scholarly journals High-Sensitivity Raman Gas Probe for In Situ Multi-Component Gas Detection

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3539
Author(s):  
Jinjia Guo ◽  
Zhao Luo ◽  
Qingsheng Liu ◽  
Dewang Yang ◽  
Hui Dong ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Optical Fibers ◽  
Signal Transmission ◽  
High Sensitivity ◽  
Multiple Reflection ◽  
Detection Sensitivity ◽  
Gas Detection ◽  
In Situ Detection ◽  
Lower Background

Multiple reflection has been proven to be an effective method to enhance the gas detection sensitivity of Raman spectroscopy, while Raman gas probes based on the multiple reflection principle have been rarely reported on. In this paper, a multi-reflection, cavity enhanced Raman spectroscopy (CERS) probe was developed and used for in situ multi-component gas detection. Owing to signal transmission through optical fibers and the miniaturization of multi-reflection cavity, the CERS probe exhibited the advantages of in situ detection and higher detection sensitivity. Compared with the conventional, backscattering Raman layout, the CERS probe showed a better performance for the detection of weak signals with a relatively lower background. According to the 3σ criteria, the detection limits of this CERS probe for methane, hydrogen, carbon dioxide and water vapor are calculated to be 44.5 ppm, 192.9 ppm, 317.5 ppm and 0.67%, respectively. The results presented the development of this CERS probe as having great potential to provide a new method for industrial, multi-component online gas detection.

scholarly journals Nanopipette/Nanorod-Combined Quartz Tuning Fork–Atomic Force Microscope

Sensors ◽  
2019 ◽  
Vol 19 (8) ◽  
pp. 1794 ◽  
Author(s):  
Sangmin An ◽  
Wonho Jhe
Keyword(s):  
Atomic Force Microscope ◽  
Tuning Fork ◽  
High Sensitivity ◽  
Quartz Tuning Fork ◽  
Force Sensor ◽  
Au Nanoparticle ◽  
Ambient Conditions ◽  
Atomic Force ◽  
In Situ Detection

We introduce a nanopipette/quartz tuning fork (QTF)–atomic force microscope (AFM) for nanolithography and a nanorod/QTF–AFM for nanoscratching with in situ detection of shear dynamics during performance. Capillary-condensed nanoscale water meniscus-mediated and electric field-assisted small-volume liquid ejection and nanolithography in ambient conditions are performed at a low bias voltage (~10 V) via a nanopipette/QTF–AFM. We produce and analyze Au nanoparticle-aggregated nanowire by using nanomeniscus-based particle stacking via a nanopipette/QTF–AFM. In addition, we perform a nanoscratching technique using in situ detection of the mechanical interactions of shear dynamics via a nanorod/QTF–AFM with force sensor capability and high sensitivity.

Applications of Raman Spectroscopy in Cu CMP: In-situ Detection of Chemical Species in the Slurry

2006 ◽  
Vol 914 ◽  
Author(s):  
Siddartha Kondoju ◽  
Pierre Lucas ◽  
Srini Raghavan ◽  
Paul Fischer ◽  
Mansour Moinpour ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Raman Spectroscopy ◽  
Continuous Flow ◽  
Corrosion Inhibitors ◽  
Chemical Species ◽  
Spectroscopic Techniques ◽  
Paper Work ◽  
In Situ Detection ◽  
Cu Cmp

AbstractSlurries used for copper CMP have a rich chemistry, which may change during the course of polishing due to consumption and decomposition of molecular species. Various aspects, such as small layer thickness (<50 μm), continuous flow of the slurry, and dynamics of the film removal process pose great challenge to the monitoring of slurry components between the pad and the wafer. The slurry constituents such as oxidants and corrosion inhibitors have unique signatures that can be detected using spectroscopic techniques. In this paper, work carried out to explore the use of Raman spectroscopy to detect and quantitate chemical species such as hydroxylamine, benzotriazole and hydrogen peroxide in-situ will be presented. More detailed study pertaining to the protonation of hydroxylamine with respect to the pH will also be presented. An abrasion cell integrated with a Raman spectrometer was used to make the measurements.

scholarly journals Quantitative and Ultrasensitive In-situ Immunoassay Technology for SARS-CoV-2 Detection in Saliva

2021 ◽  
Author(s):  
Luke Lee ◽  
Fei Liu ◽  
Yuchao Chen ◽  
Gianluca Roma
Keyword(s):  
Detection Sensitivity ◽  
Testing Methods ◽  
Health Crisis ◽  
Viral Antigens ◽  
Primary Care Settings ◽  
Sample Pooling ◽  
Chemiluminescent Immunoassay ◽  
Pooling Strategy ◽  
In Situ Detection

Abstract The COVID-19 pandemic has become an immense global health crisis. However, the lack of efficient and sensitive on-site testing methods limits early detection for timely isolation and intervention. Here, we present a Quantitative and Ultrasensitive in-situ Immunoassay Technology for SARS-CoV-2 detection in saliva (QUIT SARS-CoV-2). Our nanoporous membrane resonator generates a rapid oscillating flow to purify and concentrate SARS-CoV-2 virus in saliva by 40 folds for in-situ detection of viral antigens based on chemiluminescent immunoassay within 20 min. This method achieved a detection sensitivity below 10 0 copies/mL viral load, comparable to the bench-top PCR equipment. The portable QUIT SARS-CoV-2 system, allowing rapid and accurate on-site viral screen with high-throughput sample pooling strategy, can be performed at the primary care settings and substantially improve the detection and prevention of COVID-19.

scholarly journals Direct in situ reverse transcriptase-polymerase chain reaction

2001 ◽  
Vol 281 (2) ◽  
pp. C726-C732 ◽  
Author(s):  
Rajesh Kher ◽  
Robert Bacallao
Keyword(s):  
Reverse Transcriptase ◽  
Restriction Enzymes ◽  
Cellular Level ◽  
Detection Sensitivity ◽  
Chain Reactions ◽  
Polymerase Chain Reactions ◽  
A Cell ◽  
Polymerase Chain ◽  
In Situ Detection

In situ hybridization has been used for localization of specific nucleic acid sequences at the cellular level despite providing relatively low-detection sensitivity. In situ reverse transcriptase-polymerase chain reactions (RT-PCR) enhance sensitivity and thus enable localization of low-abundance mRNA in a cell. However, the available methods are fraught with problems of nonspecific amplifications as a result of mispriming and/or amplification from partially digested residual genomic DNA in tissue. Herein, we demonstrate that nonspecific background amplification can be eliminated by pretreatment of samples with restriction enzymes before DNase I digestion. Primers tagged with a far-red shifted fluorescent dye such as Cy5 in PCR reactions allow identification of target mRNA by fluorescence microscopy. These novel modifications lead to increased specificity and rapid in situ detection of cellular mRNA and thus may be used for pathological diagnosis.

scholarly journals In-Situ Science on Phobos with the Raman spectrometer for MMX (RAX): Preliminary Design and Feasibility of Raman Measurements

2021 ◽  
Author(s):  
Yuichiro Cho ◽  
Ute Böttger ◽  
Fernando Rull ◽  
Heinz-Wilhelm Hübers ◽  
Tomàs Belenguer ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
High Sensitivity ◽  
Performance Model ◽  
Material Transport ◽  
In Situ Raman Spectroscopy ◽  
Hydrous Minerals ◽  
Raman Spectrometer ◽  
In Situ Raman ◽  
Commercial Off The Shelf

Abstract Mineralogy is a key to understanding the origin of Phobos and its place in the context of the Solar System evolution. In-situ Raman spectroscopy on Phobos would be an important tool to achieve the science objectives of the Martian Moons eXploration (MMX) mission and maximize the science merit of sample return by characterizing the mineral composition and heterogeneity of the surface of Phobos. Conducting in-situ Raman spectroscopy under the harsh environment of Phobos requires a very sensitive, compact, lightweight, and robust Raman instrument that can be carried by the very compact MMX rover. In this context, a Raman spectrometer for MMX (RAX) is currently under development by an international collaboration between teams from Japan, Germany, and Spain. To demonstrate the capability of a compact Raman system like RAX, we built an instrument that reproduces most of the optical performance of the flight model using commercial off-the-shelf parts. Using this performance model, we measured mineral samples relevant to Phobos and Mars, such as anhydrous silicates, carbonates, and hydrous minerals. Our measurements of these samples indicate that such minerals can be measured and identified with a RAX-like Raman spectrometer with sufficiently high accuracy. We demonstrated a spectral resolution of approximately 10 cm-1 and high sensitivity of the Raman peak measurements (e.g. signal-to-noise ratios up to several 100). These results strongly suggest that the RAX instrument will be capable of determining the minerals expected on the surface of Phobos, adding valuable information to address the question on the moon’s origin, heterogeneity, and circum-Mars material transport.

A non-imaging concentrator for fiber optic mediated remote micro-Raman spectroscopy

1992 ◽  
Vol 50 (2) ◽  
pp. 1518-1519
Author(s):  
B. J. McKinley ◽  
Sang Sheem ◽  
John Lutz ◽  
Fred P. Milanovich
Keyword(s):  
Raman Spectroscopy ◽  
Optical Fibers ◽  
Near Infrared ◽  
Collection Efficiency ◽  
Raman Signal ◽  
Miniature Device ◽  
Moderate Power ◽  
Improved Performance ◽  
Ccd Detectors

The recent availability of moderate power near-infrared diode lasers (780nm) and near-infrared sensitive ccd detectors have caused a noticeable resurgence in the application of Raman spectroscopy in analytical chemistry. We have long maintained an interest in Raman spectroscopy and have established a micro-Raman facility within the Chemistry Department of our organization. Recently, we have taken advantage of the aforementioned progress in spectroscopic equipment and have upgraded our micro-Raman facility to include a ccd detector and an imaging spectrograph.Since our micro-Raman spectrometer is designed around an ellipsoidal collection mirror, with Raman signal being directed through the illumination sample stage it has application to microscopic or small transparent samples. The improved performance of the device and the availability of highly transmissive optical fibers led one of us (B.J.M.) to propose an apparatus that could replace the existing illuminator with a miniature device that maintains a high collection efficiency and can be used remotely or in-situ by utilizing optical fibers.

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