raman sensor
Recently Published Documents


TOTAL DOCUMENTS

76
(FIVE YEARS 14)

H-INDEX

10
(FIVE YEARS 1)

Sensors ◽  
2021 ◽  
Vol 21 (23) ◽  
pp. 7912
Author(s):  
Verena Weber ◽  
Laura Brigo ◽  
Giovanna Brusatin ◽  
Giovanni Mattei ◽  
Danilo Pedron ◽  
...  

This paper reports on the fabrication and characterization of a plasmonic/sol-gel sensor for the detection of aromatic molecules. The sol-gel film was engineered using polysilsesquioxanes groups to capture the analyte, through π-π interaction, and to concentrate it close to the plasmonic surface, where Raman amplification occurs. Xylene was chosen as an analyte to test the sensor. It belongs to the general class of volatile organic compounds and can be found in water or in the atmosphere as pollutants released from a variety of processes; its detection with SERS is typically challenging, due to its low affinity toward metallic surfaces. The identification of xylene was verified in comparison with that of other aromatic molecules, such as benzene and toluene. Investigations were carried out on solutions of xylene in cyclohexane, using concentrations in the range from 0 to 800 mM, to evaluate the limit of detection (LOD) of about 40 mM.


2021 ◽  
Author(s):  
Dmitry Maznichenko

A 3-D nano-fiber particle network of TiO2 nanoparticles is synthesized by pulsed femtosecond laser irradiation of a pure Ti substrate. This study investigated the properties of the resulting nanostructure for chemical and biomolecular detection by Raman spectroscopy. Controlled tuning of surface roughness, porosity and depth of the 3-D network were found to directly influence Raman detection. The presented findings support a previously unrealized detection capacity by TiO2. Crystal violet was used to test the Surface-Enhanced Raman Spectroscopy (SERS) performance of the developed TiO2 sensor pads. The corresponding Raman enhancement factor was determined to be 1.3x106 which is directly comparable to commercial Ag and Au based Raman substrates. Bisphenol-A and diclofenac sodium salt were introduced into drinking water and tested with various sensor pads to develop a Raman detection map. The results suggest an affinity towards uniform TiO2 3-D nanofibrous networks.


2021 ◽  
Author(s):  
Dmitry Maznichenko

A 3-D nano-fiber particle network of TiO2 nanoparticles is synthesized by pulsed femtosecond laser irradiation of a pure Ti substrate. This study investigated the properties of the resulting nanostructure for chemical and biomolecular detection by Raman spectroscopy. Controlled tuning of surface roughness, porosity and depth of the 3-D network were found to directly influence Raman detection. The presented findings support a previously unrealized detection capacity by TiO2. Crystal violet was used to test the Surface-Enhanced Raman Spectroscopy (SERS) performance of the developed TiO2 sensor pads. The corresponding Raman enhancement factor was determined to be 1.3x106 which is directly comparable to commercial Ag and Au based Raman substrates. Bisphenol-A and diclofenac sodium salt were introduced into drinking water and tested with various sensor pads to develop a Raman detection map. The results suggest an affinity towards uniform TiO2 3-D nanofibrous networks.


2021 ◽  
pp. 000370282110168
Author(s):  
Emmanuel Lalla ◽  
Menelaos Konstantinidis ◽  
Elizabeth A. Lymer ◽  
Cosette G. Gilmour ◽  
James Freemantle ◽  
...  

One of the primary objectives of planetary exploration is the search for signs of life (past, present, or future). Formulating an understanding of the geochemical processes on planetary bodies may allow us to define the precursors for biological processes, thus providing insight into the evolution of past life on Earth and other planets, and perhaps a projection into future biological processes. Several techniques have emerged for detecting biomarker signals on an atomic or molecular level, including laser-induced breakdown spectroscopy (LIBS), Raman spectroscopy, laser-induced fluorescence spectroscopy (LIF), and attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy, each of which addresses complementary aspects of the elemental composition, mineralogy, and organic characterization of a sample. However, given the technical challenges inherent to planetary exploration, having a sound understanding of the data provided from these technologies, and how the inferred insights may be used synergistically is critical for mission success. In this work, we present an in-depth characterization of a set of samples collected during a 28-day Mars analogue mission conducted by the Austrian Space Forum in the Dhofar region of Oman. The samples were obtained under high-fidelity spaceflight conditions and by taking into account the geological context of the test site. The specimens were analyzed using the LIBS/Raman Sensor (LIRS)⁠—a prototype instrument for future exploration of Mars. We present the elemental quantification of the samples obtained from LIBS using a previously developed linear mixture model, and validated by Scanning Electron Microscopy/Energy Dispersive Spectroscopy (SEM/EDS). Moreover, we provide a full mineral characterization obtained using UV Raman spectroscopy and LIF, which was verified through ATR-FTIR. Lastly, we present possible discrimination of organics in the samples using LIF and time-resolved LIF. Each of these methods yields accurate results, with low errors in their predictive capabilities of LIBS (median relative error ranging from 4.5% to 16.2%), and degree of richness in subsequent inferences to geochemical and potential biochemical processes of the samples. The existence of such methods of inference and our ability to understand the limitations thereof is crucial for future planetary missions, not only to Mars and Moon but also for future exoplanetary exploration.


Author(s):  
Robert D. Waterbury ◽  
Thuyan Conghuyentonnu ◽  
Hunter Hardy ◽  
Tim Molner ◽  
Ryan Robins ◽  
...  

2021 ◽  
pp. 000370282110019
Author(s):  
Shiv K. Sharma ◽  
Bruce M. Howe ◽  
Anupam K. Misra ◽  
Mark R. Rognstad ◽  
John N. Porter ◽  
...  

We describe the fabrication of an underwater time-gated standoff Raman sensor, consisting of a custom Raman spectrometer, custom scanner, and commercial diode-pumped pulsed 532 nm laser all located inside a pressure housing. The Raman sensor was tested in the laboratory with samples in air, a tank containing tap water and seawater, and in the coastal Hawaiian harbor. We demonstrate our new system by presenting standoff Raman spectra of some of the chemicals used in homemade explosive devices and improvised explosive devices, including sulfur, nitrates, chlorates, and perchlorates up to a distance of ∼6 m in seawater and tap water. Finally, the Raman spectra of these hazardous chemicals sealed inside plastic containers submersed in the Hawaiian Harbor water are also presented.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Shilpi Gupta ◽  
Chung Hao Huang ◽  
Gajendra Pratap Singh ◽  
Bong Soo Park ◽  
Nam-Hai Chua ◽  
...  

AbstractPrecision agriculture requires new technologies for rapid diagnosis of plant stresses, such as nutrient deficiency and drought, before the onset of visible symptoms and subsequent yield loss. Here, we demonstrate a portable Raman probe that clips around a leaf for rapid, in vivo spectral analysis of plant metabolites including carotenoids and nitrates. We use the leaf-clip Raman sensor for early diagnosis of nitrogen deficiency of the model plant Arabidopsis thaliana as well as two important vegetable crops, Pak Choi (Brassica rapa chinensis) and Choy Sum (Brassica rapa var. parachinensis). In vivo measurements using the portable leaf-clip Raman sensor under full-light growth conditions were consistent with those obtained with a benchtop Raman spectrometer measurements on leaf-sections under laboratory conditions. The portable leaf-clip Raman sensor offers farmers and plant scientists a new precision agriculture tool for early diagnosis and real-time monitoring of plant stresses in field conditions.


Author(s):  
B.Y. Karas ◽  
A.A. Kancer ◽  
E Miharev ◽  
A.S. Grishkanich ◽  
A.P. Zhevlakov
Keyword(s):  

2020 ◽  
Vol 45 (20) ◽  
pp. 5760
Author(s):  
Xingtao Yu ◽  
Caoxin Li ◽  
Dora Juan Juan Hu ◽  
Karolina Milenko ◽  
Guanghui Wang ◽  
...  
Keyword(s):  

2020 ◽  
Vol MA2020-01 (27) ◽  
pp. 1988-1988
Author(s):  
Benjamin Charron ◽  
Jean-Francois Masson

Sign in / Sign up

Export Citation Format

Share Document