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Dual-emission color-controllable nanoparticle based molecular imprinting ratiometric fluorescence sensor for the visual detection of Brilliant Blue
摘要： Single-component dual-emission nanoparticles were synthesized by chelating the organic ligand 8-hydroxyquinoline (HQ) to the surface of CdTe/ZnS quantum dots, namely CdTe/ZnQ2, and were used to construct a novel mesoporous structured molecular imprinting ratiometric fluorescence sensor by facile one-pot sol-gel polymerization for the visual detection of Brilliant Blue. The CdTe/ZnQ2 had bimodal fluorescence belonging to CdTe and ZnQ2 segments, respectively; significantly, the emission wavelength of CdTe was optimized to be 630 nm for the largest overlap with the absorption spectrum of Brilliant Blue. Consequently, fluorescence resonance energy transfer (FRET) efficiency was greatly enhanced, resulting in ideal determination. A favorable linearity toward Brilliant Blue was obtained within 0–1.0 μmol?L-1 along with profuse color evolution from orange to yellowish orange to yellowish green to green, and a high detectability of 8.8 nmol?L-1 was offered. Excellent recognition selectivity for Brilliant Blue over possibly coexistent food colorants was demonstrated, with a high imprinting factor of 7.1. Furthermore, endogenous Brilliant Blue was detected ranging from 0.21–41.03 mg/kg in six typical food samples with relative standard deviations lower than 3.5%, and the results agreed well with that afforded by conventional methods. Using Brilliant Blue as a model, this dual-emission color-controllable nanoparticle based imprinting ratiometric fluorescence sensor provided promising perspectives for the highly selective and sensitive, rapid, visual detection of colored substances in complicated matrices.
关键词： Molecular imprinting,Brilliant Blue,Dual-emission nanoparticles,Ratiometric fluorescence,Visual detection
更新于2025-09-23 15:23:52
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Dual Emission of a Cyclic Hexanuclear Gold(I) Complex. Interplay between Au <sub/>3</sub> and Au <sub/>2</sub> Ligand-Supported Luminophores
摘要： Finding diverse and tunable molecular structures is relevant towards the design of functional nanostructures. The photoluminescence of complex 1, featuring ligand-supported hexanuclear Au(I) framework compromising a triangular Au3 core of which each apex is connected to an external Au(I) center has revealed a remarkable dual emission at room temperature. The emission bands display maxima centered at λem = 512 and 694 nm with Stokes shift of 19530 and 14410 cm-1 and are attributed to the radiative relaxation of two excited-states centered onto the central Au6 skeleton arising from 5dσ?→6pσ excitation. As suggested by the strikingly different dioxygen dependency of the relative intensity of the two emission bands, the observed dual emission can be tentatively attributed to the incomplete equilibration between two close-lying emissive excited states with singlet and triplet character, most likely due to slow intersystem crossing (ISC) process, yielding green fluorescence and red phosphorescence, respectively; this phenomenon is rarely observed in heavy element compounds. Based on theoretical calculations, these excited-states originated from two different substructures-luminophores of the molecular skeleton, mainly i) the Au3 core, and ii) one specific Au2 unit. Thus, the dual luminescence of 1 originates from the noteworthy inclusion of two luminophores within the overall molecular structure. Both solution and solid-state emission spectra show similar characteristics owing to the intramolecular nature of the suggested luminescence mechanism. Such luminophores can be envisaged as novel metalloligands to be incorporated in larger gold nanoclusters towards the development of intense luminescent molecular devices.
关键词： Au3 and Au2 Ligand-Supported Luminophores,Cyclic Hexanuclear Gold(I) Complex,Photoluminescence,Aurophilic Interactions,Dual Emission
更新于2025-09-23 15:21:21
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Trap-Controlled White Electroluminescence From a Single Red-Emitting Thermally Activated Delayed Fluorescence Polymer
摘要： Single white-emitting polymers have been reported by incorporating the second-generation carbazole dendron into the side chain of a red-emitting thermally activated delayed ?uorescence (TADF) polymer. Due to the prevented hole trap effect, in this case, excitons can be generated simultaneously on the polymeric host and the red TADF dopant to give a dual emission. Consequently, a bright white electroluminescence is achieved even at a dopant loading as high as 5 mol.%, revealing a maximum luminous ef?ciency of 16.1 cd/A (12.0 lm/W, 8.2%) and Commission Internationale de l’Eclairage (CIE) coordinates of (0.42, 0.32). The results clearly indicate that the delicate tuning of charge trap is a promising strategy to develop ef?cient single white-emitting polymers, whose low-band-gap chromophore content can be up to a centesimal level.
关键词： carbazole dendron,thermally activated delayed ?uorescence (TADF),dual emission,charge trap,single white-emitting polymers
更新于2025-09-23 15:21:01
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Dual-Emission and Two Charge Transfer States in Ytterbium-Doped Cesium Lead Halide Perovskite Solid Nanocrystals
摘要： Some unusual phenomena besides near-infrared emission of Yb3+ ions have been observed in ytterbium-doped perovskite solid nanocrystals. A systematic study on doping kinetic and energy transfer processes is presented. The observed unique dual-peak PL emission of perovskite nanocrystals in the visible region can be attributed to radiative recombination in the near-surface region and the interior region of perovskite nanocrystals respectively. Insight studies based on dual-peak PL emission clarify the kinetic process of doping in perovskite nanocrystals. After dopant concentration of rare earth ions in the near-surface region is more than a certain value, dopant ions are starting to be immersed into the interior region of host nanocrystals. The unusual excitation spectra of ytterbium-doped perovskite solid nanocrystals could be explained by the presences of two charge transfer (CT) states at ~24000 cm-1 (CT1) and ~21460 cm-1 (CT2), and both of them could be observed in the near-surface region of the perovskite host. Furthermore, the lifetime of near-infrared emission of Yb3+ ions through the CT2 state is three orders faster than that through CT1 state (in millisecond) which should be fixed on the surface of perovskite nanocrystals. The results provide essential insights into the dynamic carrier behaviors and surface effects of all inorganic perovskite nanocrystals doped with rare earth ions for expanded functionality.
关键词： dual-emission,kinetic process,rare earth,charge transfer states,Perovskite solid nanocrystals,energy transfer
更新于2025-09-23 15:21:01
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Heterostructural CsPbX3-PbS (X=Cl,Br,I) Quantum Dots with Tunable Vis-NIR Dual Emission
摘要： Perovskite and chalcogenide quantum dots (QDs) are important nano semiconductors. It has been a challenge to synthesize heterostructural QDs combining perovskite and chalcogenide with tailorable photoelectronic properties. In this report, heterostructural CsPbX3-PbS (X=Cl, Br, I) QDs were successfully synthesized via a room temperature in-situ transformation route. The CsPbX3-PbS QDs show a tunable dual emission feature with the visible and near infrared (NIR) photoluminescence (PL) corresponding to CsPbX3 and PbS, respectively. Typically, the formation and evolution of the heterostructural CsPbBr3-PbS QDs with reaction time was investigated. Femtosecond transient absorption spectroscopy (TAS) was applied to illuminate the exciton dynamics in CsPbBr3-PbS QDs. The mild synthetic method and TAS proved perovskite to PbS energy transfer may pave the way toward high efficient QD photovoltaic and optoelectronic devices.
关键词： Perovskite,Photoluminescence,Dual Emission,Heterojunction,Quantum-Dots
更新于2025-09-23 15:19:57
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A water-stable Eu <sup>III</sup> -based MOF as a dual-emission luminescent sensor for discriminative detection of nitroaromatic pollutants
摘要： A water-stable EuIII-based metal–organic framework (MOF) with dual-emission luminescence behavior, namely {[Eu4(INO)5(μ3-OH)2Cl4(H2O)]·(NO3)·(H2O)5}n (Eu-MOF; HINO = isonicotinic acid N-oxide), was successfully constructed by the solvothermal reaction of Eu3+ ions with the organic ligand HINO. The cationic 3D framework contains microporous channels with accessible Lewis-base sites and NO3? ions as balanced anions, which all contribute to the selective detection of multifarious analytes. This MOF shows ratiometric detection of acetone, Cr2O72? ions, and nitroaromatic compounds (NACs). In particular, it shows great recognition of four NACs in water, representing the first LnIII-MOF which can display distinguishing fluorescence phenomena on NACs rather than relying on the quenching effect. Furthermore, this is also the first example of a MOF-sensor for detecting these explosives discriminatively by ratiometric methods. Additionally, the mechanisms for luminescent responses towards different analytes have been discussed in detail.
关键词： luminescent sensor,dual-emission,ratiometric detection,EuIII-based MOF,nitroaromatic pollutants,water-stable
更新于2025-09-19 17:15:36
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Ratiometric fluorometric determination of silver(I) by using blue-emitting silicon- and nitrogen-doped carbon quantum dots and red-emitting N-acetyl-L-cysteine-capped CdTe quantum dots
摘要： A ratiometric fluorometric assay for silver(I) is described. The method makes use of a dually emitting quantum dot hybrid, which is composed of (a) blue-fluorescent silicon- and nitrogen-doped carbon quantum dots (CQDs), and (b) of red-emitting CdTe quantum dots (QDs) capped with N-acetyl-L-cysteine. The red-emitting CdTe QDs undergo strong and specific quenching by Ag(I), whereas the blue-emitting N,Si-CQDs are not quenched. The two kinds of QDs are mixed and used as a ratiometric fluorescent probe. A linear relationship is found between the log of intensities [(I608/I441)0/(I608/I441)] and the concentration of Ag(I) in the range from 5.0–1000 nM, and the limit of detection (at S/N = 3) is 1.7 nM. Possible interferents (including 17 general metal ions, 12 anions and fulvic acid) do not interfere with the determination. The assay was successfully used for the determination of Ag(I) in surface water and wastewater samples. The fluorescence quenching mechanism of the ratiometric assay system was also discussed in detailed.
关键词： Fluorescence quenching mechanism,Surface water,Nitrogen-doped carbon dots,Silver ions,Silicon-doped carbon dots,Wastewaters,3-Aminopropyltriethoxysilane functionalized carbon dots,Quenching efficiency,Dual-emission quantum dots hybrid,Fluorescent probe
更新于2025-09-19 17:13:59
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Surface state-controlled C-dot/C-dot based dual-emission fluorescent nanothermometers for intra-cellular thermometry
摘要： Fluorescence-based nanothermometers have potential to offer accuracy in the measurement of temperature using non-contact approaches. Herein, a C-dot/C-dot based dual-emission temperature sensing platform is fabricated through the electrostatic self-assembly of two kinds of fluorescent CDs with opposite charges. This dual-emission platform consists of several nearly-spherical CDs with two emission centers in blue (440 nm) and orange (590 nm) regions. The orange fluorescence exhibits discernible response to external temperatures in the range of ～15 to 85 °C; on the other hand, the blue fluorescence remains nearly constant. A continuous fluorescence color change in response to temperature from orange to blue can be clearly observed by the naked eye. Thus, the as-prepared C-dot based dual-emission nanospheres can be used for optical thermometry with high reproducibility and sensitivity (0.93%/°C). Detailed characterization shows that temperature (in the 15–85 °C window) impacts the surface states of orange emissive CDs, leaving the blue emissive CDs unaffected. A model is proposed to explain the observations. Finally, by taking advantage of the excellent biocompatibility and stability, the CD based fluorescent nanothermometer is successfully used for the visual measurement of intracellular temperature variations.
关键词： intracellular thermometry,temperature sensing,nanothermometers,dual-emission,fluorescence,carbon dots
更新于2025-09-11 14:15:04
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3.4: Room Temperature Dual Emission of Fluorescence and Phosphorescence in the Solid State
摘要： A white light emission comprised of fluorescence and phosphorescence was observed at room temperature in the solid state. The OLED device used the dual emission material was fabricated and showed white EL light.
关键词： Dual emission OLED device,White emission,Dual emission,Solid state
更新于2025-09-10 09:29:36
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Synthesis of CdSe/ZnS@HPU-2 composites for highly sensitive and multicolor florescence response to Fe3+
摘要： A composite material based dual-emission probe for Fe3+ was prepared by the hybridization of a three-dimensional framework with CdSe/ZnS quantum dots (QDs)-doped silica nanoparticles. The obtained probe showed characteristic fluorescence emissions of CdSe/ZnS QDs (red) and Cd-metal-organic framework (MOF, blue) under a single exciation wavelength. Upon the detection of Fe3+, only the fluorescence of Cd-MOF was quenched, whereas the red fluorescence of CdSe/ZnS QDs particles was mostly reserved. Consequently, the variation of the two fluorescence intensity ratios displays a continuous color change from blue to red upon exposure to different amounts of Fe3+ ions, which can be easily observed under a UV lamp.
关键词： dual-emission probe,Fe3+,composite material
更新于2025-09-10 09:29:36