- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Photo-Physical Properties of Thermally Activated Delayed Fluorescent Materials upon Distortion of Central Axis of Donor Moiety
摘要： In this study, we showed the distortion of central axis of donor moiety can switch critically the rate of reverse intersystem crossing (kRISC) process, which is the trigger point to modulate the lifetime of delayed fluorescence. To achieve kRISC what we desired (105 to 106 s-1) in a series of donor-acceptor-donor (D-A-D) type thermally activated delayed fluorescence (TADF) materials, the donor groups (phenoxazine and phenothiazine) was selectively introduced. Maintaining the near orthogonality between donor and acceptor (benzonitrile) moiety, the occurrence of the distortion of central axis of donor moiety could make the effect of locally excited triplet state (3LE). In other words, the interaction between 3LE and the charge transfer counterparts (i.e., 1CT and 3CT) contributes an opposite propensity of kRISC for each target TADF materials when those are dissolved in solution and condensed in solid-state. Herein, we have theoretically and experimentally shown the photo-physical behavior of common D-A-D type TADF upon the different system.
关键词： Reverse Intersystem Crossing,Thermally Activated Delayed Fluorescence,Benzonitrile,Phenoxazine,Donor-Acceptor-Donor,Phenothiazine
更新于2025-09-09 09:28:46
-
Production and Characterization of Vacuum Deposited Organic Light Emitting Diodes
摘要： A method for producing simple and efficient thermally-activated delayed fluorescence organic light-emitting diodes (OLEDs) based on guest-host or exciplex donor-acceptor emitters is presented. With a step-by-step procedure, readers will be able to repeat and produce OLED devices based on simple organic emitters. A patterning procedure allowing the creation of personalized indium tin oxide (ITO) shape is shown. This is followed by the evaporation of all layers, encapsulation and characterization of each individual device. The end goal is to present a procedure that will give the opportunity to repeat the information presented in cited publication but also using different compounds and structures in order to prepare efficient OLEDs.
关键词： ambipolar,Donor-Acceptor,Thermally Activated Delayed Fluorescence,exciplex,Organic Electronics,patterning,thermal evaporation,Issue 141,OLED,Engineering
更新于2025-09-09 09:28:46
-
Performance characterisation of a real-time fiber dosimetry system using radiophotoluminescent glasses
摘要： We report the first demonstration of a real-time fiber-optic-coupled dosimetry system using Ag-activated phosphate glasses based on radiophotoluminescent (RPL) phenomena. The performance characterisation using real-time fiber RPL glass dosimetry is compared with that of real-time fiber plastic scintillation dosimetry. The inevitable build-up phenomena occurring in Ag-activated RPL glasses both during and after X-ray exposure were measured. The real-time RPL curves for the X-ray exposure region and the build-up region are analytically evaluated and fitted to the second-order polynomial functions and the sum of three exponentials, respectively. In addition, some resolved problems of real-time fiber RPL glass dosimetry are discussed.
关键词： X-ray exposure,real-time fiber dosimetry,build-up phenomena,radiophotoluminescent glasses,Ag-activated phosphate glasses
更新于2025-09-09 09:28:46
-
Versatile polymeric microspheres with tumor-microenvironment bioreducible degradation, pH-activated surface charge-reversal, pH-triggered “off-on” fluorescence and drug release as theranostic nanoplatforms
摘要： Facile approach has been developed for the versatile polymeric microspheres with tumor-microenvironment bioreducible degradation, pH-activated surface charge-reversal, pH-triggered “off-on” fluorescence and drug release via emulsion copolymerization of glycidyl methacrylate (GMA), poly(ethylene glycol) methyl ether methacrylate (PEGMA), N-rhodamine 6G-ethyl-acrylamide (Rh6GEAm) with N,N-bis(acyloyl)cystamine) (BACy) as disulfide crosslinker and functionalization. The final PGMA-DMMA microspheres showed excellent cytocompatibility, pH-triggered surface charge reversal at pH 5-6, strong fluorescence only in acidic media, and bioreducible degradation with high reductant level, indicating their promising application as theranostic nanoplatforms for precise imaging-guided diagnosis and chemotherapy. The DOX-loaded PGMA-DMMA microspheres with a drug-loading capacity of 18% and particle size of about 150 nm possessed unique pH/reduction dual-responsive controlled release, with a cumulative DOX release of 60.5% within 54 h at the simulated tumor microenvironment but a premature leakage of < 8.0% under the simulated physiological condition. Enhanced inhibition efficacy against HepG2 cells was achieved than the free DOX.
关键词： tumor-microenvironment bioreducible degradation,pH-triggered “off-on” fluorescence,pH-triggered drug release,theranostic nanoplatforms,pH-activated surface charge-reversal,polymeric microspheres
更新于2025-09-09 09:28:46
-
Importance of Chromophore Rigidity on the Efficiency of Blue Thermally Activated Delayed Fluorescence Emitters
摘要： Four new symmetrical donor?acceptor?donor (D?A?D)-type molecules are reported with diphenylamine (DPA) or 10,11-dihydro-5H-dibenz[b,f ]azepine (Az) as electron donors and 9,9-dimethylthioxanthene-S,S-dioxide (TXO2) as the electron acceptor. The donors are attached at different positions on the acceptor core: either para or meta to the sulfone unit. This series provides new insights into the effects of chromophore rigidity/flexibility on the efficiency of thermally activated delayed fluorescence (TADF). The molecules have been characterized by X-ray crystallography, by in-depth photophysical studies, and by theoretical calculations. The clear differences observed in the photophysical properties when using DPA or Az as a donor are shown to originate from different geometries of the donor unit which, in turn, influence the geometry of the nitrogen lone pair and the donating strength of the corresponding fragment. Thus, a para-substituted Az derivative demonstrated blue TADF in polar media, while the compounds with more flexible DPA units did not show delayed fluorescence. To obtain deep-blue emitters, weaker donating units are needed. A more flexible donor unit leads to increased local excited state (donor) LE emission and reduced TADF. However, a certain amount of flexibility has to be present to ensure deep-blue TADF.
关键词： chromophore rigidity,blue emitters,donor-acceptor-donor,photophysical properties,thermally activated delayed fluorescence
更新于2025-09-04 15:30:14
-
Cell-Penetrating Peptides Transport Noncovalently Linked Thermally Activated Delayed Fluorescence Nanoparticles for Time-Resolved Luminescence Imaging
摘要： Luminescent probes and nanoparticles (NPs) with long excited state lifetimes are essential for time-resolved biological imaging. Generally, cell membranes are physiological barriers that could prevent the uptake of many unnatural compounds. It is still a big challenge to prepare biocompatible imaging agents with high cytomembrane permeability, especially for nonmetallic NPs with long-lived luminescence. Herein, an amphiphilic cell-penetrating peptide, F6G6(rR)3R2, was designed to transport hydrophobic fluorophores across cellular barriers. Three classical thermally activated delayed fluorescence (TADF) molecules, 4CzIPN, NAI-DPAC, and BTZ-DMAC, could self-assemble into well-dispersed NPs with F6G6(rR)3R2 in aqueous solution. These NPs showed low cytotoxicity and could penetrate membranes easily. Moreover, long-lived TADF enabled them to be used in time-resolved luminescence imaging in oxygenic environments. These findings greatly expanded the applications of cell-penetrating peptides for delivery of molecules and NPs by only noncovalent interactions, which were more flexible and easier than covalent modifications.
关键词： cell-penetrating peptide,Luminescent probes,time-resolved biological imaging,nanoparticles,noncovalent interactions,thermally activated delayed fluorescence
更新于2025-09-04 15:30:14
-
Hybrid Nanomedicine Fabricated from Photosensitizer-Terminated Metal-Organic Framework Nanoparticles for Photodynamic Therapy and Hypoxia-Activated Cascade Chemotherapy
摘要： During photodynamic therapy (PDT), severe hypoxia often occurs as an undesirable limitation of PDT owing to the O2-consuming photodynamic process, compromising the effectiveness of PDT. To overcome this problem, several strategies aiming to improve tumor oxygenation are developed. Unlike these traditional approaches, an opposite method combining hypoxia-activated prodrug and PDT may provide a promising strategy for cancer synergistic therapy. In light of this, azido-/photosensitizer-terminated UiO-66 nanoscale metal–organic frameworks (UiO-66-H/N3 NMOFs) which serve as nanocarriers for the bioreductive prodrug banoxantrone (AQ4N) are engineered. Owing to the effective shielding of the nanoparticles, the stability of AQ4N is well preserved, highlighting the vital function of the nano-carriers. By virtue of strain-promoted azide–alkyne cycloaddition, the nanocarriers are further decorated with a dense PEG layer to enhance their dispersion in the physiological environment and improve their therapeutic performance. Both in vitro and in vivo studies reveal that the O2-depleting PDT process indeed aggravates intracellular/tumor hypoxia that activates the cytotoxicity of AQ4N through a cascade process, consequently achieving PDT-induced and hypoxia-activated synergistic therapy. Benefiting from the localized therapeutic effect of PDT and hypoxia-activated cytotoxicity of AQ4N, this hybrid nanomedicine exhibits enhanced therapeutic efficacy with negligible systemic toxicity, making it a promising candidate for cancer therapy.
关键词： hypoxia-activated prodrugs,cascade therapy,nanoscale metal–organic frameworks,banoxantrone,photodynamic therapy
更新于2025-09-04 15:30:14
-
High Performance Thermally Activated Delayed Fluorescence Sensitized Organic Light‐Emitting Diodes
摘要： Recently, organic light-emitting diodes (OLEDs) employing thermally activated delayed fluorescence (TADF) materials have aroused huge attention in both academia and industry. Compared with fluorescent and phosphorescent materials, TADF materials can theoretically capture 100 % excitons without incorporating noble metals, making them effective emitters and hosts for OLEDs simultaneously. Here, in this review, our recent works on mechanisms and materials of high performance TADF-sensitized phosphorescent (TSP) OLEDs, TADF-sensitized fluorescent (TSF) OLEDs and TADF-sensitized TADF (TST) OLEDs are summarized. Finally, we propose the outlook for the further development and application of TADF-sensitized OLEDs.
关键词： bipolar host,Dexter energy transfer,organic light-emitting diodes,F?rster energy transfer,thermally activated delayed fluorescence
更新于2025-09-04 15:30:14
-
FK506 suppresses hypoxia-induced inflammation and protects tight junction function via the CaN-NFATc1 signaling pathway in retinal microvascular epithelial cells
摘要： The present study aimed to identify whether FK506 suppresses hypoxia?induced inflammation and protects tight junction function via the calcineurin-nuclear factor of activated T?cells 1 (CaN?NFATc1) signaling pathway in mouse retinal microvascular endothelial cells (mRMECs). The mRMECs were treated with FK506 at different concentrations following the induction of hypoxia. Trans?epithelial electrical resistance (TEER) and cell permeability were examined to measure the integrity of the tight junctions. The concentrations of inflammatory cytokines were measured using reverse transcription-quantitative polymerase chain reaction analysis and enzyme?linked immunosorbent assays. The protein expression levels of zonula occludens-1 (ZO-1) and nuclear factor of activated T?cell 1 (NFATc1) were identified using immunofluorescent microscopy and western blot analysis. The TEER value was decreased following hypoxia, but increased following treatment with FK506 (1 and 10 μM) for 24 and 48 h. The protein expression of ZO?1 was also increased following FK506 treatment for 24 h at 1 and 10 μM. By contrast, following treatment with FK506 (1 and 10 μM) for 24 and 48 h, the elevated cell permeability in the hypoxia group was significantly downregulated. Similarly, the concentrations of inflammatory cytokines, including cyclooxygenase?2, inducible nitric oxide synthase, monocyte chemoattractant protein-1, interleukin?6, intercellular adhesion molecule?1 and vascular cell adhesion molecule?1, were downregulated following treatment with FK506 for 24 h at 1 and 10 μM. Following treatment with FK506, the level of total NFATc1 was downregulated and the level of phosphorylated NFATc1 was upregulated. Taken together, FK506 suppressed injury to the tight junctions and downregulated the expression of inflammatory cytokines in hypoxia?induced mRMECs via the CaN?NFATc1 signaling pathway. This suggests a potentially effective therapy for hypoxia?induced retinal microangiopathy.
关键词： inflammation,hypoxia,tight junction,calcineurin?nuclear factor of activated T?cells 1 signaling pathway,FK506
更新于2025-09-04 15:30:14
-
A Study on Photocatalytic Behaviors of Activated Carbon Fibers Impregnated with N-Doped Titania
摘要： Activated carbon ?bers (ACFs) impregnated with N-doped titania were prepared via the sol–gel method and sonochemical synthesis. The photocatalytic behavior of rhodamine B showed that N-doped TiO2/ACF nanocomposites exhibited enhanced photocatalytic activity. This result could be attributed to the synergistic effect between the high adsorption capacity of ACF and the visible light photocatalytic activity of N-doped TiO2. In particular, the N-doped TiO2/ACF nanocomposite that was sonicated four times had the highest photocatalytic ef?ciency and degradation rate, owing to the optimal N-doped TiO2 loading and nanocomposite pore structure.
关键词： N-doped TiO2,Sonochemical Synthesis,Activated Carbon Fibers,Photodegradation
更新于2025-09-04 15:30:14