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Chemical luminescence

K R Krishnadas, Ananya Baksi, Atanu Ghosh, Ganapati Natarajan, Anirban Som, Thalappil Pradeep
Nanoparticles exhibit a rich variety in terms of structure, composition, and properties. However, reactions between them remain largely unexplored. In this Account, we discuss an emerging aspect of nanomaterials chemistry, namely, interparticle reactions in solution phase, similar to reactions between molecules, involving atomically precise noble metal clusters. A brief historical account of the developments, starting from the bare, gas phase clusters, which led to the synthesis of atomically precise monolayer protected clusters in solution, is presented first...
July 20, 2017: Accounts of Chemical Research
Pia Gruber, Marco P C Marques, Nicolas Szita, Torsten Mayr
The quantification of key variables such as oxygen, pH, carbon dioxide, glucose, and temperature provides essential information for biological and biotechnological applications and their development. Microfluidic devices offer an opportunity to accelerate research and development in these areas due to their small scale, and the fine control over the microenvironment, provided that these key variables can be measured. Optical sensors are well-suited for this task. They offer non-invasive and non-destructive monitoring of the mentioned variables, and the establishment of time-course profiles without the need for sampling from the microfluidic devices...
July 20, 2017: Lab on a Chip
Jyun-Liang Lin, James M Wagner, Hal S Alper
Within the Design-Build-Test Cycle for strain engineering, rapid product detection and selection strategies remain challenging and limit overall throughput. Here we summarize a wide variety of modalities that transduce chemical concentrations into easily measured absorbance, luminescence, and fluorescence signals. Specifically, we cover protein-based biosensors (including transcription factors), nucleic acid-based biosensors, coupled enzyme reactions, bioorthogonal chemistry, and fluorescent and chromogenic dyes and substrates as modalities for detection...
July 16, 2017: Biotechnology Advances
Min Zhao, Anyi Chen, Dan Huang, Yaqin Chai, Ying Zhuo, Ruo Yuan
Cd-based semiconductor quantum dots (QDs) with size-tunable luminescence and high quantum yield have become the most promising electrochemiluminescence (ECL) emitters. However, their unavoidable biotoxicity limited their applications in bioassays. Here, the nontoxic and economical MoS2 QDs prepared by chemical exfoliation from the bulk MoS2 were first investigated as new ECL emitters, and then the possible luminescence mechanism of MoS2 QDs was studied using ECL-potential curves and differential pulse voltammetry (DPV) methods in detail...
July 13, 2017: Analytical Chemistry
Xisheng Chen, Fangjie Wo, Yao Jin, Jie Tan, Yan Lai, Jianmin Wu
Wound monitoring and curing is of great importance in biomedical research. This work created a smart bandage that can simultaneously monitor and inhibit wound infection. The main components of the smart bandage are luminescent porous silicon (LuPSi) particles loaded with ciprofloxacin (CIP). This dual luminescent system can undergo accelerated fluorescent color change from red to blue upon the stimulation of reactive oxygen species (ROS) and elevated pH, which are main biomarkers in the infected wound. The mechanism behind the chemical-triggered fluorescent color change was studied in detail...
July 17, 2017: ACS Nano
Zhaofeng Yang, Qianwen Wei, Meizhu Rong, Zhiyu Yang, Zhengliang Wang, Qiang Zhou, Qin Wang
New red-emitting phosphors A2HfF6:Mn(4+) (A = Rb(+), Cs(+)) with a single phase have been successfully synthesized via a simple ion exchange method, and their structures and luminescence properties were investigated. It was found that Mn(4+) ions in Rb2HfF6 and Cs2HfF6 who share wide band gaps can possess broad excitation bands in the blue regions and intense red emission with internal quantum yields of 0.556 and 0.652, respectively. Meanwhile, these red phosphors exhibit high chemical and thermal stabilities...
July 11, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
Ryan M O'Donnell, Tod A Grusenmeyer, David J Stewart, Trenton R Ensley, William M Shensky, Joy E Haley, Jianmin Shi
We report a general, photochemical method for the rapid deoxygenation of organic solvents and aqueous solutions via visible light excitation of transition metal chromophores (TMCs) in the presence of singlet oxygen scavenging substrates. Either 2,5-dimethylfuran or an amino acid (histidine or tryptophan methyl ester) was used as the substrate in conjunction with an iridium or ruthenium TMC in toluene, acetonitrile, or water. This behavior is described for solutions with chromophore concentrations that are pertinent for both luminescence and transient absorption spectroscopies...
July 11, 2017: Inorganic Chemistry
Rui-Zhi Wu, Xing Yang, Liang-Wei Zhang, Pan-Pan Zhou
Prototype lanthanide metal-organic frameworks (LnMOFs), Ln(BTC) (Ln = Eu and Tb; BTC = benzene-1,3,5-tricarboxylate), have been considered as luminescent sensors for detecting toxic anions, while their neutral pore structures have limited the entrance and encapsulation of anions to produce highly anion-responsive photoluminescence (PL). To facilitate anions to enter the pore space of Ln(BTC), a one-pot synthesis method was proposed in which BTC was partially replaced with its structural analogue L·BF4 (H3L·BF4 = 2,4,6-tricarboxy-1-methylpyridinium tetrafluoroborate) which consists of an anion affinity site of cationic methylpyridinium...
July 11, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
Jingjing Xu, Bolong Zhang, Marina Jansen, Lars Goerigk, Wallace Wong, Chris Ritchie
We report the findings of our experimental and theoretical investigation into the properties of pyridinium enolates and their potential utility in light harvesting applications such as luminescent solar concentrators (LSCs). The synthesis, structures, photophysical characterization and wavefunction-based quantum-chemical study of the five cyclobetaines are presented, meanwhile the performance of an LSC device incorporating 1e is shown to be comparable to the state-of-the-art.
July 10, 2017: Angewandte Chemie
Rolf Hofer, Philipp Wyss
Shooting samples were produced on standard textile pats of six different ammunition types: four ammunitions with exclusively infrared luminescent propellant powder particles, one containing a mixture of luminescent and non-luminescent particles and one with only non-luminescent particles. Unburned propellant powder particles in the gunshot residue (GSR) on the textile of each sample were transferred onto TLC-plates with the aid of an organic solvent. The patterns of the partially and the all-luminescent propellant powder residue on the TLC-plates were visualized in the near infrared wavelength range by the aid of an IR-sensitive camera...
June 27, 2017: Forensic Science International
Ramanathan Srinivasan, Sivasubramanian Santhakumari, Arumugam Veera Ravi
Vibrio harveyi is a potent biofilm former, which confers resistance to multiple antimicrobials, disinfectants, chemicals and biocides. The prevalence of biofilm mediated antibiotic resistance among aquatic bacterial pathogens stresses the search for novel alternative approach to treat vibriosis in aquaculture. Exploring suitable therapeutics from natural resources could be a novel area of research. Therefore, this work was executed to evaluate the inhibitory effect of Piper betle ethyl acetate extract (PBE) on bioluminescence production and biofilm formation of V...
July 4, 2017: Microbial Pathogenesis
Jiwoong Kim
Eu(3+)-doped alkali metal double molybdate and tungstate phosphors, (MEu) (Mo,WO4)2 (MEM and MEW, M = Li(+), Na(+), and K(+)), have been identified as potential candidate materials for white light-emitting diodes. However, there are no systematic considerations of the role of auxiliary alkali-metal ions (AMIs) on the structural, chemical, and luminescent properties of these phosphors. Here, a systematic investigation to elucidate the role of AMIs on MEM and MEW phosphors was performed using ab initio calculations based on experimental evidence...
July 17, 2017: Inorganic Chemistry
Sha-Sha Liu, Da-Chuan Zhu, Jin-Shan Wang, Cong Zhao, Tao Han
A series of Sr2 P2 O7 :Dy(3+) , Sr2 P2 O7 :Ce(3+) and Sr2 P2 O7 :Dy(3+) ,Ce(3+) phosphors was synthesized via the one-step calcination process for the precursors prepared by co-precipitation methods. The phases, morphology, quantum efficiency and photoluminescence properties of the obtained phosphors were characterized systematically. These results show that the near-spherical particles prepared through calcining the precursors by means of ammonium dibasic phosphate co-precipitation (method 3) have the smallest particle size and strongest emission intensity among the three methods in the paper...
July 6, 2017: Luminescence: the Journal of Biological and Chemical Luminescence
Thomas S Miller, Theo M Suter, Andrew M Telford, Loren Picco, Oliver D Payton, Freddie Russell-Pavier, Patrick L Cullen, Andrea Sella, Milo S P Shaffer, Jenny Nelson, Vasiliki Tileli, Paul F McMillan, Christopher A Howard
A primary method for the production of 2D nanosheets is liquid-phase delamination from their 3D layered bulk analogues. Most strategies currently achieve this objective by significant mechanical energy input or chemical modification but these processes are detrimental to the structure and properties of the resulting 2D nanomaterials. Bulk poly(triazine imide) (PTI)-based carbon nitrides are layered materials with a high degree of crystalline order. Here, we demonstrate that these semiconductors are spontaneously soluble in select polar aprotic solvents, that is, without any chemical or physical intervention...
July 5, 2017: Nano Letters
Tian Gao, Xi Wang, Li-Yun Yang, Huan He, Xiao-Xu Ba, Jie Zhao, Feng-Lei Jiang, Yi Liu
Owing to their excellent photoluminescence (PL) properties, good biocompatibility, and low toxicity, graphene quantum dots (GQDs) are widely applied in bioimaging, biosensing, and so forth. However, further development of GQDs is limited by their synthetic methodology and unclear PL mechanism. Therefore, it is urgent to find efficient and universal methods for the synthesis of GQDs with high stability, controllable surface properties, and tunable PL emission wavelength. By coating with polyethyleneimine (PEI) of different molecular weights, blue-, yellow-, and red-emitting GQDs were successfully prepared...
July 12, 2017: ACS Applied Materials & Interfaces
Jessica H Golden, John W Facendola, Daniel Sylvinson M R, Cecilia Quintana Baez, Peter I Djurovich, Mark E Thompson
Boron dipyrromethene (BODIPY) derivatives have found widespread utility as chromophores in fluorescent applications, but little is known about the photophysical properties of pyridine-based BODIPY analogues, dipyridylmethene dyes. Indeed, it has been reported that boron difluoride dipyridylmethene (DIPYR) is nonemissive, and that derivatives of DIPYR have modest, if any, luminescence. In this report, we explore this little-touched area of chemical space and investigate the photophysical properties of three simple DIPYR dyes: boron dipyridylmethene, boron diquinolylmethene, and boron diisoquinolylmethene...
July 11, 2017: Journal of Organic Chemistry
Jens Voskuhl, Steffen Riebe, Cecilia Vallet, Felix van der Vight, Dario Gonzalez-Abradelo, Christoph Wölper, Cristian A Strassert, Georg Jansen, Shirley Knauer
Here we report on a novel system based on aromatic thioethers with unique luminescence properties. Fifteen different compounds were investigated in detail on their luminescence properties using UV-vis absorption, steady-state and time-resolved luminescence spectroscopy. Excited state lifetimes as well as quantum yields were determined, and the toxicity towards HeLa cells was investigated. Besides X-ray analysis also quantum chemical calculations were performed to gain deeper insights in the unique behavior of this facile system...
June 29, 2017: Chemistry: a European Journal
Robert B Hayes, Sergey Sholom
Modern techniques for detection of covert nuclear material requires some combination of real time measurement and/or sampling of the material. More common is real time measurement of the ionizing emission caused by radioactive decay or through the materials measured in response to external interrogation radiation. One can expose the suspect material with various radiation types, including high energy photons such as x rays or with larger particles such as neutrons and muons, to obtain images or measure nuclear reactions induced in the material...
August 2017: Health Physics
Jonathan Owen, Louis Brus
We describe the close connection between novel chemical synthesis and optimized light emission by colloidal semiconductor quantum dots (qdots). We describe how new insights and systematic improvement in synthesis and characterization have led to highly luminescent qdots that are now used in three-color liquid-crystal displays in large televisions. We outline synthetic and structural issues that require further work to enable additional applications in solar concentrators, solid-state lighting, single-photon devices, optical computing, and in vivo infrared medical imaging...
July 19, 2017: Journal of the American Chemical Society
Zhenxu Lin, Hongfei Li, Rui Huang, Yi Zhang, Jie Song, Hongliang Li, Yanqing Guo, Chao Song, John Robertson
Luminescent SiCxOy:H films, which are fabricated at different CH4 flow rates using the plasma-enhanced chemical vapor deposition (PECVD) technique, exhibit strong photoluminescence (PL) with tuning from the near-infrared to orange regions. The PL features an excitation-wavelength-independent recombination dynamics. The silicon dangling bond (DB) defects identified by electron paramagnetic resonance spectra are found to play a key role in the PL behavior. The first-principles calculation shows that the Si DB defects introduce a midgap state in the band gap, which is in good agreement with the PL energy...
July 12, 2017: ACS Applied Materials & Interfaces
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