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Synthesis, energy transfer and multicolor luminescent property of Eu3+-doped LiCa2Mg2V3O12 phosphors for warm white light-emitting diodes
摘要： In this study, Eu3+-doped LiCa2Mg2V3O12 (LCMVO) phosphors with multicolor luminescent property were prepared by the solid phase reaction. Their structure, morphology and luminescent property were studied systematically by X-ray diffraction, scanning electron microscope and photoluminescence spectra. The LCMVO phosphors showed pure cubic crystal structure with space group (3Ia d ) and irregular spherical morphology. The excitation spectra showed a strong absorption to ultraviolet light. Under the excitation wavelength at 360 nm, they exhibited a cyan emission with a luminescence center at 520 nm. When Eu3+ ions were doped into LCMVO system, the Eu3+ characteristic emissions were also observed and the emission colors were tuned from cyan to orange via adjusting Eu3+ ion concentration. Further, electric dipole-quadrupole interaction and luminescence decay curves were adopted to explain the energy transfer from (VO4)3- to Eu3+. The emission spectra of as-obtained phosphors at different temperature were measured to evaluate their thermal stability. The quantum efficiency values were measured to be 42.5% for LCMVO host and 38.6% for LCMVO: 0.01Eu3+ sample. The final prepared LED lamp showed easeful warm white light with suitable Ra of 89 and CCT of 3847 K, respectively. These results suggest LCMVO phosphors may be applied in near ultraviolet chip-excited white light-emitting diodes.
关键词： energy transfer,multicolor luminescent,self-activated luminescence,excitation and emission spectra,vanadate phosphor,UV-LED
更新于2025-11-20 15:33:11
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Plasmonic Colorimetric Biosensor for Visual Detection of Telomerase Activity Based on Horseradish Peroxidase-Encapsulated Liposomes and Etching of Au Nanobipyramids
摘要： Telomerase aberrant activation is a critical feature in the vast majority of cancers. To visualize telomerase expression level in tumor cells, we developed a plasmonic colorimetric sensor for highly sensitive detection of telomerase activity by integrating an excellent etching substrate Au nanobipyramids (Au NBPs) with a liposome-based signal amplification strategy. Upon telomerase-triggered extension, the telomerase activity was converted into the amount of the attached horseradish peroxidase-encapsulated liposomes (HRP-Ls) on the surfaces of magnetic beads. Afterwards, HRP was liberated from the liposomes following the addition of H2O2-3,3′,5,5′-tetramethylbenzidine sulfate (TMB) substrate, and then the oxidation reaction between H2O2 and TMB was initiated to form TMB2+. The morphological evolution of Au NBPs relied on the TMB2+-mediated etching reaction, which gave rise to tremendous localized surface plasmon resonance (LSPR) responses and concomitant tonality transitions. Benefiting from cascaded signal amplification capacity of HRP-Ls and the intriguing optical properties of Au NBPs, an impressive sensitivity toward telomerase was obtained with detection limits equivalent to 1 HeLa cell for LSPR peak measurement and a visual detection limit of 20 HeLa cells. Furthermore, a facile and portable kit was fabricated for visual evaluation of telomerase activity in different cell lines.
关键词： Plasmonic colorimetry,Au nanobipyramids,Telomerase,Liposome-based amplification,Multicolor visual detection
更新于2025-11-14 17:04:02
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NIR-Fluorescent Multidye Silica Nanoparticles with Large Stokes Shifts for Versatile Biosensing Applications
摘要： We have synthesized and characterized of a series of single and multidye copolymerized nanoparticles with large to very large Stokes shifts (100 to 255 nm) for versatile applications as standalone or multiplexed probes in biological matrices. Nanoparticles were prepared via the St?ber method and covalently copolymerized with various combinations of three dyes, including one novel aminocyanine dye. Covalently encapsulated dyes exhibited no significant leakage from the nanoparticle matrix after more than 200 days of storage in ethanol. Across multiple batches of nanoparticles with varying dye content, the average yields and average radii were found to be highly reproducible. Furthermore, the batch to batch variability in the relative amounts of dye incorporated was small (relative standard deviations <2.3%). Quantum yields of dye copolymerized nanoparticles were increased 50% to 1000% relative to those of their respective dye-silane conjugates, and fluorescence intensities were enhanced by approximately three orders of magnitude. Prepared nanoparticles were surface modified with polyethylene glycol and biotin and bound to streptavidin microspheres as a proof of concept. Under single wavelength excitation, microsphere-bound nanoparticles displayed readily distinguishable fluorescence signals at three different emission wavelengths, indicating their potential applications to multicolor sensing. Furthermore, nanoparticles modified with polyethylene glycol and biotin demonstrated hematoprotective qualities and reduced nonspecific binding of serum proteins, indicating their potential suitability to in vivo imaging applications.
关键词： Fluorescent silica nanoparticles,Biocompatible nanoparticles,Large stokes shift,Near-infrared fluorescence,Multicolor assay,Resonance energy transfer
更新于2025-09-23 15:23:52
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Probing Polarity and Heterogeneity of Lipid Droplets in Live Cells Using a Push–Pull Fluorophore
摘要： Lipid droplets (LDs) are organelles composed of a lipid core surrounded by a phospholipid monolayer. Lately, LDs attracted a considerable attention due to recent studies demonstrating their role in a variety of physiological processes as well as diseases. Herein we synthesized a push-pull molecule named DAF (Dimethyl Aniline Furaldehyde) that possesses a strong positive solvatochromism in emission of 119 nm from toluene to methanol. Its impressive fluorogenic properties from water to oil (2000-fold) as well as its high quantum yields (up to 0.97) led us to investigate its ability to sense the distribution of polarity in live cells by fluorescence ratiometric imaging. When added to live cells and excited at 405 nm, DAF immediately and brightly stain lipid droplets using a blue channel (410-500 nm) and cytoplasm in a red channel (500-600 nm). DAF also proved to be compatible with fixation thus allowing 3D imaging of LDs in their cytoplasm environment. Taking advantage of DAF emission in two distinct channels, ratiometric imaging was successfully performed and led to the polarity mapping of the cell unraveling some heterogeneity in polarity within LDs of the same cell.
关键词： Environment Sensitive Fluorescent Probe,Lipid Droplets,Ratiometric Imaging,Multicolor Fluorescent imaging
更新于2025-09-23 15:23:52
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Multicolor emission from non-conjugated polymers based on a single switchable boron chromophore
摘要： Multicolor emissive and responsive materials are highly attractive due to their potential applications in various fields, and polymers are preferred for their good processability and high stability. Herein, we report a series of new polymers based on a methacrylate monomer containing a switchable boron chromophore. In spite of the unconjugated nature, interestingly, the homopolymers from this monomer display rare multicolor fluorescence in solution that is highly dependent on the degree of polymerization (DP). With an ascending DP, the local concentration of the chromophore increases, leading to a higher propensity for switching the blue emitting tricoordinate boron chromophore to the red emitting tetracoordinate one. The homopolymers also display temperature and solvent-dependent emission colour change. Furthermore, pure white-light emission could be achieved in various solvents by precisely tuning the homopolymer molecular weight, or in films/solid state by copolymerizing the emissive boron monomer with non-emissive monomers in an appropriate ratio.
关键词： Multi-responsiveness,Non-conjugated Polymer,Single Chromophore,White Light Emission,Multicolor Emission
更新于2025-09-23 15:21:21
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Multicolor Luminescent Patterning via Photoregulation of Electron and Energy Transfer Processes in Quantum Dots
摘要： Ability to create high-contrast multicolor luminescent patterns is essential to realize the full potential of quantum dots (QDs) in display technologies. The idea of using a non-emissive state is adopted in the present work to enhance the color-contrast of QD based photopatterns. This is achieved at a multicolor level by the photoregulation of electron and energy transfer processes in a single QD nanohybrid film, comprising of one QD donor and two dye acceptors. The dominance of photoinduced electron transfer over energy transfer process generates a non-luminescent QD nanohybrid film, which provides the black-background for multicolor patterning. The superior photostability of QDs over dyes is used for the photoregulation of electron and energy transfer processes. Selective photodegradation of electron acceptor dye triggered the onset of energy transfer process, thereby imparting a luminescent color to QD nanohybrid film. Further, a controlled photoregulation of energy transfer process paved the way for multicolor patterning.
关键词： Energy and electron transfer,Thin films,Quantum dots,Multicolor photopatterning,Light harvesting
更新于2025-09-23 15:21:01
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Amplified and Multicolor Emission from Films and Interfacial Layers of Lead Halide Perovskite Nanocrystals
摘要： Lead halide perovskites are promising for energy harvesting and lighting applications. We show amplified emission from films of organic-inorganic or all inorganic lead halide perovskite nanocrystals. Also, multicolor emission is detected from interfacial layers of chloride and bromide perovskites. While amplified emission originates from spatial confinement of manifold charge carriers in films, multicolor emission emanates from interfacial ion exchanged layers. In a film, the amplified emission is averaged over a large number of nanocrystals, which prevents us from detecting any spectral narrowing. Conversely, amplified spontaneous emission (ASE) and spectral narrowing are detected from an isolated perovskite microcrystal. Interestingly, under low intensity excitation, a perovskite nanocrystal film shows unusually delayed emission, which becomes extremely fast and spatially confined at higher intensities of excitation light. By precisely detecting photoluminescence from an irradiated area and outside, we reveal the migration as well as confinement of photogenerated charge carriers in the film. The migration of charge carriers is more efficient in a film of organic-inorganic perovskites than all-inorganic perovskites.
关键词： spatial confinement,multicolor emission,interfacial ion exchange,amplified emission,Lead halide perovskites,charge carriers
更新于2025-09-23 15:21:01
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Real-time naked-eye recognizable temperature monitoring based on Ho <sup>3+</sup> (or Tm <sup>3+</sup> )-activated NaYF <sub/>4</sub> upconversion nanowires <i>via</i> visual multicolor alteration
摘要： Non-contact thermometry for real-time temperature monitoring is a challenging research topic. Advances in microelectronics and biotechnology demand precise temperature monitoring with novel materials and approaches, where conventional thermometers are burdensome because of employing expensive additional equipment (e.g. spectrometers) and further data processing. Lanthanide-doped upconversion nanomaterials that can convert single near-infrared excitation into multicolor visible emissions open the door for a novel strategy to thermometry. Herein, a real-time naked-eye recognizable color change was achieved based on Ho3+ (or Tm3+)-activated NaYF4 upconversion nanowires, depending on the different spectral sensitivities of the blue, green and red upconversion emissions to temperature. Furthermore, the luminescence color can be also directly modulated by only using 975 nm laser radiation, which extended their application scope. These desirable properties make upconversion nanomaterials promising for temperature monitoring, anti-counterfeiting, and multicolor temperature probing applications with the advantages of being simple, convenient and unreplicable.
关键词： nanowires,naked-eye recognizable,upconversion,temperature monitoring,multicolor alteration
更新于2025-09-19 17:15:36
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Multicolor Flow Cytometry-based Quantification of Mitochondria and Lysosomes in T Cells
摘要： T cells utilize different metabolic programs to match their functional needs during differentiation and proliferation. Mitochondria are crucial cellular components responsible for supplying cell energy; however, excess mitochondria also produce reactive oxygen species (ROS) that could cause cell death. Therefore, the number of mitochondria must constantly be adjusted to fit the needs of the cells. This dynamic regulation is achieved in part through the function of lysosomes that remove surplus/damaged organelles and macromolecules. Hence, cellular mitochondrial and lysosomal contents are key indicators to evaluate the metabolic adjustment of cells. With the development of probes for organelles, well-characterized lysosome or mitochondria-specific dyes have become available in various formats to label cellular lysosomes and mitochondria. Multicolor flow cytometry is a common tool to profile cell phenotypes, and has the capability to be integrated with other assays. Here, we present a detailed protocol of how to combine organelle-specific dyes with surface markers staining to measure the amount of lysosomes and mitochondria in different T cell populations on a flow cytometer.
关键词： lysosome,Flow cytometry,organelle-specific dyes,mitochondria,multicolor,T cell
更新于2025-09-19 17:15:36
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Transient fiber-shaped flexible electronics comprising dissolvable polymer composites toward multicolor lighting
摘要： An efficient way to solve the issue of electronic-wastes from lighting and display related products is to build water-triggered transient light emitting devices. Herein, we report an all-solution processing method to fabricate dissolvable and flexible light emitting fibers. Using a phosphor–polymer composite emitter sandwiched between core–shell fiber-shaped conductors composed of silver nanowires (AgNWs), the as-fabricated fibers exhibit uniform and omnidirectional light emission, together with excellent flexibility as well as mechanical stability. In particular, attractive multicolor light emission ranging from yellow or blue to white can be integrated into single fibers by scalable dip-coating of different phosphor–polymer composites rationally. Impressively, the fibers assembled from nontoxic emitting and conducting materials can be thoroughly dissolved in water, providing new possibilities towards alleviating environmental pollution caused by electronic wastes.
关键词： flexible electronics,electronic waste,multicolor lighting,light emitting fibers,dissolvable polymers,transient electronics
更新于2025-09-19 17:15:36