Luminescence最新文献

Acidochromic fluorescent membranes have garnered significant research interest owing to their potential in real-time environmental monitoring and smart sensing applications. However, the rational design of membranes to optimize their structure–property interplay for enhanced acidochromic performance remains further explored. Herein, we prepared various stimulus-responsive micro/nanofibrous membranes using electrospinning technology by incorporating a fluorescent small molecule (TPECNPy-2) with thermoplastic polyurethane (TPU) to obtain specific properties. The effects of varying the TPECNPy-2 content on the chemical–physical structure and acidochromic properties of the composite membranes were analyzed. The results indicated that the addition of TPECNPy-2 had no significant impact on the chemical structure, fiber morphology, or aggregation state of the composite membranes. Morphology assessment revealed that the fabricated TPECNPy-2/TPU composite membranes exhibited uniform fiber diameters of approximately 100 nm, demonstrating excellent spinnability and reproducibility, while FL analysis revealed that all composite fiber membranes exhibited reversible acidochromic behavior. Under acid vapor exposure, the maximum fluorescence emission wavelength shifted from 505–511 to 622–625 nm. After fumigation with triethylamine, the fluorescence emission returned to its initial state, and the membrane reverted to its original color under visible light.

Phosphors, as the crucial material of phosphor-converted white light-emitting diodes (pc-WLEDs), have played an essential role in improving luminescent efficiency and regulating color rendering index (CRI). Hence, we have successfully synthesized a novel Eu²⁺ doped Sr₈(Al₁₂O₂₄)(WO₄)₂ (SAWO) green phosphor for the first time using the solid-state reaction, as well as systematically investigated its phase and crystal structure, luminescent properties, and thermal stability. The SAWO:x mol%Eu²⁺ (0.1 ≤ x ≤ 1.0) phosphors were confirmed to be pure phase through XRD Rietveld refinement. The excitation spectrum of SAWO:Eu²⁺ monitored at 516 nm exhibited a wide band from 250 to 450 nm, which is well matched with the PL spectrum for near-ultraviolet chips. Furthermore, it can be known that three distinct Sr³⁺ sites in as-synthesized samples are occupied by Eu²⁺ to form a broad emission band of 430–650 nm by the analysis of the crystal structure and spectra. Meanwhile, the optimal doping concentration of Eu²⁺ is 0.3 mol%, and the concentration quenching mechanism is electric dipole–dipole interactions. Additionally, the SAWO:Eu²⁺ phosphor shows higher color purity (82.0%) and excellent activation energy (ΔE = 0.312 eV). These results demonstrate that the SAWO:Eu²⁺ has remarkable potential as the green ingredient in a tricolor phosphor excited by near-ultraviolet in pc-WLEDs.

In the current study, the triazole antifungal terconazole (TRZ) was determined using a novel, extremely sensitive, and environmentally friendly spectrofluorimetric approach. A methanolic solution of TRZ exhibited strong native fluorescence at 373 nm when excited at 241 nm. With a correlation coefficient of 0.9999, a straight-lined calibration curve was produced over the concentration range of 5.0–600.0 ng/mL. With quantification and detection limits of 4.64 and 1.53 ng/mL, respectively, the developed approach showed ultrasensitivity reaching the nanogram scale. Due to its great sensitivity, the method could successfully estimate TRZ in human plasma samples with low %RSD values and high recoveries (98.31–101.66). The method was also effectively used to analyze the TRZ in its vaginal suppositories and creams without interference from existing excipients. With satisfactory results, the method's applicability was expanded to the analysis of TRZ in environmental water samples. Two distinct green metrics, AGSA and MoGAPI, were applied to validate the approach's greenness profile and eco-friendliness. The method's applicability and economic feasibility were also verified using the BAGI tool. According to ICHQ2 (R2) criteria, the proposed approach underwent complete validation. This work introduced the first spectrofluorimetric method for TRZ analysis, enabling its usage in pharmacological, biological, and environmental monitoring.

A novel pyrene-based fluorescent probe PYS was designed and synthesized for the sequential detection of Cu²⁺ and picric acid (PA) under identical experimental conditions. In ethanol-HEPES buffer (V/V = 8:2, pH = 7.4), Cu²⁺ was selectively detected by PYS through fluorescence enhancement with a binding constant of 7.5 × 10⁴ L/mol and a detection limit of 9.3 × 10⁻⁸ mol/L, demonstrating high sensitivity and anti-interference capability. The resulting complex PYS-Cu²⁺ functioned as a probe for PA detection, exhibiting instantaneous response (2 s) and high selectivity superior to other nitroaromatic compounds. The quenching mechanism was attributed to synergistic static quenching and inner filter effects, achieving a PA detection limit of 8.7 × 10⁻⁷ mol/L, significantly below the permissible PA concentration (0.5 mg/L) specified in China's Surface Water Environmental Quality Standard (GB 3838-2002). Furthermore, a molecular logic gate system was successfully implemented using Cu²⁺ and PA as chemical inputs, highlighting its potential for sensing applications.

Phosphors with high efficiency and excellent thermal stability for solid-state lighting have kept catching researchers' attention. Herein, a series of Ca₃Sc₂Si₃O₁₂:Ce³⁺ cyan-emitting phosphors are synthesized, and calcium vacancy is introduced into the lattice to improve emission and thermal stability. Detailed structure information is studied via X-ray diffraction and X-ray photoelectron spectroscopy to obtain the effect of Ca vacancy on the lattice structure. Absorption spectra and photoluminescence spectra of the phosphors are measured to confirm the enhanced emission of Ca₃Sc₂Si₃O₁₂:Ce³⁺ phosphors via Ca vacancy engineering. Optimized phosphor Ca_2.59Ce_0.01Sc₂Si₃O₁₂ exhibits high quantum efficiency (89.4%) and maintains 84.6% of its room-temperature emission intensity at 423 K. Optimized phosphor Ca_2.59Ce_0.01Sc₂Si₃O₁₂ is mixed with orange phosphor to fabricate white light-emitting diode (WLED) with blue chip. All the information confirms the promising application prospects of this cyan-emitting phosphor in high-quality WLED.

A novel, eco-friendly deconvoluted synchronous spectrofluorimetric method has been developed and validated for the simultaneous determination of domperidone (DOM) and safinamide (SAF), a potential combination used to address Parkinson's disease–associated gastrointestinal dysfunction. Their combined administration necessitates a reliable analytical method for therapeutic monitoring and formulation quality control. Traditional spectrofluorimetric techniques fail to resolve the significant spectral overlap between these two compounds. In this study, a deconvoluted synchronous spectrofluorimetric method, using Fourier self-deconvolution at Δλ = 30 nm, successfully resolved the overlapping fluorescence spectra without any need for physical separation. It showed excellent linearity (DOM: 10–1500 ng/mL, SAF: 50–2000 ng/mL), with low LOD (2.75 ng/mL for DOM and 11.77 ng/mL for SAF), high recovery rates in both pharmaceutical forms and spiked human plasma (above 90%), and outstanding selectivity and robustness. Sustainability of the current method was assessed using spider chart measure, green solvent selection tool, Analytical GREEnness Metric, Modified Green Analytical Procedure index, and Blue Applicability Grade Index. The proposed technique represents a simple, sensitive, and sustainable tool for routine analysis of this therapeutically significant drug pair.

Eu-MOF with rhomboid structure and strong fluorescence was successfully synthesized in this work. By combining fluorescent Eu-MOF with peroxidase mimic MnO₂ nanosheets, a novel ratiometric fluorescence sensing method was developed for the sensitive detection of piceatannol (PCT), a naturally occurring stilbene-type polyphenolic compound. The sensing mechanism relies on the strong antioxidant ability of PCT, which reductively decomposes MnO₂ nanosheets into Mn²⁺ and results in the attenuation of the fluorescence intensity of the o-phenylenediamine (OPD) oxidation product and the concomitant recovery of Eu-MOF fluorescence. Consequently, the ratio of fluorescence intensity at two distinct wavelengths is changed with the varying of PCT concentrations, facilitating the sensitive detection of PCT. The results showed that the fluorescence intensity ratio (F₄₃₀/F₅₆₀) exhibited a linear relationship with the concentration of PCT within the range of 0.125–6.25 μM, with an actual detection limit of 0.05 μM. The method was successfully applied to the detection of PCT concentration in the extracellular fluid of RAW 264.7 cells and is expected to provide a promising approach for monitoring the pharmacokinetics of PCT.

BaWO₄:Dy³⁺ nanoparticles and BaWO₄:Dy³⁺ co-doped Pb²⁺ nanoparticles were successfully synthesized via a solvothermal method at 140°C for 24 h, employing dimethyl sulfoxide (DMSO) as the solvent. From the x-ray diffraction (XRD) study, the prepared nanoparticles show a tetragonal system. The BaWO₄:Dy³⁺ nanoparticles exhibited strong luminescent behavior, which was significantly enhanced by a factor of two to three upon co-doping with Pb²⁺ ions. This enhancement is attributed to efficient energy transfer from Pb²⁺ to Dy³⁺ ions within the host lattice. Importantly, the BaWO₄:Dy³⁺ nanoparticles demonstrated selective luminescence enhancement in response to Pb²⁺ ions in aqueous media, whereas the BaWO₄:Dy³⁺ co-doped Pb²⁺ nanoparticles exhibited more luminescence quenching upon exposure to Fe³⁺ ions. These findings highlight the potential of BaWO₄:Dy³⁺ and BaWO₄:Dy³⁺ co-doped Pb²⁺ nanoparticles as effective probes for the selective detection of Pb²⁺ and Fe³⁺ ions, respectively, in water-based environments.