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A fluorescent probe for sequential sensing of MnO <sub/>4</sub><sup>?</sup> and Cr <sub/>2</sub> O <sub/>7</sub><sup>2?</sup> ions in aqueous medium based on a UCNS/TMB nanosystem
摘要： This paper reports the successful design of an UC fluorescence nanosystem for distinguishable and sequential detection of MnO4? and Cr2O72? based on the inner filter effect (IFE) between Gd2O3:Yb,Er upconversion nanospheres (UCNS) and 3,3’,5,5’-tetramethylbenzidine (TMB). The detection of MnO4? was realized by a stoichiometric oxidation reaction between TMB and Mn(VII), which resulted in quenching of the upconversion luminescence (UCL) by the blue product through IFE. The assay of Cr2O72?, in contrast, was based on the formation of complexes and the consumption of the oxidation product of the previous reaction. The sensing of MnO4? and Cr2O72? do not interfere with each other when Pb2+ was added as a masking agent. This provides a new strategy for sensitive and selective detection of MnO4? and Cr2O72?. The detection of MnO4? showed not only a low LOD of 0.243 μM but also high selectivity over other possible interfering ions. The sensitivity assay of MnO4? can be performed in the linear range of 1.85 to 69 μM. An excellent linear relationship was also found in the sensing of Cr2O72?, with a linear range of 18.3 to 250 μM and a LOD of 2.95 μM. The selectivity towards Cr2O72? was also proved to be good. Based on these properties, the UCNS–TMB nanoplatform is a potential chemosensor for both MnO4? and Cr2O72? ions in practical assays for waste water.
关键词： upconversion nanospheres,aqueous medium,UCNS/TMB nanosystem,Cr2O72?,MnO4?,TMB,fluorescent probe,inner filter effect,sequential sensing
更新于2025-11-14 17:03:37
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A mitochondria targetable and viscosity sensitive fluorescent probe and its applications for distinguishing cancerous cells
摘要： The determination of mitochondrial viscosity is of great importance owing to its crucial roles in the diffusion-mediated processes. It has demonstrated that the viscosity in cancer cells is higher than normal cells. Developing of viscosity sensitive fluorescent probes for distinguishing normal cells and cancer cells is necessary. Herein, we present a mitochondrial-targeting fluorescent probe PFV for the detection of viscosity in live cells. It exhibited outstanding sensitivity to viscosity, free from disturbing by ROS/sulfuret even at high concentrations. Equipped with mitochondria targeting ability, PFV was then applied to mitochondrial viscosity detection. Most importantly, by viscosity monitoring PFV successfully differentiated normal hepatic cells and cancerous hepatic cells. The present study would offer a broadly applicable for the determination of viscosity in complex systems.
关键词： fluorescence imaging,mitochondrial viscosity,fluorescent probe,cyanine dye,viscosity
更新于2025-11-14 15:29:11
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Photostable Ratiometric Two-photon Fluorescent Probe for Visualizing Hydrogen Polysulfide in Mitochondria and Its application
摘要： Hydrogen polysulfide (H2Sn) has currently attracted much research interest because it not only plays important physiological function in many biological and health-related events, but also considered as a newfound potent signal transducer. Small-molecule based ratiometric fluorescent probes have advantages in sensitivity and bio-detections but such approaches that intentionally developed for H2Sn detection expected to be mitochondria-accessible are still lacking. In this work, due to that triphenylphosphine group introduced into the molecular scaffold of naphthalimide derivative, Mito-NRT-HP was successfully applied to visualize intracellular H2Sn in mitochondria with excellent aqueous solubility, super photobleaching resistance, favorable cellular membrane permeability and good biocompatibility. This one- and two-photon fluorescent probe with high selectivity and sensitivity (LOD = 0.01 μM) evinced 70-fold enhancement of fluorescence ratio (I546 nm/I478 nm) in the presence of H2Sn over other reactive sulfur species (RSS). The experimental results also give Mito-NRT-HP the potential for mapping the H2Sn distribution in mitochondria and evaluating the H2Sn roles in more biological processes and demonstrated the practical application possibility of Mito-NRT-HP in early diagnosis of LPS-induced acute organ injury.
关键词： mitochondria,fluorescent probe,hydrogen polysulfide,ratiometric,two-photon
更新于2025-11-14 15:29:11
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Luminescence Tuning of Layered Rare-Earth Hydroxides (LRHs, R = Tb, Y) Composites with 3-Hydroxy-2-naphthoic Acid and Application to the Fluorescent Detection of Al <sup>3+</sup>
摘要： Tunable luminescence (quenching or blue shift) of HNA/OS-LRH composites (HNA is 3-hydroxy-2-naphthoic acid; OS is the anionic surfactant of 1-octanesulfonic acid sodium; LRHs are layered rare-earth hydroxides, R = Tb3+, Y3+) in the solid state and delaminated state is reported, which is utilized as an effective fluorescent probe for detecting metal ions. HNA/OS species are intercalated into LRH layers to generate composites of HNAxOS1?x-LTbH (x = 0.10, 0.15, 0.20 , 0.25) and HNAyOS1?y-LYH (y = 0.05, 0.10, 0.15, 0.20, 0.25, 0.30). In the solid state, LYH composites exhibit green emissions (from 493 to 504 nm) with a large blue shift in comparison to the 542 nm emission of free HNA? anions, while in the delaminated state in formamide (FM), the composites display blue emission (480 nm) relative to the green emission (512 nm) of an HNA soltuion in FM. However, LTbH composites display coquenched luminescence in both the solid state and delaminated state. Also, HNA0.25OS0.75-1:1-LYH, HNA0.25OS0.75-1:2-LYH, and HNA0.05OS0.95-1:1-LYH (1:1 and 1:2 are HNA:NaOH molar ratios) show significantly elongated fluorescence lifetimes of 15.35, 14.37, and 12.72 ns, respectively, in comparison with free HNA-Na (6.44 ns), and their quantum yields of 23.40%, 21.97%, and 22.31%, respectively, are much larger than that of free HNA-Na (4.86%). The LTbH composite (HNA0.25OS0.75-1:1-LTbH) has also a relatively higher quantum yield of 12.46%. The HNA0.25OS0.75-1:1-LYH colloid exhibits excellent recognition selectivity for Al3+ over other metal ions (Mg2+, Co2+, Ni2+, Cu2+, Zn2+, Pb2+, Cd2+, and Hg2+) with distinct fluorescence sensitization. It shows an intense change in its fluorescence emission when it is bound to Al3+ ions, giving a lower detection limit of 6.32 × 10?6 M. This is novel research on the fluorescence chemosensing of LRH composites.
关键词： Layered rare-earth hydroxides,Fluorescent detection,Chemosensing,Luminescence tuning,Al3+ ions
更新于2025-11-14 15:28:36
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[Lecture Notes in Electrical Engineering] Advances in Graphic Communication, Printing and Packaging Volume 543 (Proceedings of 2018 9th China Academic Conference on Printing and Packaging) || Application of Anthracene-Based Fluorescent Materials on Green Fluorescent Inkjet Ink
摘要： Presently, the existing green ?uorescent materials are rare earth luminescent material, which cannot reach the requirement of inkjet ink on dispersion and stability because of the inferior solubleness. In this paper, the ?uorescent inkjet inks were prepared by anthracene-based derivatives, ink’s printability was tested and the relationship between molecular structure and ink’s printability was researched systematically. Finally, the optimal formula of green ?uorescent inkjet ink was obtained. The results showed the photophysical properties of proofs a–c had obvious change comparing with inks a–c and the contact angle of ink d was the biggest of all due to the planar construction of ?uorescent material with large conjugate degree. The green ?uorescent material: 9, 10-bis (4-methoxyphenylethynyl) anthracene with 0.5% and crylic acid B817 with 12% formed the optimal formula. The printing quality of ink prepared by the optimal formula can accord with the demand of digital printing quality.
关键词： Fluorescent inkjet ink,Photophysical properties,Ink’s printability,Anthracene-based ?uorescent materials
更新于2025-11-14 15:26:12
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Linking optical and chemical signatures of dissolved organic matter in the southern Argentine shelf: Distribution and bioavailability
摘要： Fluorescence spectroscopy is commonly used to investigate the distribution and dynamics of dissolved organic matter (DOM) in marine systems. However, the direct comparison with chemical signatures is essential to substantiate the molecular composition of specific fluorescent components. Here we report the relation between optical and chemical signatures of DOM in waters of the Beagle Channel (BCW) (south-east of Tierra del Fuego, in the southern Argentine shelf) at the Pacific-Atlantic connection and neighboring coastal (CW) and oceanic (OW) waters (54.75-55.75°S, 64-68°W). The relationships among concentrations of total dissolved carbohydrates (TDCHO) and amino acids (TDAA), and fluorescent DOM (FDOM), including terrestrial “humic-like” (FDOMC) and “protein-like” compounds (FDOMT), and bioavailability of DOM components were assessed from field measurements acquired in the austral summer 2012. The maximal concentrations of TDCHO, dissolved organic carbon (DOC) and FDOMc intensities were found in BCW, while the minima in OW, displaying a negative correlation with salinity. This spatial distribution of biogeochemical signals suggests that humic compounds contributed by continental runoff contain refractory carbohydrates, and FDOMC resulted as a reliable tracer of carbon pathways in the Pacific-Atlantic connection. Conversely, TDAA and FDOMT showed the opposite distributional trend, with minimal concentrations in BCW and the maxima in CW and OW. The significant positive correlation of TDAA with salinity suggests open water sources of these components, however, phytoplankton biomass (Chla) in CW and OW was significantly lower than in BCW, ruling out the assumption of autochthonous source in open waters. TDAA were negatively correlated with the abundance of heterotrophic bacteria (HB), which displayed a consistent decrease from BCW towards OW, suggesting high bacterial uptake of TDAA in the BCW. This bacterial uptake is supported by the observed variation in carbon contribution of TDAA to DOC (amino acids carbon yield, in %), which is an indicator of DOM lability. The negative correlation found between amino acids carbon yield and HB abundance reflects intense bacterial activity in BCW, where phytoplankton biomass was maximum. Hence, higher DOM “freshness” occurs in the BCW, suggesting a tight coupling between microbial production and consumption.
关键词： Pacific-Atlantic connection.,amino acids,fluorescent dissolved organic matter,carbohydrates
更新于2025-11-14 15:26:12
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AuxAg1-x Nanocomposites with 40-Fold Emission Enhancement Formed by the Electrostatic Assembly of Gold Nanoclusters and Silver Nanoclusters for Bioimaging and Bioanalysis
摘要： Noble metal nanoclusters (NCs) have been widely used in bioimaging and bioanalysis due to their unique molecular-like structures and good biocompatibility. Bright nanomaterials with high quantum yields are in need for widespread applications. Unfortunately, the weak photoluminescence (PL) of metal NCs hampers their biomedical applications, and thus it is urgent to develop effective routes to enhance their brightness, especially in aqueous solutions. In this work, we reported a facile strategy to prepare highly luminescent AuxAg1-x nanocomposites (x: molar ratio of Au) by electrostatic-induced assembly of non-luminescent glutathione (GSH) stabilized silver NCs (GSH-Ag NCs) and weak orange-emitting GSH stabilized gold NCs (GSH-Au NCs) in aqueous solutions. Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), fluorescence spectroscopy, inductively coupled plasma mass spectrometry (ICP-MS), UV-vis absorption spectroscopy and dynamic light scattering (DLS) shed light on the mechanism of PL enhancement. It was found that the positively charged gold nanoclusters and the negatively charged silver nanoclusters formed aggregates by electrostatic force, leading to a 40-fold fluorescence intensity enhancement compared with GSH-Au NCs. This was a novel method to strengthen the fluorescence of nanoclusters with such large enhancement in aqueous solutions. With the molar ratio of Au and Ag changing from 80:1 to 2:3, the emission maximum of the AuxAg1-x nanocomposites could be tuned from 590 to 548 nm. The electrostatic force of the Au0.50Ag0.50 nanocomposites enabled them to respond to pH. The Au0.50Ag0.50 nanocomposites were fluorescent turn-on and turn-off at pH 2.6 and pH 7.5, respectively. In this respect, they can be used as a fluorescent switch and be further used as a general recyclable pH probe in the range of 2.6-7.5. This work will inspire even better strategies to further improve the brightness of noble metal NCs.
关键词： nanocomposites,fluorescent switch,electrostatic force,silver nanoclusters,fluorescence enhancement,gold nanoclusters
更新于2025-11-14 15:23:50
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Fluorescent pH Probes based on PET Quenching of Long Fluorescence Lifetime Triangulenium Dyes Martin Rosenberg, Anne Kathrine R. Junker, Thomas Just S?rensen, and Bo W. Laursen*[a]
摘要： Azaoxatriangulenium dyes with long fluorescence lifetimes offer advantages in fluorescence lifetime imaging (FLIM), time-gated detection and polarization assays. However, the long excited state lifetimes are also expected to increase sensitivity to photoinduced electron transfer (PET) quenching, potentially increasing the on-off ratio of PET probes. We report the synthesis and investigation of the optical properties of azaoxatriangulenium salts substituted with phenol substituents for pH sensing. Two series of pH probes with the phenol hydroxy group placed in the ortho, meta, or para positions to azadioxatriangulenium (ADOTA) and diazaoxatriangulenium (DAOTA) chromophores are investigated. All the phenol substituted dyes possess pH responsive fluorescence signals in the biological relevant pH window (pH 6-9) due to efficient intramolecular PET from the phenolate form of the pendant arm. While the PET mechanism is partly suppressed in the phenol form the ADOTA derivatives, it is completely suppressed in the DAOTA derivatives. The long excited state lifetimes of the triangulenium dyes ensure efficient PET quenching leading to very high on-off ratios of the pH probes. The study clearly demonstrates effects of the position of the phenol/phenolate group relative to the chromophore on both PET quenching rates and pKa values.
关键词： PET probes,triangulenium,pH probes,photoinduced electron transfer,Fluorescent probes
更新于2025-10-22 19:40:53
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A reaction-based turn-on fluorescent sensor for the detection of Cu (II) with excellent sensitivity and selectivity: Synthesis, DFT calculations, kinetics and application in real water samples
摘要： A reaction-based turn-on fluorescent chemosensor RhB-Cu, starting from rhodamine B (RhB), for Cu2+ was easily synthesized in two steps. The sensor could selectively detect Cu2+ with a 100-fold fluorescence enhancement among the common metal ions, exhibiting an extremely low detection limit of 4.7 nM. To the best of our knowledge, this was the best record for the detection of Cu2+ with organic fluorescent sensors. There was a 1:1 binding stoichiometry between RhB-Cu and Cu2+ with an association constant of 6.42 × 104 M-1. Noteworthy, it could distinguish Cu2+ from Cu+, which was hard to realize in the previous studies. In addition, the detection mechanism was proposed based on mass spectrometric analysis and density functional theory (DFT) calculations. Kinetic studies were conducted to obtain the activation energy, enthalpy and entropy, so as to elucidate the solvent effect. Interestingly, the kinetic compensation effect (KCE) was uncovered in this work. Finally, RhB-Cu was proved to have the capability to work in real water samples. It would highly contribute to the even better design of fluorescent sensor for Cu2+ in future.
关键词： fluorescent sensor,solvent effect,kinetic compensation effect (KCE),copper,density functional theory (DFT),PET mechanism
更新于2025-10-22 19:38:57
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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