- 标题
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- 实验方案
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Fluorescence sensor for facile and visual detection of organophosphorus pesticides using AIE fluorogens-SiO2-MnO2 sandwich nanocomposites
摘要： Organophosphorus pesticides (OPs) are frequently for pest control in the agriculture industry. Accumulation of OPs is harmful to the environment and human health. Thus, facile and portable detection of organophosphorus pesticides is of great importance. Among these methods, the fluorescence assay holds the advantages of high sensitivity, simplicity, nondestructive properties. Conventional fluorophores have the drawbacks of poor photostability and low signal-to-noise ratio due to their aggregation-caused quenching drawbacks at high concentration or in the aggregate state. Aggregation-induced emission fluorogens (AIEgens) are one key to develop next-generation fluorescence sensor due to their high emission efficiency in the aggregated state. 1,2-bis[4-(3-sulfonatopropoxyl) phenyl]-1,2-diphenylethene (BSPOTPE) is a typical AIE molecule containing two hydroxyl group. In this study, a fluorescence sensor based on BSPOTPE-SiO2–MnO2 sandwich nanocomposites was fabricated. Thiocholine (TCh), which produced from acetylthiocholine(ATCh) by the hydrolysis of acetylcholinesterase (AChE), can “turn on” the fluorescence sensor. Based on the inhibition effect of OPs on AChE activity and the corresponding “turn off” effect on the fluorescence sensor, an AIE-based assay for OPs determination was developed. The fabricated sensor for paraoxon determination has a good linear relationship in the range of 1–100 μg/L and the LOD of 1 μg/L. Moreover, a simple, convenient fluorescence strip for visual semi-quantitative of OPs was fabricated, indicating this “on-off” fluorescent sensor is promising for on-site and infield detection.
关键词： Organophosphorus pesticide,AIE fluorogen,Fluorescence sensor,MnO2 nanosheets
更新于2025-09-19 17:15:36
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AIE active piperazine appended naphthalimide-BODIPYs: photophysical properties and applications in live cell lysosomal tracking
摘要： Piperazine appended naphthalimide-BODIPYs (NPB1–NPB4) exhibiting solvatochromism and aggregation-induced emission with a large Stokes shift (up to 146 nm) have been described. Separation of naphthalimide and BODIPY fluorophores by piperazine in these conjugates creates a donor–acceptor system and induces twisted intramolecular charge transfer, in addition to photoinduced electron transfer. The crucial role of naphthalimide, the alkyl chain length, the piperazine ring, and the solid-state packing on AIE has been extensively investigated by various studies. Superior cell permeability coupled with bio-compatibility of these conjugates offers a unique opportunity for their potential applications in live cell lysosomal tracking.
关键词： solvatochromism,piperazine,naphthalimide,lysosomal tracking,BODIPY,AIE
更新于2025-09-19 17:15:36
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High-efficiency near-infrared fluorescent organic light-emitting diodes with small efficiency roll-off based on AIE-active phenanthro[9,10- <i>d</i> ]imidazole derivatives
摘要： The simultaneous realization of high-efficiency and low-cost in fluorescent organic light-emitting diodes (OLEDs) is still a formidable challenge in deep-red (DR)/near-infrared (NIR) region because of the intrinsic limitation of the energy-gap law and fluorescence quenching effect. Herein, three novel donor-acceptor-donor′ (D-A-D′) fluorophores, PIBz-10-PTZ, PIBz-10P-PTZ and PIBz-3-PTZ, by utilizing phenanthro[9,10-d]imidazole and phenothiazine as the donor, benzothiadiazole as the acceptor are synthesized. Owing to the unilateral steric hindrance between adjacent hydrogen atoms along the horizontal axis, PIBz-3-PTZ possesses a completely planar conformation and fully conjugated structure. PIBz-3-PTZ exhibits a strong DR emission and aggregation induced emission (AIE) property with a high photoluminescence quantum yield of 35% in neat thin film. The nondoped OLEDs achieved a maximum external quantum efficiency (EQE) of 2.02% with an emission peak at 672 nm and the brightness of up to 3403 cd m-2. In addition, the device was able to maintain an EQE of 1.69% at high luminance of 100 cd m-2, with a low efficiency roll-off of 16%, suggesting the nondoped device can keep the brightness.
关键词： Near-Infrared,High-Efficiency,AIE-active,Phenanthro[9,10-d]imidazole Derivatives,Organic Light-Emitting Diodes,Small Efficiency Roll-Off,Fluorescent
更新于2025-09-19 17:13:59
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Green-light-induced melting of self-assembled azobenzene nano/microstructures
摘要： We report the formation of green-light-responsive fluorescent aggregates composed of trigonal molecules having three ortho-dialkylated azobenzene wings at the periphery (a green-light-responsive 3BuES and an aggregation-induced emission/aggregation-induced emission enhancement [AIE/AIEE]-active 3BuAz). Exposure of the respective (3BuES and 3BuAz) spheres to green light leads to color tuning and/or fluorescence switching. The results can be rationalized in terms of green-light-induced molecular conformational changes of the trigonal azobenzene molecules and the resulting phase transition of the self-assembled structures. For instance, irradiation of 3BuES with green light produces B35% of U-shaped cis forms (i.e., approximately one-third of the trans-azobenzene units isomerizes to the cis forms), which seems to be su?cient to weaken the degree of the molecular packing of the trigonal azobenzene frameworks and lower the melting temperatures. Moreover, to apply the excellent fluorescence switching functions of 3BuAz aggregates to create new fluorescent organic materials, we used a co-assembly of 3BuES–3BuAz binary mixtures. Our important approach for obtaining green-light-responsive fluorescent nano/microstructures from the binary mixtures is phase separation based on the structural difference between 3BuES (having a planar central core) and 3BuAz (having a distorted conformation), which helps retain the fluorescence functions of the AIE/AIEE-active 3BuAz chromophore. Scanning electron microscopy (SEM), optical microscopy (OM), and fluorescence optical microscopy (FOM) observations prove apparent green-light-induced melting, color tuning and fluorescence switching of the phase-separated structures (i.e., microspheres and nanoparticles).
关键词： green-light-responsive,AIE/AIEE,azobenzene,fluorescent aggregates,fluorescence switching,phase separation
更新于2025-09-16 10:30:52
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Molecular Engineering of Thermally Activated Delayed Fluorescence Emitters with Aggregation-Induced Emission via Introducing Intramolecular Hydrogen-Bonding Interactions for Efficient Solution-Processed Nondoped OLEDs
摘要： Purely organic luminescent materials concurrently exhibiting thermally activated delayed fluorescence (TADF) and aggregation-induced emission (AIE) features are in great demand due to their high efficiency in aggregation-state toward efficient non-doped OLEDs. Herein, a class of thermally activated delayed fluorescence (TADF) emitters adopting phenyl(pyridyl)methanone as electron-accepting segment and di(tert-butyl)carbazole and 9,9-dimethyl-9,10-dihydroacridine (or phenoxazine) as electron-donating groups are designed and synthesized. The existence of intramolecular hydrogen bonding is conducive to minish the energy difference between singlet and triplet (ΔEst), suppress non-radiative decay and increase the luminescence efficiency. By using 3CPyM-DMAC as emitter, the non-doped device via solution process realize high current efficiency (CE) and external quantum efficiency (EQE) of 35.4 cd A-1 and 11.4 %, respectively, which is superior to that of CBM-DMAC with CE and EQE of 14.3 cd A-1 and 6.7 %. This work demonstrates a promising tactics to the establishment of TADF emitters with AIE features via introducing intramolecular hydrogen-bonding.
关键词： organic light-emitting diodes (OLEDs),nondoped,thermally activated delayed fluorescence (TADF),solution processed,aggregation-induced emission (AIE)
更新于2025-09-12 10:27:22
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Finely Controlled Circularly Polarized Luminescence of a Mechano-Responsive Supramolecular Polymer
摘要： We report on finely controlled circularly polarized luminescence (CPL) supramolecular polymerization based on a tetraphenylethene core with four L- or D-alanine branch side chains (L-1 and D-1) in the solution state resulting from the tuning of mechanical stimulus. Weak, green emissions of L-1 and D-1 in tetrahydrofuran (THF) were converted to strong blue emissions by tuning the mechanical stimulus. The strong blue emissions were caused by an aggregation-induced emission (AIE) effect during the formation of a supramolecular polymer. Lag time in the supramolecular polymerization was drastically reduced by the mechanical stimulus, which was indicative of the acceleration of the supramolecular polymerization. Interestingly, a significant enhancement of circular dichroism (CD) and CPL signals of the L-1 and D-1 was observed by tuning the rotational speed of the mechanical stimulus, which implies that the chiral supramolecular polymerization was accelerated by the mechanical stimulus. These results imply that the CPL signals were tuned by the strength of the external mechanical stimulus.
关键词： Helicity,AIE Effect,Mechano-Responsive Material,Circularly Polarized Luminescence,Supramolecular Polymerization
更新于2025-09-11 14:15:04
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New pyrene-based butterfly-shaped blue AIEgens: Synthesis, structure, aggregation-induced emission and their nondoped blue OLEDs
摘要： Developing the blue emitters with excellent electroluminescence (EL) performance is crucial for full-color displays and solid-state lighting. Based on the synthetic strategy for exploring highly efficient luminescent solids by constructing aggregation-induced emission (AIE) systems, two new pyrene-based butterfly-shaped blue AIEgens, Py(5,9)BTPE and Py(5,9)BTriPE, have been successfully designed and synthesized by integrating two tetraphenylethylene (TPE) or triphenylethylene (TriPE) groups into pyrene ring. The adoption of the pyrene unit with a large optical bandgap, the use of the TPE or TriPE group with AIE characteristic, the integration of the TPE or TriPE group into pyrene ring at 5,9-positions, and the highly twisted molecular conformations of present AIE systems endow the two compounds with bright blue emission in the solid state. These foregoing features ensure that the new pyrene-based compounds can serve as excellent blue-emitting materials in OLEDs. A non-doped OLED based on Py(5,9)BTPE exhibited a sky-blue emission (Von: 3.2 V) with a CIE coordinates of (0.19, 0.28), a maximum external quantum efficiency (EQEmax) of 3.35%, a current efficiency (CE) of 6.51 cd A-1 with a low efficiency roll-off that represents one of the highest value reported for sky-blue AIE-based OLEDs. An analogous device with Py(5,9)BTriPE as an emitting layer displayed a pure-blue emission (CIE: 0.16, 0.17) with a moderate EQEmax of 1.27% and a CE of 1.63 cd A-1 with a low efficiency roll-off. Furthermore, the EL emissions of the two devices display almost no change with the increasing of the current density, indicating their good color stability.
关键词： nondoped OLED,blue AIEgens,aggregation-induced emission (AIE),phenylethylene,pyrene
更新于2025-09-11 14:15:04
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Use of Aggregation-Induced Emission for Selective Detection of Phase Transformation during Evaporative Crystallization of Hexaphenylsilole
摘要： Crystallization of organic molecules is quite complicated because the crystallization process is governed by the weak intermolecular interactions. By exploiting the aggregation-induced emission (AIE), we attempted to realize the selective detection of phase transformation during the evaporative crystallization of hexaphenylsilole (HPS), which shows different fluorescence colors in the amorphous and crystalline phases. No fluorescence emission was observed in the HPS solution immediately after dropping on the glass substrate due to the non-radiative deactivation induced by intramolecular rotational or vibrational motion, suggesting that HPS exists as a monomer in solution. As time elapsed after dropping, green emission first appeared, which changed to blue after solvent evaporation, because of phase transformation from the amorphous state to the crystalline state. This phenomenon supports not only the two-step nucleation model involving an intermediate such as a liquid-like cluster prior to nucleation, but also the real time-detection of Ostwald’s rule of stages during evaporative crystallization.
关键词： molecular interaction,amorphous-crystal phase transformation,AIE,Ostwald’s rule of stages,evaporative crystallization
更新于2025-09-10 09:29:36
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Highly-efficient solid-state emission of tethered anthracene-o-carborane dyads and their visco- and thermo-chromic luminescence properties
摘要： A facile and efficient method is described to greatly improve the emission efficiency of anthracene-o-carborane dyad by linking two o-carborane building blocks together through tailored alkyl linkages. Improvement of the emission efficiency of the tethered anthracene-o-carborane dyads was achieved with the quantum yield up to 40.8% and 51.4% for BCAC4 and BCAC6 respectively, in contrast to that of CAH (4.3%) and CAA (36%), demonstrating that the cooperation advocates that one plus one is much bigger than two. In addition, these developed emissive AIE luminogens exhibit impressive response to the environmental stimuli of viscosity and temperature. DFT calculations were carried out to explore the influence of the anthryl and alkyl linkages on emission efficiency. Our materials and concepts are useful as a guideline for designing o-carborane-containing highly-efficient solid luminescent materials with stimuli-responsive properties.
关键词： Alkyl linkages,Visco- and thermochromic,Anthracene,AIE,o-Carborane
更新于2025-09-10 09:29:36
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Exploring aggregation-induced emission through tuning of ligand structure for picomolar detection of pyrene
摘要： Tuning of ligand structures through controlled variation of ring number in fused‐ring aromatic moiety appended to antipyrine allows detection of 7.8 × 10?12 M pyrene via aggregation‐induced emission (AIE) associated with 101‐fold fluorescence enhancement. In one case, antipyrine unit is replaced by pyridine to derive bis‐methylanthracenyl picolyl amine. The structures of four molecules have been confirmed by single crystal X‐ray diffraction analysis. Among them, pyrene‐antipyrine conjugate (L) undergoes pyrene triggered inhibition of photo‐induced electron transfer (PET) leading to water‐assisted AIE.
关键词： pyrene,AIE,sensor,SPE,SC‐XRD
更新于2025-09-10 09:29:36