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In Situ Synthesis of Fluorescent Mesoporous Silica–Carbon Dot Nanohybrids Featuring Folate Receptor-Overexpressing Cancer Cell Targeting and Drug Delivery
摘要： Multifunctional nanocarrier-based theranostics is supposed to overcome some key problems in cancer treatment. In this work, a novel method for the preparation of a fluorescent mesoporous silica–carbon dot nanohybrid was developed. Carbon dots (CDs), from folic acid as the raw material, were prepared in situ and anchored on the surface of amino-modified mesoporous silica nanoparticles (MSNs–NH2) via a microwave-assisted solvothermal reaction. The as-prepared nanohybrid (designated MSNs–CDs) not only exhibited strong and stable yellow emission but also preserved the unique features of MSNs (e.g., mesoporous structure, large specific surface area, and good biocompatibility), demonstrating a potential capability for fluorescence imaging-guided drug delivery. More interestingly, the MSNs–CDs nanohybrid was able to selectively target folate receptor-overexpressing cancer cells (e.g., HeLa), indicating that folic acid still retained its function even after undergoing the solvothermal reaction. Benefited by these excellent properties, the fluorescent MSNs–CDs nanohybrid can be employed as a fluorescence-guided nanocarrier for the targeted delivery of anticancer drugs (e.g., doxorubicin), thereby enhancing chemotherapeutic efficacy and reducing side effects. Our studies may provide a facile strategy for the fabrication of multifunctional MSN-based theranostic platforms, which is beneficial in the diagnosis and therapy of cancers in future.
关键词： Targeted drug delivery,Fluorescence imaging,Mesoporous silica nanoparticles,Carbon dots,Chemotherapy
更新于2025-11-14 14:48:53
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Tannic acid-derivatized graphitic carbon nitride quantum dots as an “on-off-on” fluorescent nanoprobe for ascorbic acid via copper(II) mediation
摘要： A microwave-assisted hydrothermal route was employed to prepare fluorescent tannic acid (TA)-derivatized graphitic carbon nitride quantum dots. The resulting dots display blue fluorescence (best measured at excitation/emission wavelengths of 350/452 nm) with a quantum yield as high as ~44%. The incorporated TA imparts a fluorescence switching behavior in that very low concentrations of Cu(II) can quench the fluorescence, while (AA) can restore it. It is presumed that AA causes Cu(II) to be transformed to Cu(I). Based on these findings, a fluorometric method was designed for AA detection. The probe allows AA to be detected with a 50 pM limit of detection and a linear analytical range that extends from 0.1 to 200 nM of AA. Real and spiked samples were successfully assayed by the probe to demonstrate its analytical applicability.
关键词： Fluorescence recovery,Metal ions,Graphitic nanosheets,Biomolecules,Polyphenolic compounds,Optical probe,Quantum dots
更新于2025-10-22 19:40:53
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Gold doping induced strong enhancement of carbon quantum dots fluorescence and oxygen evolution reaction catalytic activity of amorphous cobalt hydroxide
摘要： Gold doping induced strong enhancement of carbon quantum dots fluorescence and oxygen evolution reaction catalytic activity of amorphous cobalt hydroxide. Water splitting using electrocatalysts is expected to provide an alternative green energy source to meet increasing energy demands as well as addressing environmental concerns related to fossil fuels. Herein, we report one-step synthesis of sulfur, nitrogen and Au-doped carbon quantum dots (Au-SCQDs) and strong enhancement of fluorescence intensity and oxygen evolution reaction (OER) catalytic activity of amorphous Co(OH)2 nanoparticles compared to pure Co(OH)2 as well as commercial RuO2 and Pt/C catalysts. Au doping into sulfur and nitrogen co-doped CQDs showed over seventy times enhanced fluorescence. OER studies of amorphous-Co(OH)2 incorporated Au-SCQDs produced current density of 178 mA cm?2 at the applied potential of 2.07 V whereas un-doped Co(OH)2 showed current density of 59 mA cm?2. To produce geometric current density of 10 mA cm?2, amorphous Co(OH)2-Au-SCQDs (CSA) required 388–456 mV overpotential depending on the Au ion concentration used for preparing the Au-SCQDs, which is equal to or lower than overpotential required by commercial electrocatalysts. The strongly enhanced OER activity of Co(OH)2-Au-SCQDs (CSA) was attributed to the presence of electronegative metallic conducting Au atoms along with the high catalytic surface area of amorphous Co(OH)2. The present studies demonstrate a new method of exploiting amorphous Co(OH)2NPs electrocatalysts that could provide more catalytically active sites by integrating an electronegative conducting Au atom doped SCQDs matrix.
关键词： amorphous cobalt hydroxide,fluorescence,water splitting,Gold doping,carbon quantum dots,oxygen evolution reaction,electrocatalysts
更新于2025-10-22 19:40:53
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Single crystal structure and electroluminescence efficiency of blue fluorescence OLED emitters using triple core chromophores
摘要： The relationship between the single crystal structure of materials and the EL performance of doped OLED devices was investigated. The 1,6-bis-(10-[1,1′;3′,1″]terphenyl-5′-yl-anthracen-9- yl)-pyrene (1,6 DAP-TP) has a dihedral angle (α) of 78.4 ° and a dihedral angle (β) of 81.2 °, a relatively more twisted single crystal structure compared to that of 6,12-bis-(10- [1,1′;3′,1″]terphenyl-5′-yl-anthracen-9-yl)-chrysene (DAC-TP). Such a highly twisted molecular structure can improve the electroluminescence (EL) efficiency of a material because it can inhibit rotational and vibrational motions. Also, since the doped state and single crystal structure imply, respectively, a diluted state and a molecular state, the EL efficiency of the doped OLED device is related to single crystal structure. In a 4% doped OLED device, 1,6 DAP-TP and DAC- TP showed CE of 2.10 cd A-1 and 0.93 cd A-1, respectively. With its relatively more twisted single crystal structure, 1,6 DAP-TP showed higher CE in a doped OLED device than DAC-TP. Both compounds had ultra-deep blue emission y values of 0.06 or less for the color coordinates, which satisfy high density television display requirements (y value less than 0.08).
关键词： Organic light-emitting diode,single crystal,fluorescence,dopant,blue
更新于2025-10-22 19:40:53
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Raman/XRF/EDX microanalysis of 2nd-century stuccoes from Domus Valeriorum in Rome
摘要： 2nd-century stucco fragments from the roman Domus Valeriorum were analyzed by Raman spectroscopy (Raman), imaging X-ray fluorescence (XRF) and energy dispersive X-ray microanalysis (EDX) in order to identify the pigments and materials thereon. Cinnabar, malachite, hematite, goethite and Egyptian blue were detected by the synergistic use of these techniques whereas calcite, with some traces of gypsum, was detected as materials for the bas-relief figures and the pictorial background. This non-destructive characterization is the first carried out on the Domus Valeriorum finds. The multi-analytical approach highlighted the complementarity and versatility of these techniques, suitable for both laboratory and in-situ analysis, on macroscopic or microscopic fragments without preliminary manipulation.
关键词： Energy dispersive X-ray fluorescence,X-ray fluorescence imaging,Domus Valeriorum,Pigments,Raman spectroscopy
更新于2025-09-23 15:23:52
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5-aminolevulinic acid induced protoporphyrin IX (ALA-PpIX) fluorescence guidance in meningioma surgery
摘要： Introduction 5-aminolevulinic acid induced protoporphyrin IX (5-ALA-PpIX) fluorescence guidance has emerged as a valuable surgical adjunct for resection of intracranial tumors. Methods Here we present a focused review on 5-ALA-PpIX fluorescence guidance for meningiomas. Results We discuss the clinical studies and specific applications to date as well as the two main intraoperative fluorescence technologies applied to meningiomas. Conclusions The use of 5-ALA-PpIX in meningiomas holds promising potential so neurosurgeons can improve surgical outcomes for patients with meningiomas as well as be pioneers in developing improved fluorescence imaging technologies.
关键词： Meningioma,Quantitative fluorescence,5-Aminolevulinic acid,Fluorescence-guided surgery,Protoporphyrin IX,Spectroscopy
更新于2025-09-23 15:23:52
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A comprehensive photophysical and NMR investigation on the interaction of a 4-methylumbelliferone derivative and cucurbit[7]uril
摘要： The host-guest interaction of a 7-hydroxycoumarin (3-[2-(diethylamino)ethyl]-7-hydroxy-4-methylcoumarin, 3ED4MU) with cucurbit[7]uril, CB7, was investigated in aqueous solution. From the steady-state fluorescence Job plot and 1H NMR spectroscopy the formation of a 1:1 inclusion complex, with a binding constant of 1.75×105 M?1 was obtained. Time-resolved fluorescence data in water, DMSO and dioxane for 3ED4MU and for umbelliferone (UM, here taken has the model compound) show that the decays are double or triple-exponentials mirroring the presence of excited neutral (N*), anionic (A*), tautomeric (T*) and zwiterionic (T*’) species (the latter only present in 3ED4MU). In the time-resolved experiments, the interaction of 3ED4MU with CB7 is mirrored by an increase of the pre-exponential factor associated to the zwiterionic species (thus giving support for the stabilization of this species when interacting with CB7) and a dramatic change in the pKa* value (from ~ 0.5 to ~8), associated to a displacement of the water environment probed by 3ED4MU.
关键词： Time-resolved fluorescence,Host-guest chemistry.,Binding constant,Fluorescence,Hydroxycoumarins,Cucurbit[7]uril
更新于2025-09-23 15:23:52
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Circularly Polarized Luminescence from Chiral Conjugated Poly(carbazole-ran-acridine)s with Aggregation-Induced Emission and Delayed Fluorescence
摘要： Pure organic materials with circularly polarized luminescence (CPL) and delayed fluorescence have gained increasing interest from academic and technological areas. To enhance the solid-state emission and exciton utilization in chiral optoelectronic devices, a synthetic strategy to impart conjugated polymers with CPL and aggregation-induced delayed fluorescence was proposed. Herein, two conjugated macromolecules with electron-donating poly(carbazole-ran-acridine) backbones, electron-withdrawing dibenzothiophen-2-yl(phenyl)methanone and chiral alanine moieties were designed and synthesized. Their neat films exhibited strong green emission with quantum yields of 6.7% and 10.3% and delayed fluorescence with lifetime of 1.358 μs and 1.366 μs, respectively. Both Cotton effect and CPL with dissymmetry factor of –2.01 × 10–3 and –1.39 × 10–3 were determined in the solid state. Such unique conjugated polymers were employed as solution-processed emitting layers in organic light emitting diodes, which displayed maximum brightness of 1477 cd/m2 and maximum current efficiency of 2.52 cd/A.
关键词： OLEDs,conjugated polymers,aggregation-induced emission,delayed fluorescence,aggregation-induced delayed fluorescence,circularly polarized luminescence
更新于2025-09-23 15:23:52
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Quantitative Image Analysis of Cellular Morphology Using Amnis???? ImageStreamX Mark II Imaging Flow Cytometer: A Comparison against Conventional Methods
摘要： Chemotaxis, the directional cell migration guided by chemoattractant gradients, plays essential roles in many physiological processes, such as recruitment of neutrophils to sites of inflammation. Neutrophils detect chemoattractants by G protein-coupled receptors (GPCRs). Chemoattractant stimuli activate multiple signaling pathways to regulate directional migration of neutrophils. Recently, we identified a novel GPCR-mediated PLCβγ/ PKCβ/PKD1 signaling axis that regulates cofilin activity through cofilin phosphatase slingshot 2 (SSH2) and remodels actin cytoskeleton during neutrophil chemotaxis. In the future, it will be important to understand how multiple signaling pathways are spatiotemporally regulated to precisely control the rapid remodeling of actin cytoskeleton in the leading front of chemotaxing neutrophils.
关键词： Flow,Brightfield,Imaging,Fluorescence,Cytometry
更新于2025-09-23 15:23:52
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A Concept for Molecular Addressing by Means of Far-reaching Electromagnetic Interactions in the Visible
摘要： A pronounced concentration dependence of the time constant of fluorescence decay was found, disproving Strickler-Berg’s equation restricting molecular light emission to a local process. Thus, interactions were found significantly extending to more than 100 nm and make such systems promising for interfaces between molecular dots or more complex molecular arrangements and conventional macroscopic electronics.
关键词： Interfaces,Fluorescence,Strickler-Berg-equation,Molecular electronics
更新于2025-09-23 15:23:52