Luminescent complexes of terbium ion for molecular recognition of ibuprofen

The complexation behavior and luminescent properties of terbium (Tb³⁺) complexes containing bi‐dental ligands were studied: nitrogen – 1,10‐phenanthroline, and oxygen – trifluoroacetylacetone as well as acetylacetone ligands with ibuprofen (Ibu; a non‐steroidal anti‐inflammatory drug). Aqueous and aqueous alcohol microheterogeneous solutions were used as media. The effects of solubilization by various micellar solutions, pH and ligand type on luminescent properties of Tb³⁺ complexes were investigated. Sensitized luminescence of mixed ligand complex Tb(1,10‐phenanthroline)‐Ibu and dynamic quenching effect in complex Tb(trifluoroacetylacetone)₃‐Ibu allow Ibu determination with the limit of detection 5.3 × 10^–8 mol/L and 1.26 × 10^–6 mol/L, respectively. Copyright © 2013 John Wiley & Sons, Ltd.     

Inhibition of luminol-dependent luminescence and simultaneous generation of native luminescence of activated human polymorphonuclear leukocytes by addition of albumin

Luminol-dependent luminescence (LDL) and luminol-independent, native luminescence (NL) of polymorphonuclear leukocytes were investigated with respect to the effects generated by the addition of albumin to the reaction medium. The cells were activated: (1) by simple surface attachment to a hydrophilic plastic, (2) by opsonized zymosan, (3) by phorbol myristate acetate, (4) by formylmethionyl-leucyl-phenylalaline. Both kinds of emissions were recorded simultaneously using a method of spectral discrimination. The addition of albumin resulted in an inhibition of LDL, which coincided with a generation of NL. The extent of the inhibition of LDL depended on the type of stimulus used. Maximum inhibition occurred with cells activated by attachment to plastic surfaces and minimum inhibition was observed with cells stimulated by opsonized zymosan. Different contributions of extracellularly released reactive oxygen-species may be responsible for this. It appears possible to discriminate between intra- and extracellular sites of oxygen-metabolites production using albumin simultaneously as extracellular quencher of LDL and as luminescent probe for NL.     

Luminescent properties of novel red‐emitting M7Sn(PO4)6:Eu3+ (M = Sr,Ba) for light‐emitting diodes

Novel red‐emitting phosphors, Eu³⁺‐activated M₇Sn(PO₄)₆ (M = Sr, Ba), were synthesized at 1200°C by conventional solid‐state reaction method. The luminescent properties of M₇Sn(PO₄)₆:Eu³⁺ (M = Sr, Ba) phosphors were investigated, and the critical concentration of the activator (Eu³⁺) concentration were found to be 0.175 mol and 0.21 mol per formula unit for Sr_7‐xSn(PO₄)₆:xEu³⁺ and Ba_7‐xSn(PO₄)₆:xEu³⁺, respectively. These phosphors presented red luminescence under the excitation of 395 or 465 nm, perfectly matching with the emissions wavelength of near‐ultraviolet (UV) light‐emitting diodes (LEDs) and InGaN blue LED.     

Synthesis and luminescence properties of novel 8‐hydroxyquinoline derivatives and their Eu(III) complexes

Six novel 8‐hydroxyquinoline derivatives were synthesized using 2‐methyl‐8‐hydroxyquinoline and para‐substituted phenol as the main starting materials, and were characterized by ¹H nuclear magnetic resonance (NMR), mass spectrometry (MS), ultraviolet (UV) light analysis and infra‐red (IR) light analysis. Their complexes with Eu(III) were also prepared and characterized by elemental analysis, molar conductivity, UV light analysis, IR light analysis, and thermogravimetric–differential thermal analysis (TG–DTA). The results showed that the ligand coordinated well with Eu(III) ions and had excellent thermal stability. The structure of the target complex was EuY^1–6(NO₃)₃.2H₂O. The luminescence properties of the target complexes were investigated, the results indicated that all target complexes had favorable luminescence properties and that the introduction of an electron‐donating group could enhance the luminescence intensity of the corresponding complexes, but the addition of an electron‐withdrawing group had the opposite effect. Among all the target complexes, the methoxy‐substituted complex (–OCH₃) had the highest fluorescence intensity and the nitro‐substituted complex (–NO₂) had the weakest fluorescence intensity. The results showed that 8‐hydroxyquinoline derivatives had good energy transfer efficiency for the Eu(III) ion. All the target complexes had a relatively high fluorescence quantum yield. The fluorescence quantum yield of the complex EuY³(NO₃)₃.2H₂O was highest among all target complexes and was up to 0.628. Because of excellent luminescence properties and thermal stabilities of the Eu(III) complexes, they could be used as promising candidate luminescent materials.     

Silica‐modified luminescent LaPO4:Eu@LaPO4@SiO2 core/shell nanorods: Synthesis,structural and luminescent properties

Monoclinic‐type tetragonal LaPO₄:Eu (core) and LaPO₄:Eu@LaPO₄ (core/shell) nanorods (NRs) were successfully prepared using a urea‐based co‐precipitation process under ambient conditions. An amorphous silica layer was coated around the luminescent core/shell NRs via the sol–gel process to improve their solubility and colloidal stability in aqueous and non‐aqueous media. The prepared nano‐products were systematically characterized by X‐ray diffraction pattern, transmission electron microscopy, energy dispersive X‐ray analysis, and FTIR, UV/Vis, and photoluminescence spectroscopy to examine their phase purity, crystal phase, surface chemistry, solubility and luminescence characteristics. The length and diameter of the nano‐products were in the range 80–120 nm and 10–15 nm, respectively. High solubility of the silica‐modified core/shell/Si NRs was found for the aqueous medium. The luminescent core NRs exhibited characteristic excitation and emission transitions in the visible region that were greatly affected by surface growth of insulating LaPO₄ and silica layers due to the multiphonon relaxation rate. Our luminescence spectral results clearly show a distinct difference in intensities for core, core/shell, and core/shell/Si NRs. Highly luminescent NRs with good solubility could be useful candidates for a variety of photonic‐based biomedical applications.     

Luminescent properties of single‐phase Ba2‐x‐1.5y‐1.5zP2O7:xEu2+,yCe3+, zTb3+ phosphors for white light‐emitting diode

A series of Ba₂P₂O₇:xEu²⁺,yCe³⁺,zTb³⁺ phosphors was synthesized via a co‐precipitation method, then their crystal structure, quantum efficiency and luminescent properties were analyzed by XRD and FL, respectively. The results showed that these phosphors not only presented the excitation characteristics of Ba₂P₂O₇:xEu²⁺,zTb³⁺, but also exhibited that of the Ba₂P₂O₇:yCe³⁺,zTb³⁺ phosphor. Meanwhile, the tri‐doped phosphor showed a stronger absorption around 320 nm in contrast with the Eu²⁺/Ce³⁺:Tb³⁺ co‐doped phosphor. Not only can energy transfer from Ce³⁺→Eu²⁺ be observed; the energy transfer mechanism from Eu²⁺ to Tb³⁺ is discussed in the tri‐doped system. Ce³⁺ affects the luminescence properties of Ba₂P₂O₇:xEu²⁺,yCe³⁺,zTb³⁺ phosphors just as the sensitizer whereas Eu²⁺ is considered both as the sensitizer and the activator. The chromaticity coordinates of tri‐doped phosphors excited at 320 nm stayed steadily in the bluish‐white light region,and the emitted color and color temperature (CCT) of these phosphors could be tuned by adjusting the relative contents of Eu²⁺, Ce³⁺ and Tb³⁺. Hence, the single phase Ba₂P₂O₇:xEu²⁺,yCe³⁺,zTb³⁺ phosphors may be considered as potential candidates for white light‐emitting diodes.     

Synthesis and photoluminescence properties of co‐polyamides with anthrazoline‐containing units in the main chain

A series of anthrazoline‐containing monomers are synthesized, and eight co‐polyamides of different chemical structures, containing 1,9‐anthrazoline fragments in the main chain, are obtained and investigated. Photoluminescent, stress–strain, and thermal properties of these polymers are studied. It is shown that polymers with fragments of 4,4′‐(pyrido[3,2‐g]‐quinoline‐2,8‐diyl)dianiline and 4,4′‐(10‐methylpyrido[3,2‐g]quinoline‐2,8‐diyl)dianiline possess an intense luminescence in the range 550–650 nm. The performed investigations made it possible to determine the effect of substituents of various natures in the anthrazoline cycle and the position of amide group (meta‐ and para‐configurations) on optical, stress‐strain, and thermal properties of copolymers, opening up a prospect for further developments of principles of design of polymers with optimal characteristics.     

A novel red emitting phosphor LiBaB9O15:Sm2+/Sm3+, li+ with broad excitation band for white LEDs

A novel tunable red emitting phosphor LiBaB₉O₁₅:Sm²⁺/Sm³⁺, Li⁺ with broad excitation band was synthesized by a high temperature solid‐state method. Luminescence properties were investigated in detail by luminescence, X‐ray photoelectron spectroscopy (XPS) spectra and CIE chromaticity coordinates. XPS data confirmed that there were Sm³⁺ in LiBaB₉O₁₅:Sm³⁺ and Sm²⁺/Sm³⁺ in LiBaB₉O₁₅:Sm²⁺/Sm³⁺, respectively. Spectral property of LiBaB₉O₁₅:Sm³⁺, LiBaB₉O₁₅:Sm³⁺/Sm²⁺ and LiBaB₉O₁₅:Sm²⁺, Li⁺ presented that the excitation band of Sm³⁺ widened and the excitation band of Sm²⁺ ranged from 350 to 450 nm. And the red light color is tunable with changing Li⁺ concentration. The results indicated that LiBaB₉O₁₅:Sm²⁺/Sm³⁺, Li⁺ may be promising red phosphor for white light emitting diodes.     

Back Cover: Characterization and application of porous gold nanoparticles as 2‐photon luminescence imaging agents: 20‐fold brighter than gold nanorods (J. Biophotonics 2/2018)

Gold nanoparticles serve as imaging contrast agents useful for two‐photon nonlinear microscopy of biological cells and tissues. In this study, 100‐nm‐sized gold particles with a multitude of nanopores embedded inside have been physically synthesized and investigated for the plasmonic enhancement in two‐photon luminescence. Exhibiting remarkable potential for two‐photon imaging, the porous gold nanoparticles boost near‐infrared light absorption substantially and allow emission signals 20 times brighter than gold nanorods being currently used as typical imaging agents. Further details can be found in the article by Joo H. Park et al. ( e201700174 )

     

不同类型植物种子在萌发期的超弱发光研究

小麦、红小豆、绿豆及早熟禾种子萌发期超弱发光有各自的发光曲线,可以反映不同物种萌发时期的代谢变化。进一步分析表明：种苗根部发光强,胚芽（子叶）及种皮（胚乳）发光次之;逆境条件下植物发光降低;氧化剂可使植物萌发时发光有不同程度的增强。