Active media based on polyurethane doped with a binary dye mixture

Subject and Purpose. The article is concerned with the spectral-luminescent and lasing characteristics of the radiation from solid-state active media based on polyurethane activated by a binary mixture of dyes. The purpose of these studies is to demonstrate a possibility of the spectral range expansion of the emission from solid-state dye lasers with polyurethane active elements. Methods and Methodology. Specially prepared samples of polyurethane active media having the same donor (Rhodamine 6G) concentration but various acceptor (Sulforhodamine 101) concentrations are experimentally studied for their spectral-luminescent and lasing characteristics. Results. The main spectroscopic characteristics of Rhodamine 6G and Sulforhodamine 101 in polyurethane have been measured, the nonradiative energy transfer parameters in this molecular pair estimated. It has been demonstrated that the matrix emission spectrum can be purposefully transformed by selection of relative concentrations of dyes in the mixture. In a broadband resonator, either a single- or two-band emission with different positions and various intensities of spectral bands is observed depending on the acceptor concentration. In a dispersive resonator under the same conditions, the tuning range of the lasing spectrum expands and extends to the longer wavelengths. Conclusion. The prospects of using donor-acceptor dye mixtures for improving spectral characteristics of polyurethane active elements in solid-state dye lasers have been confirmed. It has been shown that signatures of the emission characteristics of these media are governed by the mechanism of the excitation energy transfer between dye molecules. Lasing has been obtained on polyurethane matrices with the emission wavelength tuning throughout the “green-red” region of the spectrum.

Polyurethane-coated luminescent dye@MOF composites for highly-stable white LEDs

A blue-excitable phosphor was obtained by encapsulating pyrromethene 546, pyrromethene 605 and sulforhodamine 101, into the MOF ZIF-8. Utilizing polyurethane as a protective coating, the photostability was remarkably enhanced by 52.54%.

A highly efficient light-harvesting system with sequential energy transfer based on a multicharged supramolecular assembly

A highly efficient light-harvesting system with two-step sequential energy transfer was designed by the nonconvalent interaction of pillar[5]arene with pyridinium modified tetraphenylethene, sulforhodamine 101 and sulfonated aluminum phthalocyanine.

Investigation of Five Organic Dyes in Ethanol and Butanol for Two-Color Laser-Induced Fluorescence Ratio Thermometry

In this article, we compare absorption and temperature-dependent fluorescence spectra of five organic dyes for 2c-LIF (two-color laser-induced fluorescence) thermometry in ethanol and butanol. The dyes fluorescein, eosin Y, rhodamine B, rhodamine 6G, and sulforhodamine 101 individually mixed in ethanol and butanol were studied at liquid temperatures of 25–65 °C. The self-absorption spectral bands are analyzed along with intensity ratios and the respective sensitivities for one-dye and two-dye 2c-LIF thermometry are deduced. For one-dye 2c-LIF, rhodamine B showed the highest sensitivity of 2.93%/°C and 2.89%/°C in ethanol and butanol, respectively. Sulforhodamine 101 and rhodamine 6G showed the least sensitivities of 0.51%/°C and 1.24%/°C in ethanol and butanol, respectively. For two-dye 2c-LIF, rhodamine B/sulforhodamine 101 exhibited the highest temperature sensitivities of 2.39%/°C and 2.54%/°C in ethanol and butanol, respectively. The dye pair eosin Y/sulforhodamine 101 showed the least sensitivities of 0.15%/°C and 0.27%/°C in ethanol and butanol, respectively.

Dosimetry and Toxicity Studies of the Novel Sulfonamide Derivative of Sulforhodamine 101([18F]SRF101) at a Preclinical Level

Background: The SR101 N-(3-[18F]Fluoropropyl) sulfonamide ([18F]SRF101) is a Sulforhodamine 101 derivative that was previously synthesised by our group. The fluorescent dye SR101 has been reported as a marker of astroglia in the neocortex of rodents in vivo. Objective: The aim of this study was to perform a toxicological evaluation of [18F]SRF101 and to estimate human radiation dosimetry based on preclinical studies. Methods: Radiation dosimetry studies were conducted based on biokinetic data obtained from a mouse model. A single-dose toxicity study was carried out. The toxicological limit chosen was <100 μg, and allometric scaling with a safety factor of 100 for unlabelled SRF101 was selected. Results: The absorbed and effective dose estimated using OLINDA/EXM V2.0 for male and female dosimetric models presented the same tendency. The highest total absorbed dose values were for different sections of the intestines. The mean effective dose was 4.03 x10-3 mSv/MBq and 5.08 x10-3 mSv/MBq for the male and female dosimetric models, respectively, using tissue-weighting factors from ICRP-89. The toxicity study detected no changes in the organ or whole-body weight, food consumption, haematologic or clinical chemistry parameters. Moreover, lesions or abnormalities were not found during the histopathological examination. Conclusion: The toxicological evaluation of SRF101 verified the biosafety of the radiotracer for human administration. The dosimetry calculations revealed that the radiation-associated risk of [18F]SRF101 would be of the same order as other 18F radiopharmaceuticals used in clinical applications. These study findings confirm that the novel radiotracer would be safe for use in human PET imaging.