We demonstrated that fluorescence anisotropy can be effectively decreased or increased in the presence of light quenching, depending on relative polarizations of excitation and quenching pulses. For parallel light quenching, anisotropy decreases to 0.103 and z-axis symmetry is preserved. In the presence of perpendicular light quenching, the steady-state anisotropy of a pyridine-2-glycerol solution increases from 0.368 for an unquenched sample to 0.484 for a quenched one. We show that the angular distribution of transition moments loses z-axis symmetry in the presence of perpendicular light quenching. In these cases we used more general definitions of anisotropy. Induced by light quenching, anisotropy can be applied in both steady-state and time-resolved measurements. In particular, the systems with low or no anisotropy can be investigated with the proposed technique.
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Pharmaceutics
December 2024
Department of Pharmacy, Faculty of Health and Medical Science, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark.
: This study aims to broaden the knowledge on co-amorphous phospholipid systems (CAPSs) by exploring the formation of CAPSs with a broader range of poorly water-soluble drugs, celecoxib (CCX), furosemide (FUR), nilotinib (NIL), and ritonavir (RIT), combined with amphiphilic phospholipids (PLs), including soybean phosphatidylcholine (SPC), hydrogenated phosphatidylcholine (HPC), and mono-acyl phosphatidylcholine (MAPC). : The CAPSs were initially prepared at equimolar drug-to-phospholipid (PL) ratios by mechano-chemical activation-based, melt-based, and solvent-based preparation methods, i.e.
View Article and Find Full Text PDFMolecules
December 2024
Guangdong Key Laboratory for Hydrogen Energy Technologies, Key Laboratory of Digital Decorative Materials for Building Ceramics in Guangdong Province, School of Materials and Energy, Foshan University, Foshan 528000, China.
Traditional organic light-emitting materials hinder their anti-counterfeiting application in solid state due to their aggregation-caused quenching effect. A facile and straightforward method was reported to introduce AIE molecules into microspheres and manipulate different reaction parameters to prepare AIE microspheres with different morphologies. In this strategy, fluorescent microspheres with spherical, apple-shaped, and hemoglobin-like types were synthesized.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Center of Super-Diamond and Advanced Films (COSDAF) and Department of Chemistry, City University of Hong Kong, Hong Kong SAR, 999077, P. R. China.
A new aggregation-induced emission (AIE) luminogen is obtained by dimerizing acridin-9(10H)-one (Ac), an aggregation-caused quenching (ACQ) effect monomer via an N─N bond and forming 9H,9'H-[10,10'-biacridine]-9,9'-dione (DiAc) with D symmetry. The quenching of DiAc in solution is ascribed to the enhanced basicity promoting hydrogen bonding and then a hydrogen abstraction (HA) reaction and/or an unallowed transition in frontier orbitals with the same symmetry facilitating intersystem crossing. It is found that emissive Ac is one product of the non-emissive DiAc solution in the HA reaction activated by UV irradiation.
View Article and Find Full Text PDFLight Sci Appl
January 2025
Institute of Functional Nano & Soft Materials (FUNSOM), Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices, Soochow University, Suzhou, China.
Perovskite quantum dots (PQDs) show promise in light-emitting diodes (LEDs). However, near-infrared (NIR) LEDs employing PQDs exhibit inferior external quantum efficiency related to the PQD emitting in the visible range. One fundamental issue arises from the PQDs dynamic surface: the ligand loss and ions migration to the interfacial sites serve as quenching centers, resulting in trap-assisted recombination and carrier loss.
View Article and Find Full Text PDFJ Phys Chem Lett
January 2025
Department of Chemistry and Biochemistry, University of California, Santa Cruz, California 95064, United States.
Lead-free halide double perovskites (DPs) have become a research hotspot in the field of photoelectrons due to their unique optical properties and flexible compositional tuning. However, the luminescence of DPs exhibits thermal quenching at high temperatures, which severely affects their further application. Herein, we synthesized the rare earth Dy and transition metal Mn codoped CsNaYCl rare earth DPs and characterized the optical properties using temperature-dependent photoluminescence spectra and time-resolved photoluminescence decay profiles at different temperatures.
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