- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Introducing Trifluoromethyl to Strengthen Hydrogen Bond for High Efficiency Organic Solar Cells
摘要： Nowadays, the ternary strategy has become a common way to improve the power conversion efficiency (PCE) of organic solar cells (OSCs). The intermolecular interaction between the third component and donor or acceptor plays a key role in achieving a high performance. However, hydrogen bond as a strong intermolecular interaction is rarely considered in ternary OSCs. In this work, we introduce trifluoromethyl on a newly synthesized small molecular DTBO to strength hydrogen bonds between DTBO and IEICO-4F. Due to the existence of hydrogen bonds has a strong impact on electrostatic potential (ESP) and benefits π-π stacking in the active layer, the ternary OSCs show superior charge extraction and low charge recombination. In DTBO, PTB7-Th and IEICO-4F based ternary devices, the PCE increases from 11.02 to 12.48%, and short-circuit current density (JSC) increases from 24.94 to 26.43 mA/cm2 compared with typical binary devices. Moreover, the addition of DTBO can realize an energy transfer from DTBO to PTB7-Th and broaden the absorption spectrum of blend films. Grazing-incidence wide-angle X-ray scattering (GIWAXS) patterns show that the π-π stacking distance of IEICO-4F decreased after adding 10 wt% DTBO. The effect of the hydrogen bond is also achieved in the PM6: Y6 system, showing 16.64% efficiency by comparison to the 15.49% efficiency of binary system. This work demonstrates that introduce trifluoromethyl to enhance hydrogen bond which improve π-π stacking can achieve higher performance in OSCs.
关键词： energy transfer,ternary devices,organic solar cells,hydrogen bond,π-π stacking
更新于2025-09-23 15:19:57
-
Human Neutrophil Elastase Activated Fluorescent Probe for Pulmonary Diseases Based on Fluorescence Resonance Energy Transfer Using CdSe/ZnS Quantum Dots
摘要： There is an increasing demand for effective noninvasive diagnosis against common pulmonary diseases which are rising sharply due to the serious air pollution. Human neutrophil elastase (HNE), a typical protease highly involved in pulmonary inflammatory diseases and lung cancer, is a potential predictor for disease progression. Currently, few of HNE-targeting probes is applicable In Vivo due to the limitation in sensitivity and biocompatibility. Herein we reported the achievement of In Vitro detection and In Vivo imaging of HNE, by incorporating the HNE-specific peptide substrate, quantum dots (QDs) and organic dyes into the fluorescence resonance energy transfer (FRET) system. The refined nanoprobe, termed as QDP, could specifically measure the HNE with excellent sensitivity of 7.15 pM at aqueous solution, and successfully image the endogenous and exogenous HNE in living cells. In addition, this nanoprobe enabled the HNE imaging in the mouse models of lung cancer and acute lung injury, and continuously monitored the HNE activity at high temporal and spatial resolution. Most importantly, QDP successfully discriminated the serums of patients with lung diseases from those of the healthy controls based on the HNE activity determination. Overall, this study demonstrates the advantages of FRET system-based nanoprobe in imaging performance and provides an applicable tool for In Vivo HNE detection and pulmonary diseases diagnosis.
关键词： human neutrophil elastase,quantum dots,pulmonary diseases,lung cancer,fluorescence resonance energy transfer
更新于2025-09-23 15:19:57
-
Single-molecule F?rster Resonance Energy Transfer Measurement Reveals Dynamic Partially Ordered Structure of the Epidermal Growth Factor Receptor C-tail Domain
摘要： Intrinsically disordered proteins (IDPs) or regions (IDRs) are thought to exhibit unique functionalities without forming ordered structures. However, these molecular mechanisms are not easily elucidated, partly because of the difficultly of measuring structural information. In this study, we applied the alternative laser excitation (ALEX) method and circular dichroism (CD) spectroscopy to investigate the structure of the C-terminal tail (CTT) domain of the human epidermal growth factor receptor (EGFR). The single-molecule distributions of F?rster resonance energy transfer (FRET) obtained by ALEX under solution conditions modified by the addition of potassium chloride (KCl), urea or guanidinium chloride (GdmCl) allowed us to separately examine the influences of charge interactions and secondary structure formation. The CD spectrum analyses indicated the types of included secondary structure. The results suggested that the structure of the CTT is influenced by secondary structure formation, which is principally antiparallel β-sheet, rather than by charge interactions, and that phosphorylation of the major Grb2-binding sites partially denature that secondary structure. Our findings suggest that the EGFR CTT might regulate ligand binding kinetics by local β-sheet formation or by the disruption associated with phosphorylation states.
关键词： Circular dichroism,Epidermal Growth Factor Receptor,F?rster resonance energy transfer,Secondary structure,Intrinsically disordered proteins
更新于2025-09-23 15:19:57
-
Synergy of light harvesting and energy transfer as well as short-range charge shift reactions in multicomponent conjugates
摘要： We report herein on the design, the synthesis, and the characterization of a panchromatic, charge stabilizing electron donor–acceptor conjugate: (BBPA)3–ZnPor–ZnPc–SubPc 1. Each component, that is, bis(biphenyl)phenylamine (BBPA), Zn(II) porphyrin (ZnPor), Zn(II) phthalocyanine ZnPc, and subphthalocyanine (SubPc), has been carefully chosen and modified to enable a cascade of energy and charge transfer processes. On one hand, ZnPor, has been functionalized with three electron-donating BBPA as primary and secondary electron donors and to stabilize the final charge-separated state, and, on the other hand, a perfluorinated SubPc has been selected as ultimate electron acceptor. In addition, the ZnPc unit contains several trifluoromethylphenyl moieties to match its energy levels to those of the other components. In fact, irradiation of the heteroarray 1 triggers a cascade of light harvesting across the entire visible range, unidirectional energy transfer, exergonic charge separating, and short-range charge shifting to afford a (BBPA)3(cid:129)+–ZnPor–ZnPc–SubPc(cid:129)? charge-separated state. The lifetime of the latter reaches well into the range of tens of nanoseconds with a 14% quantum yield.
关键词： charge stabilizing,light harvesting,panchromatic,charge transfer,energy transfer,porphyrinoids,electron donor–acceptor conjugate
更新于2025-09-19 17:15:36
-
Fluorogenic “photoclick” labelling of DNA using a Cy3 dye
摘要： Two 2’-deoxyuridines as new building blocks for automated DNA synthesis carry a small aryltetrazole as “photoclickable” group at their 5-positions. The postsynthetic “photoclick” labeling of such presynthesized DNA using a maleimide-modified Cy3 dye shows an up to 17-fold fluorogenicity due to an energy transfer between the pyrazoline moiety and the Cy3 fluorophore in the DNA products. This concept is also applicable to other maleimide-modified dyes.
关键词： Fluorogenic labeling,DNA,tetrazole,photoclick reaction,energy transfer,Cy3 dye
更新于2025-09-19 17:15:36
-
Energy Transfer Networks Within Upconverting Nanoparticles Are Complex Systems With Collective, Robust, and History-Dependent Dynamics
摘要： Applications of photon upconverting nanoparticles (UCNPs) in biological imaging and solar energy conversion demand that their anti-Stokes luminescence be both tunable and efficient. Rational design of more efficient UCNPs requires an understanding of energy transfer (ET) between their lanthanide dopants – dynamics that are typically characterized by measuring luminescence lifetimes. Existing knowledge, however, cannot explain basic observations in lifetime experiments such as their dependence on excitation power, significantly limiting the generality and reliability of lifetime measurements. Here, we elucidate the origins of the ET dynamics and luminescence lifetimes of Yb3+,Er3+-codoped NaYF4 UCNPs using time-resolved luminescence and novel applications of rate equations and stochastic simulations. Experiments and calculations consistently show that, at high concentrations of Er3+, the luminescence lifetimes of UCNPs decrease as much as 6-fold when excitation power densities are increased over six orders of magnitude. Since power-dependent lifetimes cannot be explained by intrinsic relaxation rates of individual transitions, we analyze lifetime data by treating each UCNP as a complex ET network. We find that UCNP ET networks exhibit four distinguishing characteristics of complex systems: collectivity, nonlinear feedback, robustness, and history dependence. We conclude that power-dependent lifetimes are the consequence of thousands of minor relaxation pathways that act collectively to depopulate and repopulate Er3+ emitting levels. These ET pathways are dependent on past excitation power because they originate from excited donors and excited acceptors; however, each transition has an unexpectedly small impact on lifetimes due to negative feedback in the network. This robustness is determined by systematically 'knocking out,' or disabling, ET transitions in kinetic models. Our classification of UCNP ET networks as complex systems explains why UCNP luminescence lifetimes do not match the intrinsic lifetimes of emitting states. In the future, UCNP networks may be engineered to rival the complexity of biological networks that pattern features with unmatched precision.
关键词： complex systems,energy transfer,upconverting nanoparticles,lanthanide dopants,power dependence,luminescence lifetimes
更新于2025-09-19 17:15:36
-
Diversity-Oriented Synthesis and Optical Properties of Bichromophoric Pyrrole-Fluorophore Conjugates
摘要： The mild reaction conditions of the palladium-copper coupling-isomerization reaction open a highly convergent, chromogenic route to blue emissive pyrroles in the sense of a consecutive four-component reaction. By virtue of this strategy a phenol derivative can be readily accessed, which can be transformed in a level-2 transformation to a library of bichromophoric pyrrol-fluorophore conjugates by facile alkylation with fluorophore halides. The photophysics of the underlying blue emitter derivative and the conjugates is studied by absorption and emission spectroscopy, furnishing intramolecular energy transfer at short distances as well as competing fluorescence quenching. In some cases partial energy transfer results in the occurrence of dual emission, for instance seen as magenta-rose emission arising from blue and red orange luminescence. The experimental photophysical studies are rationalized by DFT and TD-DFT calculations.
关键词： DFT,multicomponent reaction,energy transfer,level-2 functionalization,absorption,emission,bichromophores,pyrrole
更新于2025-09-19 17:15:36
-
Coherence turned on by incoherent light
摘要： One of the most pertinent problems in the debate on non-trivial quantum effects in biology concerns natural photosynthesis. Since sunlight is composed of thermal photons, it was argued to be unable to induce quantum coherence in matter, and that quantum mechanics is therefore irrelevant for the dynamical processes following photoabsorption. Our present analysis of a toy 'molecular aggregate'—composed of two dipole–dipole interacting two-level atoms treated as an open quantum system—however shows that incoherent excitations indeed can trigger persistent, coherent dynamics in both the site and the exciton bases: we demonstrate that collective decay processes induced by the dipole–dipole interactions create coherent intermolecular transport—regardless of the coherence properties of the incoming radiation. Our analysis shows that the steady state coherence is mediated by the population imbalance between the molecules and, therefore, increases with the energy difference between the two-level atoms. Our results establish the importance of collective decay processes in the study of ultrafast photophysics, and especially their potential role to generate stationary coherence in incoherently driven quantum transport.
关键词： molecular aggregate,energy transfer,coherence,dipole–dipole interaction,thermal photons
更新于2025-09-19 17:15:36
-
Illuminating the intermolecular vs intramolecular excited state energy transfer quenching by Europium(III) ions
摘要： Bright lanthanide based probes relies on sensitised lanthanide luminescence. The outcome of the excited state energy transfer cascade—from sensitizer chromophore to lanthanide(III) ion—should be population of the lanthanide excited state with unity efficiency. This is rarely the case, and is a particular problem for europium(III) due to the low energy of the Eu(II)/Eu(III) redox couple. Thus, photoinduced electron transfer quenching can be an efficient drain for the excited state energy, reducing the brightness of a probe. Here, the effect of intramolecular PeT in a lanthanide based probe is investigated by contrasting intramolecular processes in coumarin-appended 1,4,7,10-tetraazacyclododecane-1,4,7-triacetate (DO3A) complexes to intermolecular processes induced through collisional quenching. We find that the excited energy transfer processes involving terbium(III) and europium(III) are slow in the complex when compared to collisional quenching. Further, we show that the quenching event may lead to lanthanide luminescence and suggest that the fate of a PeT quenching event may not be non-radiative loss of the excitation energy.
关键词： Lanthanides,Fluorescence,Luminescence,Excited State Energy Transfer,Solution Structure
更新于2025-09-19 17:15:36
-
Energy transfer and luminescence quenching of Cr3+-doped LiGaW2O8
摘要： Luminescence properties of the Cr3+-doped LiGaW2O8 crystals are investigated by laser excitation spectroscopy. The powder samples for various Cr3+ concentration were prepared by high-temperature solid state reaction. The temperature behaviors of the emission intensity and the decay time of the self-activated LiGaW2O8 host are discussed. The emission spectra and decay times of LiGa1-xW2O8:xCr3+ are measured under UV excitation in the temperature range 10 - 300 K. The luminescence quenching of LiGaW2O8:Cr3+ as functions of temperature and Cr3+-concentration is explained by structural and spectral characteristics.
关键词： luminescence quenching,temperature dependence.,energy transfer
更新于2025-09-19 17:15:36