scholarly journals High-yield fabrication of nm-size gaps in monolayer CVD graphene

Nanoscale ◽  
2014 ◽  
Vol 6 (13) ◽  
pp. 7249-7254 ◽  
Author(s):  
Cornelia Nef ◽  
László Pósa ◽  
Péter Makk ◽  
Wangyang Fu ◽  
András Halbritter ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Single Layer ◽  
High Yield ◽  
Cvd Graphene

Herein we demonstrate the controlled and reproducible fabrication of sub-5 nm wide gaps in single-layer CVD graphene electrodes with an electroburning process and inferred the temperatures during the electroburning using Raman spectroscopy.

Synthesis of 3,4-Dihydropyrano[c]chromenes Using Carbon Microsphere Supported Copper Nanoparticles (Cu-NP/C) Prepared from Loaded Cation Exchange Resin as a Catalyst

2019 ◽  
Vol 16 (2) ◽  
pp. 288-293
Author(s):  
Yogesh W. More ◽  
Sunil U. Tekale ◽  
Nitishkumar S. Kaminwar ◽  
László Kótai ◽  
Tibor Pasinszki ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Cation Exchange ◽  
Copper Nanoparticles ◽  
Exchange Resin ◽  
Cation Exchange Resin ◽  
Environmentally Benign ◽  
High Yield ◽  
Carbon Microsphere ◽  
Catalytic Material ◽  
Operational Simplicity

Aim and Objective: The present study was performed with the aim to develop an efficient and environmentally benign protocol for the synthesis of biologically siginifcant 3, 4-dihydropyrano[c]chromenes using a new catalytic material. The protocol involves the use of a reusable, environment friendly materials and solvents with operational simplicity. Materials and Methods: Carbon microsphere supported copper nanoparticles (Cu-NP/C) prepared from loaded cation exchange resin were synthesized, characterized with well versed analytical techniques such as XRD, SEM and Raman spectroscopy and the synthesized material was used as a catalyst for the environmentally benign synthesis of 3,4-dihydropyrano[c]chromenes. Results: The formation of carbon microsphere supported copper nanoparticles (Cu-NP/C) prepared from loaded cation exchange resin was confirmed by XRD, SEM and Raman spectroscopy which was employed as a heterogeneous material for the synthesis of 3,4-dihydropyrano[c]chromenes. The products formed were characterized by the analysis of spectroscopic data - NMR, IR and mass. The safe catalytic system offers several advantages including operational simplicity, environmental friendliness, high yield, and reusability of catalyst and green chemical transformation. Conclusion: Herein we report an easy and efficient protocol for the one-pot synthesis of dihydropyrano[ c]chromenes using environmentally benign MCR approach in ethanol as the green solvent. The method developed herein constitutes a valuable addition to the existing methods for the synthesis of titled compounds.

Improved hydrothermal synthesis of MoS2 sheathed carbon nanotubes

2012 ◽  
Vol 66 (12) ◽  
Author(s):  
Jaciel Robles-Nuñez ◽  
Fernando Chiñas-Castillo ◽  
Manuel Sanchez-Rubio ◽  
Javier Lara-Romero ◽  
Rafael Huirache-Acuña ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Raman Spectroscopy ◽  
Hydrothermal Synthesis ◽  
Reaction Temperature ◽  
High Yield ◽  
Hydrothermal Route ◽  
Simple Process ◽  
Toxic Materials ◽  
Resultant Material ◽  
Full Body

AbstractMoS2 sheathed carbon nanotubes have been successfully synthesized using a hydrothermal route under controlled conditions. The resultant material was studied by XRD, EDS, HRTEM, and Raman spectroscopy. Advantages of the preparation presented here compared to other methods are: a) lower reaction temperature, b) high yield of sheathed nanotubes including ends and full body, c) simple process with non-toxic materials, and d) no damage inflicted to nanotubes.

Interaction of single-layer CVD graphene with a metasurface of terahertz split-ring resonators

2013 ◽  
Author(s):  
Federico Valmorra ◽  
Giacomo Scalari ◽  
Curdin Maissen ◽  
Wangyang Fu ◽  
Christian Schönenberger ◽  
...  
Keyword(s):  
Single Layer ◽  
Ring Resonators ◽  
Split Ring ◽  
Split Ring Resonators ◽  
Cvd Graphene

scholarly journals The role of positively charge poly-L-lysine in the formation of high yield gold nanoplates on the surface for plasmonic sensing application

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0259730
Author(s):  
Marlia Morsin ◽  
Suratun Nafisah ◽  
Rahmat Sanudin ◽  
Nur Liyana Razali ◽  
Farhanahani Mahmud ◽  
...  
Keyword(s):  
Substrate Surface ◽  
Surrounding Medium ◽  
Resonance Effect ◽  
Maximum Yield ◽  
Single Layer ◽  
Localized Surface Plasmon ◽  
High Yield ◽  
Synthesis Process ◽  
Wavelength Shift ◽  
Plasmonic Sensor

An anisotropic structure, gold (Au) nanoplates was synthesized using a two-step wet chemical seed mediated growth method (SMGM) directly on the substrate surface. Prior to the synthesis process, poly-l-lysine (PLL) as a cation polymer was used to enhance the yield of grown Au nanoplates. The electrostatic interaction of positive charged by PLL with negative charges from citrate-capped gold nanoseeds contributes to the yield increment. The percentage of PLL was varied from 0% to 10% to study the morphology of Au nanoplates in term of shape, size and surface density. 5% PLL with single layer treatment produce a variety of plate shapes such as hexagonal, flat rod and triangular obtained over the whole substrate surface with the estimated maximum yield up to ca. 48%. The high yield of Au nanoplates exhibit dual plasmonic peaks response that are associated with transverse and longitudinal localized surface plasmon resonance (TSPR and LSPR). Then, the PLL treatment process was repeated twice resulting the increment of Au nanoplates products to ca. 60%. The thin film Au nanoplates was further used as sensing materials in plasmonic sensor for detection of boric acid. The anisotropic Au nanoplates have four sensing parameters being monitored when the medium changes, which are peak position (wavelength shift), intensity of TSPR and LSPR, and the changes on sensing responses. The sensor responses are based on the interaction of light with dielectric properties from surrounding medium. The resonance effect produces by a collection of electron vibration on the Au nanoparticles surface after hit by light are captured as the responses. As a conclusion, it was found that the PLL treatment is capable to promote high yield of Au nanoplates. Moreover, the high yield of the Au nanoplates is an indication as excellent candidate for sensing material in plasmonic sensor.

Raman spectroscopy of strongly doped CVD-graphene

2013 ◽  
Vol 250 (12) ◽  
pp. 2659-2661 ◽  
Author(s):  
Zuzana Komínková ◽  
Martin Kalbáč
Keyword(s):  
Raman Spectroscopy ◽  
Cvd Graphene

Raman spectroscopy of CVD graphene during transfer process from copper to SiO2/Si substrates

2018 ◽  
Vol 6 (1) ◽  
pp. 015601 ◽  
Author(s):  
C Bautista-Flores ◽  
R Y Sato-Berrú ◽  
D Mendoza
Keyword(s):  
Raman Spectroscopy ◽  
Transfer Process ◽  
Cvd Graphene ◽  
Si Substrates

scholarly journals Labeled vs. Label-Free Raman Imaging of Lipids in Endothelial Cells of Various Origins

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5752
Author(s):  
Basseem Radwan ◽  
Adriana Adamczyk ◽  
Szymon Tott ◽  
Krzysztof Czamara ◽  
Katarzyna Kaminska ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Endothelial Cells ◽  
Lipid Content ◽  
Single Layer ◽  
Vascular Diseases ◽  
Raman Imaging ◽  
Dependent Manner ◽  
Label Free ◽  
Necrosis Factor Alpha ◽  
Cellular Lipids

Endothelial cells (EC) constitute a single layer of the lining of blood vessels and play an important role in maintaining cardiovascular homeostasis. Endothelial dysfunction has been recognized as a primary or secondary cause of many diseases and it manifests itself, among others, by increased lipid content or a change in the lipid composition in the EC. Therefore, the analysis of cellular lipids is crucial to understand the mechanisms of disease development. Tumor necrosis factor alpha (TNF-α)-induced inflammation of EC alters the lipid content of cells, which can be detected by Raman spectroscopy. By default, lipid detection is carried out in a label-free manner, and these compounds are recognized based on their spectral profile characteristics. We consider (3S,3′S)-astaxanthin (AXT), a natural dye with a characteristic resonance spectrum, as a new Raman probe for the detection of lipids in the EC of various vascular beds, i.e., the aorta, brain and heart. AXT colocalizes with lipids in cells, enabling imaging of lipid-rich cellular components in a time-dependent manner using laser power 10 times lower than that commonly used to measure biological samples. The results show that AXT can be used to study lipids distribution in EC at various locations, suggesting its use as a universal probe for studying cellular lipids using Raman spectroscopy. The use of labeled Raman imaging of lipids in the EC of various organs could contribute to their easier identification and to a better understanding of the development and progression of various vascular diseases, and it could also potentially improve their diagnosis and treatment.

Experimental demonstration of mid-IR absorption enhancement in single layer CVD graphene

2020 ◽  
Vol 45 (14) ◽  
pp. 3861 ◽  
Author(s):  
Abedin Nematpour ◽  
Nicola Lisi ◽  
Rosa Chierchia ◽  
Maria Luisa Grilli
Keyword(s):  
Single Layer ◽  
Absorption Enhancement ◽  
Ir Absorption ◽  
Experimental Demonstration ◽  
Cvd Graphene
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