RESUMO
The reporter-spacer-receptor (RSR) approach is prevalent to develop molecular turn-on sensors. However, the fluorescent RSR sensors barely operate in solid state, which hinders their fabrication into devices for practical applications. Herein, we present a novel strategy to achieve solid-state luminescence turn-on sensing by assembling RSR architectures within MOF frameworks. Unlike the regular RSR systems, the framework-confined fluorophore and receptor are well arranged and separated even in the solid state. This concept is illustrated by a multicomponent MOF (Fc@NU-1000), which contains organic linkers with a highly luminescent pyrene core as the reporter, Zr6 nodes with unsaturated sites as the receptor, and the incorporated Fc molecules as the quencher. The separate incorporation of pyrene core and Fc in the multicomponent MOF favors an efficient pseudointramolecular photoinduced electron transfer (PET) process, resulting in significant luminescence quenching. Interestingly, such PET process can be blocked via the quencher displacement initiated by the phosphate analyte, therefore recovering the solid-state luminescence of MOF microcrystals. We found that Fc@NU-1000 is shown as a sensitive solid-state luminescence turn-on probe for phosphate with the naked-eye response at a low content. What's more, this study is the first example of confining a quencher displacement-based RSR system in the MOF framework for solid-state luminescence turn-on sensing, thus also providing new opportunities for MOF materials to develop luminescence turn-on sensors.
RESUMO
Developing smart materials capable of solid-state multicolor photoluminescence (PL) switching in response to multistimuli is highly desirable for advanced anticounterfeiting. Here, a ternary MOF hybrid showing hydro-photo-thermo-responsive multicolor PL switching in the solid state is presented. This hybrid is constructed by co-immobilizing Eu3+ and methyl viologen (MV) cations within an anionic MOF via the cation-exchange approach. The confined guest cations are well arranged in the framework channels, facilitating the synergistic realization of stimuli-responsive multiple PL color-switching through intermolecular coupling. The hybrid undergoes a rapid and reversible PL color-switching from red to blue upon water simulation, which is achieved by activating the blue emission of the framework linker while simultaneously quenching the Eu3+ emission. Furthermore, the hybrid displays photo-thermo-responsive PL switching from red to dark. UV-light irradiation or heating triggers the chromic conversion of MV to its colored radical form, which exhibits perfect spectral overlap with Eu3+ , thus activating Förster resonance energy transfer (FRET) from Eu3+ to MV radicals and quenching the Eu3+ emission. Inspired by these results, PL morse patterns are designed and fabricated using a novel triple-level encryption strategy, showcasing the exciting potential of this hybrid in advanced anticounterfeiting applications.
RESUMO
Spinel LiNi0.5 Mn1.5 O4 (LNMO) is a promising cathode candidate for the next-generation high energy-density lithium-ion batteries (LIBs). Unfortunately, the application of LNMO is hindered by its poor cycle stability. Now, site-selectively doped LNMO electrode is prepared with exceptional durability. In this work, Mg is selectively doped onto both tetrahedral (8a) and octahedral (16c) sites in the Fd 3 â¾ m structure. This site-selective doping not only suppresses unfavorable two-phase reactions and stabilizes the LNMO structure against structural deformation, but also mitigates the dissolution of Mn during cycling. Mg-doped LNMOs exhibit extraordinarily stable electrochemical performance in both half-cells and prototype full-batteries with novel TiNb2 O7 counter-electrodes. This work pioneers an atomic-doping engineering strategy for electrode materials that could be extended to other energy materials to create high-performance devices.
RESUMO
The development of simple, rapid-response sensors for water detection in organic solvents is highly desirable in the chemical industry. Here we demonstrate a unique luminescence water sensor based on a dual-emitting europium-organic framework (Eu-MOF), which is assembled from a purposely selected 2-aminoterephthalic acid ligand with responsive fluorescence inherent in its intramolecular charge transfer (ICT) process. This ICT process can be rapidly switched-on in the presence of water owing to its ability to boost and stabilize the ICT state. In contrast, the Eu3+ emission within the framework is insensitive to water and can serve as a reference, thus enabling highly sensitive water detection in a turn-on and ratiometric way. In addition, the significant ratiometric luminescence response induced by water makes Eu-MOF undergo a distinct change of emitting color from red to blue, which is favorable for visual analysis with the naked eye. Sensitive determination of water content (0.05-10% v/v) in various organic solvents is achieved in multiple readouts including ratiometric emission intensity, emission color, or the Commission Internationale de l'Eclairage (CIE) chromaticity coordinate. The present Eu-MOF sensor featuring high sensitivity and reusability, self-calibration, simple fabrication and operation, and capability for real-time and in situ detection is expected to have practical applications in water analysis for industrial processes.
RESUMO
The feasibility of transition metal carbides (TMCs) as promising high-rate electrodes is still hindered by low specific capacity and sluggish charge transfer kinetics. Improving charge transport kinetics motivates research toward directions that would rely on heterostructures. In particular, heterocomposing with carbon-rich TMCs is highly promising for enhancing Li storage. However, due to limited synthesis methods to prepare carbon-rich TMCs, understanding the interfacial interaction effect on the high-rate performance of TMCs is often neglected. In this work, a novel strategy is proposed to construct a binary carbide heteroelectrode, i.e. incorporating the carbon-rich TMC (M=Mo) with its metal-rich TMC nanowires (nws) via an ingenious in situ disproportionation reaction. Results show that the as-prepared MoC-Mo2 C-heteronanowires (hnws) electrode could fully recover its capacity after high-rates testing, and also possesses better lithium accommodation performance. Kinetic analysis verified that both electron and ion transfer in MoC-Mo2 C-hnws are superior to those of its singular counterparts. Such improvements suggest that by taking utilization of the interfacial component interactions of stoichiometry tunable heterocarbides, the electrochemical performance, especially high-rate capability of carbides, could be significantly enhanced.
RESUMO
1-Hydroxypyrene (1-HP) is a urinary metabolite of polycyclic aromatic hydrocarbons (PAHs), and can function as a convenient biomarker for human intoxication of PAH carcinogens. The development of simple 1-HP sensors with high sensitivity and fast response is highly desirable. Herein, we demonstrate that a robust microcrystalline MOF with fluorescent pyrene cores, NU-1000, exhibits sensitive luminescence detection of urinary 1-HP. The pyrene core within NU-1000 behaves as the signal converter, whose luminescence is significantly quenched upon coming into contact with 1-HP owing to the efficient π-π charge transfer interactions between highly conjugated 1-HP and pyrene cores in NU-1000. The pore confinement effect of the molecular-sized channel of NU-1000 facilitates the preconcentration of 1-HP within NU-1000, which makes 1-HP contact with NU-1000 more sufficient therefore enhancing the detection efficiency. The charge transfer-related quenching mechanism is elucidated by diffuse-reflectance UV-vis and electron paramagnetic resonance (EPR) measurements, and a radical pair state is observed in NU-1000 upon accommodation of 1-HP. This work provides important insights into the development of MOF-based luminescent sensors for 1-HP, and should stimulate further studies toward designing more efficient MOFs with highly conjugated luminescent cores for 1-HP sensing.
Assuntos
Biomarcadores/urina , Carcinógenos/análise , Estruturas Metalorgânicas , Hidrocarbonetos Policíclicos Aromáticos/urina , Pirenos/urina , Exposição Ambiental , HumanosRESUMO
OBJECTIVE: To investigate the expression of CD22 and its downstream signal molecule spleen tyrosine kinase (SYK) and their phosphorylation of B lymphocytes in patients with immune related pancytopenia(IRP), and to explore the role of CD22 in pathogenesis of IRP. METHODS: The expression of CD22, SYK and their phosphorylation, along with the expression of IgG and IgM, which obtained from B lymphocytes in peripheral blood of 46 patients with IRP(22 new diagnosed and 24 remitted patients returned to normal after treatment), 22 healthy controls and 12 chronic lymphocytic leukemia(CLL) patients from February to December 2014 were analyzed by flow cytometry. And the mRNA expression of CD22 in peripheral blood mononuclear cell was determined by real-time quantitative PCR. RESULTS: The ratios of CD22+ cells and phosphorylated CD22(pCD22)+ cells of B lymphocytes in new diagnosed group (60. 03% ± 20. 94% 71. 32% ± 11. 16%) were significantly higher than those in remission group (46. 92% ± 20. 04%, 55. 82% ± 14. 42%), normal control group (46. 86% ± 17. 78%, 53. 28% ± 14. 76%) and CLL group (39. 74% ± 18. 96%, 59. 07% ± 17.09%) (all P <0.05). The ratios of phosphorylated SYK( pSYK) + cells in the four groups had the same trend (all P <0. 05). The ratio of pCD22+ cells/pSYK+ cells in new diagnosed group was significantly lower than that in normal control group and CLL group (27. 39 (5. 06 - 102. 70) vs 55. 95 (15. 25 - 298. 53), 56. 92(5. 60 - 228. 96), both P <0. 05), and pCD22+ cells positively correlated to pSYK+ cells ( r = 0. 341, P < 0. 05). The expression of IgG in new diagnosed group and remission group was significantly higher than that in normal control group, and the expression of IgM in new diagnosed group was significantly higher than that in normal control group and CLL group (all P <0. 05). The expression levels of CD22 mRNA in new diagnosed group was significantly higher than that in remission group, normal control group and CLL group (all P <0. 05). CONCLUSIONS: The BCR signal pathway of B lymphocyte in IRP patients is enhanced, and the quantity and function of CD22 are increased, while which are still insufficient to inhibit B cell proliferation, and these may have some relationships with the pathogenesis of IRP. [Key words] Pancytopenia; Antigens, CD22; Immune related pancytopenia; Spleen tyrosine kinase; Phosphorylation
Assuntos
Leucócitos Mononucleares , Pancitopenia , Citometria de Fluxo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Leucemia Linfocítica Crônica de Células B , Fosforilação , Proteínas Tirosina Quinases , RNA Mensageiro , Reação em Cadeia da Polimerase em Tempo Real , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico , Transdução de Sinais , Quinase SykRESUMO
A class of novel multifunctional hybrids assembled by lanthanide polyoxometalates, ionic liquid and lanthanide complexes were prepared through the reactions of ion exchange and coordination in mild conditions. These hybrids possess two luminescence centers, one is lanthanide polyoxometalates ([EuW10O36](9-) or [TbW10O36](9-)), the other is lanthanide complexes of 1,10-phenanthroline (phen) (or 2,2'-bipyridine (bpy)) and ionic liquid (1-methyl-3-propionic imidazole unit). Fourier transform infrared (FTIR) spectra, X-ray diffraction (XRD) analysis, thermo-gravimetric analysis (TGA), UV/vis diffuse reflectance spectra and photoluminescent properties are utilized to characterize these hybrid materials. The results reveal that all hybrids possess amorphous microstructures and are composed of inorganic polyoxometalates and lanthanide nitrate through chemical bonds. Most hybrids exhibit outstanding luminescent properties such as high quantum efficiency and long lifetimes. Moreover, the luminescent color of them can be tuned and even the white luminescence can be integrated.
RESUMO
The development of efficient and stable white-light emissive materials is highly desirable in displays and solid-state lighting. Here we present a high-quality white-light emitter based a dual-emitting MOF hybrid, which is achieved by dye encapsulation engineering within a robust Zr-MOF (PCN-128W) containing a highly luminescent tetraphenylethylene-based ligand. The pore confinement effect well isolates the incorporated dye molecules (trans-4-[4-(Dimethylamino)styryl]-1-methylpyridinium iodide (DSM)) and therefore suppress the aggregation caused luminescence quenching. The dye emission is mainly sensitized by PCN-128W host through Förster resonance energy transfer (FRET), and the FRET process is incomplete, thus enabling the hybrid to feature dual emissions upon a single excitation. The emission color of DSM@PCN-128W hybrid can be systematically tuned from blue to white, and to orange by regulating the dye encapsulation content. A broad white-light emission with a considerably high quantum yield (21.2%) is obtained in the case of dye contents of 0.15 wt%. The luminescence of DSM@PCN-128W hybrid is stable in ambient air for over 1 month, and show good resistance to continuous UV light irradiation, owing to the protective MOF Matrix that largely inhibits the UV exposure to dye molecules. What's more, by combining DSM@PCN-128W with a commercial UV LED chip, we fabricate a white-light emitting prototype device showing CIE chromaticity coordinates of (0.34, 0.33), a CRI of 79.1, and a CCT of 5525 K.
RESUMO
Aqueous ZIBs are one of the most promising next-generation rechargeable batteries because of the high capacity, high hydrogen evolution overpotential, and chemically stable reversible plating/stripping of the zinc electrode in the mild aqueous electrolyte. However, there are limited cathode materials that can store Zn2+ reversibly with superior cycling and rate capability. Herein, hierarchically porous nanorods composed of twinborn α-(Mn2O3-MnO2) heterostructures are proposed as a robust cathode for Zn storage. Thanks to the hierarchically porous nanorod morphology and the abundant interface of the heterostructures involving a built-in electric field, the as-obtained twinborn α-(Mn2O3-MnO2) electrode delivers a high capacity of 170 mA h g-1 for 2000 cycles at 500 mA g-1 and shows an excellent rate capability of up to 1.5 A g-1 with a capacity of 124 mA h g-1. The inspiring results achieved exhibit the enormous potential of the high-performance heterostructure cathode for fast and stable ZIBs.
RESUMO
As an important class of multielectron reaction materials, the applications of transition-metal oxides (TMOs) are impeded by volume expansion and poor electrochemical activity. To address these intrinsic limitations, the renewal of TMOs inspires research on incorporating an advanced interface layer with multiple anionic characteristics, which may add functionality to support properties inaccessible to a single-anion TMO electrode. Herein, a transition-metal oxycarbide (TMOC, M = Mo) with more than one anionic species was prepared as an interface layer on a corresponding oxide. A multiple anionic TMOC possesses advantages of structural stability, abundant active sites, and elevated metal cation valence states. Such merits mitigate volume changes and enhance multielectron reactions significantly. The TMOC nanocomposite has a well-maintained capacity after 1000 cycles at 2 A·g-1 and fully resumed rate performance. In situ synchrotron X-ray powder diffraction (SXRPD) analysis unveils negligible volume expansions occurring upon oxycarbide layer coupling, with lattice spacing variation less than 1% during cycling. The lithium storage mechanism is further inspected by combined analysis of kinetics, SXRPD, and first-principles calculations. Superior to TMO, multielectron reactions of the TMOC electrode have been boosted due to easier rupture of the metal-oxygen bond. Such improvements underscore the importance of incorporating an oxycarbide configuration as a strategy to expand applications of TMOs.
RESUMO
Borohydride solid-state electrolytes with room-temperature ionic conductivity up to ≈70 mS cm-1 have achieved impressive progress and quickly taken their place among the superionic conductive solid-state electrolytes. Here, the focus is on state-of-the-art developments in borohydride solid-state electrolytes, including their competitive ionic-conductive performance, current limitations for practical applications in solid-state batteries, and the strategies to address their problems. To open, fast Li/Na/Mg ionic conductivity in electrolytes with BH4 - groups, approaches to engineering borohydrides with enhanced ionic conductivity, and later on the superionic conductivity of polyhedral borohydrides, their correlated conductive kinetics/thermodynamics, and the theoretically predicted high conductive derivatives are discussed. Furthermore, the validity of borohydride pairing with coated oxides, sulfur, organic electrodes, MgH2 , TiS2 , Li4 Ti5 O12 , electrode materials, etc., is surveyed in solid-state batteries. From the viewpoint of compatible cathodes, the stable electrochemical windows of borohydride solid-state electrolytes, the electrode/electrolyte interface behavior and battery device design, and the performance optimization of borohydride-based solid-state batteries are also discussed in detail. A comprehensive coverage of emerging trends in borohydride solid-state electrolytes is provided and future maps to promote better performance of borohydride SSEs are sketched out, which will pave the way for their further development in the field of energy storage.
RESUMO
Luminescent MOF materials with tunable emissions and energy/charge transfer processes have been extensively explored as ratiometric temperature sensors. However, most of the ratiometric MOF thermometers reported thus far are based on the MOFs containing photoactive lanthanides, which are potentially facing cost issue and serious supply shortage. Here, we present a ratiometric luminescent thermometer based on a dual-emitting lanthanide-free MOF hybrid, which is developed by encapsulation of a fluorescent dye into a robust nanocrystalline zirconium-based MOF through a one-pot synthesis approach. The structure and morphology of the hybrid product was characterized by Powder X-ray diffraction (PXRD), N2 adsorption-desorption measurement and Scanning electron microscopy (SEM). The pore confinement effect well isolates the guest dye molecules and therefore suppresses the nonradiative energy transfer process between dye molecules. The incorporated dye emission is mainly sensitized by the organic linkers within MOF through fluorescence resonance energy transfer. The ratiometric luminescence of the MOF hybrid shows a significant response to temperature due to the thermal-related back energy transfer process from dye molecules and organic linkers, thus can be exploited for self-calibrated temperature sensing. The maximum thermometric sensitivity is 1.19% °C-1 in the physiological temperature range, which is among the highest for the ratiomtric MOF thermometers that operating in 25-45°C. The temperature resolution is better than 0.1°C over the entire operative range (20-60°C). By integrating the advantages of excellent stability, nanoscale nature, and high sensitivity and precision in the physiological temperature range, this dye@MOF hybrid might have potential application in biomedical diagnosis. What' more, this work has expanded the possibility of non-lanthanide luminescent MOF materials for the development of ratiometric temperature sensors.
RESUMO
In this paper, we put forward a strategy to assemble a novel series of multi-component photofunctional hybrid materials (named as Eu-Si-P1(2,3)) centered with europium polyoxometalates (Na9EuW10O36·32H2O, abbreviated as EuW10) and polyester modified silane (P1-Si, P2-Si, P3-Si, P1 = poly glycohol, P2 = bis(2-hydroxyethyl)ether, P3 = 2-hydroxyethyl methacrylate) through an ionic liquid compound (1-methyl-3-(trimethoxysilylpropyl) imidazolium chloride, IM(+)Cl(-)) as the double functional linker. Furthermore, using Pluronic P123 surfactant as a template to control the sol-gel process of organically modified siloxane precursors, Eu-SBA15-P1(2,3) hybrids with mesoporous silica are constructed correspondingly. The results reveal that Eu-Si-P1(2,3) hybrids present the lower red/orange intensity ratio, longer lifetime and higher quantum yield than Eu-SBA15-P1(2,3) hybrids. The luminescent lifetime and quantum efficiency of Eu-Si-P1(2,3) hybrids are comparable with EuW10 compounds in spite of their low concentration of photoactive EuW10, which is important for practical applications. The CIE chromatic coordinates of some systems are close to the cool-white region and can be expected to be utilized as cool white lighting (close to sunlight).
RESUMO
By using cylindrical sediment sampler and Peeper' s interstitial water sampler, the intact sediment and interstitial water were collected from different zones of Nansi Lake in Shandong Province in summer and winter. The distribution characteristics of the sediment phosphorus forms and of the phosphate (PO4(3-)-P) in interstitial water were analyzed, and their correlations were discussed. In the sediments of Nansi Lake, phosphorus was richer, and had a significant spatial differentiation, with an overall decreasing trend from north to south, which was related to the seriously polluted Northern Nansi Lake near Jining City. Among the phosphorous forms, inorganic phosphorus (IP) had the highest concentration, accounting for 52.3%-87.2% and 60.6%-88.3% of the total phosphorus (TP) in summer and winter, respectively. The TP concentrations in 5 cm surface sediment of four sub-lakes were all higher in summer than in winter, which could be related to the human activities such as exuberant aquaculture, more chemical fertilizers application around lake, and frequent tourism activities, etc. in summer. In vertical direction, the PO4(3-)-P concentration in interstitial water decreased after an initial increase in summer and winter, and was obviously higher in summer than in winter, suggesting that the phosphorous in sediment had a higher potential to release to the overlying water in summer. The organic phosphorus (OP) and IP in sediment had a significant correlation in summer but less correlation in winter, indicating that the transformation between sediment IP and OP was more active in summer than in winter. The iron and aluminum bound phosphorus (Fe/Al-P) and IP in sediment were significantly positively correlated with the PO4(3-)-P in interstitial water. In summer and winter, the average PO4(3-)-P concentration in interstitial water collected by Peeper' s interstitial water sampler was about 20%-50% higher than that collected by the conventional centrifugal method, suggesting that using Peeper' s interstitial water sampler could be more precise.