- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Pyrophosphate Prompted Aggregation-Induced Emission: Chemosensor Studies, Cell Imaging, Cytotoxicity, and Hydrolysis of the Phosphoester Bond with Alkaline Phosphatase
摘要： Two zinc complexes [(Zn)2(L2)2Cl2(DMSO)2] (R1) and [Zn(L2)2(NO3)2(H2O)2] (R2) were synthesized and characterized with various spectroscopic data. The single X-ray structure determination reveals that complex R1 is dinuclear and tetrahedral in geometry, while complex R2 is mononuclear and octahedral in geometry. Further, both zinc complexes were investigated for pyrophosphate sensing in an aqueous medium. Complex R1 is found to be selective towards pyrophosphate; it leads to 5.5-fold enhancement in the emission intensity due to aggregation-induced emission. However, complex R2 has shown binding with all, ATP, AMP, ADP, and pyrophosphate, which is attributed to the chelate effect. Consequently, complex R1 was utilized for the intracellular detection of pyrophosphate in HeLa cells. Furthermore, the PPi based zinc complex R1 is also used as a bio-analytical tool to construct a real-time fluorescence assay for the enzymatic activity of alkaline phosphatases (ALP).
关键词： Intracellular detection,Sensors,Fluorescence,Zinc,ALP activity,Pyrophosphate
更新于2025-11-21 11:24:58
-
Structural, optical and photoluminescence studies of sol-gel synthesized pure and iron doped TiO2 photocatalysts
摘要： Pure and Iron doped TiO2 nanoparticles were synthesized using the sol-gel method. These materials were characterized by X-ray diffractometer (XRD), high-resolution transmission electron microscope (HR-TEM), scanning electron microscope (SEM), Energy dispersive X-ray (EDX), UV-Vis diffuse reflectance spectroscopy (DRS), Fourier-transform infrared (FTIR), Raman and fluorescence spectrometer. XRD analysis revealed that all the samples were a single phase with anatase nanocrystallite structures. The crystallite size of titania reduced from 9.64 nm to 7 nm with Fe doping. The HRTEM images of the TiO2 and 3% Fe doped TiO2 have revealed that all the particles have a spherical shape with an average particle size of 10 nm and 8 nm respectively. The characteristic peak at 482 cm-1 of the Ti–O bond stretching vibrations can be evidently observed from FTIR analysis. The Raman blue shift was found in the Fe doped TiO2 samples. Fe-doped TiO2 nanoparticles showed a significant red-shift in band edge as compared with pure TiO2 nanoparticles. The redshift of band gap was detected in Fe doped TiO2 nanoparticles. The photoluminescence (PL) emission intensity of Fe doped TiO2 nanoparticles decreases with an increase in Fe doping concentration. The photocatalytic efficiencies of the Fe-doped TiO2 nanoparticles have shown a strong photocatalytic activity (PCA) response. At constant irradiation time, the Fe-doped titania nanoparticles display more catalytic activity compared to undoped TiO2. The photodegradation efficiencies typically decline with an increase in the concentration of Fe+3 doping for the decolorization of methylene blue (MB) under visible light irradiation.
关键词： band gap,Raman modes,photocatalytic activity,TiO2 nanoparticles,methylene blue,PL emission
更新于2025-11-21 11:18:25
-
Chemically exfoliated 1T-phase transition metal dichalcogenide nanosheets for transparent antibacterial applications
摘要： Two-dimensional transition metal dichalcogenides (TMDs) are promising materials for a range of applications owing to their intriguing properties including the excellent electrical performance and biocompatibility. Strikingly, 1T-phase TMDs have attracted significant interest based on their metallic properties with octahedral metal coordination where the phase transition can occur from the semiconducting 2H-phase to metallic 1T-phase by chemical intercalation-induced exfoliation process. In this regard, 1T-phase TMDs have great potential in antibacterial agents in terms of effective charge transfer between the bacterial membrane and TMD nanosheets while their biological interactions have been underexplored. To bridge this gap, we herein investigate the antibacterial activities of various 1T-phase TMDs including molybdenum disulfide (MoS2), tungsten disulfide (WS2), and molybdenum diselenide (MoSe2) toward Gram-negative bacteria Escherichia coli that exhibit the reduction of bacterial viability caused by the production of reactive oxygen species, oxidation of glutathione and other chemical functionalities. The effective antibacterial capacity of metallic 1T-phase TMDs is observed and their bactericidal mechanisms are investigated in terms of their electrical conductivity and chemical oxidation property that induce the charge transfer from bacterial membrane to TMDs leading to the continuous disruption of bacteria and loss of cellular components. Furthermore, we demonstrated the transparent antibacterial films consisting of 1T-phase TMDs in which TMD nanosheets are immobilized on the surfaces and their basal planes play an important role in antibacterial actions for practical biomedical applications. Thus, our findings provide new insights into the great potential of 1T-phase TMDs as promising building blocks for antibacterial surfaces and contribute to the widespread use of 1T-phase TMDs for practical biomedical applications.
关键词： 1T-phase,charge transfer,antibacterial activity,oxidative stress,transition metal dichalcogenide
更新于2025-11-21 11:08:12
-
Hollow hierarchical structure Co0.85Se as efficient electrocatalyst for the triiodide reduction in dye-sensitized solar cells
摘要： The exploration of nonprecious metal-based electrocatalysts with high efficiency for the triiodide reduction is critical for the practical applications of the dye-sensitized solar cells. Herein, we develop a facile one-step hydrothermal method to synthesize hollow hierarchical structure Co0.85Se. Under the methanol-water reaction system, the product named as hollow hierarchical structure Co0.85Se-M has the largest specific surface area (215.36 m2 g?1) and the best crystallinity than other products obtained from other alcohol-water reaction systems. When this electrocatalyst is applied as a counter electrode for the dye-sensitized solar cells, it exhibits a small peak-to-peak separation (Epp, 97 mV) for the reduction of I3?/I? redox couple. It is found that the catalytic activity of Co0.85Se is closely dependent on the crystallinity. Moreover, the reactivity pathway is identified by density functional theory, which confirms that triiodide is reduced to iodide ion on Co0.85Se with a smaller energy barrier (～0.65 eV) than on Pt (～1.18 eV). Both experimental and theoretical results demonstrate Co0.85Se-M as an ideal counter electrode material for the dye-sensitized solar cells with a higher power conversion efficiency (8.76%) than Pt counter electrode (7.20%).
关键词： Dye-sensitized solar cells,Hollow hierarchical structure,Cobalt selenides,Electrocatalytic activity,Triiodide reduction
更新于2025-11-21 11:03:13
-
TiO2/SnO2 and SnO2/TiO2 heterostructures as photocatalysts for degradation of stearic acid and methylene blue under UV irradiation
摘要： The effect TiO2/SnO2 (TiO2 is on the top and SnO2 at the bottom) and SnO2/TiO2 (SnO2 is on the top and TiO2 at the bottom) heterostructures towards photocatalytic degradation of stearic acid and methylene blue is reported. The two heterostructures, wherein SnO2 (or TiO2) is the top or bottom layer, are prepared by the sol-gel technique. TiO2/SnO2 film exhibit better photocatalytic activity as compared to SnO2/TiO2, TiO2 and SnO2 films. Wettability studies reveal that TiO2/SnO2 films modified with stearic acid (8mM concentration of stearic acid in ethyl alcohol) tend towards superhydrophobic regime with contact angle as high as 137o. Further, TiO2/SnO2 films are efficient in degrading the stearic acid under UV irradiation. Interestingly, TiO2/SnO2 films that display flake like structures, with increased charge separation, are responsible for better degradation of pollutants under UV irradiation because of coupling heterostructures.
关键词： Bilayer film,Wettability,Superhydrophobic,Photocatalytic activity
更新于2025-11-19 16:56:35
-
Opposite changing dual-emission luminescence of gold nanoparticles by sulfhydryl to develop a pesticide biosensing strategy
摘要： As the merit of ratiometric assay is impregnable due to potentially interfering processes, a ratiometric method for pesticide detection was developed. By adjusting glutathione : HAuCl4 to an appropriate ratio, dual-emission luminescent ultra-small gold nanoparticles (AuNPs) with a high emission at 800 nm and a low emission at 600 nm were synthesized. Interestingly, the sulfhydryl-containing compounds were found to result in completely opposite changes to strengthen the 600 nm emission and weaken the 800 nm emission. Therefore, dual-emitted AuNPs were engaged to develop a ratiometric pesticide biosensing strategy. In the presence of acetylcholinesterase (AChE), acetylthiocholine can be hydrolyzed into thiocholine, whose newly generated sulfhydryl can interact with AuNPs, resulting in the opposite change of the dual emissions. While adding pesticide as an AChE inhibitor, the catalytic activity of AChE is inhibited and less thiocholine was produced. The biosensing system shows an obvious sensitivity to the pesticide with a limit of detection (LOD) of 0.2 nM for aldicarb and 0.07 nM for chlorpyrifos. Therefore, this simple assay is suitable for AChE activity and pesticide detection, even in vegetable samples.
关键词： sulfhydryl,ratiometric assay,gold nanoparticles,AChE activity,biosensing,pesticide detection
更新于2025-11-19 16:56:35
-
A “turn off-on” fluorescent nanoprobe consisting of CuInS2 quantum dots for determination of the activity of β-glucosidase and for inhibitor screening
摘要： A fluorescent “turn off-on” nanoprobe is described for highly sensitive and selective determination of the activity of the enzyme β-glucosidase (β-Glu). Firstly, cysteine modified CuInS2 quantum dots (Cys-CuInS2 QDs) were prepared from indium(III) and copper(II) salts and the presence of thiourea. The red fluorescence of the Cys-CuInS2 QDs, with excitation/emission maxima at 590/656 nm, is quenched by Cu(II). However, in the presence of β-Glu and the cyanogenic glycoside, enzymatic hydrolysis leads to the formation of cyanide. The latter competitively binds to Cu(II) owing to its high affinity for cyanide. This restores the fluorescence of the Cys-CuInS2 QDs. Under the optimum conditions, fluorescence increases linearly in the 0.5–700 U·L?1 β-Glu activity range. The detection limit is 0.2 U·L?1. The nanoprobe was applied to analyze spiked soil samples, and satisfactory results were obtained. The average recoveries of β-Glu were in the range of 96–103%, and the RSD was lower than 4.0%. The fluorescent probe can also be used to screen for β-Glu inhibitors as demonstrated for castanospermine as an example.
关键词： Cys-CuInS2 QDs,Cu(II),Cyanide,Competitively binds,Cyanogenic glycoside,Soil,Enzyme activity,Fluorescence,Amygdalin,Castanospermine
更新于2025-11-19 16:46:39
-
Synthesis of CoNi bimetallic alloy nanoparticles wrapped in nitrogen-doped graphite-like carbon shells and their electrocatalytic activity when used in a counter electrode for dye-sensitized solar cells
摘要： Nanoparticles of the bimetallic alloy CoNi wrapped in nitrogen-doped graphite-like carbon shells and dispersed on nitrogen-doped graphite-like carbon sheets (CoxNi1?x@NC) were synthesized by calcining CoNi metal–organic frameworks that were prepared through a facile solvothermal reaction using various raw-material molar ratios Co:Ni and CoNi:ethylenedinitrilotetraacetic acid. After depositing CoxNi1?x@NC for use as a counter electrode film in dye-sensitized solar cells, it was found that the electrocatalytic activity of the CoxNi1?x@NC counter electrode towards triiodide reduction could be optimized by simply tuning the molar ratios (Co:Ni and CoNi:ethylenedinitrilotetraacetic acid) appropriately during CoxNi1?x@NC synthesis. Cells that utilized a CoxNi1?x@NC counter electrode exhibited strong chemical-composition-dependent photovoltaic performance. Under optimal conditions, the CoxNi1?x@NC counter electrode presented an impressive energy conversion efficiency of 3.58%, suggesting that it is a highly promising counter electrode for application in dye-sensitized solar cells. This counter electrode has the advantages that it is considerably less expensive than a Pt counter electrode and that it provides the basis for the design and preparation of other inexpensive and efficient counter electrodes to replace Pt.
关键词： Photovoltaic performance,Dye-sensitized solar cells,CoNi alloy bimetallic nanoparticles,Counter electrode,Electrocatalytic activity
更新于2025-11-14 17:04:02
-
One-pot synthesis of 3D Cu <sub/>2</sub> S–MoS <sub/>2</sub> nanocomposites by an ionic liquid-assisted strategy with high photocatalytic activity
摘要： Novel 3D Cu2S–MoS2(x : y) nanocomposites with different proportions of Cu2S (x) and MoS2 (y) are synthesized successfully by a one-step hydrothermal method with the assistance of the ionic liquid [BMIM]SCN. The characterization results show that the nanocomposites are self-assembled from nanosheets of Cu2S and MoS2, they display nanoflower morphology and a typical mesoporous structure. The fabrication mechanism of the nanocomposites is investigated using time-dependent experiments, which indicate the key role of the ionic liquid (IL) in the synthesis process. Furthermore, TAA is used as a sulfur source instead of the IL to form a Cu2S–MoS2 nanocomposite, with the aim of further investigating the effects of the IL on the morphology of the composite. Photodegradation of MB under visible light irradiation experiments were used as probe reactions to evaluate the photocatalytic performance of the as-prepared samples. All the nanocomposites show better catalytic activity than Cu2S and MoS2 monomers. Among the different Cu2S–MoS2(x : y) nanocomposites, the Cu2S–MoS2(1 : 1) composite exhibits the most excellent photocatalytic performance and cycling stability.
关键词： Cu2S–MoS2 nanocomposites,hydrothermal synthesis,photocatalytic activity,ionic liquid,methylene blue degradation
更新于2025-11-14 17:04:02
-
Bifunctional gold nanoclusters enable ratiometric fluorescence nanosensing of hydrogen peroxide and glucose
摘要： The accurate quantification of hydrogen peroxide (H2O2) and glucose is essential significance in clinical diagnosis. Herein a selective and sensitive ratiometric fluorescent nanosensor was developed for the determination of H2O2 and glucose by integrating peroxidase–like catalytic and fluorescent bifunctional properties of glutathione protected gold nanoclusters (GSH–AuNCs). The GSH–AuNCs exhibit inherent peroxidase–like activity and accelerate the decomposition of H2O2 into hydroxyl radicals. The produced hydroxyl radicals oxidize terephthalic acid (TA), a typical non–fluorescent substrate of peroxidase, to a highly fluorescent product hydroxyterephthalate (TAOH). Upon excitation with single–wavelength at 315 nm, dual–emission fluorescence peaks were recorded at 430 and 600 nm simultaneously. The fluorescence signal of TAOH at 430 nm continuously increased with increasing the concentration of H2O2 while the fluorescence signal of GSH–AuNCs at 600 nm remained unchangeable. Based upon on these facts, a ratiometric fluorescent nanosensor was fabricated for H2O2 assay with TAOH as response unit and GSH–AuNCs as reference, respectively. By converting glucose into H2O2 with catalytic oxidation of glucose oxidase (GOx), this nanosensor was further exploited for glucose assay. Under the optimum conditions, the detection limits of 10 nmol/L H2O2 and 20 nmol/L glucose were acquired. The relative standard deviations were less than 5% for both H2O2 and glucose (5.0 μmol/L solution, n = 11). The practicability of the nanosensor was verified by the determination of glucose in human serum samples. This nanosensor can be easily expanded as a general platform for the detection of other substances involving H2O2 produced or consumed.
关键词： Intrinsic peroxidase-like activity,Fluorescent gold nanoclusters,Hydrogen peroxide,Glucose,Ratiometric fluorescence,Nanosensor
更新于2025-11-14 17:03:37