Journal of Luminescence最新文献

Zn²⁺, is one of the indispensable microelements in organisms and plays an important role in organisms. Therefore, it is of great significance to monitor effectively the Zn²⁺ concentration in organisms for the diagnosis and treatment of the related diseases. However, the fluorescence probes have many outstanding advantages, such as high selectivity, good sensitivity, high spatial resolution, simple operation and biological imaging conveniently. The biological imaging can directly show the distribution of Zn²⁺ and the difference of Zn²⁺ concentration in organisms. Thus, it can provide reference for disease diagnosis. In this review, Zn²⁺ fluorescent probes which have been reported in recent ten years are systematically reviewed, including naphthol, 1,8-naphthalimide, pyrene, triphenylamine, quinoline, coumarin, fluorescein, rhodamine and other fluorophores. The discussion of each probe concentrates mainly on its biological imaging. It is believed that the paper will provide a novel insight into the development and research of Zn²⁺ fluorescent probes with low detection limit, good water solubility, perfect biological imaging effect and so on.

Low-dimensional organic-inorganic hybrid metal halides (OIMHs) have become an emerging class of light-emitting materials. Two zero-dimensional (0D) lead-free organic (EnrofloH₂)₄Mn₃X₁₂ (X = Cl, Br) has been reported in this work. Upon 338 and 340 nm excitation, (EnrofloH₂)₄Mn₃Cl₁₂·2Cl and (EnrofloH₂)₄Mn₃Br₁₂·2Br exhibit emission peaking at 460, 514 nm and 460, 520 nm respectively. It was noticed that the choice of the halide could profoundly govern the luminescent subjects (ENR or Mn²⁺) through the altered energy transfer. Different halogens could influence the rigidity of ENR organic cations by changing their stacking patterns and band gaps, thus manipulating their luminescent properties. The bandgap behaviors have been revealed by density functional theory calculations. Based on the results, the emission of both compounds come from organic cations (EnrofloH₂²⁺) and ⁴D-⁶A₁ transition of Mn²⁺ ions. The spectral interplay of these emission bands is governed by the temperature and the possibility of exchanging mechanisms between two emission centers.

Near-infrared phosphor-converted light-emitting diodes (NIR pc-LED) prepared with near-infrared (NIR) phosphors have potential applications in various aspects. In this paper, Cr³⁺-activated Mg₂LaTaO₆ (MLTO: Cr³⁺) phosphors were prepared by the conventional high-temperature solid-phase method. The structure, morphology, and photoluminescence (PL) spectra of MLTO: Cr³⁺ phosphor were investigated. There is broadband NIR emission and the emission peak is red-shifted with the increase of doping concentration. The crystal field strengths of the samples were calculated and the relationship between the emission peak positions of the samples and the crystal field strengths was investigated. In addition, the concentration quenching mechanism of the samples was discussed, which is mainly attributed to dipole-dipole interactions. The internal quantum efficiency (IQE) of the MLTO: 0.4 mol% Cr³⁺ sample was measured with an IQE value of 76.48 %. NIR pc-LED devices were fabricated by combining the prepared MLTO: Cr³⁺ phosphor and blue-emitting LED chips, which are capable of emitting NIR light.

Recently, Chen et al. designed and synthesized a new multi-purpose dye probe P-TNS with bifunctional groups, which has an ultra-fast excited state intramolecular proton transfer characteristic (ESIPT) (Spectrochim Acta A Mol Biomol Spectrosc., 2021, 262: 120084.). The P-TNS molecules are very sensitive to hydrazine (N2H4) and cyanide (CN-), which makes it have a good practical application prospect in the field of probe detection. However, the corresponding optical properties and the related mechanisms have not been systematically investigated in experiments. In the present work, the proton transfer pathways as well as the photophysical properties changes in the transfer path of P-TNS with three intramolecular hydrogen bonds (HB1, HB2 and HB3) are revealed for the first time. First, the analysis of potential energy surface and potential energy curve determined the stable conformation of P-TNS molecule and its isomer structure, and clarified the reaction mechanism of ESIPT process. Subsequently, the analysis of the frontier molecular orbitals reveal that the charge difference is the driving force required for the proton transfer process from the microscopic level, which led to the determination that the HB1 structure without the charge difference could not complete the ESIPT process. Finally, the variation of hydrogen bond strength and the path of proton transfer are demonstrated from several perspectives of hydrogen bond parameters, hydrogen bond energy, infrared vibrational frequency (IR) and reduced density gradient (RDG) surface. This study essentially explains the photophysical properties and proton transfer pathways of a new multipurpose dye probes for organic luminescence with bifunctional groups, which are important for the fields of spectroscopy and measurement technology, and also provides ideas for the design and synthesis of new fluorescent probes.

The 2.85 μm band has garnered significant attention for its wide range of applications in the mid-infrared region, and Ho³⁺ doped fluorotellurite fiber shows great promise as a gain medium for the 2.85 μm fiber laser. To achieve efficient population inversion for Ho³⁺ ions at 2.85 μm, Ho³⁺/Nd³⁺ co-doped fluorotellurite glasses with low hydroxyl were synthesized. The deactivation effect of Nd³⁺ ions to Ho³⁺: ⁵I₇ levels was investigated through emission spectra and lifetime decay curves under 890 nm excitation. The results show that Nd³⁺ ions can effectively quench the Ho³⁺: 2.05 μm emission and help the Ho³⁺: ⁵I₆ → ⁵I₇ transition to overcome the bottleneck of particle population inversion. Ultimately, the particle population inversion corresponding to 2.85 μm luminescence was realized in the Ho³⁺/Nd³⁺ co-doped fluorotellurite glass, and indicates that a maximum of 1.64 W laser at 2.85 μm with a slope efficiency of 8.72 % can be realized under 890 nm pump by numerical simulations.

With the rapid development of animal husbandry, animal food safety issues are increasingly exposed. Detecting pathogenic bacteria and residual antibiotics in animal food is of great significance for the early detection and regulation of harmful substances that threaten food safety. However, developing a fluorescent sensor that can detect both pathogenic bacteria and antibiotics is challenging. In this study, an interesting dual-channel ratiometric nanoprobe (CDs-Eu) based on europium-functionalized carbon dots was developed to realize the visual detection of Bacillus anthracis marker (DPA) and tetracycline antibiotics (TC) in a water environment under different excitation channels. This method had high sensitivity, comprehensive response range, anti-interference ability, and visualization for detecting DPA and TC. Combined with intelligent phone color scanning applications, a portable agarose gel nanosensor was designed to achieve multicolor on-site assessment of DPA and TC. In addition, an advanced three-to-six logic gate analysis method was also developed, which was expected to achieve intelligent sensing of DPA and TC in food safety.

In this work, trivalent dysprosium was incorporated with lithium yttrium phosphate LiY₅P₂O₁₃ (LYP), obtaining a yellow-emitting material. The crystallographic sites of introduced Dy³⁺ activators are determined through the comprehensive analysis of the XRD investigation, DFT computation, and experimental luminescence spectra. Under 353 nm excitation, the LYP:Dy³⁺ phosphor shows bright yellow emission owing to dominant ⁴F_9/2 → ⁶H_13/2 transition (577 nm) of Dy³⁺. The luminescence quenching occurs when the Dy³⁺ content exceeds 0.07 mol, originating from the dipole–dipole interaction. Furthermore, the excellent thermal stability behavior (84 % at 423 K) and good resistance to color shifting (0.00634 at 473 K) for title phosphor are manifested by temperature-dependent investigation. Eventually, the w-LED fabricated with LYP:0.07Dy³⁺ and commercial materials exhibits stable white-emitting output (0.3595, 0.3179) with high R_a (85) and low CCT (4203 K). All the study demonstrates that the LYP:Dy³⁺ material is a perspective candidate in solid-state illustration field.