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Chemical luminescence

Johan Borglin, Robert Selegård, Daniel Aili, Marica B Ericson
There is a need for biochemical contrast mediators with high signal to noise ratios enabling non-invasive biomedical sensing, e.g., for neural sensing, protein-protein interactions, in addition to cancer diagnostics. The translational challenge is to develop a biocompatible approach ensuring high biochemical contrast while avoiding a raise of the background signal. We here present a concept where gold nanoparticles (AuNPs) can be utilized as a stimuli responsive contrast medium by chemically triggering their ability to exhibit multiphoton induced luminescence (MIL) when performing multi-photon laser scanning microscopy (MPM)...
February 20, 2017: Nano Letters
Tian A Qiu, Thu Ha Thi Nguyen, Natalie V Hudson-Smith, Peter L Clement, Dona-Carla Forester, Hilena Frew, Mimi N Hang, Catherine J Murphy, Robert J Hamers, Z Vivian Feng, Christy L Haynes
Current high-throughput approaches evaluating toxicity of chemical agents toward bacteria typically rely on optical assays, such as luminescence and absorbance, to probe the viability of the bacteria. However, when applied to toxicity induced by nanomaterials, scattering and absorbance from the nanomaterials act as interferences that complicate quantitative analysis. Herein, we describe a bacterial viability assay that is free of optical interference from nanomaterials and can be performed in a high-throughput format on 96-well plates...
February 7, 2017: Analytical Chemistry
Bhavesh Parmar, Yadagiri Rachuri, Kamal Kumar Bisht, Ridhdhi Laiya, Eringathodi Suresh
Isostructural Zn(II)/Cd(II) mixed ligand coordination polymers (CPs) {[M(IPA)(L)]}n (CP1 and CP2) built from isophthalic acid (H2IPA) and 3-pyridylcarboxaldehyde nicotinoylhydrazone (L) were prepared using versatile synthetic routes: viz., diffusion of precursor solutions, conventional reflux methods, and green mechanochemical (grinding) reactions. Both robust CPs synthesized by different routes were characterized by various analytical methods, and their thermal and chemical stability as well as the phase purity was established...
February 16, 2017: Inorganic Chemistry
Cloé Azarias, Roberto Russo, Lorenzo Cupellini, Benedetta Mennucci, Denis Jacquemin
The excitation energy transfer (EET) allowing the concentration of the energy has been investigated in several multi-BODIPY architectures with the help of an approach coupling time dependent density functional theory to an implicit solvation scheme, the polarizable continuum model. We have first considered several strategies to compute the electronic coupling in a dyad varying the size of the donor/acceptor units, the bridge, the geometries and conformations. We have next studied the electronic coupling in three different architectures for which the EET rate constants have been experimentally measured both from luminescence and transient absorption data and from Förster theory...
February 15, 2017: Physical Chemistry Chemical Physics: PCCP
Milla Högmander, Catherine J Paul, Sandy Chan, Elina Hokkanen, Ville Eskonen, Tapio Pahikkala, Sari Pihlasalo
Methods for simple and fast detection and differentiation of bacterial species are required, for instance, in medicine, water quality monitoring, and the food industry. Here, we have developed a novel label array method for the counting and differentiation of bacterial species. This method is based on the nonspecific interactions of multiple unstable lanthanide chelates and selected chemicals within the sample leading to a luminescence signal profile that is unique to the bacterial species. It is simple, cost-effective, and/or user-friendly compared to many existing methods, such as plate counts on selective media, automatic (hemocytometer-based) cell counters, flow cytometry, and polymerase chain reaction (PCR)-based methods for identification...
February 20, 2017: Analytical Chemistry
Yan Zhou, Fenghe Wang, Jinzhong Wan, Jian He, Qun Li, Qiang Chen, Jay Gao, Yusuo Lin, Shengtian Zhang
Traditionally, the toxicity of river contaminants is analyzed chemically or physically through river bed sediments. The biotoxicity of polluted sediment leachates has not caught our attention. This study aims to overcome this deficiency through a battery of biotests which were conducted to monitor comprehensive toxicity of sediment leachates for the Yaogang River in East Jiangsu Province of China, which is in close proximity to former pesticide plants. The general physical and chemical parameters of major pollutants were analyzed from river bed sediments collected at five strategic locations...
February 13, 2017: Environmental Science and Pollution Research International
Jinhui Zhang, Shuming Gong, Jinbo Yu, Peng Li, Xuejie Zhang, Yuwei He, Jianbang Zhou, Rui Shi, Huanrong Li, Aiyun Peng, Jing Wang
Nowadays, it is still a great challenge for lanthanide complexes to be applied in solid state lighting, especially for high-power LEDs because they will suffer severe thermal-induced luminescence quenching and transmittance loss when LEDs are operated at high current. In this paper, we have not only obtained high efficient and thermally chemical stable red emitting hybrid material by introducing europium complex into nanozeolite (NZ) functionalized with the imidazolium-based stopper but also abated its thermal-induced transmittance loss and luminescence quenching behavior via coating it onto a heat-resistant luminescent glass (LG) with high thermal conductivity (1...
February 17, 2017: ACS Applied Materials & Interfaces
Hülya Karaca Gençer, Serkan Levent, Ulviye Acar Çevik, Yusuf Özkay, Sinem Ilgın
Owing to the growing need for novel antibacterial agents, we synthesized a novel series of fluoroquinolones including 7-substituted-1-(2,4-difluorophenyl)-6-fluoro-4-oxo-1,4-dihydro[1,8]naphthyridine-3-carboxylic acid derivatives, which were tested against clinically relevant Gram positive and Gram negative bacteria. Chemical structures of the synthesized compounds were identified using spectroscopic methods. In vitro antimicrobial effects of the compounds were determined via microdilution assay. Microbiological examination revealed that compounds 13 and 14 possess a good antibacterial profile...
January 26, 2017: Bioorganic & Medicinal Chemistry Letters
Xin Zhang, Zhong-Jie Wang, Shu-Guang Chen, Zhen-Zhen Shi, Jin-Xi Chen, He-Gen Zheng
Four Cd(ii)-based compounds (1-4) were synthesized from solvothermal reactions involving the in situ aldimine condensation of an o-diamino-functionalized precursor 3,6-di(4H-imidazol-4-yl)benzene-1,2-diamine (L), Cd(NO3)2·4H2O and aldehyde. Two modes of cycloaddition ([4 + 1] cycloaddition and [4 + 2] cycloaddition) occurred during condensation, causing the in situ generation of two benzimidazole derivative ligands (L1 and L3) and a quinoxaline derivative ligand (L2). Furthermore, the chemical selectivity of the condensation was studied, where the condensation of o-diamino and the aldehyde is more stable and easy to operate...
January 31, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
Yun-Jian Li, Yu-Ling Wang, Qing-Yan Liu
The highly odd-numbered 15-connected nonanuclear [Ln9(μ3-O)2(μ3-OH)12(O2C-)12(HCO2)3] and 9-connected trinuclear [Ln3(μ3-O)(O2C-)6(HCO2)3] lanthanide-carboxylate clusters with triangular and linear carboxylate bridging ligands were synergistically combined into Ln-MOFs, [(CH3)2NH2]3{[Ln9(μ3-O)2(μ3-OH)12(H2O)6][Ln3(μ3-O)(H2O)3](HCO2)3(BTB)6}·(solvent)x (abbreviated as JXNU-3, Ln = Gd, Tb, Er; BTB(3-) = benzene-1,3,5-tris(4-benzoate)), displaying a (3,9,15)-connected topological net. The JXNU-3(Tb) exhibits highly selective CO2 adsorption capacity over CH4 that resulted from the high localized charge density induced by the presence of the nonanuclear and trinuclear cluster units...
February 20, 2017: Inorganic Chemistry
Massimo Baroncini, Monica Semeraro, Alberto Credi
Nonlinear input-output relations are at the basis of the regulation of biochemical processes in living organisms and are important for the development of digital logic circuits based on molecules. In this article we show that a linear change of a chemical input can be translated into an exponential change of a luminescence output in a simple fluorescent acid-base switch based on 8-methoxyquinoline. Such an unconventional behaviour arises from the fact that part of the light emitted by the switch in its basic form is reabsorbed by the acid form, and is made possible by the particular spectroscopic properties of the two forms...
January 30, 2017: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
Peta A Neale, Frederic D L Leusch, Beate I Escher
Pharmaceuticals and antibiotics co-occur in the aquatic environment but mixture studies to date have mainly focused on pharmaceuticals alone or antibiotics alone, although differences in mode of action may lead to different effects in mixtures. In this study we used the Bacterial Luminescence Toxicity Screen (BLT-Screen) after acute (0.5 h) and chronic (16 h) exposure to evaluate how non-specifically acting pharmaceuticals and specifically acting antibiotics act together in mixtures. Three models were applied to predict mixture toxicity including concentration addition, independent action and the two-step prediction (TSP) model, which groups similarly acting chemicals together using concentration addition, followed by independent action to combine the two groups...
January 5, 2017: Chemosphere
Alaa A Fadhel, Madeleine Johnson, Khang Trieu, Eda Koculi, Andres D Campiglia
A novel sensing approach is presented for the analysis of phosphate ions in human urine samples. The new sensor is based on the fluorescence energy transfer between a luminescent probe ([Tb-EDTA](-1)) and gold nanoparticles capped with a cetyltrimethylammonium bromide (Au NPs-CTAB). The strong affinity between CTAB receptors and phosphate ions results in a highly selective assay with minimum sample preparation steps. Possible chemical interference is monitored on real-time basis via luminescence lifetime analysis...
March 1, 2017: Talanta
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 that 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 a 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 absorption but practically identical fluorescence spectra, why the fluorescence quantum yield and the population of a "dark" state are temperature-dependent, and why initially twisted tolanophanes phosphoresce in glassy media at 77 K while planar ones do not...
February 9, 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
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