Luminescence最新文献

This work represents a highly sensitive, low-cost, and eco-friendly method that relies on using onion and lemon juices, which are easily available materials. It depends on the synthesis of highly fluorescent carbon dots (λex/em 350.0–430.0 nm) using a one-step microwave-assisted carbonization method. Characterization of the formed carbon dots was performed using transmission electron microscopy (TEM), Fourier transform infrared (FTIR), Zeta potential analysis, fluorescence spectroscopy UV–Visible spectroscopy, and X-ray photoelectron spectroscopy (XPS). The formed carbon dots appeared to be spherical in shape, with a 2.0- to 3.5-nm average particle size. The synthesized carbon dots were used for the determination of tinidazole by static fluorescence quenching mechanism and inner filter effect. The quenching effect on the synthesized carbon dots' fluorescence signal was utilized for the determination of tinidazole in pure form in concentration samples (2.0–30 μM) with a %recovery of 99.86 ± 1.38 in pure form, 100.0 ± 1.67 in tablet and 99.56 ± 4.18 in urine. The validity of the method was assessed according to the recommendations of the International Conference on Harmonization. The greenness of the method was evaluated using different greenness assessment tools. The proposed probe is eco-friendly due to using water as the only solvent in the absence of other organic solvents.

The development of multiactive photosensitizers integrating the functions of photodynamic therapy (PDT) and photoacid therapy (PAT) provides a new strategy for overcoming tumor drug resistance and enhancing therapeutic efficacy. In this study, we designed and synthesized an organic photosensitizer, CzC, with a twisted molecular structure consisting of carbazole and thiophene linked by covalent bonds. This molecular design endowed CzC with excellent light absorption, good photostability and efficient ROS and H⁺ release under 365-nm laser irradiation. This bifunctional response mechanism synergistically disrupts intracellular acid–base homeostasis and triggers oxidative stress to promote tumor cell apoptosis. In vitro, CzC showed good cellular uptake, potent ROS/H⁺ generation, and very low dark toxicity; in vivo in a mouse 4T-1 tumor model, CzC significantly inhibited tumor growth under light activation, and no systemic toxicity or organ damage was observed. This study demonstrates that CzC is an organic photosensitizer with structural designability, photostability, and bimodal therapeutic function, and provides a powerful candidate molecule for next-generation phototherapy.

The binding behavior of the antioxidant supplement chromium picolinate (CPN) with bovine serum albumin (BSA) was examined under simulated physiological conditions using a variety of spectroscopic techniques, including Fourier transform infrared (FTIR), fluorescence, and UV–visible absorption spectroscopy, complemented by molecular docking analyses. Fluorescence quenching studies revealed that the formation of the BSA–CPN complex resulted in the quenching of HSA's intrinsic fluorescence. A portion of the quenching arises from the inner filter effect (IFE), while the remainder occurs through a dynamic mechanism, with a binding affinity of 3.47 × 10⁷ L mol⁻¹ at 298 K. Thermodynamic analysis via the van't Hoff equation provided key parameters, with an enthalpy change (ΔH°) of −238.89 kJ mol⁻¹ and an entropy change (ΔS°) of −671.146 J mol⁻¹ K⁻¹. These values, along with spectral data, suggested that the stability of the BSA–CPN complex was primarily governed by hydrogen bonding and van der Waals forces. Further structural analysis using FTIR and UV–vis spectroscopy pointed out that CPN binding made conformational changes in BSA, particularly altering its secondary structure due to interactions with hydrophobic pocket residues. Competitive binding assays with site-specific probes suggested that CPN is likely binding to BSA at a location analogous to Site I.

This study presents the synthesis of Mo⁴⁺-doped Cs₄ZnBi₂Cl₁₂ double perovskite through a hydrothermal method, demonstrating efficient near-infrared (NIR) emission at 1110 nm with a full width at half maximum (FWHM) of 45 nm. The emission originates from the d-d transition of Mo⁴⁺ ions within an octahedral crystal field. Structural analysis using powder X-ray diffraction (PXRD) confirms the phase purity and lattice contraction as a result of Mo⁴⁺ substitution at Bi³⁺ sites, supported by X-ray photoelectron spectroscopy (XPS) and elemental mapping. The material exhibits broad excitation compatibility (348–590 nm) and achieves a photoluminescence quantum yield (PLQY) of 45.3% with a microsecond-scale lifetime of 6.78 μs. Thermal stability tests demonstrate sustained emission intensity (58% at 420 K) and resilience to prolonged heating or UV exposure. This work highlights Mo⁴⁺-doped Cs₄ZnBi₂Cl₁₂ as a stable and efficient NIR emitter, advancing lead-free perovskites for optoelectronic applications in bioimaging, agriculture, and sensing.

Through performance regulation of long afterglow luminescent materials (color, decay time of afterglow, and regulation of excitation mode), the multifunctional applications in bio-labeling and information encryption fields have been extensively developed. At present, a common approach is to regulate the afterglow performance by adjusting the trap concentration, but the effect is limited. Therefore, regulating the trap distribution of long afterglow luminescent materials is considered an effective means of controlling its performance. Herein, a series of Mg_2-xZn_xSnO₄ (x = 0, 0.25, 0.5, 0.75, and 1) powder samples were prepared. As can be seen from the afterglow decay spectra, materials exhibited cyan photoluminescence under the excitation wavelength of 254 nm. Meanwhile, in the process of trap regulation, we controlled the distribution of traps by adjusting the doping concentration of Zn²⁺, thus obtaining trap adjustable materials. The proportion of shallow traps gradually enhances with the increase of the concentration of Zn²⁺. Lastly, only shallow traps remain in Mg_1.25Zn_0.75SnO₄ and MgZnSnO₄ samples. In order to demonstrate the feasibility of phosphors for anti-counterfeiting, we create two optical devices. The dynamic information encryption of numbers and patterns was achieved. This dynamic luminescence phosphor shows important potential in anti-counterfeiting and information encryption.

This study demonstrates the creation and verification of a selective and sensitive spectrofluorometric approach for the quantification of lefamulin via its reaction at pH 7.5 with fluorescamine, utilizing borate buffer to yield a highly luminous result. The fluorescence intensity of the resultant product was quantified at 480 nm following illumination at 390 nm. The experimental variables affecting the production, stability, and fluorescence intensity of the resultant product were examined and optimized. The proposed approach demonstrated linearity within the concentration range of 50 to 1500 ng/mL; 48.57 and 16.03 ng/mL were the quantitation and detection limits, respectively. Pharmaceutical tablets of lefamulin were successfully evaluated in dosage form and spiked biological fluid, and the suggested approach has been validated in accordance with the International Council for Harmonization (ICH) criteria. Additionally, the approach was used to examine the content uniformity in accordance with US Pharmacopeia requirements. Furthermore, the results of the ecology scale scores indicated that the analytical process involved was green.

The development of single component, multifunctional phototheranostic platforms remains a crucial objective in precision cancer therapy. Here, we design near-infrared (NIR) light-activated nanoparticles (NPs) by assembling IDIC with DSPE-PEG-NH₂ to achieve high photothermal conversion efficiency, reactive oxygen species generation, and biocompatibility. The resulting IDIC NPs exhibit strong NIR absorption and fluorescence, high photostability, and good aqueous stability. Upon 635-nm laser irradiation, they reach a photothermal conversion efficiency of 52.8% and a singlet oxygen quantum yield of 43.0%, enabling synergistic photothermal and photodynamic therapy. In vitro, IDIC NPs show negligible dark toxicity but induce potent tumor cell ablation upon irradiation through mitochondrial membrane disruption and immunogenic cell death, evidenced by calreticulin exposure, HMGB1 release, and ATP secretion. In vivo, they enable effective NIR imaging, inhibit tumor growth, prolong survival, and cause minimal systemic toxicity. Laser-treated tumors exhibit enhanced apoptosis, reduced proliferation, and macrophage polarization toward an M1 phenotype. These findings establish IDIC NPs as a robust, single-component nanotheranostic agent integrating NIR imaging, photothermal/photodynamic synergy, and immune activation for cancer treatment.

A NiO-ZnO-MgO ternary heterojunction nanocomposite was synthesized in this work using a microwave-assisted green precipitation approach to improve the photocatalytic removal of methylene blue (MB) dye driven by visible light. Structural analysis via SEM explored round-shaped particles with an average dimension of 14 nm, whereas FTIR established the existence of Zn-O (512 cm⁻¹), Ni-O (564 cm⁻¹), and Mg-O (1399 cm⁻¹) vibrational modes. BET surface analysis demonstrated a high specific surface area of 77.26 m²/g, a pore radius of 15.98 Å, and a pore volume of 0.037 cc/g. Under optimized conditions (pH 9.2, 40°C, visible light intensity of 100 W), the nanocomposite achieved a MB dye degradation efficiency of 90.9% within 120 min, which is superior to many conventional photocatalysts such as TiO₂ (15%–30%), ZnO (70%–85%), and binary ZnO-NiO composites (~80%–85%) under similar light exposure conditions. The quantum yield (QY) and space–time yield (STY) were estimated as 7.49 × 10⁻⁷ molecules/photon and 6.57 × 10⁻⁸ molecules/photon·mg, respectively. Degradation performance was further enhanced by the creation of defect states and reactive oxygen species (ROS), especially superoxide radicals (•O₂⁻). The NiO-ZnO-MgO nanocomposite's promise as an economical and ecologically friendly photocatalyst for wastewater treatment is shown by these results.

This research focuses on the preparation and comprehensive characterization of Li₂Sr.₂Al₂PO₄F₉ phosphors doped with Dy³⁺ ions. The material was synthesized via combustion method utilizing urea as a fuel source. Structural and luminescence properties are investigated through X-ray diffraction and photoluminescence (PL) techniques. The PL excitation spectrum of Li₂Sr.₂Al₂PO₄F₉:Dy³⁺ revealed multiple excitation bands between 300 and 400 nm, attributed to 4f electronic transitions of Dy³⁺ ions. Upon excitation at 348 nm, the PL emission spectrum exhibited characteristic emissions at 478 nm (blue), corresponding to ⁴F₉/₂ → ⁶H₁₅/₂ transition, and at 571 nm (yellow), associated with the ⁴F₉/₂ → ⁶H₁₃/₂ transition of Dy³⁺.

Using several spectroscopic methods, such as fluorescence spectroscopy, Fourier transform infrared (FTIR), UV–visible spectroscopy, thermodynamic investigations, and molecular modeling (MD), is a recent trend in investigating the binding interactions between pharmaceuticals and proteins. The current research examines how nicorandil (NCL) interacts with bovine serum albumin (BSA), a major blood plasma carrier protein, under simulated physiological circumstances (pH 7.4). Fluorescence data and ultraviolet spectra proved that the intrinsic fluorescence of BSA was diminished by NCL through an integration of dynamic and static quenching mechanisms. Studies indicated that NCL binds weakly to BSA with a single binding site (6.35 × 10² M⁻¹ at 298 K), which is consistent with the reported plasma protein binding percentage (approximately 25%). Analysis of the thermodynamic parameters revealed that the NCL-BSA interaction was spontaneous with an enthalpy change (ΔH) of 174.85 kJ mol⁻¹. Hydrophobic forces were the primary binding forces; the entropy change (ΔS) was 639.96 kJ mol⁻¹. Competitive binding experiments proposed that NCL was primarily attached to Site I of BSA's hydrophobic cavity. In addition, synchronous fluorescence spectroscopy, FTIR, and ligand-protein docking studies have deduced the conformational alteration in the BSA secondary structure when it interacts with NCL. Docking results were in accordance with experimental results.