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The early diagnosis and real-time prognosis of cardiovascular diseases (CVDs) at the bedside are important. However, real-time detection of myocardial infarction involves the use of large-scale instrumentation and long test times. Herein, a simple, rapid and sensitive lateral flow immunochromatographic strip (LFIS) based on Yb/Er co-doped NaYF 4 upconversion nanoparticles (UCNPs) was demonstrated for use in the detection of myocardial infarction. First, through heavy Yb/Er doping and an inert NaYF 4 shell coating on the nanoparticles, the surface-related luminescence quenching effect of UCNPs was eliminated to enhance the upconversion luminescence. Second, through uniform coating of a SiO 2 layer on the UCNPs, the biological affinity was improved to couple UCNPs and antibody proteins. Finally, through modification and activation with a specific antibody protein (serum amyloid A (SAA)), the UCNPs exhibited intense upconversion luminescence and high specificity when applied as a lateral flow immunochromatographic strip (LFIS). The developed UC-LFIS was highly sensitive (0.1 μg mL -1 ) and specific for detecting SAA in only 10 μL of serum. The UC-LFIS holds great potential for the early diagnosis and prognosis of CVDs.

Chiral perovskite nanocrystals have emerged as an interesting chiral excitonic platform that combines both structural flexibility and superior optoelectronic properties. Despite several recent demonstrations of optical activity in various chiral perovskite nanocrystals, efficient circularly polarized luminescence (CPL) with tunable energies remains a challenge. The chirality imprinting mechanism as a function of perovskite nanocrystal dimensionality remains elusive. Here, atomically thin inorganic perovskite nanoplatelets (NPLs) are synthesized with precise control of layer thickness and are functionalized by chiral surface ligands, serving as a unique platform to probe the chirality transfer mechanism at the organic/perovskite interface. It is found that chirality is successfully imprinted into mono‐, bi‐, and tri‐layer inorganic perovskite NPLs, exhibiting tunable circular dichroism (CD) and CPL responses. However, chirality transfer decreases in thicker NPLs, resulting in decreased CD and CPL dissymmetry factors for thicker NPLs. Aided by large‐scale first‐principles calculations, it is proposed that chirality transfer is mainly mediated through a surface distortion rather than a hybridization of electronic states, giving rise to symmetry breaking in the perovskite lattice and spin‐split conduction bands. The findings described here provide an in‐depth understanding of chirality transfer and design principles for distorted‐surface perovskites for chiral photonic applications. [ABSTRACT FROM AUTHOR]

Introducing chirality into the metal‐halide hybrids has enabled many emerging properties including chiroptical activity, spin‐dependent transport, and ferroelectricity. However, most of the chiral metal‐halide hybrids to date are non‐emissive, and the underlying mechanism remains elusive. Here, we show a new strategy to turn on the circularly polarized luminescence (CPL) in chiral metal‐halide hybrids. We demonstrate that alloying Sb3+ into chiral indium‐chloride hybrids dramatically increases the photoluminescence quantum yield in two new series of chiral indium‐antimony chlorides. These materials exhibit strong CPL signals with tunable energy and a high dissymmetry factor up to 1.5×10−2. Mechanistic studies reveal that the emission originates from the self‐trapped excitons centered in 5s2 Sb3+. Moreover, near‐ultraviolet pumped white light is demonstrated with a polarization up to 6.0 %. Our work demonstrates new strategies towards highly luminescent chiral metal‐halide hybrids. [ABSTRACT FROM AUTHOR]

A series of isomorphic lanthanide metal-organic frameworks (MOFs) Ln(TATAB)⋅(DMF)4(H2O)(MeOH)0.5 (LnTATAB, Ln=Eu, Tb, Sm, Dy, Gd; H3TATAB=4,4′,4′′-s-triazine-1,3,5-triyltri- p-aminobenzoic acid) have been solvothermally synthesized and structurally characterized. Among these MOFs, TbTATAB exhibits good water stability and a high fluorescence quantum yield. Because mercury ions (Hg2+) have a high affinity to nitrogen atoms, and the space between multiple nitrogen atoms from triazine and imino groups is suitable for interacting with Hg2+ ions, TbTATAB shows highly selective and sensitive detection of Hg2+ in aqueous solution with a detection limit of 4.4 n m. Furthermore, it was successfully applied to detect Hg2+ ions in natural water samples. [ABSTRACT FROM AUTHOR]

A strategy by encapsulating organic dyes into the pores of a luminescent metal-organic framework (MOF) is developed to achieve white-light-emitting phosphor. Both the red-light emitting dye 4-( p-dimethylaminostyryl)-1-methylpyridinium ( DSM) and the green-light emitting dye acriflavine ( AF) are encapsulated into a blue-emitting anionic MOF ZJU-28 through an ion-exchange process to yield the MOF⊃dye composite ZJU-28⊃DSM/AF. The emission color of the obtained composite can be easily modulated by simply adjusting the amount and component of dyes. With careful adjustment of the relative concentration of the dyes DSM and AF, the resulting ZJU-28⊃DSM/AF (0.02 wt% DSM, 0.06 wt% AF) exhibits a broadband white emission with ideal CIE coordinates of (0.34, 0.32), high color-rendering index value of 91, and moderate correlated color temperature value of 5327 K. Such a strategy can be easily expanded to other luminescent MOFs and dyes, thus opening a new perspective for the development of white light emitting materials. [ABSTRACT FROM AUTHOR]

A strategy of encapsulation of organic dyes into the pores of a luminescent metal–organic framework (MOF) to achieve a white‐light‐emitting phosphor has been developed by G. Qian and co‐workers on page 4796. The resultant MOF ⊃ dye composite exhibits a broadband white emission with ideal CIE coordinates of (0.34, 0.32), high CRI value of 91, and moderate CCT value of 5327 K. [ABSTRACT FROM AUTHOR]

Abstract: Rare earth doped NaLa(WO4)2 nanoparticles have been prepared by a simply hydrothermal synthesis procedure. The X-ray diffraction (XRD) pattern shows that the Eu3+-doped NaLa(WO4)2 nanoparticles with an average size of 10–30nm can be obtained via hydrothermal treatment for different time at 180°C. The luminescence intensity of Eu3+-doped NaLa(WO4)2 nanoparticles depended on the size of the nanoparticles. The bright upconversion luminescence of the 2mol% Er3+ and 20mol% Yb3+ codoped NaLa(WO4)2 nanoparticles under 980nm excitation could also be observed. The Yb3+–Er3+ codoped NaLa(WO4)2 nanoparticles prepared by the hydrothermal treatment at 180°C and then heated at 600°C shows a 20 times stronger upconversion luminescence than those prepared by hydrothermal treatment at 180°C or by hydrothermal treatment at 180°C and then heated at 400°C. [Copyright &y& Elsevier]

Abstract: The hydrothermal synthesis process and luminescence properties of Ln3+ doped NaY(WO4)2 nanoparticles have been investigated. Nearly spherical Eu3+ doped NaY(WO4)2 nanoparticles can be observed. The luminescence concentration quenching of Eu3+ in the NaY(WO4)2 nanoparticles was found to be similar to that in the NaY(WO4)2 crystals. The upconversion luminescence intensity of the Yb3+–Er3+ codoped NaY(WO4)2 nanoparticles was found to be much stronger than that of the Er3+ doped NaY(WO4)2 nanoparticles. [Copyright &y& Elsevier]

Abstract: Erbium chelates including tris(acetylacetonato) erbium(III) monohydrate, tris(acetylacetonato)(1,10-phenanthroline) erbium(III) and tris(trifluoroacetylacetonato)(1,10-phenanthroline) erbium(III) are synthesized. Judd–Ofelt theory is employed on basis of the UV–Vis–NIR absorption spectra of erbium chelates dissolved in methanol. Judd–Ofelt parameters of erbium chelates are determined by a least square fitting and dealt with the chemical structure of erbium chelates. Photoluminescence characteristics of erbium chelates are investigated upon excitation at 488nm by an Ar+ laser. The qualitative correlation of Judd–Ofelt parameters with photoluminescence properties for erbium chelates is also discussed. It is found that larger Ω 6 value for erbium chelate is and larger photoluminescence intensity at 1.54μm is, and Ω 2 value should contribute to the photoluminescence full width at half maximum (FWHM) at 1.54μm. The changes of Judd–Ofelt parameters result from the introduction of the second ligand phenathroline or the substitution of electron-drawing group CF3 in β-diketone for erbium chelates. [Copyright &y& Elsevier]

Abstract: Vinyltriethoxysilane-derived organically modified silicate (ORMOSIL) films doped with the organic complex neodymium tris(2-theonyltrifluoroacetonate)bis(triphenylphosphine oxide) by a multistep sol–gel process exhibit near-infrared luminescence at ca. 1330 nm (4F3/2→4I13/2). Spectral properties of as-doped films with a series of doping concentration from 1 to 10 mol.% (Nd related to Si) are investigated for the optimum doping concentration. The vinyltriethoxysilane-derived ORMOSIL host matrix is considered to have little effect on spectral properties of Nd3+ ions due to the ligands'' protection. The effect of heat-treatment on photoluminescence properties is also revealed. [Copyright &y& Elsevier]

Abstract: Vinyltriethoxysilane (VTES)-derived ORMOSIL films directly doped with various erbium organic complexes were prepared through a multistep sol–gel process, among which VTES-derived film doped with erbium tris(hexafluoroacetylacetonate)bis(triphenylphosphine oxide) (Er(HFA)3(TPPO)2) exhibited the maximum photoluminescence intensity at 1.53μm as the erbium doping concentration was 5mol%. Moreover, the complex erbium tris(8-hydroxyquinolate) (ErQ3) was in situ synthesized successfully in the VTES-derived film as expected and the film also exhibited comparatively intense 1.53μm luminescence. [Copyright &y& Elsevier]

A water-stable metal-organic framework (MOF) EuNDC has been synthesized for selective detection of the well-known contaminant and toxicant picric acid (PA) in aqueous solution. Due to the photo-induced electron transfer and self-absorption mechanism, EuNDC displayed rapid, selective and sensitive detection of PA with a detection limit of 37.6 ppb. Recyclability experiments revealed that EuNDC retains its initial luminescent intensity and same quenching efficiency in each cycle, suggesting high photostability and reusability for long-term sensing applications. The excellent detection performance of EuNDC makes it a promising PA sensing material for practical applications. [ABSTRACT FROM AUTHOR]

Abstract: A fluorescent chemosensor, ortho-methylated boron-dipyrromethene (o-MBDP) has been synthesized and characterized. It featured excellent selectivity and sensitivity for Ag+ and Hg2+ ions, which could enhance the weak fluorescence of o-MBDP drastically by several hundred times through coordination and as a result, behave as an efficient “turn-on” fluorescent probe. The detection upper limit for Ag+ ion could be decreased by at least one order of magnitude with the introduction of the ortho-methyl group, in comparison with analogous boron-dipyrromethene (BDP) sensors, indicating the feasibility in extensive application areas as chemosensors. [Copyright &y& Elsevier]

Abstract: In this study, the near-infrared luminescence emission of erbium ions is enhanced by 6-folds in intensity with an ion-associated erbium complex consisting of an IR140 dye cation. The energy-transfer process from the IR140 dye cation to the erbium ion has been modeled. Near-infrared luminescence of the erbium ion is sensitized intra-molecularly by the IR140 dye cation effectively, although the residual IR140 dye emission is still observed, indicating an incomplete energy transfer between the IR140 dye cation and the erbium ion. The main path of energy-transfer process is through the T1 → 4I11/2 transition with the operative mechanism to be Förster type. [Copyright &y& Elsevier]

Abstract: Rare earth ternary chelates Ln(TFA)3(TPPO)2 (Ln=Eu, Tb and Eu/Tb) were synthesized in gel glasses via in situ technique. Pure Ln(TFA)3(TPPO)2 chelates were also synthesized for a comparative study. Photoluminescence properties of the in situ chelates in gel glasses and the pure chelates were studied. In order to investigate the energy transfer mechanism from Tb3+ ions to Eu3+ ions in Eu/Tb(TFA)3(TPPO)2 chelates, photoluminescence spectra and fluorescence decay curves have been measured at the temperature range from 10K to 293K. It is found that the energy transfer rate constants calculated from the fluorescence lifetimes do not vary with temperature, which suggests that Dexter mechanism is responsible for the energy transfer from Tb3+ ions to Eu3+ ions in both pure and in situ Eu/Tb ternary chelate. [Copyright &y& Elsevier]

Abstract: Laser dyes such as coumarin 440 (C440) and coumarin 500 (C500) were doped into vinyltriethoxysilane (VTES)-derived organically modified silicates (ORMOSILs) by sol–gel process. The fluorescence properties of these two dyes doped in VTES-derived ORMOSILs with various initial dye concentrations were studied. A longitudinal pumped solid-state dye laser was established with a Q-switched Nd:YAG laser source. The laser performances of C440 and C500 dyes doped in VTES-derived ORMOSILs were also measured. [Copyright &y& Elsevier]

Abstract: Near-infrared (NIR) luminescent ternary and hydrated binary neodymium β-diketonates emitting at ca. 1330 nm are presented. The effects of ligand moieties on the photoluminescence properties of Nd3+ ions are discussed. Moreover, the neodymium organic complex neodymium tris(2-theonyltrifluoroacetonate)bis(triphenylphosphine oxide), Nd(TTA)3(TPPO)2, which has the best photoluminescence properties among all investigated neodymium complexes, is incorporated into vinyltriethoxysilane-derived ORMOSIL (organically modified silicate) film by a multistep sol–gel process. The Nd doping concentration was up to 5 mol% related to Si. The spectroscopic results about as-doped ORMOSIL films indicate that the ligands around Nd3+ ions indeed shield effectively Nd3+ ions from luminescence-quenching impurities in the host matrix, such as OH groups. [Copyright &y& Elsevier]

Abstract: A new rare-earth free phosphor Y2O2S:Ti with long afterglow was synthesized by solid-state reaction. A strong and broad emission band, which is suggested to come from the recombination of trapped electrons in the donating level and holes in the accepting level, was observed under 382nm irradiation with a peak at 565nm. The luminescence intensity and afterglow of the phosphors are enhanced with increase of doped Ti concentration. Furthermore, the best yellow long afterglow for present materials was found in the sample with 9mol% doping Ti content, and its afterglow can last over 5h with recognizable intensity level (0.32mcd/m2) after the removal of the excitation light. [Copyright &y& Elsevier]

Abstract: NaLa(WO4)2 powders doped with Eu3+, Nd3+, and Er3+ have been synthesized by a mild hydrothermal method and a crystal of exclusive scheelite phase could be obtained at low temperature. From the spectrum of Eu3+ it has been concluded that the dopant Eu3+ ion occupies a La3+ site and mainly takes the site with symmetry. The higher quenching concentration can be observed in the Eu3+-doped NaLa(WO4)2 powders. The Er3+- and Nd3+-doped NaLa(WO4)2 powders exhibit luminescence in the near infrared (Er3+ at 1550nm, and Nd3+ at 1060nm). The transition mechanism of the up-conversion luminescence of the Er3+-doped NaLa(WO4)2 powders can be ascribed to two photons absorption process. [Copyright &y& Elsevier]