scholarly journals Absorption and emission of light in red emissive carbon nanodots

2021 ◽  
Author(s):  
Neeraj Soni ◽  
Shivendra Singh ◽  
Shubham Sharma ◽  
Gayatri Batra ◽  
Kush Kaushik ◽  
...  
Keyword(s):  
Carbon Nanodots ◽  
Precursor Molecule ◽  
Absorption And Emission

Herein we unveil the presence of a molecular fluorophore quinoxalino[2,3-b]phenazine-2,3-diamine (QXPDA) in a colossal amount in red emissive CNDs synthesized from o-phenylenediamine, a well-known precursor molecule used for CND synthesis.

Some Results of the Spectroscopic Study of Four Close Binary Systems of Early Spectral Types

1965 ◽  
Vol 5 ◽  
pp. 120-130
Author(s):  
T. S. Galkina
Keyword(s):  
Spectroscopic Study ◽  
Spectral Type ◽  
Spectroscopic Investigation ◽  
Binary Systems ◽  
Quantitative Information ◽  
Close Binary ◽  
Physical Parameters ◽  
Absorption And Emission ◽  
Close Binary Systems ◽  
Quantitative Estimates

It is necessary to have quantitative estimates of the intensity of lines (both absorption and emission) to obtain the physical parameters of the atmosphere of components.Some years ago at the Crimean observatory we began the spectroscopic investigation of close binary systems of the early spectral type with components WR, Of, O, B to try and obtain more quantitative information from the study of the spectra of the components.

Polarimetric Observations of Red Variables: A Study of Gas and Particle Interactions

1979 ◽  
Vol 46 ◽  
pp. 386-408 ◽  
Author(s):  
G. V. Coyne ◽  
I. S. McLean
Keyword(s):  
Wavelength Dependence ◽  
Stellar Atmosphere ◽  
Molecular Absorption ◽  
Absorption Bands ◽  
Absorption And Emission ◽  
Mira Variables ◽  
Stellar Photosphere ◽  
Regular Variable ◽  
Red Supergiants ◽  
Balmer Lines

AbstractIn recent years the wavelength, dependence of the polarization in a number of Mira variables, semi-regular variables and red supergiants has been measured with resolutions between 0.3 and 300 A over the range 3300 to 11000 A. Variations are seen across molecular absorption bands, especially TiO bands, and across atomic absorption and emission lines, especially the Balmer lines. In most cases one can ignore or it is possible to eliminate the effects due to interstellar polarization, so that one can study the polarization mechanisms operating in the stellar atmosphere and environment. The stars Omicron Ceti. (Mira), V CVn (semi-regular variable) and Mu Cephei (M2 la), in addition to other stars similar to them, will be discussed in some detail.Models to explain the observed polarization consider that the continuum flux is polarized either by electron, molecular and/or grain scattering or by temperature variations and/or geometrical asymmetries over the stellar photosphere. This polarized radiation is affected by atomic and molecular absorption and emission processes at various geometric depths in the stellar atmosphere and envelope. High resolution spectropolarimetry promises, therefore, to be a power-rul tool for studying stratification effects in these stars.

Utilizing ICG Spectroscopical Properties for Real-Time Nanoparticle Release Quantification In vitro and In vivo in Imaging Setups

2020 ◽  
Vol 26 (31) ◽  
pp. 3828-3833 ◽  
Author(s):  
Tuula Peñate-Medina ◽  
Eike Kraas ◽  
Kunliang Luo ◽  
Jana Humbert ◽  
Hanwen Zhu ◽  
...  
Keyword(s):  
Release Kinetics ◽  
Pure Water ◽  
Squamous Carcinoma ◽  
Peak Shift ◽  
Intensity Increase ◽  
Nude Mouse Model ◽  
Absorption And Emission ◽  
Squamous Carcinoma Cells

Background: Nanoparticle imaging and tracking the release of the loaded material from the nanoparticle system have attracted significant attention in recent years. If the release of the loaded molecules could be monitored reliably in vivo, it would speed up the development of drug delivery systems remarkably. Methods: Here, we test a system that uses indocyanine green (ICG) as a fluorescent agent for studying release kinetics in vitro and in vivo from the lipid iron nanoparticle delivery system. The ICG spectral properties like its concentration dependence, sensitivity and the fluctuation of the absorption and emission wavelengths can be utilized for gathering information about the change of the ICG surrounding. Results: We have found that the absorption, fluorescence, and photoacoustic spectra of ICG in lipid iron nanoparticles differ from the spectra of ICG in pure water and plasma. We followed the ICG containing liposomal nanoparticle uptake into squamous carcinoma cells (SCC) by fluorescence microscopy and the in vivo uptake into SCC tumors in an orthotopic xenograft nude mouse model under a surgical microscope. Conclusion: Absorption and emission properties of ICG in the different solvent environment, like in plasma and human serum albumin, differ from those in aqueous solution. Photoacoustic spectral imaging confirmed a peak shift towards longer wavelengths and an intensity increase of ICG when bound to the lipids. The SCC cells showed that the ICG containing liposomes bind to the cell surface but are not internalized in the SCC-9 cells after 60 minutes of incubation. We also showed here that ICG containing liposomal nanoparticles can be traced under a surgical camera in vivo in orthotopic SCC xenografts in mice.

scholarly journals Light Absorption and Emission Dominated by Trions in the Type-I van der Waals Heterostructures

ACS Photonics ◽  
2021 ◽  
Author(s):  
Hyemin Bae ◽  
Suk Hyun Kim ◽  
Seungmin Lee ◽  
Minji Noh ◽  
Ouri Karni ◽  
...  
Keyword(s):  
Light Absorption ◽  
Van Der Waals ◽  
Type I ◽  
Van Der Waals Heterostructures ◽  
Absorption And Emission

scholarly journals Influence of Nitrogen-Doped Carbon Dot and Silver Nanoparticle Modified Carbon Paste Electrodes on the Potentiometric Determination of Tobramycin Sulfate: A Comparative Study

Chemosensors ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 52
Author(s):  
Nermine V. Fares ◽  
Passant M. Medhat ◽  
Christine M. El Maraghy ◽  
Sherif Okeil ◽  
Miriam F. Ayad
Keyword(s):  
Silver Nanoparticle ◽  
Carbon Nanodots ◽  
Carbon Paste ◽  
X Ray Diffraction ◽  
Loteprednol Etabonate ◽  
Carbon Paste Electrodes ◽  
Transmission Electron ◽  
Nernstian Slope ◽  
Nitrogen Doped Carbon ◽  
Modified Carbon Paste Electrodes

Two inexpensive and simple methods for synthesis of carbon nanodots were applied and compared to each other, namely a hydrothermal and microwave-assisted method. The synthesized carbon nanodots were characterized using transmission electron microscopy (TEM), ultraviolet-visible (UV-Vis), photoluminescence (PL), Fourier transform-infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The synthesized microwave carbon nanodots had smaller particle size and were thus chosen for better electrochemical performance. Therefore, they were used for our modification process. The proposed electrodes performance characteristics were evaluated according to the IUPAC guidelines, showing linear response in the concentration range 10−6–10−2, 10−7–10−2, and 10−8–10−2 M of tobramycin with a Nernstian slope of 52.60, 58.34, and 57.32 mV/decade for the bare, silver nanoparticle and carbon nanodots modified carbon paste electrodes, respectively. This developed potentiometric method was used for quantification of tobramycin in its co-formulated dosage form and spiked human plasma with good recovery percentages and without interference of the co-formulated drug loteprednol etabonate and excipients.

High-Responsivity Solar-Blind Ultraviolet Photodetectors Based on Carbon Nanodots/Graphene Hybrids

2021 ◽  
Vol 68 (3) ◽  
pp. 1101-1106
Author(s):  
Yong Fang ◽  
Zhiwei Zhao ◽  
Mengru Zhu ◽  
Zhengjin Weng ◽  
Chao Fang ◽  
...  
Keyword(s):  
Carbon Nanodots ◽  
High Responsivity ◽  
Solar Blind ◽  
Ultraviolet Photodetectors

Carbon nanodots enhanced performance of Cs0.15FA0.85PbI3 perovskite solar cells

Nano Research ◽  
2021 ◽  
Author(s):  
Yu Gao ◽  
Wenzhan Xu ◽  
Fang He ◽  
Pengbo Nie ◽  
Qingdan Yang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Perovskite Solar Cells ◽  
Carbon Nanodots
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