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Chemical luminescence

Christiane Geithe, Franziska Noe, Johanna Kreissl, Dietmar Krautwurst
Key food odorants are the most relevant determinants by which we detect, recognize, and hedonically evaluate the aroma of foods and beverages. Odorants are detected by our chemical sense of olfaction, comprising a set of approximately 400 different odorant receptor types. However, the specific receptor activity patterns representing the aroma percepts of foods or beverages, as well as the key food odorant agonist profiles of single-odorant receptors, are largely unknown. We aimed to establish comprehensive key food odorant agonist profiles of 2 unrelated, broadly tuned receptors, OR1A1 and OR2W1, that had been associated thus far with mostly non-key food odorants and shared some of these agonists...
December 4, 2016: Chemical Senses
Stephan Sinn, Frank Biedermann, Luisa De Cola
A reactive phosphorescent probe for aza-heterocyclic drugs and toxins was developed, affording a supramolecular emission-switch-on chemosensor in water. Complex formation of the heterocycles with a platinum(II) precursor proceeds readily at ambient conditions, allowing for facile analyte screening. 52 structurally diverse compounds were tested, out of which 23 pyridines, imidazole, and triazoles formed strongly emissive complex aggregates. Importantly, they all can be clearly distinguished from each other through a principal component analysis, but often already by simple visual inspection, e...
December 1, 2016: Chemistry: a European Journal
Yujin Cho, Benjamin Dierre, Takashi Sekiguchi, Takayuki Suehiro, Kohsei Takahashi, Takashi Takeda, Rong-Jun Xie, Yoshinobu Yamamoto, Naoto Hirosaki
Nitride and oxynitride (Sialon) phosphors are good candidates for the ultraviolet and visible emission applications. High performance, good stability and flexibility of their emission properties can be achieved by controlling their composition and dopants. However, a lot of work is still required to improve their properties and to reduce the production cost. A possible approach is to correlate the luminescence properties of the Sialon particles with their local structural and chemical environment in order to optimize their growth parameters and find novel phosphors...
November 15, 2016: Journal of Visualized Experiments: JoVE
G Deokar, N S Rajput, P Vancsó, F Ravaux, M Jouiad, D Vignaud, F Cecchet, J-F Colomer
Vertically aligned MoS2 nanosheets (NSs) with exposed edges were successfully synthesized over a large area (∼2 cm(2)). The NSs were grown using an ambient pressure chemical vapor deposition technique via rapid sulfurization of sputter deposited thick molybdenum films. Extensive characterization of the grown MoS2 NSs has been carried out using high resolution scanning and transmission electron microscopy (SEM & TEM). A special care was given to the TEM lamella preparation process by means of a focused ion beam to preserve the NS growth direction...
December 1, 2016: Nanoscale
Mohsen Nami, Rhett F Eller, Serdal Okur, Ashwin K Rishinaramangalam, Sheng Liu, Igal Brener, Daniel F Feezell
Controlled bottom-up selective-area epitaxy (SAE) is used to tailor the morphology and photoluminescence properties of GaN/InGaN core-shell nanowire arrays. The nanowires are grown on c-plane sapphire substrates using pulsed-mode metal organic chemical vapor deposition. By varying the dielectric mask configuration and growth conditions, we achieve GaN nanowire cores with diameters ranging from 80 to 700 nm that exhibit various degrees of polar, semipolar, and nonpolar faceting. A single InGaN quantum well (QW) and GaN barrier shell is also grown on the GaN nanowire cores and micro-photoluminescence is obtained and analyzed for a variety of nanowire dimensions, array pitch spacings, and aperture diameters...
December 1, 2016: Nanotechnology
Aldo Roda, Hua Cui, Chao Lu
No abstract text is available yet for this article.
December 2016: Analytical and Bioanalytical Chemistry
Shuwen Zhao, Donglin Xia, Ruimin Zhao, Hao Zhu, Yiru Zhu, Yuda Xiong, Youfa Wang
Hexagonal-phase NaGdF4: Yb, Er upconversion nanocrystals (UCNCs) with tunable morphology and properties were successfully prepared via a thermal decomposition method. The influences of the adding sequence of the precursors on the morphology, chemical composition, luminescence and magnetic properties were investigated by transmission electron microscopy (TEM), inductively coupled plasma-atomic emission spectrometry (ICP-AES), upconversion (UC) spectroscopy, and a vibrating sample magnetometer (VSM). It was found that the resulting nanocrystals, with different sizes ranging from 24 to 224 nm, are in the shape of spheres,  hexagonal plates and flakes; moreover, the composition percentage of Yb(3+)-Er(3+) and Gd(3+) ions was found to vary in a regular pattern with the adding sequence...
January 6, 2017: Nanotechnology
Yan-Yuan Jia, Xiao-Ting Liu, Wen-He Wang, Li-Zhu Zhang, Ying-Hui Zhang, Xian-He Bu
Metal-organic frameworks (MOFs) are typically built by assembly of metal centres and organic linkers, and have emerged as promising crystalline materials in a variety of fields. However, the stability of MOFs is a key limitation for their practical applications. Herein, we report a novel Sr 2+: -MOF [Sr4(Tdada)2(H2O)3(DMF)2] (denoted as NKU- 105: , NKU = Nankai University; H4Tdada = 5,5'-((thiophene-2,5-dicar bonyl)bis(azanediyl))diisophthalic acid; DMF = N,N-dimethylformamide) featuring an open square channel of about 6 Å along the c-axis...
January 13, 2017: Philosophical Transactions. Series A, Mathematical, Physical, and Engineering Sciences
Petr Masner, Barbora Javůrková, Luděk Bláha
The present study demonstrates development of a rapid testing protocol based on a small portable luminometer using flash kinetic assessment of bacterial bioluminescence. The laboratory comparisons based on six model organic toxicants and two metals showed significant correlations between responses of freshwater bacteria Photorhabdus luminescens and standard marine bacterial species Vibrio fisheri. While P. luminescens was less sensitive in standard arrangements, the responses of both organisms were comparable in the newly introduced portable luminometer setup...
November 26, 2016: Environmental Science and Pollution Research International
Johann Bosson, Geraldine M Labrador, Simon Pascal, François-Alexandre Miannay, Oleksandr Yushchenko, Haidong Li, Laurent Bouffier, Neso Sojic, Roberto C Tovar, Gilles Muller, Denis Jacquemin, Adèle D Laurent, Boris Le Guennic, Eric Vauthey, Jérôme Lacour
The physicochemical properties of cationic dioxa (1), azaoxa (2), and diaza (3) [6]helicenes demonstrate a much higher chemical stability of the diaza adduct 3 (pKR+ =20.4, Ered1/2 =-0.72 V) compared to its azaoxa 2 (pKR+ =15.2, Ered1/2 =-0.45 V) and dioxa 1 (pKR+ =8.8, Ered1/2 =-0.12 V) analogues. The fluorescence of these cationic chromophores is established, and ranges from the orange to the far-red regions. From 1 to 3, a bathochromic shift of the lowest energy transitions (up to 614 nm in acetonitrile) and an enhancement of the fluorescence quantum yields and lifetimes (up to 31 % and 9...
November 25, 2016: Chemistry: a European Journal
Miaofei Meng, Xiying Ma
We investigated the surface morphologies, crystal structures, and optical characteristics of rare earth element erbium (Er)-doped MoS2 (Er: MoS2) thin films fabricated on Si substrates via chemical vapor deposition (CVD). The surface mopography, crystalline structure, light absorption property, and the photoelectronic characteristics of the Er: MoS2 films were studied. The results indicate that doping makes the crystallinity of MoS2 films better than that of the undoped film. Meanwhile, the electron mobility and conductivity of the Er-doped MoS2 films increase about one order of magnitude, and the current-voltage (I-V) and the photoelectric response characteristics of the Er:MoS2/Si heterojunction increase significantly...
December 2016: Nanoscale Research Letters
Zhengrong Yao, Kun Tang, Zhonghua Xu, Jiandong Ye, Shunming Zhu, Shulin Gu
Vertically aligned N-doped ZnO microrods with a hexagonal symmetry were fabricated via the chemical vapor transport with abundant N2O as both O and N precursors. We have demonstrated the suppression of the zinc interstitial-related shallow donor defects and have identified the zinc vacancy-related shallow and deep acceptor states by temperature variable photoluminescence in O-rich growth environment. Through spatially resolved cathodoluminescence spectra, we found the luminescent inhomogeneity in the sample with a core-shell structure...
December 2016: Nanoscale Research Letters
Soma Mukherjee, Shrabani Talukder
A new coumarin based chemosensor has been developed for selective fluorescent recognition of Cu(2+) in MeOH/H2O (4:1, v/v at pH = 7.2 aqueous solution) medium with 1:1 binding stoichiometry. The in-situ prepared Cu(2+) complex displays high selectivity towards CN(-) via Cu(2+) displacement approach with detection limit in the micro molar range. Moreover, in presence of Cu(2+), the receptor exhibits reversible emission change with EDTA and thus offers an interesting property of molecular 'IMPLICATION' logic gate with Cu(2+) and EDTA as chemical inputs...
November 22, 2016: Journal of Fluorescence
Marte van der Linden, Arjan Barendregt, Arnoldus J van Bunningen, Patrick T K Chin, Dominique Thies-Weesie, Frank M F de Groot, Andries Meijerink
Luminescent Ag clusters are prepared with lipoic acid (LA) as the ligand. Using a combination of mass spectrometry, optical spectroscopy and analytical ultracentrifugation, the clusters are found to be highly monodisperse with mass 5.6 kDa. We assign the chemical composition [Ag29(LA)12](3-) to the clusters, where LA likely binds in a bidentate fashion. The Ag29 clusters show slow degradation, retaining their deep red emission for at least 18 months if stored in the dark. Purification or exposure to light results in faster degradation...
December 1, 2016: Nanoscale
Thomas Lécuyer, Eliott Teston, Gonzalo Ramirez-Garcia, Thomas Maldiney, Bruno Viana, Johanne Seguin, Nathalie Mignet, Daniel Scherman, Cyrille Richard
Imaging nanoprobes are a group of nanosized agents developed for providing improved contrast for bioimaging. Among various imaging probes, optical sensors capable of following biological events or progresses at the cellular and molecular levels are actually actively developed for early detection, accurate diagnosis, and monitoring of the treatment of diseases. The optical activities of nanoprobes can be tuned on demand by chemists by engineering their composition, size and surface nature. This review will focus on researches devoted to the conception of nanoprobes with particular optical properties, called persistent luminescence, and their use as new powerful bioimaging agents in preclinical assays...
2016: Theranostics
Zhanjun Li, Yuanwei Zhang, Ling Huang, Yuchen Yang, Yang Zhao, Ghida El-Banna, Gang Han
Calcium Fluoride (CaF2) based luminescent nanoparticles exhibit unique, outstanding luminescent properties, and represent promising candidates as nanoplatforms for theranostic applications. There is an urgent need to facilitate their further development and applications in diagnostics and therapeutics as a novel class of nanotools. Here, in this critical review, we outlined the recent significant progresses made in CaF2-related nanoparticles: Firstly, their physical chemical properties, synthesis chemistry, and nanostructure fabrication are summarized...
2016: Theranostics
Carolin Martina Kobras, Thorsten Mascher, Susanne Gebhard
Whole-cell biosensors, based on the visualization of a reporter strain's response to a particular stimulus, are a robust and cost-effective means to monitor defined environmental conditions or the presence of chemical compounds. One specific field in which such biosensors are frequently applied is drug discovery, i.e., the screening of large numbers of bacterial or fungal strains for the production of antimicrobial compounds. We here describe the application of a luminescence-based Bacillus subtilis biosensor for the discovery of cell wall active substances...
2017: Methods in Molecular Biology
Shanshan Li, Li Zhou, Yongpeng Yao, Keqiang Fan, Zilong Li, Lixin Zhang, Weishan Wang, Keqian Yang
A wide range of chemicals can be sensed by allosteric transcription factors (aTFs) in bacteria. Herein, we report a biosensing platform by using isolated aTFs as recognition elements in vitro. Moreover, a general strategy to increase the sensitivity of the aTF-based biosensors is provided. As a proof-of-concept, we obtained by far the most sensitive uric acid and oxytetracycline biosensors by using aTF HucR and OtrR as recognition elements, respectively. As a large number of aTFs are present in bacteria, our work opens a novel route to develop sensitive aTF-based biosensors...
November 21, 2016: Chemical Communications: Chem Comm
H -Y He
This work presents the manufacture and potential application of the ZnO materials with various cation dopings in recent literature and patents and then focus on La codoping effects of Al-doped ZnO films were studied. The films were deposited by a chemical solution deposition and characterized by X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, UV-vis and luminescent spectrophotometries, and electrical measurement. The films showed nanoscale particle size increased as the increase in La/Al ratio...
September 29, 2016: Recent Patents on Nanotechnology
Qiwen Pan, Dandan Yang, Shiliang Kang, Jianrong Qiu, Guoping Dong
Rare earth doped mid-infrared (MIR) fluorescent sources have been widely investigated due to their various potential applications in the fields of communication, chemical detecting, medical surgery and so forth. However, with emission wavelength extended to MIR, multiphonon relaxation process that strongly quenched the MIR emission is one of the greatest challenges for such practical applications. In our design, we have described a controllable gas-aided annealing strategy to modulate the phase, crystal size, morphology and fluorescent performance of a material simultaneously...
November 15, 2016: Scientific Reports
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