concentration information. Acetylene was selected as the target gas to verify the performance of the sensor. The experimental results show that the signal amplitude with a flat mirror was 1.41 times that without a flat mirror, and 2.47 times that of traditional QEPTS sensor. The system has a minimum detection limit (MDL) of 1.10 ppmv, corresponding to a normalized noise equivalent absorption coefficient (NNEA) of 7.14 × 10cm·W·Hz. Allan variance analysis results show that when the integration time is 700 s, the MDL of the system is 0.21 ppmv. The proposed gas sensor can play an important role on detecting trace gas in many fields.
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http://dx.doi.org/10.1364/OE.521916 | DOI Listing |
Food Chem X
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Institute of Agricultural Engineering, ARO, Volcani Institute, Rishon LeZion, Israel.
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View Article and Find Full Text PDFLangmuir
January 2025
Department of Chemical and Biological Sciences, National Institute of Technology Meghalaya, Shillong 793003, India.
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View Article and Find Full Text PDFIntroduction: Endotracheal tubes (ETT) are used in patients who require ventilatory support. Colonization of ETTs by microorganisms is associated with developing ventilator-associated pneumonia (VAP). Thus, this meta-analysis aims to compare conventional endotracheal tubes with those made using materials designed to prevent colonization.
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Fungal infections caused by yeast have increased in recent decades, becoming a major threat to public health. Antifungal therapy represents a challenging problem because, in addition to presenting many side effects, fungal resistance has been increasing in recent years. As a result, the search for new therapeutic agents has advanced with the use of new technologies such as nanoparticles (NPs).
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
Institute for Materials Discovery, University College London, London WC1E 7JE, U.K.
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