H-type molecular aggregation as assembly with chromophore dipoles arranged parallel to each other has been observed in absorption and luminescence spectra of divinylbenzoxazolylbiphenyl thin films deposited on quartz glass substrate by thermovacuum method. The reversible changes of fluorescence anisotropy have been observed under film heating below the glass transition temperature correlating with lifetime changes. The addition of oxygen was found to cause an essential luminescence quenching. The hexyloxy group in the side chain of dibenzoxazolylbiphenyl molecule decreases H-type molecular aggregation and energy migration, and increases luminescence quenching induced by adsorbed oxygen owing to the formation of more porous film morphology.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1007/s10895-008-0325-2 | DOI Listing |
Biosensors (Basel)
January 2025
Laboratory of Biochemistry, Molecular Biology and Bioluminescent Systems Technology, Department of Physics, Chemistry and Mathematics, Federal University of Sao Carlos (UFSCAR), Rodovia João Leme dos Santos, km 110, Sorocaba 18052-780, SP, Brazil.
Firefly luciferases have been extensively used for bioanalytical applications, including their use as bioluminescent reporters, biosensors, and for bioimaging biological and pathological processes. Due to their intrinsic pH- sensitivity, in recent years we have demonstrated that firefly luciferases can also be harnessed as color- tuning sensors of intracellular pH. However, it is known that mammalian cells require temperatures higher than 36 °C, which red-shift the bioluminescence spectra of most firefly luciferases, decreasing their activities and the resolution of ratiometric pH analysis.
View Article and Find Full Text PDFRSC Adv
January 2025
Departamento de Física Aplicada, Facultade de Óptica e Optometríae Instituto de Materiais (iMATUS) Campus Vida, Universidade de Santiago de Compostela (USC) 15782 Galicia Spain.
The Cr and Sm doped GdAlO perovskite with formula GdSmAlCrO, was synthesized a solid-state reaction method, and its structure, morphology, and photoluminescence properties were thoroughly investigated. The compound crystallizes in the orthorhombic space group, with Cr transition-metal ions substituting Al in the octahedral symmetry site, and Sm lanthanide (rare-earth) ions occupying the tetrahedral site. The material's morphology and chemical composition homogeneity were evaluated through Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray analysis.
View Article and Find Full Text PDFLuminescence
January 2025
Department of Display Science and Engineering, Pukyong National University, Busan, Republic of Korea.
The influence of Eu concentration on the crystal structure and photoluminescence (PL) properties of Ca(PO):xEu (0.06 ≤ x ≤ 0.10) phosphors is systematically investigated using X-ray diffraction (XRD) Rietveld refinement, scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, UV-visible spectroscopy, and PL spectroscopy.
View Article and Find Full Text PDFThe GSAG:Ce scintillator represents a promising and cost-effective alternative to the expensive GGAG:Ce. Recent studies have attributed its low light yield to the thermal quenching effect. In this study, we employed the strategy of adding an yttrium (Y) admixture to the GSAG matrix to increase the thermal activation energy of thermal quenching.
View Article and Find Full Text PDFLuminescence
January 2025
Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, Assam, India.
The fused heterocycle 1-(imidazo[5,1-a]isoquinolin-3-yl)naphthalen-2-ol (LH) has been synthesized and characterized by spectroscopic methods. Probe LH upon irradiation with λ = 336 nm exhibited strong fluorescence with λ = 437 nm in MeOH/HEPES buffer (5 mM, pH = 7.4, 2:8, v/v).
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!