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Journal articles on the topic 'Luminescence'

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Author: Grafiati
Published: 4 June 2021
Last updated: 31 July 2024

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1

Fritzen, Douglas L., Luidgi Giordano, Lucas C. V. Rodrigues, and Jorge H. S. K. Monteiro. "Opportunities for Persistent Luminescent Nanoparticles in Luminescence Imaging of Biological Systems and Photodynamic Therapy." Nanomaterials 10, no. 10 (October 13, 2020): 2015. http://dx.doi.org/10.3390/nano10102015.

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The use of luminescence in biological systems allows us to diagnose diseases and understand cellular processes. Persistent luminescent materials have emerged as an attractive system for application in luminescence imaging of biological systems; the afterglow emission grants background-free luminescence imaging, there is no need for continuous excitation to avoid tissue and cell damage due to the continuous light exposure, and they also circumvent the depth penetration issue caused by excitation in the UV-Vis. This review aims to provide a background in luminescence imaging of biological systems, persistent luminescence, and synthetic methods for obtaining persistent luminescent materials, and discuss selected examples of recent literature on the applications of persistent luminescent materials in luminescence imaging of biological systems and photodynamic therapy. Finally, the challenges and future directions, pointing to the development of compounds capable of executing multiple functions and light in regions where tissues and cells have low absorption, will be discussed.
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2

Claes, Julien M., Steven H. D. Haddock, Constance Coubris, and Jérôme Mallefet. "Systematic Distribution of Bioluminescence in Marine Animals: A Species-Level Inventory." Life 14, no. 4 (March 24, 2024): 432. http://dx.doi.org/10.3390/life14040432.

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Bioluminescence is the production of visible light by an organism. This phenomenon is particularly widespread in marine animals, especially in the deep sea. While the luminescent status of numerous marine animals has been recently clarified thanks to advancements in deep-sea exploration technologies and phylogenetics, that of others has become more obscure due to dramatic changes in systematics (themselves triggered by molecular phylogenies). Here, we combined a comprehensive literature review with unpublished data to establish a catalogue of marine luminescent animals. Inventoried animals were identified to species level in over 97% of the cases and were associated with a score reflecting the robustness of their luminescence record. While luminescence capability has been established in 695 genera of marine animals, luminescence reports from 99 additional genera need further confirmation. Altogether, these luminescent and potentially luminescent genera encompass 9405 species, of which 2781 are luminescent, 136 are potentially luminescent (e.g., suggested luminescence in those species needs further confirmation), 99 are non-luminescent, and 6389 have an unknown luminescent status. Comparative analyses reveal new insights into the occurrence of luminescence among marine animal groups and highlight promising research areas. This work will provide a solid foundation for future studies related to the field of marine bioluminescence.
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3

Shvalagin, Vitaliy, Galyna Grodziuk, Olha Sarapulova, Misha Kurmach, Vasyl Granchak, and Valentyn Sherstiuk. "Influence of Nanosized Silicon Oxide on the Luminescent Properties of ZnO Nanoparticles." Journal of Nanotechnology 2016 (2016): 1–7. http://dx.doi.org/10.1155/2016/2708638.

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For practical use of nanosized zinc oxide as the phosphor its luminescence quantum yields should be maximized. The aim of this work was to enhance luminescent properties of ZnO nanoparticles and obtain high-luminescent ZnO/SiO2composites using simpler approaches to colloidal synthesis. The luminescence intensity of zinc oxide nanoparticles was increased about 3 times by addition of silica nanocrystals to the source solutions during the synthesis of ZnO nanoparticles. Then the quantum yield of luminescence of the obtained ZnO/SiO2composites is more than 30%. Such an impact of silica is suggested to be caused by the distribution of ZnO nanocrystals on the surface of silica, which reduces the probability of separation of photogenerated charges between the zinc oxide nanoparticles of different sizes, and as a consequence, there is a significant increase of the luminescence intensity of ZnO nanoparticles. This way of increasing nano-ZnO luminescence intensity facilitates its use in a variety of devices, including optical ultraviolet and visible screens, luminescent markers, antibacterial coatings, luminescent solar concentrators, luminescent inks for security printing, and food packaging with abilities of informing consumers about the quality and safety of the packaged product.
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4

Мирочник, А. Г., Е. В. Федоренко, and А. Ю. Белолипцев. "Люминесценция дитолуоилметаната дифторида бора. Образование J-агрегатов." Оптика и спектроскопия 130, no. 2 (2022): 237. http://dx.doi.org/10.21883/os.2022.02.52006.1717-21.

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The processes of the formation of J-aggregates during the dissolution 2,2-difluoro-4,6-di(4’-methylphenyl)-1,3,2-dioxaborine crystals (1) and their subsequent dissociation have been studied by absorption and luminescence spectroscopy and quantum-chemical modeling. It is shown that two luminescent centers are observed in the solution 1: monomeric luminescence and luminescence of J-aggregates (dual luminescence). Evolution of absorption, luminescence excitation and luminescence spectra is observed over time, indicating a slow dissociation of J-aggregates.
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5

Kondo, Mizuho, Yuya Morita, and Nobuhiro Kawatsuki. "Blue-Shifting Mechanofluorochromic Luminescent Behavior of Polymer Composite Films Using Gelable Mechanoresponsive Compound." Crystals 11, no. 8 (August 15, 2021): 950. http://dx.doi.org/10.3390/cryst11080950.

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Mechanochromic luminescent dyes change their luminescence color upon exposure to external mechanical stimuli. In this study, we synthesized a liquid crystalline mechanochromic luminescent dye containing a terminal cholesterol molecule. The dissolution of the dye in 1,4-dioxane resulted in the formation of a gel. The luminescence of the xerogel obtained from the dioxane solution changed from green to blue upon grinding, indicating mechanochromic luminescence behavior. The anisotropic patterning of short-wavelength-shifted luminescence color change by directional handwriting on surface layer of liquid crystal was successfully demonstrated. Furthermore, blue-shifting mechanoresponsive polymer composite surface was fabricated by using the luminophore.
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6

Tai, Xi Shi. "Preparation and Luminescence Properties of Two Novel Magnesium Complex Materials." Advanced Materials Research 321 (August 2011): 121–24. http://dx.doi.org/10.4028/www.scientific.net/amr.321.121.

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In order to prepare efficient luminescence material, two kinds of novel magnesium luminescence materials were synthesized by the reaction of magnesium chloride with 2-acetyl-1-naphthol-diethylenetriamine (1) and 2-acetyl-1-naphthol-triethylenetetramine (2), respectively. The luminescent properties of two novel magnesium luminescence materials were investigated in solid and in DMSO solutions. The results show that two magnesium luminescence materials have high blue. The DMSO solvent could enhance the luminescence of complex (1), and also quench the luminescence of complex (2).
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7

Mirochnik A. G., Fedorenko E.V., and Beloliptsev A. Yu. "Luminescence of boron difluoride ditoluoylmethanate. Formation of J-aggregatess." Optics and Spectroscopy 132, no. 2 (2022): 236. http://dx.doi.org/10.21883/eos.2022.02.53212.1717-21.

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The processes of the formation of J-aggregates during the dissolution 2,2-difluoro-4,6-di(4'-methylphenyl)-1,3,2-dioxaborine crystals ( 1) and their subsequent dissociation have been studied by absorption and luminescence spectroscopy and quantum-chemical modeling. It is shown that two luminescent centers are observed in the solution 1: monomeric luminescence and luminescence of J-aggregates (dual luminescence). Evolution of absorption, excitation and luminescence spectra is observed over time, indicating a slow dissociation of J-aggregates. Keywords: luminescence, absorption spectra, boron difluoride complexes, J-aggregates.
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8

Chinweike Unoma Dokubo, Bright Obidinma Uba, Chisom Precious Nnubia, and Ifeanyi Patience Akaun. "Evaluation of toxicity and resistant effects of heavy metals and antibiotics on the growth of marine bioluminescent bacteria." International Journal of Frontline Research in Science and Technology 1, no. 2 (December 30, 2022): 030–37. http://dx.doi.org/10.56355/ijfrst.2022.1.2.0041.

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Luminescence is the emission of light by an object. Living organisms including certain bacteria are capable of luminescence. Bacteria are the most abundant luminescent organisms in nature. Bacterial luminescence has been studied most extensively in several marine bacteria. Bacterial luminescence is due to the action of the enzyme called luciferase. The luminescent bacteria exist in nature either as free-living bacteria or in symbiotic association with certain marine organisms. Research on luminescent bacteria has always been a fascinating one. In the present study, ten free living luminescent bacteria initially isolated from marine origin were characterized for their tolerance to heavy metals and antibiotics. Copper, zinc, cobalt and cadmium metals at 1 mg/mL concentration have inhibited the growth and luminescence of the all strains except strains 1, 2 and 7. Surprisingly, lead metal at the same concentration dd not inhibit any of the ten strains. However, at 2 mg/mL concentration, similar trend was observed on the growth and luminescence of all the 10 strains. Also, all the tested isolates were sensitive (1 cm >) to all Gram negative and positive antibiotics being tested except isolates 3, 6 and 8, respectively which were resistant (0 – 0.9 cm) to all the antibiotics tested. Thus, the strains isolated from the different sample types have good beneficial potentials such as heavy metal tolerance and antibiotic sensitivity.
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9

Sami, Hussain, Osama Younis, Yui Maruoka, Kenta Yamaguchi, Kumar Siddhant, Kyohei Hisano, and Osamu Tsutsumi. "Negative Thermal Quenching of Photoluminescence from Liquid-Crystalline Molecules in Condensed Phases." Crystals 11, no. 12 (December 13, 2021): 1555. http://dx.doi.org/10.3390/cryst11121555.

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The luminescence of materials in condensed phases is affected by not only their molecular structures but also their aggregated structures. In this study, we designed new liquid-crystalline luminescent materials based on biphenylacetylene with a bulky trimethylsilyl terminal group and a flexible alkoxy chain. The luminescence properties of the prepared materials were evaluated, with a particular focus on the effects of phase transitions, which cause changes in the aggregated structures. The length of the flexible chain had no effect on the luminescence in solution. However, in crystals, the luminescence spectral shape depended on the chain length because varying the chain length altered the crystal structure. Interestingly, negative thermal quenching of the luminescence from these materials was observed in condensed phases, with the isotropic phase obtained at high temperatures exhibiting a considerable increase in luminescence intensity. This thermal enhancement of the luminescence suggests that the less- or nonemissive aggregates formed in crystals are dissociated in the isotropic phase. These findings can contribute toward the development of new material design concepts for useful luminescent materials at high temperatures.
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10

Mar’ina, Ul’ana A., Viktor A. Vorob’ev, and Alexandr P. Mar’in. "IR luminescence of CaGa 2O 4 : Yb 3+ excited by 940 and 980 nm radiation." Modern Electronic Materials 6, no. 1 (March 30, 2020): 31–36. http://dx.doi.org/10.3897/j.moem.6.1.55165.

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Existing calcium gallate CaGa2O4 based luminescent materials radiating in visible IR region have been reviewed. IR luminophores have been studied but slightly but their practical implementation is of interest. CaGa2O4 specimens activated with Yb3+ rare-earth ions have been synthesized using the solid-state method. The structure and luminescent properties of CaGa2O4 : Yb3+ have been studied. CaGa2O4 : Yb3+ excitation with 940 and 980 nm radiation generates luminescence in the 980–1100 nm region. Data on the electron level structure in Yb3+ ions suggest that the excitation and luminescence occur directly in the Yb3+ ions with only a passive role of the base lattice. The luminescence spectra contain three peaks at 993, 1025 and 1080 nm. These luminescence peaks are caused by electron optical transitions from excited to main state in Yb3+ ions. 993 nm band luminescence intensity has been studied as a function of Yb3+ activator ions concentration. Introduction of Na+ ions into the luminophore increases IR luminescence intensity. Optimum (Ca1-x-yYbxNay)Ga2O4 luminophore composition has been suggested at which the 993 nm luminescence intensity is the highest.
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11

Wang, Yangbo, Yingdong Han, Runfa Liu, Cunping Duan, and Huaiyong Li. "Excitation-Controlled Host–Guest Multicolor Luminescence in Lanthanide-Doped Calcium Zirconate for Information Encryption." Molecules 28, no. 22 (November 16, 2023): 7623. http://dx.doi.org/10.3390/molecules28227623.

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Efficient control over lanthanide luminescence by regulating excitations offers a real-time and reversible luminescence-managing strategy, which is of great importance and highly desirable for various applications, including multicolor display and information encryption. Herein, we studied the crystal structure, luminescence properties, and mechanisms of undoped and Tb3+/Eu3+-doped CaZrO3 in detail. The intrinsic purple-blue luminescence from host CaZrO3 and the introduced green/red luminescence from guest dopants Tb3+/Eu3+ were found to have different excitation mechanisms and, therefore, different excitation wavelength ranges. This enables the regulation of luminescent color through controlling the excitation wavelengths of Tb3+/Eu3+-doped CaZrO3. Furthermore, preliminary applications for information encryption with these materials were demonstrated using portable UV lamps of 254 and 302 nm. This study not only promotes the development of multicolor luminescence regulation in fixed-composition materials, but also advances the practical applications of lanthanide luminescent materials in visually readable, high-level anti-counterfeiting and information encryption.
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12

Zhao, Zhihuan, Yao Wang, Haoyang Jiang, Jixian Liu, Linjun Huang, Yanna Zhang, Yanqi Wang, Laurence A. Belfiore, and Jianguo Tang. "Optical Features of Lanthanide Luminescent Hydrogel Based on Polyethylene Glycol with Silica Nanoparticles." Science of Advanced Materials 13, no. 1 (January 1, 2021): 123–30. http://dx.doi.org/10.1166/sam.2021.3850.

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Inorganic/polymer hybrid hydrogels generally exhibit excellent mechanical properties, while extra function include luminescence are extremely explored due to the further application in sensors and optoelectronic devices. Herein, we report the rare-earth (RE) complex/silica nanoparticles (SNs) luminescent hybrid polyethylene glycol (PEG) hydrogels showing stable luminescence. The hybrid hydrogels coordinated with RE (Eu3+) complex are fabricated via a convenient in situ photocrosslinked procedure. The coordination polymers showed red luminescent color under the 365 nm UV irradiation. Furthermore, the hybrid hydrogel exhibited long luminescence lifetime. These properties of hybrid luminescent hydrogel gave rise to a great improvement in the potential applications as a soft material.
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13

Buzanov, Oleg A., Nina S. Kozlova, Nikita A. Siminel, and Evgeniya V. Zabelina. "Luminescence in lanthanum-gallium tantalate." Modern Electronic Materials 4, no. 3 (September 1, 2018): 97–101. http://dx.doi.org/10.3897/j.moem.4.3.39454.

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The optical and luminescent properties of undoped La3Ga5.5Ta0.5O14 lanthanum- gallium tantalate crystals grown in different atmospheres of pure argon gas and argon gas with different oxygen percentages have been studied. The optical absorption α(λ) spectra that characterize integral absorption and reflection have been measured in the 250–700 nm region. The spectral absorption functions have been calculated from the measured α(λ) spectra using the Kubelka–Munk formula. Luminescence has been observed in all the test specimens over a wide spectral region (375 to 650 nm) at 95 and 300 K. The luminescence spectra of the test crystals have a fine dispersed pattern represented by low-intensity discrete luminescence peaks. The 95 K luminescence peak maxima are more pronounced and shifted towards shorter wavelengths by ~16 nm (~0.1 eV) relative to the respective room temperature peaks. The crystal growth atmosphere has been demonstrated to largely affect the luminescent properties of the crystals: the higher the oxygen concentration in the growth atmosphere, the lower the luminescence intensity due to concentration quenching, the luminescence peak maxima shifting towards longer wavelengths. The positions of discrete luminescence peaks have been shown to correlate with the main 420 and 480 nm absorption bands with the respective ~20 nm (~0.2 eV) Stokes shift for crystals grown in different atmospheres. The luminescence in lanthanum-gallium tantalate crystals is a complex process involving several luminescence mechanisms.
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14

Yam, Vivian Wing-Wah. "Molecular design of luminescent metal-based materials." Pure and Applied Chemistry 73, no. 3 (January 1, 2001): 543–48. http://dx.doi.org/10.1351/pac200173030543.

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A series of soluble di- and polynuclear transition-metal acetylides with rich luminescence behavior have been designed and successfully isolated. The photophysical and photochemical properties have been studied. Luminescent polynuclear metal complexes have also been obtained based on the metal chalcogenide building block. These high-nuclearity transition-metal chalcogenide complexes have been structurally characterized and shown to display rich luminescence behavior. Various approaches and strategies to design and synthesize luminescent polynuclear metal complexes that may find potential applications as chemosensors and luminescence signalling devices will also be described.
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15

Hanna, S. A., Igor Yu Prosanov, and Anatoly A. Sidelnikov. "Luminescence of polyvinyl alcohol – CdS compounds doped with Cu, Al and Mn." Applied photonics 10, no. 3 (July 1, 2023): 23–35. http://dx.doi.org/10.15593/2411-4375/2023.3.03.

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Polyvinyl alcohol – CdS compounds doped with different concentrations of Cu, Al and Mn were produced. It is expected that these compounds have one-dimensional (polymeric) structure. Their luminescence spectra were investigated with the aim of use of luminescence for the structure characterization through comparison of luminescent properties of compounds and other CdS based materials. It was found that addition of copper leads to luminescence quenching while intensity of luminescence of compound doped with manganese reaches maximum at some concentration of additive and aluminum does not influence noticeably on the luminescence intensity of the compound. Luminescence spectra were not significantly changed at the doping. They are different from spectrum of crystalline CdS and similar to luminescence of CdS dissolved in glass. It was also found that luminescence of compounds is highly polarized, luminescence of glass is less polarized and luminescence of crystal CdS is not polarized.
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16

Dukin A. A. and Golubev V. G. "Modeling of luminescence spectra in spherical microresonators with an emitting shell." Optics and Spectroscopy 130, no. 13 (2022): 2033. http://dx.doi.org/10.21883/eos.2022.13.53986.2266-21.

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The luminescence spectra of a microresonator structure consisting of a spherical core of small diameter (3.5-6 mcm) covered with a luminescent shell with a refractive index less than that of the core are modeled. Shell luminescence spectra, radial distribution of the whispering gallery mode (WGM) field, and mode parameters (wavelength, width, quality factor) are calculated using the expansion of the electromagnetic wave field in the basis of vector spherical harmonics and the method of spherical wave transfer matrices. The dependence of the luminescence spectra and WGM parameters on the geometric and optical parameters of the structure --- the shell thickness, the refractive index of the shell, and the core diameter --- is studied. Keywords: spherical microresonator, luminescent shell, whispering gallery modes, modeling of luminescence spectra.
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17

Beltyukova, S. V., and O. V. Malinka. "Determination of platyphylline hydrotartrate by luminescence quenching of the complex yttrium (iii) with rutin." Farmatsevtychnyi zhurnal, no. 3-4 (September 4, 2018): 30–37. http://dx.doi.org/10.32352/0367-3057.3-4.18.05.

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Drugs used in the form of salts of organic bases are often determined by the anionic portion of these salts. Thus, titrimetric, spectrophotometric, electrochemical, chromatographic and luminescent methods of analysis are proposed for the determination of various tartrate-ion preparations. The purpose of this study was to develop a method of luminescent determination of platyphylline hydrotartrate in dosage forms using a luminescent probe-yttrium complex (III) with rutin (Rut). The luminescent determination of platyphylline hydrotartrate is offered to use a complex of yttrium (III)–rutin in the presence of bovine serum albumin (BSA). It has been experimentally established that tartrate ions quench of luminescence intensity of the Y (III)–Rut complex in the presence of BSA. The spectral and luminescent properties of the Y (III)–Rut complex in the presence of BSA were studied. The luminescence spectrum of the Y (III)–Rut complex in the presence of BSA has a maximum at λ = 570 nm, in the presence of platyphylline hydrotartrate of luminescence intensity of the Y (III)–Rut complex decreases and the maximum luminescence shifts to the long wavelength region of the spectrum (λ = 590 nm). It was established that the maximum quenching effect of the luminescence intensity of the Y (III)–rutin complex in the presence of BSA could be observed at the pH 6.0–7.0, which was created in solution with the help of urotropine. It is known that the luminescence quenching may be caused by various processes, including reactions in the excited state, energy transfer, formation of complexes and collisional quenching. It can be assumed that the quenching effect of Y (III)–Rut complex due to the complexation reaction of Y (III) with platyphylline hydrotartrate, that leads to the destruction of the Y (III)–Rut complex. Luminescence quenching of the Y (III)–Rut complex in the presence of BSA by platyphylline hydrotartrate follows the Stern–Volmer relationship. The Stern–Volmer constant is 1 230 l/mol. The luminescence method of the determination of platyphylline hydrotartrate in the dosage form (solution for injection) was developed. The received results were verified by method of spiked samples. The method is based on quenching of a rutin's molecular luminescence in the complex of the Y (III)–rutin by tartrate ions associated with the protonated form of platyphylline.
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18

Zhou, Pei, Nirmal Goswami, Tiankai Chen, Xiaoman Liu, and Xin Huang. "Engineering Au Nanoclusters for Relay Luminescence Enhancement with Aggregation-Induced Emission." Nanomaterials 12, no. 5 (February 25, 2022): 777. http://dx.doi.org/10.3390/nano12050777.

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The research of aggregation-induced emission (AIE) has been growing rapidly for the design of highly luminescent materials, as exemplified by the library of AIE-active materials (or AIEgens) fabricated and explored for diverse applications in different fields. Herein, we reported a relay luminescence enhancement of luminescent Au nanoclusters (Au NCs) through AIE. In addition, we demonstrated the emergence of reduced aggregation-caused luminescence by adjusting the temperature of the Au NC solution. The key to induce this effect is to attach a thermosensitive polymer poly(N-isopropylacrylamide) (PNIPAAm) on the surface of Au NCs, which will shrink at high temperature. More interestingly, the as-synthesized Au NCs-PNIPAAm can self-assemble into vesicles, resulting in an obvious decrease in the luminescence intensity in aqueous solution. The combination of relay luminescence enhancement (by AIE) and luminescence decrease (induced by thermosensitive polymers) will be beneficial to the understanding and manipulation of the optical properties of Au NCs, paving the way for their practical applications.
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19

Xie, Dini, Hongshang Peng, Shihua Huang, and Fangtian You. "Core-Shell Structure in Doped Inorganic Nanoparticles: Approaches for Optimizing Luminescence Properties." Journal of Nanomaterials 2013 (2013): 1–10. http://dx.doi.org/10.1155/2013/891515.

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Doped inorganic luminescent nanoparticles (NPs) have been widely used in both research and application fields due to their distinctive properties. However, there is an urgent demand to improve their luminescence efficiency, which is greatly reduced by surface effects. In this paper, we review recent advances in optimizing luminescence properties of doped NPs based on core-shell structure, which are basically classified into two categories: one is by use of surface coating with nonmetal materials to weaken the influence of surface effect and the other is with metal shell via metal enhanced luminescence. Different materials used to coat NPs are surveyed, and their advantages and disadvantages are both commented on. Moreover, problems in current core-shell structured luminescent NPs are pointed out and strategies furthering the optimization of luminescence properties are suggested.
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20

Huang, Tao, and Bingsuo Zou. "Luminescent Behavior of Sb3+-Activated Luminescent Metal Halide." Nanomaterials 13, no. 21 (October 29, 2023): 2867. http://dx.doi.org/10.3390/nano13212867.

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Metal halide perovskites have unparalleled optoelectronic properties and broad application potential and are expected to become the next epoch-making optoelectronic semiconductors. Although remarkable achievements have been achieved with lead halide perovskites, the toxicity of lead inhibits the development of such materials. Recently, Sb3+-activated luminescent metal halide perovskite materials with low toxicity, high efficiency, broadband, large Stokes shift, and emission wavelengths covering the entire visible and near-infrared regions have been considered one of the most likely luminescent materials to replace lead halide perovskites. This review reviews the synthesis, luminescence mechanism, structure, and luminescence properties of the compounds. The basic luminescence properties of Sb3+-activated luminescent metal halide perovskites and their applications in WLED, electroluminescence LED, temperature sensing, optical anti-counterfeiting, and X-ray scintillators are introduced. Finally, the development prospects and challenges of Sb3+-activated luminescent metal halide perovskites are discussed.
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21

Gao, Dangli, Jie Gao, Feng Gao, Qingqing Kuang, Yong Pan, Yafei Chen, and Zhengwei Pan. "Quintuple-mode dynamic anti-counterfeiting using multi-mode persistent phosphors." Journal of Materials Chemistry C 9, no. 46 (2021): 16634–44. http://dx.doi.org/10.1039/d1tc04568g.

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Multi-level, dynamic optical anti-counterfeiting has been achieved using multi-mode phosphors as luminescent inks. The ZGGO:Cr,Yb,Er phosphors exhibit quintuple luminescence modes, while the ZLGO:Mn phosphors possess quadruple luminescence modes.
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22

Li, Gen, Shuai-Liang Yang, Wan-Shan Liu, Meng-Yue Guo, Xiao-Yan Liu, Ran Bu, and En-Qing Gao. "Photoinduced versus spontaneous host–guest electron transfer within a MOF and chromic/luminescent response." Inorganic Chemistry Frontiers 8, no. 22 (2021): 4828–37. http://dx.doi.org/10.1039/d1qi01079d.

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The MOF shows charge-transfer sensitized Eu(iii) emission and spontaneous/photoinduced guest-to-host electron transfer, which allow chromic and luminescent sensing of NH3 (luminescence turn-off) and O2 (luminescence turn-on).
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23

Myasnikova, L. N., A. G. Maratova, and K. Sh Shunkeyev. "The features of deformation-stimulated RbI luminescence." Eurasian Journal of Physics and Functional Materials 5, no. 4 (December 10, 2021): 218–28. http://dx.doi.org/10.32523/ejpfm.2021050406.

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This paper studies deformation-stimulated features of radiative relaxation of self-trapped excitons and recombination assembly of exciton-like luminescence in RbI crystal. Methods of research were luminescence and thermal activation spectroscopy. The identity of the mechanism of manifestation of the X-ray luminescence, tunnel luminescence and thermally stimulated luminescence spectra were found in the elastically deformed RbI crystal, interpreted by the luminescence of self-trapped exciton, tunnel recharge of F′, VK -pairs and thermally stimulated recombination of e−, VK -centres, respectively.The temperatures of the maximum destruction peaks of thermally stimulated luminescence, their spectral composition and activation energies were determined experimentally, on the basis of which the mechanisms of recombination assembly of exciton-like luminescences in a RbI crystal were interpreted. Uniaxial elastic deformation leads to the effective formation of point radiation defects ( F′, HA, VK -centers) in comparison with an unbroken lattice, where the predominant mechanism is the association of interstitial atoms ( H -centres) with the formation of I3−-centres.
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24

Gao, Dangli, Peng Wang, Feng Gao, William Nguyen, and Wei Chen. "Tuning Multicolor Emission of Manganese-Activated Gallogermanate Nanophosphors by Regulating Mn Ions Occupying Sites for Multiple Anti-Counterfeiting Application." Nanomaterials 12, no. 12 (June 13, 2022): 2029. http://dx.doi.org/10.3390/nano12122029.

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The ability to manipulate the luminescent color, intensity and long lifetime of nanophosphors is important for anti-counterfeiting applications. Unfortunately, persistent luminescence materials with multimode luminescent features have rarely been reported, even though they are expected to be highly desirable in sophisticated anti-counterfeiting. Here, the luminescence properties of Zn3Ga2GeO8:Mn phosphors were tuned by using different preparation approaches, including a hydrothermal method and solid-state reaction approach combining with non-equivalent ion doping strategy. As a result, Mn-activated Zn3Ga2GeO8 phosphors synthesized by a hydrothermal method demonstrate an enhanced red photoluminescence at 701 nm and a strong green luminescence with persistent luminescence and photostimulated luminescence at 540 nm. While Mn-activated Zn3Ga2GeO8 phosphors synthesized by solid-state reactions combined with a hetero-valent doping approach only exhibit an enhanced single-band red emission. Keeping the synthetic method unchanged, the substitution of hetero-valent dopant ion Li+ into different sites is valid for spectral fine-tuning. A spectral tuning mechanism is also proposed. Mn-activated Zn3Ga2GeO8 phosphors synthesized by a hydrothermal approach with multimodal luminescence is especially suitable for multiple anti-counterfeiting, multicolor display and other potential applications.
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25

Đačanin Far, Ljubica, and Miroslav D. Dramićanin. "Luminescence Thermometry with Nanoparticles: A Review." Nanomaterials 13, no. 21 (November 5, 2023): 2904. http://dx.doi.org/10.3390/nano13212904.

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Luminescence thermometry has emerged as a very versatile optical technique for remote temperature measurements, exhibiting a wide range of applicability spanning from cryogenic temperatures to 2000 K. This technology has found extensive utilization across many disciplines. In the last thirty years, there has been significant growth in the field of luminous thermometry. This growth has been accompanied by the development of temperature read-out procedures, the creation of luminescent materials for very sensitive temperature probes, and advancements in theoretical understanding. This review article primarily centers on luminescent nanoparticles employed in the field of luminescence thermometry. In this paper, we provide a comprehensive survey of the recent literature pertaining to the utilization of lanthanide and transition metal nanophosphors, semiconductor quantum dots, polymer nanoparticles, carbon dots, and nanodiamonds for luminescence thermometry. In addition, we engage in a discussion regarding the benefits and limitations of nanoparticles in comparison with conventional, microsized probes for their application in luminescent thermometry.
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Grmela, Lubomír, Pavel Tománek, and Pavel Škarvada. "Near-Field Study of Hot Spot Photoluminescence Decay in ZnS:Mn Nanoparticles." Materials Science Forum 567-568 (December 2007): 241–44. http://dx.doi.org/10.4028/www.scientific.net/msf.567-568.241.

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The local spatial distribution of photoluminescence due to the creation of hot luminescence centers was measured in the optical near-field by Scanning near-field optical microscope at emission peaks of materials (λ =595nm), which is due to the luminescence of Mn2+ in ZnS. The excitation bandgap of ZnS forms exitons, and these excitons get the center of Mn2+ through nonradiation dominates, by means of transition of 4T1 – 6A1 luminescence. This spectrum is evidence that Mn2+ has been incorporated into the ZnS nanoparticles. In comparison with the bulk ZnS:Mn phosphors these nanoparticles have clearly higher luminescent efficiency with its luminescent decay time at least 4 orders of magnitude slower. It means that the oscillator intensity of luminescent centers in ZnS:Mn nanocrystal enhances at least 4 orders of magnitude than that in corresponding bulk ZnS:Mn.
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27

Chen, Wei. "Nanoparticle Fluorescence Based Technology for Biological Applications." Journal of Nanoscience and Nanotechnology 8, no. 3 (March 1, 2008): 1019–51. http://dx.doi.org/10.1166/jnn.2008.301.

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Fluorescence is widely used in biological detection and imaging. The emerging luminescent nanoparticles or quantum dots provide a new type of biological agents that can improve these applications. The advantages of luminescent nanoparticles for biological applications include their high quantum yield, color availability, good photo-stability, large surface-to-volume ratio, surface functionality, and small size. In this review article, we first introduce quantum size confinement, photoluminescence and upconversion luminescence of nanoparticles, then describe the preparation and conjugation of water soluble nanoparticles and introduce the applications of luminescence nanoparticles for in vitro and in vivo imaging, fluorescence resonance energy based detection, and the applications of luminescence nanoparticles for photodynamic activation.
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Kang, Jie, Ai Ling Wang, Yan Rong Qu, Hai Bin Chu, and Yong Liang Zhao. "Preparation and Luminescent Property of EuxYy(TPTZ)2(POA)6 Complexes." Advanced Materials Research 1078 (December 2014): 118–21. http://dx.doi.org/10.4028/www.scientific.net/amr.1078.118.

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Using anion ligand phenoxyacetic acid (HPOA) and neutral ligand 2,4,6-tri(2-pyridyl)-s-triazine (TPTZ), a series of novel europium complexes EuxYy(TPTZ)2(POA)6·6H2O. The luminescence spectra, luminescence lifetimes and emission quantum efficiencies of the complexes were studied. The results show that doping appropriate amount of Y3+ can significantly increase the luminescence intensities, prolong the luminescent lifetime and improve the emission quantum efficiencies.
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Dementeva E. V., Dementev P. A., Korenko N. P., Shkarupa I. I., Kremleva A. V., Panov D. Yu., Spiridonov V. A., et al. "Luminescence features of bulk crystals β-(Ga-=SUB=-x-=/SUB=-Al-=SUB=-1-x-=/SUB=-)-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=-." Semiconductors 56, no. 4 (2022): 262. http://dx.doi.org/10.21883/sc.2022.04.53230.9776.

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This work is devoted to the study of the luminescence inhomogeneity nature of bulk (GaxAl1-x)2O3 samples grown by the Czochralski method. In the study of sample cleavages by the local cathodoluminescence method, regions with different luminescence were observed. To determine the cathodoluminescence contrast nature, we studied the uniformity of the aluminum distribution, the surface topography, and compared the luminescence spectra and the kinetics of emission bands for different regions of the sample. Also, to determine the luminescence bands nature, the crystal was annealed in air at 1000oC. This made it possible to observe the change in luminescence for the same region of the sample. Based on the studies performed, it was concluded that inhomogeneous luminescence is associated with the distribution of point defects. Upon annealing in air, the transformation of nonradiative recombination centers into luminescent centers was observed. Keywords: gallium oxide, luminescence, point defects.
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Chiatti, Chiara, Claudia Fabiani, and Anna Laura Pisello. "Long Persistent Luminescence: A Road Map Toward Promising Future Developments in Energy and Environmental Science." Annual Review of Materials Research 51, no. 1 (July 26, 2021): 409–33. http://dx.doi.org/10.1146/annurev-matsci-091520-011838.

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In recent decades, research on persistent luminescence has led to new phosphors and promising performances. Efforts to improve the quality of phosphors’ afterglow have paved the way toward innovative solutions for many disciplines. However, there are few examples of the implementation of luminescent materials. In addition to providing a general background on persistent luminescence, the techniques used for its analysis, and its multidisciplinary potential in energy and environmental science, this article aims to explain the existing gap between the physical-chemical approach and the effective implementation of luminescent materials in larger-scale applications. It investigates engineering solutions in terms of the possible benefits of luminescence in lighting energy savings and passive cooling of urban surfaces. Finally, this article aims to reduce the abovementioned gap by suggesting what is most needed for the successful application of luminescent materials in the built environment.
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31

Beltyukova, S. V., O. V. Malynka, and O. O. Livencova. "Determination of citrat ions in drugs on molecular luminescence of rutine in complex with yttrium (III)." Farmatsevtychnyi zhurnal, no. 5 (October 29, 2019): 86–91. http://dx.doi.org/10.32352/0367-3057.5.19.09.

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The development of methods for qualitative and quantitative analysis of drugs can guarantee their identity and quality. Drugs used in the form of salts of organic bases are often determined by the anionic part of these salts. Citrate ions are a part of many drugs in the form of citric acid, salts of alkaline and alkaline earth metals. The purpose of this study was to develop a method for the luminescent determination of citrate ions in dosage forms using a complex of yttrium (III) with rutine (Rut) as a luminescent probe. It has been experimentally established that citrate ions increase the luminescence intensity of the Y(III)–Rut complex. The spectral and luminescence characteristics of the complex was studied. The luminescence spectrum of the Y(III)–Rut complex has a maximum at λlum = 570 nm. The luminescence intensity of the Y(III)–Rut complex increases and the luminescence peak shifts to the short-wave region of the spectrum (λlum = 522 nm) in the presence of sodium citrate. The maximum effect is observed at a pH of 6.5–7.5. The dependencies of the luminescence intensity on the concentration of Y(III) and Rut for the Y(III)–Rut–Cit complex at the constant concentration of citrate ions (1·10-3 mol/l) were studied. It was established that the maximum luminescence intensity was observed at concentrations of Y(III) – 2·10-3 mol/l and Rut – 5·10-4 mol/l. The linear region of the dependence of the luminescence intensity of the complex on the concentrations of Y(III) and Rut is observed in the range of yttrium concentrations 0.3–2.0·10-3 mol/l and rutine 0.5–5.0·10-4 mol/l. The method of luminescent determination of citrate ions in dosage forms has been developed. The method is based on the use of rutine molecular luminescence in the multi-ligand complex Y(III)–Rut–Cit. The method of determination of citrate ions in dosage forms differs favorably from the existing absence of toxic reagents, expensive equipment, short-term analysis time, allows rapid screening of samples of drugs.
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32

Elena V. Sorokina, Ilya R. Vodolazov, and Alexander V. Oleskin. "Stimulatory and Toxic Effects of Neurotransmitters on the lux Operon-Dependent Bioluminescence of Escherichia coli K12 TGI." Journal of Pharmacy and Nutrition Sciences 9, no. 3 (June 5, 2019): 136–43. http://dx.doi.org/10.29169/1927-5951.2019.09.03.1.

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Background: The normal functioning of the brain requires neuromediators, i.e., substances that transmit messages between nervous cells. Neurochemicals also function as signals that are involved in communication among the microorganisms that inhabit the human organism. While the impact of “classical” neurotransmitters including catecholamines, serotonin, and histamine on microorganisms has been investigated in a number of recent publications, this work provides evidence for the stimulatory and inhibitory (toxic) effects of some other important neurochemicals that have not received sufficient attention in the literature.Methods: The biosensor was based on a GM Escherichia coli K12 strain (TGI) that contained the lux operon of the luminescent soil bacterium Photorhabdus luminescencens ZMI. The biosensor was exposed to the action of the tested neurotransmitters for 15 mins to 144 hrs. The intensity of bacterial luminescence (counts / second) was monitored in the control and the experimental samples with an 1251 BioOrbit luminometer (Finland).Results: Neurochemicals such as putrescine, acetylcholine, taurin, and indole were found to stimulate, at low concentrations (0.1-10 µM), the luminescence of the strain E. coli K12 TGI containing the lux operon from Photorhabdus luminescencens ZMI. At higher concentrations, putrescine, taurin, and indole exerted a weak toxic influence, i.e. they marginally attenuated the luminescence of E. coli K12 TGI.Conclusions: Based on the data obtained, a regulatory, presumably receptor-dependent, effect is exerted by the tested neurochemicals on the bacterium E. coli K12 TGI, in an analogy to their impact on nervous, immune, and other specialized types of eukaryotic cells. However, high neurochemical concentrations are likely to produce nonspecific effects on the bacterial luciferase system and/or on membrane phosphorylation.
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33

Bremaeker, N. D., F. Baguet, M. C. Thorndyke, and J. Mallefet. "Modulatory effects of some amino acids and neuropeptides on luminescence in the brittlestar amphipholis squamata." Journal of Experimental Biology 202, no. 13 (July 1, 1999): 1785–91. http://dx.doi.org/10.1242/jeb.202.13.1785.

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Amphipholis squamata is a polychromatic luminescent ophiuroid. The effects of amino acids (γ -aminobutyric acid, GABA, taurine, glycine and glutamate), N-methyl-d-aspartate (NMDA) and the invertebrate neuropeptides Antho-RFamide, FMRFamide and SALMFamides S1 and S2 were tested on acetylcholine-induced luminescence from isolated arms of clear and black specimens of Amphipholis squamata. The results showed that GABA, glycine and Antho-RFamide inhibited ACh-induced luminescence of clear specimens and had no significant effect on black specimens. Glutamic acid had no significant effect on ACh-induced luminescence, but triggered luminescence in the absence of ACh in both types of specimen. Taurine, NMDA and FMRFamide showed no significant effects on either clear or black specimens. S1 potentiated ACh-induced luminescence of clear and black specimens, while S2 had no clear modulatory effect on luminescence. These results suggest that, in addition to the previously described cholinergic system in Amphipholis squamata, there is also a modulatory component to luminescence control. Moreover, we observed a difference in modulation of luminescence between clear and black specimens.
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34

Song, Ya, Guo Gong, Jingjing Du, Shaowen Xie, Min Ouyang, Yahui Feng, Jianxiong Xu, and Lijian Xu. "Synthesis and Inkjet Printing of NaYF4:Ln3+@NaYF4 Core–Shell Nanoparticles with Enhanced Upconversion Fluorescence for Anti-Counterfeiting Applications." Journal of Nanoscience and Nanotechnology 20, no. 3 (March 1, 2020): 1511–19. http://dx.doi.org/10.1166/jnn.2020.17353.

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Recently, lanthanide-doped upconversion luminescent materials have showed great potential in optical data storage, information encryption and anti-counterfeiting. However, the low upconversion luminescence still limited their applications. In this work, we fabricated RGB NaYF4:Ln3+@NaYF4 core–shell nanoparticles (CSNPs) with enhanced upconversion luminescence by coating an inert NaYF4 shell onto NaYF4:Ln3+ core nanoparticles via thermal decomposition method. The effect of increased shell temperature and addition of shell precursors on crystal phase, morphology and luminescent property of the synthesized CSNPs were systematically investigated. It was demonstrated that high shell growing temperature facilitated the formation of pure β-NaYF4 CSNPs. Upon increasing amount of shell precursors, the morphologies of hexagonal phase NaYF4 CSNPs changed from nanorod to nanocube and showed different luminescent properties. Pure hexagonal phase NaYF4 CSNPs with highest upconversion luminescence of about 15 times higher than NaYF4:Ln3+ core nanoparticles can be prepared at 310 °C with the addition of shell precursors at 3 mmol. Moreover, three-primary-color (RGB) CSNPs with enhanced upconversion luminescence were successfully prepared by changing the doping pair of lanthanide ions in core. The synthesized RGB CSNPs were fabricated into environment friendly luminescent ink by sequential surface modification by PAA ligand and dispersing in mixture solvent of ethanol, water and glycerol. Comparative results showed that the fluorescence enhanced RGB CSNPs inks were more suitable for inkjet printing of multicolored, complex and high resolution luminescent anti-counterfeiting patterns on paper substrates.
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35

Yu, Mingke, Xu Yao, Xinyu Wang, Yuxin Li, and Guangming Li. "White-Light-Emitting Decoding Sensing for Eight Frequently-Used Antibiotics Based on a Lanthanide Metal-Organic Framework." Polymers 11, no. 1 (January 9, 2019): 99. http://dx.doi.org/10.3390/polym11010099.

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Developing multi-selective luminescence sensing technology to differentiate serial compounds is very important but challenging. White-light-emitting decoding sensing based on lanthanide metal-organic frameworks (Ln-MOFs) is a promising candidate for multi-selective luminescence sensing application. In this work, three isomorphic Ln-MOFs based on H3dcpcpt (3-(3,5-dicarboxylphenyl)-5-(4-carboxylphenl)-1H-1,2,4-triazole) ligand, exhibiting red, blue, and green emission, respectively, have been synthesized by solvothermal reactions. The isostructural mixed Eu/Gd/Tb-dcpcpt is fabricated via the in-situ doping of different Ln3+ ions into the host framework, which can emit white light upon the excitation at 320 nm. It is noteworthy that this white-light-emitting complex could serve as a convenient luminescent platform for distinguishing eight frequently-used antibiotics: five through luminescence-color-changing processes (tetracycline hydrochloride, yellow; nitrofurazone, orange; nitrofurantoin, orange; sulfadiazine, blue; carbamazepine, blue) and three through luminescence quenching processes (metronidazole, dimetridazole, and ornidazole). Moreover, a novel method, 3D decoding map, has been proposed to realize multi-selective luminescence sensing applications. This triple-readout map features unique characteristics on luminescence color and mechanism. The mechanism has been systematically interpreted on the basis of the structural analysis, energy transfer and allocation process, and peak fitting analysis for photoluminescence spectra. This approach presents a promising strategy to explore luminescent platforms capable of effectively sensing serial compounds.
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36

Zhang, Ning, and Shiqing Man. "Luminescent Properties of a Novel Mn2+ doped 3CaO-CaF2-2SiO2 Glasses." Journal of Physics: Conference Series 2076, no. 1 (November 1, 2021): 012048. http://dx.doi.org/10.1088/1742-6596/2076/1/012048.

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Abstract The transition metal Mn2+ ions doped materials have been widely reported for the luminescent properties for its broad emission band from green to red due to the spin-forbidden 4T1→6A1 transitions. To investigate the luminescent properties of Mn2+ ions in cuspidine glass, the 3CaO-CaF2-2SiO2 glasses doped with different Mn2+ concentration were prepared with traditional melt-quenching method. The luminescence emission spectra, excitation spectra and luminescence decay curves were recorded and analyzed. The tunable broadband emission from orange to red was obtained. The luminescence intensity and lifetime of Mn2+: 4T1 level showed different quenching points with the increasing of Mn2+ concentration. All these results indicate that Mn2+ doped 3CaO-CaF2-2SiO2 glass could be applied as light conversion material for solid-state lighting applications.
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37

ZHAO, YUE, DONGSHENG LI, WENBIN SANG, DEREN YANG, and MINHUA JIANG. "STUDY OF OPTICAL PROPERTIES OF POROUS SILICON PRODUCED BY METAL-AID." Modern Physics Letters B 21, no. 29 (December 20, 2007): 1989–97. http://dx.doi.org/10.1142/s0217984907014401.

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We presented fluorescence spectra and cathode-luminescence spectra of as-prepared porous silicon under different preparation conditions. The luminescence of porous silicon may be related to the luminescent centers on porous silicon surface. The luminescent efficiency depended on the porosity of porous silicon, which further depended on the oxidative level of porous silicon with metal assistance. Under back illumination, the higher the oxidative degree of the metal is, the higher is the porosity and the luminescent efficiency of porous silicon. But under front illumination, the results exhibited an opposite tendency, which can be explained by the formation theory of PS.
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38

Li, You, Heng Jian Huang, Li Min Dong, Dan Li, Wen Hao Shi, and Jia Rong Yin. "Preparation and luminescence properties of Mg2Sr2-XTiO4: Eu3+, Gd3+ red phosphors." Digest Journal of Nanomaterials and Biostructures 18, no. 1 (March 2023): 253–62. http://dx.doi.org/10.15251/djnb.2023.181.253.

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Titanate-based luminescent materials have a strong absorption capacity for blue and near-ultraviolet light. Here, a sol-gel method is used to prepare a high-efficiency red phosphor of magnesium titanate Mg2Sr2-xTiO4: Eu3+, Gd3+ doped with rare-earth ions. The optimal doping concentrations of the activator rare earth ion Eu3+ and the sensitizer Gd3+ were investigated. Furthermore, the doping of a certain amount of Sr2+ and Na+ effectively improves the luminescence properties of silicate luminescent materials. The luminescence spectrum shows that the luminescent material has red monochromaticity and the strongest red-light emission is 614nm, which can be used for WLED.
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39

Han, Qingyan, Yaqiong Zhang, Zebin Ren, Zhaojin Wang, Wei Gao, Enjie He, and Hairong Zheng. "Ag@SiO2/LaF3:Eu3+ Composite Nanostructure and Its Surface Enhanced Luminescence Effect." Journal of Nanoscience and Nanotechnology 16, no. 4 (April 1, 2016): 3759–62. http://dx.doi.org/10.1166/jnn.2016.11813.

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Ag@SiO2/LaF3:Eu3+ core–shell nanostructure was synthesized with a wet chemical method in which the SiO2 layer functioned as a separation layer between Ag-core and LaF3:Eu3+ luminescence material. With this system, surface enhanced luminescene of LaF3:Eu3+ with Ag substrate was investigated, and an obvious enhancement effect was observed. The dependence of the luminescence enhancement on the distance between the luminescence shell and the metallic core was studied too. It is believed that the enhancement effect presented by the current hybrid nanostructure system has great potential in the development of photovoltaic cells.
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40

Zamoryanskaya, M. V., Kseniia N. Orekhova, Grigorii A. Gusevs://orcid.org/0, Sofya M. Masloboeva, Azalia A. Shakirova, Ekaterina V. Dementieva, and Boris E. Burakov. "Ceramic radiation-resistant scintillators for high-energy radiation detection." Transactions of the Kоla Science Centre of RAS. Series: Engineering Sciences 1, no. 1/2023 (March 29, 2023): 52–56. http://dx.doi.org/10.37614/2949-1215.2023.14.1.009.

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Complex oxides of Y3Al5O12, Gd(Nb,Ta)O4, (Zr,Hf,Y)O2, (Zr,Y)O2, activated with trivalent rare earth ions Nd3+, Eu3+ and Tb3+ have been studied in terms of their luminescent properties. These materials are promising scintillators with high radiation, chemical, and mechanical stability. The aim of the work was to develop ceramic radiation-resistant scintillators based on oxides activated by rare-earth ions. The study included: an evaluation of changes in the intensity and kinetics of luminescence decay from single crystal samples to ceramics; a study of the complete or partial replacement of light elements by heavier ones effect on the luminescent properties; a study of the possibility of using a sensitizer to increase the luminescence yield when luminescence is excited by an electron beam of medium energies.
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41

Ricci, Giulia, Andrea Maurizio Monti, Renato Pagano, Marco Martini, Luisa Caneve, and Gilberto Artioli. "Unusual Luminescence of Quartz from La Sassa, Tuscany: Insights on the Crystal and Defect Nanostructure of Quartz." Minerals 11, no. 12 (November 30, 2021): 1345. http://dx.doi.org/10.3390/min11121345.

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Quartz from La Sassa (Tuscany, Italy) presents a unique luminescence related to intrinsic and extrinsic defects in the crystal lattice due to the growth mechanisms in hydrothermal conditions. The bright fluorescence under the UV lamp was apparent to collectors since the early 1970s, and it entered the literature as a reference case of yellow-luminescent quartz. Early reports present the history of the discovery, the geological context, and preliminary luminescence measurements of the quartz nodules, suggesting various activators as potentially responsible of the peculiar luminescence effects: uranyl groups (UO22+), rare earths (Tb3+, Eu3+, Dy3+, Sm3+, Ce3+) and polycyclic aromatic compounds (PAH). Here, we report a full investigation of the La Sassa material, by a multi-analytical approach encompassing cathodoluminescence optical microscopy (OM-CL), laser-induced fluorescence (LIF), wavelength resolved thermally stimulated luminescence (WR-TSL), trace elements analysis by mass spectrometry (ICP-MS) and Raman spectroscopy (RS). The results provide a significant step forward in the interpretation of the luminescence mechanisms: the main luminescent centres are identified as alkali-compensated (mainly Li+ and Na+, K+ and H+) aluminum [AlO4/M+]0 centres substituting for Si, where the recombination of a self-trapped exciton (STE) or an electron at a nonbridging oxygen hole centre (NBOHC) are active.
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42

Meng, Shuai, Dengke Cheng, Hailing Gu, Yuchen Li, Yukun Qin, Jing Tan, and Qijun Li. "Mechanical Force-Induced Color-Variable Luminescence of Carbon Dots in Boric Acid Matrix." Molecules 28, no. 8 (April 12, 2023): 3388. http://dx.doi.org/10.3390/molecules28083388.

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Mechano-luminescent materials that exhibit distinct luminescence responses to force stimuli are urgently anticipated in view of application needs in the fields of sensing, anti-counterfeiting, optoelectronic devices, etc. However, most of the reported materials normally exhibit force-induced changes in luminescent intensity, whereas materials that possess force-induced color-variable luminescence remain rarely reported. Herein, for the first time, a novel mechanical force-induced color-variable luminescence material from carbon dots (CDs) in boric acid (CD@BA) is reported. At low CDs concentration, the luminescence of CD@BA exhibits a grinding-induced color variable from white to blue. This grinding-induced color variable can be switched to yellow-to-white changing by increasing the CDs concentration in BA. The grinding-induced color-variable luminescence originates from dynamic variation in emission ratio of fluorescence and room temperature phosphorescence, due to the influence of oxygen and water vapor in the air. At high CDs concentration, short-wavelength fluorescence undergoes more severe reabsorption compared to room temperature phosphorescence, leading to grinding-induced color-variable switching from white-to-blue to yellow-to-white. Based on the unique properties of CD@BA powder, the applications of recognizing and visualizing fingerprints on the surfaces of various of materials are demonstrated.
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43

De Bremaeker, N., F. Baguet, and J. Mallefet. "Effects of catecholamines and purines on luminescence in the brittlestar Amphipholis squamata (Echinodermata)." Journal of Experimental Biology 203, no. 13 (July 1, 2000): 2015–23. http://dx.doi.org/10.1242/jeb.203.13.2015.

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The effects of catecholamines (dopamine, adrenaline, noradrenaline and its derivatives), 5-hydroxytryptamine and purines (adenosine, ATP and their derivatives) on the acetylcholine-induced luminescence of isolated arms and dissociated photocytes of the luminescent ophiuroid Amphipholis squamata were tested. The results showed that catecholamines and 5-hydroxytryptamine (10(−)(5) to 10(−)(3)mol l(−)(1)) had a strong dose-dependent inhibitory effect on acetylcholine-induced luminescence. In contrast, purines (10(−)(4) and 10(−)(3)mol l(−)(1)) triggered luminescence in the absence of acetylcholine and/or potentiated acetylcholine-induced luminescence. The results with specific purinergic agonists and antagonists indicated the involvement of P(1)- and P(2)-like purinoceptors in the control of luminescence. Our study suggests that, in addition to the previously described cholinergic system in Amphipholis squamata, there may be a purinergic system, acting in synergy with acetylcholine, and an inhibitory neuromodulatory catecholaminergic system, all associated with the control of luminescence.
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44

Venevtsev I. D., Muslimov A. E., Tarasov A. P., Emiraslanova L. L., Ismailov A. M., and Kanevsky V. M. "X-ray Luminescent Properties of Zinc Oxide Films on the Sapphire M and A-Plane." Optics and Spectroscopy 130, no. 11 (2022): 1458. http://dx.doi.org/10.21883/eos.2022.11.55106.3845-22.

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The results of comparative studies of the processes of high-temperature synthesis, luminescence and scintillation characteristics of ZnO films on M(100)- and A(110)-orientation sapphire substrates are presented. It is shown that the use of the magnetron deposition method makes it possible to form, against the background of a continuous film, ensembles of individual [001] ZnO microcrystals with pronounced X-ray luminescent properties. The X-ray luminescence kinetics is characterized by two components: a fast component with a decay time in the order of a nanosecond and a slow luminescence component. The study of the films by photoluminescence spectroscopy revealed the features of the near-band-edge luminescence spectra of the samples, in particular, the presence of various excitonic emission channels. Differences in the spectral parameters of the near-band-edge luminescence band in the case of optical and X-ray excitation are found and interpreted. Keywords: Films, microcrystals, zinc oxide, X-ray luminescence, photoluminescence, excitonic emission.
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45

Vocat, Anthony, Ruben C. Hartkoorn, Benoit Lechartier, Ming Zhang, Neeraj Dhar, Stewart T. Cole, and Claudia Sala. "Bioluminescence for Assessing Drug Potency against Nonreplicating Mycobacterium tuberculosis." Antimicrobial Agents and Chemotherapy 59, no. 7 (April 20, 2015): 4012–19. http://dx.doi.org/10.1128/aac.00528-15.

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ABSTRACTTargeting dormantMycobacterium tuberculosisrepresents a challenge to antituberculosis drug discovery programs. We previously reported and validated the use of the streptomycin (STR)-dependentM. tuberculosis18b strain as a tool for assessing drug potency against nonreplicating bacteria bothin vitroandin vivo. In this study, we generated a luminescent 18b strain, named 18b-Lux, by transforming the bacteria with a vector expressing theluxCDABEoperon fromPhotorhabdus luminescens. Luciferase expression was demonstrated under replicating conditions, and, more importantly, luminescence levels significantly above background were detected following STR removal. The sensitivity of STR-starved 18b-Lux to approved and candidate antituberculosis therapeutic agents was evaluated by means of a luciferase assay in a 96-well format. Results mirrored the data obtained with the standard resazurin reduction microplate assay, and the luminescence readout allowed time course assessments of drug efficacyin vitro. Specifically, we proved that bedaquiline, the rifamycins, and sutezolid displayed time-dependent activity against dormant bacteria, while pyrazinamide and SQ109 showed bactericidal effects at the highest concentrations tested. Overall, we established the optimal conditions for an inexpensive, simple, and very sensitive assay with great potential for future applications.
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46

Santos Magalhães, Evellyn, Ahmed Sedda, Bartosz Bondzior, Sami Vuori, David Van der Heggen, Philippe F. Smet, Mika Lastusaari, and Laeticia Petit. "CaWO4:Yb3+,Tm3+ Crystals and SrAl2O4:Eu2+,Dy3+ Phosphors in Glass-Based Composites for Green Afterglow after NIR Excitation." EPJ Web of Conferences 287 (2023): 05043. http://dx.doi.org/10.1051/epjconf/202328705043.

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Here, we present the preparation of composites with green persistent luminescence using melting process. The composites are phosphate glass (75NaPO3-25CaF2 and 90NaPO3-10NaF (in mol%)) with embedded phosphors: CaWO4: Yb3+, Tm3+ crystals with blue upconversion and SrAl2O4:Eu2+,Dy3+ with green persistent luminescence. Green persistent luminescence above 0.3 mcd/m2 can be seen for ~ 30 minutes after charging with 980 nm due to energy transfer between the blue upconverter crystals and the persistent luminescent phosphors. Challenges related to the fabrication of such composites are discussed.
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47

Okamura, Tatsunori, and Kazuyoshi Ogasawara. "Theoretical Analysis of Anomalous Emission of Eu2+ in Crystals By First-Principles Calculation." ECS Meeting Abstracts MA2023-02, no. 50 (December 22, 2023): 2471. http://dx.doi.org/10.1149/ma2023-02502471mtgabs.

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The 5d-4f transition energies of lanthanides are very versatile, especially the 4f65d1-4f75d0 transition energy of Eu2+ has high luminescence efficiency and is used in various luminescent materials such as phosphors like SrxCa1-xAlSiN3: Eu2+, scintillators, and solid-state lasers, etc. However, there are materials that do not undergo pure 5d-4f transitions, showing the so-called anomalous luminescence instead. The anomalous luminescence is caused by the formation of excitons due to the overlap of the 5d level of Eu2+ with the conduction band and the transition of electrons from the conduction band to the 4f level, resulting in a shift to a lower energy than the general 5d-4f transition energy. A more detailed analysis of this phenomenon is important for the development of novel luminescent materials using Eu2+. In this study, we aimed to theoretically analyze the anomalous luminescence based on first-principles electronic structure calculations. The model clusters of Eu2+-doped crystals consisting of Eu2+ at the substitution site and the surrounding ions were created. Then molecular orbital calculations were performed by the relativistic discrete-variational Xα (DV-Xα) method and subsequently multiplet calculations were performed by the relativistic discrete-variational multi-electron (DVME) method. These first-principles calculations were carried out for Eu2+-doped crystals that show anomalous luminescence and those that do not show anomalous luminescence, and the electronic states of these materials were compared in detail.
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48

Shibaeva, Darya N., Alena A. Kompanchenko, Victor V. Bulatov, and Danil A. Asanovich. "Express Assessment of Apatite Content in Apatite–Nepheline Ores of Ultrabasic Alkaline Complexes Based on Its Luminescent Properties (The First Study Stage)." Minerals 13, no. 1 (December 26, 2022): 37. http://dx.doi.org/10.3390/min13010037.

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The article presents the results of the first study stage aimed at analyzing the luminescent properties of the main and minor minerals composing the apatite–nepheline ores and host rocks in the deposits of the Khibiny rock massif (Kola Peninsula, Russia). The main purpose of the work was a search of a stable identification feature providing fast and safe determination of fluorapatite in the mineral mixture of apatite–nepheline ores and solving technological tasks, namely sampling the borehole walls in open pits. The first stage includes studies carried out on pure mono-fractions of four minerals occurring in fluorapatite deposits and possessing obvious luminescent properties: fluorapatite, nepheline, calcite, and sodalite. The authors have revealed luminescence spectra of these minerals and established correlation of their spectral characteristics with the literature data and their consistency. However, the high intensity of sodalite luminescence in a wide band can complicate identification of fluorapatite by the luminescence spectrum in many cases. Therefore, it is reasonable to use the color and intensity of luminescence rather than spectral characteristics.
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49

Mihail, Nazarov, and Zamoryanskaya Maria. "Luminescence of yttrium tantalate doubly activated with europium and terbium under x-ray and electron beam excitations." Moldavian Journal of the Physical Sciences 21, no. 1 (December 2022): 18–24. http://dx.doi.org/10.53081/mjps.2022.21-1.01.

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This paper reports the luminescence spectra of YTaO4 activated with rare-earth ions, such as Eu3+ and Tb3+. The effect of these rare-earth ions on the luminescence of yttrium tantalate phosphors is studied. The luminescent properties are studied under X-ray and electron beam excitations. It is found that, under these excitations, the emission centers of the rare-earth activators (Eu3+, Tb3+) efficiently contribute to the overall luminescence. Color cathodoluminescence images clearly show the dependence of chromaticity on the different activators. These rare-earth activated phosphors exhibiting various luminescence chromaticities are promising materials for optoelectronic applications and for X-ray intensifying screens in medical diagnosis, because they provide a broad variation of visible photoluminescence from blue to red.
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50

Bunkin, N. F., S. V. Bashkin, P. N. Bolotskova, S. V. Gudkov, and V. A. Kozlov. "Luminescence Intensity ELF Oscillations from a Polymer Membrane in the Aqueous Salt Solutions." Herald of the Bauman Moscow State Technical University. Series Natural Sciences, no. 2 (107) (April 2023): 50–82. http://dx.doi.org/10.18698/1812-3368-2023-2-50-82.

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The paper studies luminescence from the Nafion polymer membrane surface at its swelling in the isotonic aqueous solutions and bi-distilled water using the experimental photo luminescent spectroscopy. Liquid samples were preliminarily treated with the electric pulses with duration of 1 µs and amplitude of 0.1 V using antenna in the form of a flat capacitor. Experiments in photo luminescent spectroscopy were carried out 20 min after the electric pulse treatment. Typical luminescence intensity dependence on the membrane swelling time could be represented as the exponentially decreasing function. Characteristic decay time of the corresponding functions and stationary level of the membrane luminescence intensity depend on the electrical pulses repetition rate. The obtained dependencies could well be reproduced. However, dependence of the luminescence intensity at certain pulse repetition rates appears to be a random function, and the reproducibility is missing. It could be assumed that these stochastic effects are associated with exposure to random external force of the electromagnetic nature acting on the polymer membrane during swelling. Low-frequency pulsations of neutron stars or white dwarfs are the source of this random force according to the authors of the work. This effect is associated with depolarization during the low-frequency electromagnetic field scattering caused by the neutron stars pulsation. Depolarization effect arises due to scattering on long-living anisotropic clusters of nano-bubbles, which, in turn, are becoming anisotropic in the external field of a flat capacitor. Depolarized scattered radiation causes stochastic oscillations of the polymer fibers unwound into the bulk liquid. In this case, luminescence should also acquire the stochastic character taking into account the effect of resonant luminescence energy transfer from a donor to the luminescence acceptor
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