Shortwave Infrared Absorptive and Emissive Pentamethine-Bridged Indolizine Cyanine Dyes

2021 ◽  
Author(s):  
David Ndaleh ◽  
Cameron Smith ◽  
Mahesh Loku Yaddehige ◽  
Abdul Kalam Shaik ◽  
Davita L. Watkins ◽  
...  
Keyword(s):  
Cyanine Dyes ◽  
Shortwave Infrared

A New Method for the Synthesis of Heptamethine Cyanine Dyes:  Synthesis of New Near Infrared Fluorescent Labels

1997 ◽  
Vol 62 (26) ◽  
pp. 9387-9387 ◽  
Author(s):  
Narasimhachari Narayanan ◽  
Lucjan Strekowski ◽  
Malgorzata Lipowska ◽  
Gabor Patonay
Keyword(s):  
Near Infrared ◽  
Cyanine Dyes ◽  
New Method ◽  
Fluorescent Labels

Two-Dimensional Near-Infrared and Shortwave Infrared Molecular Aggregates: Taking Kasha’s Model to the Next Dimension

2019 ◽  
Author(s):  
Arundhati Deshmukh ◽  
Danielle Koppel ◽  
Chern Chuang ◽  
Danielle Cadena ◽  
Jianshu Cao ◽  
...  
Keyword(s):  
Near Infrared ◽  
Photophysical Properties ◽  
Satellite Telemetry ◽  
Transition Dipole Moment ◽  
Short Wave ◽  
Tissue Imaging ◽  
Transition Dipole ◽  
Deep Tissue Imaging ◽  
Excitonic States ◽  
Shortwave Infrared

Technologies which utilize near-infrared (700 – 1000 nm) and short-wave infrared (1000 – 2000 nm) electromagnetic radiation have applications in deep-tissue imaging, telecommunications and satellite telemetry due to low scattering and decreased background signal in this spectral region. However, there are few molecular species, which absorb efficiently beyond 1000 nm. Transition dipole moment coupling (e.g. J-aggregation) allows for redshifted excitonic states and provides a pathway to highly absorptive electronic states in the infrared. We present aggregates of two cyanine dyes whose absorption peaks redshift dramatically upon aggregation in water from ~ 800 nm to 1000 nm and 1050 nm with sheet-like morphologies and high molar absorptivities (e ~ 10<sup>5 </sup>M<sup>-1</sup>cm<sup>-1</sup>). To describe this phenomenology, we extend Kasha’s model for J- and H-aggregation to describe the excitonic states of <i> 2-dimensional aggregates</i> whose slip is controlled by steric hindrance in the assembled structure. A consequence of the increased dimensionality is the phenomenon of an <i>intermediate </i>“I-aggregate”, one which redshifts yet displays spectral signatures of band-edge dark states akin to an H-aggregate. We distinguish between H-, I- and J-aggregates by showing the relative position of the bright (absorptive) state within the density of states using temperature dependent spectroscopy. Our results can be used to better design chromophores with predictable and tunable aggregation with new photophysical properties.

Synthesis, photosensitization and antimicrobial activity evaluation of some novel Merocyanine dyes

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Aspergillus Flavus ◽  
Elemental Analysis ◽  
Cyanine Dyes ◽  
Fungal Strains ◽  
Activity Evaluation ◽  
Visible Spectra ◽  
Merocyanine Dyes

Novel acyclic and cyclic merocyanine dyes derived from the nucleu of furo [(3,2-d) pyrazole; ( d 2 , 3 )imidazole]were prepared. The electronic visible absorptionspectra of all the synthesized new cyanine dyes were examined in 95% ethanolsolution to evaluate their photosensitization properties. Antibacterial andantifungal activities for some selected dyes were tested against various bacterialand fungal strains (Escherichia coli, Staphylococcus aureus, Aspergillus flavus andCandida albicans) to evaluate their antimicrobial activity. Structural identificationwas carried out via elemental analysis, visible spectra, IR and 1H NMRspectroscopic data.

Synthesis and in vitro evaluation of the antitumoral phototherapeutic potential of squaraine cyanine dyes derived from indolenine

2019 ◽  
Vol 167 ◽  
pp. 98-108 ◽  
Author(s):  
Eurico Lima ◽  
Octávio Ferreira ◽  
Vanessa S.D. Gomes ◽  
Adriana O. Santos ◽  
Renato E. Boto ◽  
...  
Keyword(s):  
Cyanine Dyes ◽  
In Vitro Evaluation

ChemInform Abstract: Cyanine Dyes (VI), (VII), (IX), (XI), (XIII), (XV) from 4-Methyl-6-hydroxyquinoline (I).

ChemInform ◽  
1988 ◽  
Vol 19 (43) ◽  
Author(s):  
I. L. MUSHKALO ◽  
O. A. IL'CHENKO ◽  
A. I. TOLMACHEV ◽  
B. M. GUTSULYAK
Keyword(s):  
Cyanine Dyes

scholarly journals Nonlinear Mixing Characteristics of Reflectance Spectra of Typical Mineral Pigments

Minerals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 626
Author(s):  
Shuqiang Lyu ◽  
Die Meng ◽  
Miaole Hou ◽  
Shuai Tian ◽  
Chunhao Huang ◽  
...  
Keyword(s):  
Nonlinear Model ◽  
Experimental Approach ◽  
Spectral Characteristics ◽  
Chinese Painting ◽  
Mixing Models ◽  
Nonlinear Mixing ◽  
Shortwave Infrared ◽  
Fully Constrained Least Squares ◽  
Spectral Mixing ◽  
Continuum Removal

Hyperspectral technology has been used to identify pigments that adhere to the surfaces of polychrome artifacts. However, the colors are often produced by the mixing of pigments, which requires that the spectral characteristics of the pigment mixtures be considered before pigment unmixing is conducted. Therefore, we proposed an experimental approach to investigate the nonlinear degree of spectral reflectance, using several mixing models, and to evaluate their performances in the study of typical mineral pigments. First, five mineral pigments of azurite, malachite, cinnabar, orpiment, and calcite were selected to form five groups of samples, according to their different mass ratios. Second, a fully constrained least squares algorithm based on the linear model and three algorithms based on the nonlinear model were employed to calculate the proportion of each pigment in the mixtures. We evaluated the abundance accuracy as well as the similarity between the measured and reconstructed spectra produced by those mixing models. Third, we conducted pigment unmixing on a Chinese painting to verify the applicability of the nonlinear model. Fourth, continuum removal was also introduced to test the nonlinearity of mineral pigment mixing. Finally, the results indicated that the spectral mixing of different mineral pigments was more in line with the nonlinear mixing model. The spectral nonlinearity of mixed pigments was higher near to the wavelength corresponding to their colors. Meanwhile, the nonlinearity increased with the wavelength increases in the shortwave infrared bands.

scholarly journals Shortwave infrared-absorbing squaraine dyes for all-organic optical upconversion devices

2021 ◽  
Author(s):  
Karen Strassel ◽  
Wei-Hsu Hu ◽  
Sonja Osbild ◽  
Daniele Padula ◽  
Daniel Rentsch ◽  
...  
Keyword(s):  
Squaraine Dyes ◽  
Shortwave Infrared ◽  
Optical Upconversion

scholarly journals Identification of peat type and humification by laboratory VNIR/SWIR hyperspectral imaging of peat profiles with focus on fen-bog transition in aapa mires

2020 ◽  
Author(s):  
L. Granlund ◽  
M. Keinänen ◽  
T. Tahvanainen
Keyword(s):  
Hyperspectral Imaging ◽  
Near Infrared ◽  
Support Vector ◽  
High Resolution Imaging ◽  
Factors Affecting ◽  
Vector Machines ◽  
Resolution Imaging ◽  
Shortwave Infrared ◽  
Type Classification ◽  
Wide Potential

Abstract Aims Hyperspectral imaging (HSI) has high potential for analysing peat cores, but methodologies are deficient. We aimed for robust peat type classification and humification estimation. We also explored other factors affecting peat spectral properties. Methods We used two laboratory setups: VNIR (visible to near-infrared) and SWIR (shortwave infrared) for high resolution imaging of intact peat profiles with fen-bog transitions. Peat types were classified with support vector machines, indices were developed for von Post estimation, and K-means clustering was used to analyse stratigraphic patterns in peat quality. With separate experiments, we studied spectral effects of drying and oxidation. Results Despite major effects, oxidation and water content did not impede robust HSI classification. The accuracy between Carex peat and Sphagnum peat in validation was 80% with VNIR and 81% with SWIR data. The spectral humification indices had accuracies of 82% with VNIR and 56%. Stratigraphic HSI patterns revealed that 36% of peat layer shifts were inclined by over 20 degrees. Spectral indices were used to extrapolate visualisations of element concentrations. Conclusions HSI provided reliable information of basic peat quality and was useful in visual mapping, that can guide sampling for other analyses. HSI can manage large amounts of samples to widen the scope of detailed analysis beyond single profiles and it has wide potential in peat research beyond the exploratory scope of this paper. We were able to confirm the capacity of HSI to reveal shifts of peat quality, connected to ecosystem-scale change.

Synthesis of novel tetracationic asymmetric monomeric monomethine cyanine dyes - highly fluorescent dsDNA probes

2010 ◽  
Vol 127 (1) ◽  
pp. 69-74 ◽  
Author(s):  
Aleksey Vasilev ◽  
Todor Deligeorgiev ◽  
Stefka Kaloyanova ◽  
Stanimir Stoyanov ◽  
Vera Maximova ◽  
...  
Keyword(s):  
Cyanine Dyes

scholarly journals Mineral Detection Using Sharpened VNIR and SWIR Bands of Worldview-3 Satellite Imagery

2021 ◽  
Vol 13 (10) ◽  
pp. 5518
Author(s):  
Honglyun Park ◽  
Jaewan Choi
Keyword(s):  
Spatial Resolution ◽  
Satellite Imagery ◽  
Near Infrared ◽  
False Negative ◽  
Similarity Score ◽  
Majority Voting ◽  
Similarity Analysis ◽  
Spectral Angle Mapper ◽  
Mineral Detection ◽  
Shortwave Infrared

Worldview-3 satellite imagery provides panchromatic images with a high spatial resolution and visible near infrared (VNIR) and shortwave infrared (SWIR) bands with a low spatial resolution. These images can be used for various applications such as environmental analysis, urban monitoring and surveying for sustainability. In this study, mineral detection was performed using Worldview-3 satellite imagery. A pansharpening technique was applied to the spatial resolution of the panchromatic image to effectively utilize the VNIR and SWIR bands of Worldview-3 satellite imagery. The following representative similarity analysis techniques were implemented for the mineral detection: the spectral angle mapper (SAM), spectral information divergence (SID) and the normalized spectral similarity score (NS3). In addition, pixels that could be estimated to indicate minerals were calculated by applying an empirical threshold to each similarity analysis result. A majority voting technique was applied to the results of each similarity analysis and pixels estimated to indicate minerals were finally selected. The results of each similarity analysis were compared to evaluate the accuracy of the proposed methods. From that comparison, it could be confirmed that false negative and false positive rates decreased when the methods proposed in the present study were applied.

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