Results 61 to 70 of about 3,931 (172)

Small-Size Resonant Photoacoustic Cell of Inclined Geometry for Gas Detection

open access: yes, 2009
A photoacoustic cell intended for laser detection of trace gases is represented. The cell is adapted so as to enhance the gas-detection performance and, simultaneously, to reduce the cell size.
A. L. Ulasevich   +34 more
core   +1 more source

On-chip mid-infrared photothermal spectroscopy using suspended silicon-on-insulator microring resonators [PDF]

open access: yes, 2016
Mid-infrared spectroscopic techniques rely on the specific "fingerprint" absorption lines of molecules in the mid-infrared band to detect the presence and concentration of these molecules.
Baets, Roel   +5 more
core   +3 more sources

Hydrogen Halide Gas Sensors: Active Materials, Operation Principles, and Emerging Technologies

open access: yesInterdisciplinary Materials, EarlyView.
This review considers hydrogen halide (HX) gas sensors across functional materials and principles: acoustic, chemical, optical and nanophotonic. The strong acidity and reactivity of HX gases are discussed as constraints for stability and selectivity of these devices.
Xiuzhen Liu   +12 more
wiley   +1 more source

Microfabricated Neural Biosensors for Detection of Neurotransmitters, Biomarkers, and Small Molecules: Emerging Trends on Self‐Sustained Systems and Energy Harvesting

open access: yesAdvanced Sensor Research, Volume 5, Issue 1, January 2026.
This paper reviews the state of the art and recent developments in thin‐film biosensors for the detection of neurotransmitters, small molecules, and biomarkers within flexible, implantable bioelectronic systems. It covers the main sensing modalities, including electrochemical, plasmonic, acoustic, and magnetic, alongside their materials, transduction ...
Massimo Mariello
wiley   +1 more source

Terahertz Photoacoustic Spectroscopy Using an MEMS Cantilever Sensor [PDF]

open access: yes, 2014
In this paper, a microelectromechanical systems cantilever sensor was designed, modeled, and fabricated to measure the photoacoustic (PA) response of gases under very low vacuum conditions.
Coutu, Ronald A., Jr.   +3 more
core   +1 more source

Visible‐Light Photoswitchable Covalent Tetra‐Ortho‐Fluoro‐Azobenzene Carbon Nanodot Hybrids for Optostimulation

open access: yesChemPhotoChem, Volume 9, Issue 12, December 13, 2025.
Tetra‐ortho‐fluoroazobenzene hybrids bound to carbon nanodots (CNDs) are prepared by covalent amide coupling. These show reversible switching between trans and cis using visible light (448 nm/530 nm), while retaining emission. The hybrids are nontoxic to cells and enable optical stimulation and offering potential for advanced light‐controlled ...
Paul P. Debes   +14 more
wiley   +1 more source

Front-End Amplifiers for Tuning Forks in Quartz Enhanced PhotoAcoustic Spectroscopy

open access: yesApplied Sciences, 2020
A study of the front-end electronics for quartz tuning forks (QTFs) employed as optoacoustic transducers in quartz-enhanced photoacoustic spectroscopy (QEPAS) sensing is reported.
Giansergio Menduni   +11 more
doaj   +1 more source

Broadband detection of methane and nitrous oxide using a distributed-feedback quantum cascade laser array and quartz-enhanced photoacoustic sensing

open access: yesPhotoacoustics, 2020
Here we report on the broadband detection of nitrous oxide (N2O) and methane (CH4) mixtures in dry nitrogen by using a quartz-enhanced photoacoustic (QEPAS) sensor exploiting an array of 32 distributed-feedback quantum cascade lasers, within a spectral ...
Marilena Giglio   +14 more
doaj   +1 more source

Light-emitting diodes and photodiodes in the deep ultra-violet range for absorption photometry in liquid chromatography, capillary electrophoresis and gas sensing [PDF]

open access: yes, 2016
Absorbance measurement in the deep ultra-violet range (below 300 nm) has been one of the most widely used detection methods for analytical techniques as a large number of organic compounds have strong absorption bands in the deep UV region.
Bui, Duy Anh
core   +1 more source

Fiber evanescent wave quartz-enhanced photoacoustic spectroscopy

open access: yesActa Physica Sinica, 2018
In a conventional system of quartz-enhanced photoacoustic spectroscopy (QEPAS), the size of block-like optical collimation focusing lens group is difficult to reduce, and the structural stability is poor, which makes it hard to adapt itself to some special conditions, such as narrow space and vibrating circumstance.
null He Ying   +4 more
openaire   +1 more source

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