Novel Photophysical Properties of Gold Selenide Complexes:  Photogeneration of Singlet Oxygen by [Au18Se8(dppe)6]Br2and Near-Infrared Photoluminescence of [Au10Se4(dpppe)4]Br2

2002 ◽  
Vol 106 (35) ◽  
pp. 9019-9026 ◽  
Author(s):  
Sergei Lebedkin ◽  
Timo Langetepe ◽  
Paloma Sevillano ◽  
Dieter Fenske ◽  
Manfred M. Kappes
Keyword(s):  
Singlet Oxygen ◽  
Near Infrared ◽  
Photophysical Properties

scholarly journals New Approach in the Application of Conjugated Polymers: The Light-Activated Source of Versatile Singlet Oxygen Molecule

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1098
Author(s):  
Agata Blacha-Grzechnik
Keyword(s):  
Conjugated Polymers ◽  
Singlet Oxygen ◽  
Near Infrared ◽  
Photophysical Properties ◽  
Short Review ◽  
The Novel ◽  
New Approach ◽  
Intermolecular Energy ◽  
Intermolecular Energy Transfer ◽  
High Absorption

For many years, the research on conjugated polymers (CPs) has been mainly focused on their application in organic electronics. Recent works, however, show that due to the unique optical and photophysical properties of CPs, such as high absorption in UV–Vis or even near-infrared (NIR) region and efficient intra-/intermolecular energy transfer, which can be relatively easily optimized, CPs can be considered as an effective light-activated source of versatile and highly reactive singlet oxygen for medical or catalytic use. The aim of this short review is to present the novel possibilities that lie dormant in those exceptional polymers with the extended system of π-conjugated bonds.

Low toxic ytterbium complexes of 2,4-dimethoxyhematoporphyrin IX for luminescence diagnostics of tumors

2013 ◽  
Vol 2 (3) ◽  
Author(s):  
Andrey V. Ivanov ◽  
Valentina D. Rumyantseva ◽  
Igor P. Shilov ◽  
Valerii M. Markushev ◽  
Andrey I. Panas ◽  
...  
Keyword(s):  
Singlet Oxygen ◽  
Near Infrared ◽  
Tumor Tissue ◽  
Malignant Tumors ◽  
Photophysical Properties ◽  
Oxygen Generation ◽  
Ytterbium Complexes ◽  
Order Of Magnitude ◽  
Low Toxic ◽  
Selective Accumulation

Abstract:This article deals with the creation of new low-toxic photosensitizers on the basis of Ytterbium-2,4-dimethoxyhematoporphyrin IX (Yb-DMHP) and their application for the luminescence diagnostics of cancer. These substances were found to weakly generate singlet oxygen, exhibit pronounced luminescence, and retain the tumor-tropic properties of therapeutic photosensitizers. Basic photophysical properties of Yb-DMHP were studied, and the primary toxicological and pharmacokinetic investigations were performed in the organisms of experimental animals. The 4f-luminescence of Yb-DMHP in the near infrared (NIR) spectral region was observed. Comparative investigations were performed for one of the photodynamic medications which have been approved for clinical application: “Photoditazin”, a diglucosamine salt of chlorin e6. It was shown that the efficiency of singlet oxygen generation is lower by approximately one order of magnitude in the case of Yb-DMHP. The experimental data prove that Yb-DMHP-based substances are promising as non-toxic markers for the luminescence diagnostics of malignant tumors in the NIR spectral range (900–1100 nm), because they are free of the phototoxicity that is typical of conventional porphyrins, while at the same time providing a relatively high luminescence contrast and a selective accumulation in tumor tissue.

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.

scholarly journals Photophysical Properties of Protoporphyrin IX, Pyropheophorbide-a, and Photofrin® in Different Conditions

2021 ◽  
Vol 14 (2) ◽  
pp. 138
Author(s):  
Bauyrzhan Myrzakhmetov ◽  
Philippe Arnoux ◽  
Serge Mordon ◽  
Samir Acherar ◽  
Irina Tsoy ◽  
...  
Keyword(s):  
Singlet Oxygen ◽  
Photophysical Properties ◽  
Protoporphyrin Ix ◽  
Fluorescence Emission ◽  
Solvent Polarity ◽  
Visible Absorption ◽  
Light Dosimetry ◽  
Time Resolved ◽  
Pyropheophorbide A ◽  
Influence Of Solvent

Photodynamic therapy (PDT) is an innovative treatment of malignant or diseased tissues. The effectiveness of PDT depends on light dosimetry, oxygen availability, and properties of the photosensitizer (PS). Depending on the medium, photophysical properties of the PS can change leading to increase or decrease in fluorescence emission and formation of reactive oxygen species (ROS) especially singlet oxygen (1O2). In this study, the influence of solvent polarity, viscosity, concentration, temperature, and pH medium on the photophysical properties of protoporphyrin IX, pyropheophorbide-a, and Photofrin® were investigated by UV-visible absorption, fluorescence emission, singlet oxygen emission, and time-resolved fluorescence spectroscopies.

Biodegradable Nano-photosensitizer with Photoactivatable Singlet Oxygen Generation for Synergistic Phototherapy

2021 ◽  
Author(s):  
Jiaxin Shen ◽  
Dandan Chen ◽  
Ye Liu ◽  
Guoyang Gao ◽  
Zhihe Liu ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Cancer Therapy ◽  
Singlet Oxygen ◽  
Near Infrared ◽  
Promising Method ◽  
Normal Cells ◽  
Oxygen Generation ◽  
Singlet Oxygen Generation ◽  
Nir Light

Photodynamic therapy (PDT) is a promising method for cancer therapy and also may initiate unexpected damages to normal cells and tissues. Herein, we developed a near-infrared (NIR) light-activatable nanophotosensitizer, which...

scholarly journals Photoreactivity of Hair Melanin from Different Skin Phototypes—Contribution of Melanin Subunits to the Pigments Photoreactive Properties

2021 ◽  
Vol 22 (9) ◽  
pp. 4465
Author(s):  
Krystian Mokrzynski ◽  
Shosuke Ito ◽  
Kazumasa Wakamatsu ◽  
Theodore G. Camenish ◽  
Tadeusz Sarna ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Singlet Oxygen ◽  
Near Infrared ◽  
Paramagnetic Resonance ◽  
Time Resolved ◽  
W Band ◽  
Epr Oximetry ◽  
X Band ◽  
Hair Samples ◽  
Electron Paramagnetic

Photoreactivity of melanin has become a major focus of research due to the postulated involvement of the pigment in UVA-induced melanoma. However, most of the hitherto studies were carried out using synthetic melanin models. Thus, photoreactivity of natural melanins is yet to be systematically analyzed. Here, we examined the photoreactive properties of natural melanins isolated from hair samples obtained from donors of different skin phototypes (I, II, III, and V). X-band and W-band electron paramagnetic resonance (EPR) spectroscopy was used to examine the paramagnetic properties of the pigments. Alkaline hydrogen peroxide degradation and hydroiodic acid hydrolysis were used to determine the chemical composition of the melanins. EPR oximetry and spin trapping were used to examine the oxygen photoconsumption and photo-induced formation of superoxide anion, and time-resolved near infrared phosphorescence was employed to determine the singlet oxygen photogeneration by the melanins. The efficiency of superoxide and singlet oxygen photogeneration was related to the chemical composition of the studied melanins. Melanins from blond and chestnut hair (phototypes II and III) exhibited highest photoreactivity of all examined pigments. Moreover, melanins of these phototypes showed highest quantum efficiency of singlet oxygen photogeneration at 332 nm and 365 nm supporting the postulate of the pigment contribution in UVA-induced melanoma.

Synthesis of NIR-emitting O-chelated BODIPYs fused with benzene and acenaphthylene

2014 ◽  
Vol 18 (08n09) ◽  
pp. 752-761 ◽  
Author(s):  
Tetsuo Okujima ◽  
Yoichi Shida ◽  
Keishi Ohara ◽  
Yuya Tomimori ◽  
Motoyoshi Nishioka ◽  
...  
Keyword(s):  
Near Infrared ◽  
Photophysical Properties ◽  
Fluorescence Emission ◽  
Fluorescence Measurement ◽  
Aromatic Rings ◽  
Nir Absorption ◽  
Intense Absorption ◽  
Near Infrared Dye

A series of O-chelated BODIPYs fused with aromatic rings such as benzene and acenaphthylene at β,β-positions was synthesized as a near-infrared dye. The photophysical properties were examined by UV-vis-NIR absorption and fluorescence measurement. Acenaphthylene-fused O-BODIPYs showed a intense absorption at 750–840 nm with the ε of 105 M-1.cm-1. and a fluorescence emission at 770–850 nm with the high Φ value of 0.06–0.43.

The Photophysical Properties of Pyropheophorbide-a in Different Laser Light and PDT Efficiency for Eca-109 Cell In Vitro

2011 ◽  
Vol 393-395 ◽  
pp. 1029-1032
Author(s):  
Hui Jing Mao ◽  
Zhi Long Chen ◽  
Ying Ye
Keyword(s):  
Singlet Oxygen ◽  
Laser Light ◽  
Photophysical Properties ◽  
Oxygen Probe ◽  
Oxygen Production ◽  
Light Power ◽  
Oxygen Generation ◽  
Pyropheophorbide A ◽  
Single Oxygen

Pyropheophorbid-a (PyroPheo) is one of the well-known photosensitizers which can be useful for future clinical applications. This work is aimed to compare and measure generation rates of single oxygen through activation of pyropheophorbide-a by four different wavelength, and observe the sensitivity of pyropheophorbide-a mediated photodynamic therapy for eca-109 cell. Methods: UV-vis spectrophotometrics was used to measure decrease of singlet oxygen probe 9,10-dimethylanthracene(DPBF) so as to evaluate singlet oxygen production generation. The Eca-109 cells were were exposed to light (650nm) with a constant light power of 200mW/cm2, at a distance of 5cm, for 25 to 200 seconds. The results were measured by MTT assay. Results: pyropheophorbide-a in DMF solution irradiation by different light power can produce singlet oxygen quickly. Comparison of single oxygen generation rate has proved that photodynamic effect at 532nm is fastest, followed by 650nm, 635nm, 690nm which has correlation with absorbance of pyropheophorbide-a. The survival rate of cells dropped after irradiation by light what was significantly different from other groups. Conclusion: pyropheophorbide-a is an excellent photosensitizer and prooxidant. Through activated by different wavelength it could be apply to different disease

scholarly journals Unsymmetrical Heptamethine Dyes for NIR Dye-Sensitized Solar Cells

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Thomas Geiger ◽  
Iuliia Schoger ◽  
Daniel Rentsch ◽  
Anna Christina Véron ◽  
Frédéric Oswald ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Solar Cells ◽  
Solar Cell ◽  
Near Infrared ◽  
Photophysical Properties ◽  
Dye Sensitized Solar Cells ◽  
Dye Sensitized ◽  
Sensitized Solar Cells ◽  
Nir Dye ◽  
Proof Of Principle

Seven unsymmetrical heptamethine dyes with carboxylic acid functionality were synthesized and characterized. These near-infrared dyes exhibit outstanding photophysical properties depending on their heterocyclic moieties and molecular structure. As proof of principle, the dyes were used as photosensitizers in dye-sensitized solar cells. Using the most promising dye, an overall conversion efficiency of 1.22% and an almost colorless solar cell were achieved.

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