Journal of Fluorescence最新文献

Fluorination is an effective strategy to fine-tune the electronic structure and optoelectronic response of organic semiconductors by modulating frontier orbital energies, intramolecular charge transfer, and solid-state/solution interactions. Herein, four fluorinated derivatives (DFBT1-DFBT4) were rationally designed by introducing fluorine substituents on the central core of a reference molecule (DFBT-PMTP), and their properties were evaluated using density functional theory (DFT) and time-dependent density functional theory (TD-DFT). Relative to the DFBT-PMTP (HOMO = -4.91 eV; LUMO = -1.87 eV), fluorination systematically stabilizes the LUMO (down to -2.10 eV) and increases electron affinity (0.94 to 1.04 eV), while moderately tuning the HOMO (-4.90 to -5.01 eV) and narrowing the bandgap (2.83 to 2.98 eV). TD-DFT predicts a modest red-shift in absorption, with [Formula: see text] spanning 389-409 nm in gas phase and 399-419 nm in the chlorobenzene, accompanied by intense electronic transitions (high oscillator strengths). Solvation free energies indicate favorable stabilization in chlorobenzene and dimethyl sulfoxide ([Formula: see text] ≈ -8.18 to -8.86 and - 10.87 to -11.66, respectively), consistent with moderate hydrophobicity (LogP ≈ 2.72-2.93). Charge-transport descriptors improve upon fluorination, with reduced internal reorganization energies ([Formula: see text] down to 0.5308 eV for DFBT4; [Formula: see text] down to 0.4756 eV for DFBT3), and enhanced Marcus-type hole transfer rates relative to DFBT-PMTP (up to 3.85 × 10¹² s^- 1 for DFBT2). Overall, fluorination offers a practical handle to balance energy-level tuning, optical response, solubility tendency, and charge-transport propensity; notably, DFBT2 is highlighted for the highest predicted hole-transfer kinetics, while DFBT4 (and DFBT3) stand out for minimized reorganization losses, together identifying the most promising candidates for hole-transport layers in perovskite solar cells.

In this work, a new thiourea-based compound, TH4, was synthesized and its structure was investigated through FTIR, ¹H NMR and DFT analyses. The sensing properties of TH4 were systematically assessed against a wide range of metal ions to determine its selectivity and sensitivity. Among these, TH4 exhibited a pronounced fluorescence "turn-on" response selectively in the presence of Hg²⁺, indicating a strong and specific interaction. The formation of a stable TH4-Hg²⁺ complex was supported by Job's plot analysis, which revealed a 1:2 binding stoichiometry. The sensor demonstrated excellent sensitivity with a detection limit of0.0036 ppm and a quantification limit of 0.012 ppm, enabling trace-level mercury detection. To assess its practical utility, TH4 was applied to the detection of Hg²⁺in environmental water samples including tap, pond, river, and lake water) and biological fluids (blood serum and urine). The sensor delivered high recovery rates ranging from 91.0 ± 0.22% to 104.8 ± 0.41%, confirming its reliability in real-world conditions. Additionally, both the free ligand and its Hg²⁺ complex displayed notable antimicrobial activity against selected bacterial and fungal strains. These findings demonstrate the dual-functional capability of TH4 as an effective fluorescent probe for mercury ion sensing and a potential antimicrobial agent, underscoring its significance in environmental analysis and biomedical research.

The exploitation of an extremely sensitive and reliable nanozyme based colorimetric sensor for highly sensitive detection of hydrogen peroxide (H₂O₂) in living body system is extensively carping owing to fact that it garnered a prime role in causing toxic diseases. In this work, a highly novel catalyst named as Cerium oxide (CeO₂) nanosheets (NSs) was precisely prepared by using a simple one pot hydrothermal method, thereby dowered with a strong intrinsic peroxidase like capability of catalyzing the oxidation-reaction of colorless 3,3',5,5'-tetramethylbenzidine (TMB) to generate a blue color reaction in the presence of H₂O₂. Hence, a sensitive visible assessment platform related to CeO₂ NSs was engineered, which not only exhibited a wider detection range of 0.01-1000 µM with R² value of 0.9998, but also perceives exceptional selectivity, tremendous cycling and long term stability. Further, the sensor also evaluates lowest detection limit (LOD) 0.29 ± 0.03 µM and quantification limit (LOQ) of 2.3 ± 0.03 µM. In addition, it also endorses impressive practicality with stronger sensitivity and favorable accuracy in serum samples. Thus, this research-work not only contributed upon CeO₂ NSs an outstanding capacity to detect H₂O₂, but also expands the realm of applications for CeO₂ NSs in the domains of environmental preservation, biomedical diagnosis and forensic sciences.

Dicyanoisophorone-based fluorophores (DF) hold broad application prospects in the fields of fluorescent probes and biomedicine. However, the structure-activity relationship (SAR) of these fluorophores following the introduction of different substituents at distinct sites remains unclear, which limits their further application and performance optimization. In this study, we systematically investigated the effects of introducing electron-donating groups (Me, OMe, NH₂, NMe₂ and NPh₂) and electron-withdrawing groups (F, NO₂, COOH, CN and SO₃H) at the C3, C4, and C6 sites of the benzene ring on the structure and properties of DF from a theoretical perspective, thereby providing a theoretical basis and reference for the subsequent modification and improvement of this class of fluorescent probes.

The development of highly selective and sensitive fluorescent chemosensors is urgently needed to detect toxic aluminum ions (Al³⁺) ions in environmental and biological systems. This work presents the development of a novel Schiff-base fluorescent probe L, which was efficiently synthesized via a one-pot condensation reaction between 3,5-di-tert-butylsalicylaldehyde and 4,5-dimethyl-1,2-phenylenediamine. The molecular structure of the probe L was characterized using nuclear magnetic resonance spectroscopy (¹H/¹³CNMR) and infrared spectroscopy (FT-IR). Fluorescence spectroscopy studies have shown that probe L exhibits specific recognition of Al³⁺ in ethanol/PBS solutions. After adding Al³⁺, the fluorescence at 547 nm is significantly enhanced, displaying a bright green fluorescence under 365 nm ultraviolet light, and it is not interfered with by other metal ions such as Na⁺, K⁺, Ca²⁺, Mg²⁺, Fe³⁺, Cu²⁺, and Zn²⁺. Job's plot and theoretical calculations confirm that probe L forms a 1:1 complex with Al³⁺, with a binding constant (K_a) of 2.64 × 10⁴ ± 44.67 M^- 1, and a detection limit (LOD) as low as 1.19 µM. This probe maintains stable recognition performance under a wide range of environmental conditions and has significant potential applications in environmental monitoring.

Two novel Co(II)-based coordination polymers, [Co(HDNA)(bibp)(H₂O)]ₙ (CP1) and {[Co₃(DCPN)₂(4,4'-bibp)₃(H₂O)₄]}ₙ (CP2), were synthesized via hydrothermal reactions using H₃DCPN and different N-donor co-ligands. Structural analysis revealed that CP1 forms a 2D layered network, while CP2 adopts a 1D chain structure extended into a 3D supramolecular framework. Both CP1 and CP2 exhibited excellent fluorescence sensing abilities toward sulfamethoxazole (SMX), with strong enhancement responses. CP1 showed a linear Stern-Volmer relationship (R² = 0.9944) and a binding constant of 1.37 × 10⁴ M⁻¹, while CP2 gave R² = 0.9936 and K = 1.54 × 10⁴ M⁻¹. Both materials displayed high selectivity, anti-interference capacity, and good cycling stability, demonstrating their potential as reusable fluorescent sensors for SMX detection.

A series of phosphors based on a pellyite-type BCZSO (Ba₂CaZn₂Si₆O₁₇) silicate host were synthesized via the conventional solid-state reaction method by co-doping with various combinations of metal ions (Pb²⁺, Bi³⁺) and rare-earth ions (Bi³⁺, Eu³⁺; Bi³⁺, Tb³⁺; Bi³⁺, Tb³⁺, Eu³⁺; and Pb²⁺, Eu³⁺) at different concentrations. The structural and morphological characteristics of the prepared samples were examined using powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM). Their photoluminescence (PL) properties were systematically investigated. The efficiency of energy transfer between sensitizer and activator ions was analyzed in the co-doped systems. Luminescence decay profiles revealed that the lifetimes of the doped ions fall within the microsecond (Pb²⁺, Eu³⁺) and millisecond (Bi³⁺, Eu³⁺; Bi³⁺, Tb³⁺, Eu³⁺) ranges. The chromatic properties of the phosphors were evaluated using CIE chromaticity coordinates, and the correlated color temperature (CCT) values indicated that Bi³⁺, Eu³⁺ co-doped samples emit in the cold white region, while Bi³⁺, Tb³⁺; Bi³⁺, Tb³⁺, Eu³⁺; and Pb²⁺, Eu³⁺ doped samples emit in the warm white region. Given their promising thermal stability and efficient near-white light emission, the BCZSO-based phosphors demonstrate potential as suitable candidates for use in phosphor-converted white light-emitting diodes (pc-WLEDs).