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Chemical luminescence

Valeriy M Yashchuk, Vladislav Yu Kudrya
This paper summarizes the results of studies of the spectral properties-optical absorption, fluorescence and phosphorescence-of DNA and RNA macromolecules and synthetic poly-, oligo- and mono-nucleotides, which have been carried out in our laboratory. The system of first excited singlet and triplet energy levels for DNA and RNA is evaluated using low-temperature (4.2 K-77 K) luminescent measurements. The traps of the singlet and triplet electronic excitations in these compounds are identified. An important self-protection mechanism against photo-damage of DNA and RNA by UV photons or penetrative radiation based on the capture of triplet electronic-energy excitations by the most photostable centers-in DNA, the complex formed by neighboring adenosine (A) and thymidine (T) links; in RNA, the adenosine links-is described...
January 18, 2017: Methods and Applications in Fluorescence
Tobias Wimmer, Eva Schroeter, Birgit Lorenz, Knut Stieger
In this paper we describe a two-component BRET (bioluminescence resonance energy transfer)-based method to detect vascular endothelial growth factor (VEGF) molecules in unknown samples as the basis for subsequent in vivo use. A luminescent VEGF binding molecule, which binds in the receptor binding motif of VEGF, is used as the energy donor, transferred to a fluorophore-coupled VEGF binding molecule (acceptor), which binds to the neuropilin binding motif of VEGF, thus enabling energy transfer from the donor to the acceptor molecule...
January 13, 2017: Sensors
Yao Yao, Cheng-Shuai Jiang, Na Sun, Wei-Qi Li, Yang Niu, Huai-Qin Han, Zhen-Hua Miao, Xun-Xia Zhao, Jing Zhao, Juan Li
Chemical investigation of Tamarix ramosissima Ledeb, a traditional herbal medicine used for rheumatoid arthritis (RA) treatment in northwest China, led to the discovery of a new phenolic aromatic rings substituted lactam, tamaractam (1), together with the previously reported compounds cis-N-feruloyl-3-O-methyldopamine (2) and trans-N-feruloyl-3-O-methyldopamine (3). The structures of the compounds were determined by high resolution electrospray ionization mass spectroscopy (HRESIMS) and 1D and 2D-NMR experiments, as well as comparison with the literature data...
January 10, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Maximilian Krämer, Uwe H F Bunz, Andreas Dreuw
Diphenylacetylene (tolane) exhibits a rich photochemistry which depends on the relative orientation of the phenyl rings and the external conditions. Here state-of-the-art quantum chemical methods based on the algebraic diagrammatic construction scheme for the polarization propagator of second order are employed to investigate the luminescence properties of tolane and its derivatives. It is explained why different derivatives of tolane exhibit different absorbtion but practically identical fluorescence spectra, why the fluorescence quantum yield and the population of a "dark" state is temperature dependent and why initially twisted tolanophanes phosphoresce in glassy media at 77K while planar ones do not...
January 6, 2017: Journal of Physical Chemistry. A
Katsunori Teranishi
The chemical mechanisms underlying visible bioluminescence in the fungus Mycena chlorophos are not clear. A combination of dihydronicotinamide adenine dinucleotide phosphate (NADPH) and hispidin, which has been reported to increase the intensity of in vitro luminescence in crude cold-water extracts prepared from the bioluminescent fruiting bodies of M. chlorophos, exhibited potential bioluminescence activation in the early bioluminescence stages, in which the bioluminescence was ultra-weak, for living gills and luminescence activation for non-bioluminescent gills, which was collapsed by freezing and subsequent thawing, at all bioluminescence stages...
January 5, 2017: Luminescence: the Journal of Biological and Chemical Luminescence
Linna Pang, LIxiang Ba, Wei Pan, Wenzhong Shen
Carbon nanodots (C-dots) have attracted great attention for their biocompatibility and strong tunable photoluminescence (PL). However, aggregation-induced PL quenching blocks their practical application in solid-state optoelectronics. Here, we report a luminescent C-dots freestanding film with a substantially enhanced high quantum yield (QY) of 72.3%. A facile template method, rather than complicate lithography and etching technique is proposed to fabricate the C-dots composite films with large-area (8 inch  8 inch) ordered micro-scale inverted-pyramid patterns on the surface...
January 5, 2017: Nanotechnology
Alexandra A P Mansur, Fernanda G de Carvalho, Rafael L Mansur, Sandhra M Carvalho, Luiz Carlos de Oliveira, Herman S Mansur
In this study, it is reported the use of sodium carboxymethyl cellulose (CMCel) as a multifunctional biocompatible polysaccharide for the direct synthesis of fluorescent alloyed-ZnCdS quantum dot (QD) nanoconjugates via aqueous "green" process at room temperature. The nanoconjugates were extensively characterized by spectroscopical (NMR, FTIR, UV-vis, PL) and morphological techniques (DLS, TEM) for accessing their structural and physicochemical properties associated with X-ray photoelectron spectroscopy (XPS) for surface and interface analysis...
December 31, 2016: International Journal of Biological Macromolecules
Erin Wachter, Diego Moyá, Edith C Glazer
A chemically reactive Ru(II) "building block", able to undergo condensation reactions with substituted diamines, was utilized to create a small library of luminescent "light switch" dipyrido-[3,2-a:2',3'-c] phenazine (dppz) complexes. The impact of substituent identity, position, and the number of substituents on the light switch effect was investigated. An unbiased, parallel screening approach was used to evaluate the selectivity of the compounds for a variety of different biomolecules, including protein, nucleosides, single stranded DNA, duplex DNA, triplex DNA, and G-quadruplex DNA...
December 28, 2016: ACS Combinatorial Science
Qing Wan, Meiying Liu, Liucheng Mao, Ruming Jiang, Dazhuang Xu, Hongye Huang, Yanfeng Dai, Fengjie Deng, Xiaoyong Zhang, Yen Wei
Self-assembly of amphiphilic luminescent copolymers is a general route to fabricate fluorescent polymeric microparticles (FPMs). In this work, the FPMs with aggregation-induced emission (AIE) feature were fabricated via the combination of the chain transfer free radical polymerization and "one-pot" multicomponent reaction, which conjugated the aldehyde-containing AIE active dye AIE (CHO-An-CHO) and amino-terminated hydrophilic polymer (ATPPEGMA) using mercaptoacetic acid (MTA) as the "lock" molecule. The structure, chemical compositions, optical properties as well as biological properties of the PPEGMA-An-PPEGMA FPMs were characterized and investigated by means of a series of techniques and experiments in detail...
March 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
N Bouazizi, T Boudharaa, R Bargougui, J Vieillard, S Ammar, F Le Derf, A Azzouz
In this paper, a new synthetic strategy towards functionalized ZnO-HMD@ZnO-Fe/Cu core-shell using sol-gel process modified by chemical grafting of hexamethylenediamine (HMD) on the core and in-situ dispersion of Cu(0)/Fe(0) as metallic nanoparticles (M-NPs) on the shell. The as-prepared core-shell materials were fully characterized by transmission electron microscopy, X-ray powder diffractometry, diffuse reflectance and FT-IR spectrophotometery, photoluminescence, and complexes impedance spectroscopy measurements...
December 18, 2016: Journal of Colloid and Interface Science
Chang Seop Hong, Kwang Soo Lim, So Yeon Jeong, Dong Won Kang, Jeong Hwa Song, Hyuna Jo, Woo Ram Lee, Won Ju Phang, Dohyun Moon
With regard to the fluorescence quenching commonly observed during metal ion detection, "turn-on" chemical sensing has been rarely reported but could be extremely important because it facilitates the selective recognition of target objects of interest against a dark background. We prepared a metal-organic framework (MOF) chemosensor that serves as an efficient platform for the selective detection of Cu2+ and Cd2+ ions over other metal ions. In particular, this framework shows the highest fluorescence enhancement (~60 fold relative to Cd-free MOF) for the hazardous metal ion Cd2+ among luminescent MOFs and displays excellent reusability in repeated cycles...
December 23, 2016: Chemistry: a European Journal
M Latzel, P Büttner, G Sarau, K Höflich, M Heilmann, W Chen, X Wen, G Conibeer, S H Christiansen
Nanotextured surfaces provide an ideal platform for efficiently capturing and emitting light. However, the increased surface area in combination with surface defects induced by nanostructuring e.g. using reactive ion etching (RIE) negatively affects the device's active region and, thus, drastically decreases device performance. In this work, the influence of structural defects and surface states on the optical and electrical performance of InGaN/GaN nanorod (NR) light emitting diodes (LEDs) fabricated by top-down RIE of c-plane GaN with InGaN quantum wells was investigated...
February 3, 2017: Nanotechnology
Paulo C de Sousa Filho, Eric Larquet, Diana Dragoë, Osvaldo A Serra, Thierry Gacoin
Rare earth (RE) phosphates and vanadates are structurally similar compositions that display distinct but complementary luminescent properties. The properties of these phosphors can be combined in REPO4-REVO4 heterostructures during the development of new sensing technologies for biological applications. This work presents the synthesis of hollow RE phosphate/vanadate colloidal particles and evaluates their applicability as luminescent markers. Hydrothermal treatments of RE hydroxycarbonate particles in the presence of the PO4(3-) and VO4(3-) precursors afforded the final REPO4-REVO4 solids in a two-step template synthesis...
January 18, 2017: ACS Applied Materials & Interfaces
Shanyuan Niu, Huaixun Huyan, Yang Liu, Matthew Yeung, Kevin Ye, Louis Blankemeier, Thomas Orvis, Debarghya Sarkar, David J Singh, Rehan Kapadia, Jayakanth Ravichandran
Transition metal perovskite chalcogenides are a new class of versatile semiconductors with high absorption coefficient and luminescence efficiency. Polycrystalline materials synthesized by an iodine-catalyzed solid state reaction show distinctive optical colors and tunable bandgaps across the visible range in photoluminescence, with one of materials' external efficiency approaching the level of single crystal InP and CdSe.
December 22, 2016: Advanced Materials
Dario Cambié, Fang Zhao, Volker Hessel, Michael G Debije, Timothy Noël
The use of solar light to promote chemical reactions holds significant potential with regard to sustainable energy solutions. While the number of visible light-induced transformations has increased significantly, the use of abundant solar light has been extremely limited. We report a leaf-inspired photomicroreactor that constitutes a merger between luminescent solar concentrators (LSCs) and flow photochemistry to enable green and efficient reactions powered by solar irradiation. This device based on fluorescent dye-doped polydimethylsiloxane collects sunlight, focuses the energy to a narrow wavelength region, and then transports that energy to embedded microchannels where the flowing reactants are converted...
December 22, 2016: Angewandte Chemie
Malak Safi, Tatiana Domitrovic, Anshika Kapur, Naiqian Zhan, Fadi Aldeek, John E Johnson, Hedi Mattoussi
We describe a new quantum dot (QD)-conjugate prepared with a lytic peptide, derived from a nonenveloped virus capsid protein, capable of bypassing the endocytotic pathways and delivering large amounts of QDs to living cells. The polypeptide, derived from the Nudaurelia capensis Omega virus, was fused onto the C-terminus of maltose binding protein that contained a hexa-HIS tag at its N-terminus, allowing spontaneous self-assembly of controlled numbers of the fusion protein per QD via metal-HIS interactions. We found that the efficacy of uptake by several mammalian cell lines was substantial even for small concentrations (10-100 nM)...
January 18, 2017: Bioconjugate Chemistry
Júlia C Soares, Kisla P F Siqueira, Paulo C de Sousa Filho, Roberto L Moreira, Anderson Dias
PrLuO3 interlanthanides were prepared at temperatures ranging from 800 °C to 1600 °C using hydrothermally-derived precursors. The chemical reactions observed include the conversion and segregation of Pr(OH)3 and LuO(OH), respectively, into PrO2 and Lu2O3 cubic oxides below 1200 °C, followed by the production of a mixture of hexagonal P63/mmc and orthorhombic Pnma PrLuO3 phases at 1400 °C. Phase-pure orthorhombic PrLuO3 was obtained at 1600 °C, which was corroborated by Raman and micro far-infrared spectroscopic analyses...
December 21, 2016: Dalton Transactions: An International Journal of Inorganic Chemistry
Alejandro Mitrani Viggiano, José Luis Ruvalcaba Sil, Mayra D Manrique Ortega, Victoria Corregidor Berdasco
Jadeite was greatly appreciated by pre-Hispanic cultures in Mesoamerica. Despite its importance, knowledge of its mining sources was lost after the Spanish conquest. In the 1950s the only confirmed jadeite deposits in Mesoamerica were found in the Motagua River Fault (MRF), Guatemala. The aim of this study is to present a methodology that is appropriate for the study of archeological jadeite objects using non-destructive spectroscopic and micro-ion beam analysis techniques. This methodology has been applied to perform mineral, elemental, and luminescence characterization of five jadeite samples from the MRF, with white, lilac, and green colors...
December 2016: Microscopy and Microanalysis
Joris J Snellenburg, Sergey P Laptenok, Richard J DeSa, Panče Naumov, Kyril M Solntsev
The color variations of light emitted by some natural and mutant luciferases are normally attributed to collective factors referred to as microenvironment effects; however, the exact nature of these interactions between the emitting molecule (oxyluciferin) and the active site remains elusive. Although model studies of noncomplexed oxyluciferin and its variants have greatly advanced the understanding of its photochemistry, extrapolation of the conclusions to the real system requires assumptions about the polarity and proticity of the active site...
December 21, 2016: Journal of the American Chemical Society
Youngjin Jang, Arthur Shapiro, Maya Isarov, Anna Rubin-Brusilovski, Aron Safran, Adam K Budniak, Faris Horani, Joanna Dehnel, Aldona Sashchiuk, Efrat Lifshitz
Semiconductor colloidal quantum dots (CQDs) have attracted vast scientific and technological interest throughout the past three decades, due to the unique tuneability of their optoelectronic properties by variation of size and composition. However, the nanoscale size brings about a large surface-to-bulk volume ratio, where exterior surfaces have a pronounced influence on the chemical stability and on the physical properties of the semiconductor. Therefore, numerous approaches have been developed to gain efficient surface passivation, including a coverage by organic or inorganic molecular surfactants as well as the formation of core/shell heterostructures (a semiconductor core epitaxially covered by another semiconductor shell)...
December 20, 2016: Chemical Communications: Chem Comm
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