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Dynamically Switching the Electronic and Electrostatic Properties of Indium Tin Oxide Electrodes with Photochromic Monolayers: Toward Photo-Switchable Optoelectronic Devices
摘要： The chemical modification of electrodes with organic materials is a common approach to tune the electronic and electrostatic landscape between interlayers in optoelectronic devices, thus facilitating charge injection at the electrode/semiconductor interfaces and improving their performance. The use of photochromic molecules for the surface modification allows dynamic control of the electronic and electrostatic properties of the electrode and thereby enables additional functionalities in such devices. Here, we show that the electronic properties of a transparent indium tin oxide (ITO) electrode are reversibly and dynamically modified by depositing organic photochromic switches (diarylethenes) in the form of self-assembled monolayers (SAMs). By combining a range of surface characterization and density functional theory calculations, we present a detailed picture of the SAM binding onto ITO, the packing density of molecules, their orientation, as well as the work function modification of the ITO surface due to the SAM deposition. Upon illumination with ultraviolet and green light, we observe a reversible shift of the frontier occupied levels by 0.7 eV, and concomitantly a reversible work function change of ca. 60 meV. Our results prove the viability of dynamic switching of the electronic properties of the electrode with external light stimuli upon modification with a monolayer of photochromic molecules, which could be used to fabricate ITO-based photo-switchable optoelectronic devices.
关键词： self-assembled monolayer,diarylethene,ITO,photochromic switch,interface electronic properties
更新于2025-11-14 14:32:36
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Synthesis and the effect of alkyl chain length on photochromic properties of diarylethene derivatives
摘要： A new class of photochromic diarylethenes bearing pyrrole and thiophene units with different length of alkyl chains at 2-position of thiophene rings have been synthesized. Their characteristics, including photochromism and fatigue resistance were investigated systematically, and each diarylethene derivative showed good photochromic properties whether in solution or in PMMA films. The alkyl group moiety was connected directly to the central cyclopentene ring as a heteroaryl unit and availably participated in photoisomerization reaction. And some properties, for example, the conversion ratio in the photostationary state(PSS) and the absorption coefficient of the ring-closed isomers in acetonitrile were significantly affected by the alkyl chain length. The results revealed that substituents of alkyl chain played an important role in the photoisomerization process of diarylethenes.
关键词： alkyl chain length,photochromism,pyrrole and thiophene units.,diarylethene
更新于2025-09-23 15:23:52
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A new fluorescence probe based on diarylethene with a benzothiazine unit for selective detection of Cd2+
摘要： A novel photochromic diarylethene derivative containing a benzothiazine unit has been synthesized. Its photochromism and fluorescent selectivity to metal ions were studied in detail in methanol solution. Under the stimulation of Cd2+ ions, the derivative showed a significant fluorescence enhancement and obvious red shift, accompanied by the fluorescent color changed from dark purple to bright blue. The 1 : 1 stoichiometry between the derivative and Cd2+ was verified by titration experiments and high resolution mass spectrometry. In addition, a molecular logic circuit was designed with the emission intensity at 476 nm as output and the stimuli of Cd2+/EDTA and UV/vis as inputs.
关键词： Fluorescence probe,Cadmium,Logic circuit,Diarylethene
更新于2025-09-23 15:21:21
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Quaternary Supramolecular Nanoparticles as a Photoerasable Luminescent Ink and Photocontrolled Cella??Imaging Agent
摘要： Photoswitchable luminescent supramolecular assemblies based on cyclodextrins have attracted considerable attention owing to their potential applications as smart materials, but most of the assemblies reported to date emit green or blue light with low contrast and high interference. In this study, novel photoluminescent red-luminescent quaternary supramolecular nanoparticles (2) are constructed from a dithienylethene derivative (1), a β-cyclodextrin-functionalized ruthenium complex (Ru-HOP-CD), Pluronic F-127, and cetrimonium bromide. Compared with the binary assembly 1@Ru-HOP-CD, the quaternary nanoparticles exhibit high fluorescence resonance energy transfer efficiency, with Ru-HOP-CD acting as the donor and 1 as the acceptor. Owing to the reversible photoswitched interconversion of the two forms of the dithienylethene component, the fluorescence of the nanoparticles could be switched on/off by irradiation with UV or visible light, both in solution and in the solid state. As a result, the nanoparticles could be used as a photoerasable red-luminescent ink and as a photocontrolled cell-imaging agent. These functional nanoparticles can be expected to be useful in the fields of information security and biology.
关键词： anticounterfeiting,cell imaging,cyclodextrin,photoerasable luminescent ink,diarylethene
更新于2025-09-23 15:21:01
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Diarylethene moiety as an enthalpy-entropy switch: photoisomerizable stapled peptides for modulating p53/MDM2 interaction
摘要： Analogs of the known inhibitor (peptide pDI) of the p53/MDM2 protein–protein interaction are reported, which are stapled by linkers bearing a photoisomerizable diarylethene moiety. The corresponding photoisomers possess significantly different affinities to the p53-interacting domain of the human MDM2. Apparent dissociation constants are in the picomolar-to-low nanomolar range for those isomers with diarylethene in the 'open' configuration, but up to eight times larger for the corresponding 'closed' isomers. Spectroscopic, structural, and computational studies showed that the stapling linkers of the peptides contribute to their binding. Calorimetry revealed that the binding of the 'closed' isomers is mostly enthalpy-driven, whereas the 'open' photoforms bind to the protein stronger due to their increased binding entropy. The results suggest that conformational dynamics of the protein-peptide complexes may explain the differences in the thermodynamic profiles of the binding.
关键词： Photoisomerizable stapled peptides,Thermodynamic profiles,p53/MDM2 interaction,Diarylethene,Conformational dynamics
更新于2025-09-23 15:21:01
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Structure-Activity Relationships of Photoswitchable Diarylethene-Based β-Hairpin Peptides as Membranolytic Antimicrobial and Anticancer Agents
摘要： Five series (28 structures) of photoswitchable β-hairpin peptides were synthesized, based on the cyclic scaffold of the natural antibiotic gramicidin S. Cell-type selectivity was compared for all activated (diarylethene ring-open) and deactivated (closed) forms in terms of antibacterial activity (MIC against E. coli and B. subtilis), anticancer activity (IC50 against HeLa cell line), and hemolytic cytotoxicity (HC50 against human erythrocytes). Correlations between the conformational plasticity of the peptides, their hydrophobicity and their bioactivity were also analyzed. Considerable improvements in selectivity were achieved compared to the reference compound. We found a dissociation of the anticancer activity from hemolysis. Phototherapeutic indices (PTI) – HC50(closed)/MIC(open) and HC50(closed)/IC50(open) – were introduced for the peptides as safety criteria. The highest PTI for HeLa-selective toxicity were observed among analogues containing hydroxyleucine on the hydrophobic face. For one compound, high PTIs were demonstrated across a range of different cancer cell lines, including a doxorubicin-resistant one.
关键词： photoswitchable diarylethene-based β-hairpin peptides,antimicrobial,phototherapeutic indices,gramicidin S,anticancer,hemolytic cytotoxicity
更新于2025-09-23 15:21:01
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A Polymerizable Photoswitchable Fluorophore for Super-Resolution Imaging of Polymer Self-Assembly and Dynamics
摘要： Single-molecule super-resolution microscopy has become a standard imaging tool in the life sciences for visualizing nanostructures in situ, but the application of this technique in polymer science is much less explored. A key bottleneck is the lack of fluorophores and simple covalent attachment strategies onto polymer chains. Here, we report a functional diarylethene-based photoswitchable fluorophore that can be directly incorporated into polymer backbones through copolymerization, which significantly streamlines the labeling strategy, with no further postcoupling reactions or purifications needed. The attachment of fluorophores onto selectively labeled polymers enables super-resolution imaging of a series of model polymer blend systems with different nanostructures and chemical compositions. As each individual fluorophore is able to switch several times on average between its bright and dark state, multiple time-lapse images can be acquired to observe the dynamic nanostructural evolution of polymer blends upon solvent vapor annealing. With this demonstration of a universal, simplified labeling strategy and the ability to image polymer assembly under native conditions, this reported fluorophore may promote the widespread use of super-resolution microscopy in the polymer community.
关键词： diarylethene,polymer dynamics,super-resolution microscopy,photoswitchable fluorophore,polymer self-assembly
更新于2025-09-23 15:21:01
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Photoinduced Regulation of the Heat Resistance in Polymer Networks with Diarylethene-Conjugated Reversible Covalent Cross-Links
摘要： A cross-linker with a diarylethene-conjugated Diels?Alder adduct (DAE/DA) was synthesized and applied in a radical polymerization system to afford polymer networks whose dynamic nature can be changed reversibly by photo-irradiation. Free-radical polymerization of hexyl methacrylate and the DAE/DA-based cross-linker furnished an insoluble and transparent poly(hexyl methacrylate) network with DAE/DA moieties at their cross-linking points, which undergo de-cross-linking via a thermally induced retro-DA reaction upon heating. The photoregulation of such a thermal de-cross-linking reaction in DAE/DA-based polymer networks was demonstrated by swelling experiments and tensile tests, revealing drastic changes in the heat resistance and mechanical properties upon exposure to UV?vis irradiation.
关键词： heat resistance,mechanical properties,polymer networks,diarylethene,photo-irradiation,Diels?Alder adduct
更新于2025-09-23 15:19:57
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A colorimetric and fluorescent chemosensor for Hg <sup>2+</sup> based on a photochromic diarylethene with a quinoline unit
摘要： A new colorimetric and fluorescent 'on–off' chemosensor, 1O, based on a photochromic diarylethene with a quinoline unit was designed and synthesized. The chemosensor 1O demonstrated selective and sensitive detection of Hg2+ ions in the presence of other competitive metal ions in acetonitrile. The stoichiometric ratio of the sensor 1O for Hg2+ was determined to be 1 : 1, and the limit of detection of the probe 1O was calculated to be 56.3 nM for Hg2+. In addition, a molecular logic circuit with four inputs and one output was successfully constructed with UV/vis light and metal-responsive behavior. ESI-MS spectroscopy, Job's plot analysis, and 1H NMR titration experiments confirm the binding behavior between 1O and Hg2+.
关键词： quinoline,logic circuit,fluorescent,Hg2+,colorimetric,diarylethene,chemosensor,photochromic
更新于2025-09-19 17:15:36
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Novel multi-responsive fluorescence switch for Hg2+ and UV/vis lights based on diarylethene-rhodamine derivative
摘要： A new multi-responsive fluorescent switch DTE-Pip-Rho 1O has been designed and synthesized in this study. For this molecule, the reactive site of spirolactam ring is far away from the diarylethene unit through the intramolecular piperazine. It exhibited high selectivity and sensitivity to Hg2+ in addition to obvious color change (colorless-pink) and fluorescence “off-on” (dark-orange) during this process. It is believed that the color change is due to Hg2+-assisted hydrolysis of rhodamine hydrazide. Therefore, the new molecule can be used as colorimetric and fluorescent chemosensor for Hg2+ with high selectivity. The detection limits of absorbance and fluorescence for Hg2+ were calculated to be 1.15 μM and 1.16 μM, respectively. The resulting DTE-Pip-Rho 1O-Hg2+ could also function as a reversible fluorescence photo-switch in response to UV/vis light owing to FRET mechanism. Moreover, it has been demonstrated that the photo-switchable system displayed excellent fatigue resistance and remarkable anti-photobleaching capability.
关键词： Multi-responsive,Fluorescent switch,Diarylethene,FRET mechanism,Sensor,Rhodamine
更新于2025-09-19 17:15:36