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Chemical luminescence

Ruslan Álvarez-Diduk, Jahir Orozco, Arben Merkoçi
Simple, inexpensive and rapid sensing systems are very demanded for a myriad of uses. Intrinsic properties of emerging paper-based analytical devices have demonstrated considerable potential to fulfill such demand. This work reports an easy-to-use, low cost, and disposable paper-based sensing device for rapid chemical screening with a smartphone readout. The device comprises luminescent graphene quantum dots (GQDs) sensing probes embedded into a nitrocellulose matrix where the resonance energy transfer phenomenon seems to be the sensing mechanism...
April 20, 2017: Scientific Reports
Kinga Gazda, Michal Bazała, Tomasz Węgierski
Calcium is a second messenger that plays a key role in various cellular processes. Monitoring calcium levels is a prerequisite to their understanding. The first calcium indicators for microscopy were the luminescent protein aequorin and chemical probes. These indicators, however, have serious drawbacks, limiting their use in many types of experiments. Cloning of cDNA for the A. victoria GFP and creation of its first spectral variants has initiated the development of fluorescent, genetically encoded calcium indicators (GECI)...
2017: Postepy Biochemii
Sung-Min Lee, Purnim Dhar, Huandong Chen, Angelo Montenegro, Lauren Liaw, Dongseok Kang, Boju Gai, Alexander V Benderskii, Jongseung Yoon
Ultrathin silicon solar cells fabricated by anisotropic wet chemical etching of single-crystalline wafer materials represent an attractive materials platform that could provide many advantages for realizing high-performance, low-cost photovoltaics. However, their intrinsically limited photovoltaic performance arising from insufficient absorption of low-energy photons demands careful design of light management to maximize the efficiency and preserve the cost-effectiveness of solar cells. Herein we present an integrated flexible solar module of ultrathin, nanostructured silicon solar cells capable of simultaneously exploiting spectral upconversion and downshifting in conjunction with multispectral luminescent waveguides and a nanostructured plasmonic reflector to compensate for their weak optical absorption and enhance their performance...
April 12, 2017: ACS Nano
Deepti Pateria, R N Baghel, D P Bisen, Piyush Jha, V K Chandra, B P Chandra
The present paper reports the thermoluminescence (TL) of (ZnS)1-x (MnTe)x nanophosphors that were prepared by a wet chemical synthesis method. The structure investigated by X-ray diffraction patterns confirms the formation of a sphalerite phase whose space group was found to be F 4¯3m. From XRD, TEM and SEM analyses the average sizes of the particles were found to be 12 nm, 11 nm and 15 nm, respectively. Initially the TL intensity increased with increasing values of x because the number of luminescence centres increased; however, for higher values of x the TL intensity decreased because of the concentration quenching...
May 2017: Luminescence: the Journal of Biological and Chemical Luminescence
Nianfang Wang, Sungjun Koh, Byeong Guk Jeong, Dongkyu Lee, Whi Dong Kim, Kyoungwon Park, Min Ki Nam, Kangha Lee, Yewon Kim, Baek-Hee Lee, Kangtaek Lee, Wan Ki Bae, Doh C Lee
We present facile synthesis of bright CdS/CdSe/CdS@SiO2 nanoparticles with 72% of quantum yields (QYs) retaining ca 80% of the original QYs. The main innovative point is the utilization of the highly luminescent CdS/CdSe/CdS seed/spherical quantum well/shell (SQW) as silica coating seeds. The significance of inorganic semiconductor shell passivation and structure design of quantum dots (QDs) for obtaining bright QD@SiO2 is demonstrated by applying silica encapsulation via reverse microemulsion method to three kinds of QDs with different structure: CdSe core and 2 nm CdS shell (CdSe/CdS-thin); CdSe core and 6 nm CdS shell (CdSe/CdS-thick); and CdS core, CdSe intermediate shell and 5 nm CdS outer shell (CdS/CdSe/CdS-SQW)...
May 5, 2017: Nanotechnology
Gleb Baryshnikov, Boris Minaev, Hans Ågren
Phosphorescence is a phenomenon of delayed luminescence that corresponds to the radiative decay of the molecular triplet state. As a general property of molecules, phosphorescence represents a cornerstone problem of chemical physics due to the spin prohibition of the underlying triplet-singlet emission and because its analysis embraces a deep knowledge of electronic molecular structure. Phosphorescence is the simplest physical process which provides an example of spin-forbidden transformation with a characteristic spin selectivity and magnetic field dependence, being the model also for more complicated chemical reactions and for spin catalysis applications...
April 7, 2017: Chemical Reviews
Anna Li Volsi, Cinzia Scialabba, Valeria Vetri, Gennara Cavallaro, Mariano Licciardi, Gaetano Giammona
Folate-targeted gold nanorods (GNRs) are proposed as selective theranostic agents for osteosarcoma treatment. An amphiphilic polysaccharide based graft-copolymer (INU-LA-PEG-FA) and an amino derivative of the α,β-poly(N-2-hydroxyethyl)-d,l-aspartamide functionalized with folic acid (PHEA-EDA-FA), have been synthesized to act as coating agents for GNRs. The obtained polymer-coated GNRs were characterized in terms of size, shape, zeta potential, chemical composition, and aqueous stability. They protected the anticancer drug nutlin-3 and were able to deliver it efficiently in different physiological media...
April 14, 2017: ACS Applied Materials & Interfaces
Bong Je Park, A-Ra Hong, Suntak Park, Ki-Uk Kyung, Kwangyeol Lee, Ho Seong Jang
Core/shell (C/S)-structured upconversion nanophosphor (UCNP)-incorporated polymer waveguide-based flexible transparent displays are demonstrated. Bright green- and blue-emitting Li(Gd,Y)F4:Yb,Er and Li(Gd,Y)F4:Yb,Tm UCNPs are synthesized via solution chemical route. Their upconversion luminescence (UCL) intensities are enhanced by the formation of C/S structure with LiYF4 shell. The Li(Gd,Y)F4:Yb,Er/LiYF4 and Li(Gd,Y)F4:Yb,Tm/LiYF4 C/S UCNPs exhibit 3.3 and 2.0 times higher UCL intensities than core counterparts, respectively...
April 3, 2017: Scientific Reports
Che-Yuan Yang, Sudipta Som, Subrata Das, Chung-Hsin Lu
Novel chemical vapor deposition (CVD) process was successfully developed for the growth of Sr2Si5N8:Ce(3+) phosphors with elevated luminescent properties. Metallic strontium was used as a vapor source for producing Sr3N2 vapor to react with Si3N4 powder via a homogeneous gas-solid reaction. The phosphors prepared via the CVD process showed high crystallinity, homogeneous particle size ranging from 8 to 10 μm, and high luminescence properties. In contrast, the phosphors prepared via the conventional solid-state reaction process exhibited relative low crystallinity, non-uniform particle size in the range of 0...
March 31, 2017: Scientific Reports
Rebeca Manzano, Pedro Jiménez-Peñalver, Elvira Esteban
Abandoned waste piles from ancient mining activities are potential hot spots for the pollution of the surrounding areas. A pot experiment was carried out to check the potential toxicity of the dumping material present in one of these scenarios, and several amendments were tested to attenuate the spread of the contamination events. The waste material had an acid pH and a large total concentration of As and Cu. A dose-response experiment was performed with this material following OCDE 208 test. A proportion 90:10 uncontaminated soil: dumping material (% w/w) was selected for the following experiment, in order to surpass the amount of dumping material that caused 50% reduction in plant growth...
March 27, 2017: Ecotoxicology and Environmental Safety
Nikolai G Kalugin, Aaron J Roy, Kateryna Artyushkova, Alexey Serov
Thermal reduction of erbium nitrate and S-doped reduced graphene oxide (rGO) mixture resulted in the formation of small (∼3-18 nm sized) Er2O3-Er2SO2 nanoparticles with a high degree of surface coverage on the reduced GO support. The morphology, structure, and the chemical composition of the synthesized nanoparticles have been studied by scanning and transmission electron microscopy, x-ray photoelectron spectroscopy, x-ray diffraction, and by optical spectroscopies. The rGO-supported Er2O3-Er2SO2 nanoparticles (Er2O3-Er2SO2/rGO) demonstrate sufficiently strong light emission (luminescence and upconversion) in the visible and near-infrared range via intra-4f Er(3+) optical transitions...
May 12, 2017: Nanotechnology
Rocío Estefanía Rojas-Hernandez, Fernando Rubio-Marcos, Aida Serrano, Adolfo Del Campo, José Francisco Fernandez
Intensive research has been focused on the synthesis of long-lasting SrAl2O4:EuDy in luminescent materials field. Traditionally, SrAl2O4:EuDy is synthesized in bulk form by solid state. However, their development remains restrained due to this technique is not compatible with large-scale production, sustainability and nanometer-scale requirements. Despite nano-range particles have been obtained by chemical routes, photoluminescence response decreases and application became unpractical. It remains a challenge to synthesize nonrare-earth (RE) phosphors with high photoluminescence...
March 28, 2017: Scientific Reports
Verena Ihrig, Wolfgang M J Obermann
Deletion of a single phenylalanine residue at position 508 of the protein CFTR (cystic fibrosis transmembrane conductance regulator), a chloride channel in lung epithelium, is the most common cause for cystic fibrosis. As a consequence, folding of the CFTRΔF508 protein and delivery to the cell surface are compromised, resulting in degradation of the polypeptide. Accordingly, decreased surface presence of CFTRΔF508 causes impaired chloride ion conductivity and is associated with mucus accumulation, a hallmark of cystic fibrosis...
January 1, 2017: SLAS Discovery
Yiming Wu, Yanmeng Dai, Shenlong Jiang, Chao Ma, Yue Lin, Dongxue Du, Yukun Wu, Huaiyi Ding, Qun Zhang, Nan Pan, Xiaoping Wang
Aluminium (Al)-doped zinc oxide (ZnO) nanowires (NWs) with a unique core-shell structure and a Δ-doping profile at the interface were successfully grown using a combination of chemical vapor deposition re-growth and few-layer AlxOy atomic layer deposition. Unlike the conventional heavy doping which degrades the near-band-edge (NBE) luminescence and increases the electron-phonon coupling (EPC), it was found that there was an over 20-fold enhanced NBE emission and a notably-weakened EPC in this type of interfacially Al-doped ZnO NWs...
March 27, 2017: Physical Chemistry Chemical Physics: PCCP
Nelson A M Pereira, Mafalda Laranjo, João Casalta-Lopes, Arménio C Serra, Marta Piñeiro, João Pina, J Sérgio Seixas de Melo, Mathias O Senge, M Filomena Botelho, Liliana Martelo, Hugh D Burrows, Teresa M V D Pinho E Melo
Novel near-infrared luminescent compounds based on platinum(II) 4,5,6,7-tetrahydropyrazolo[1,5-a]pyridine-fused chlorins are described. These compounds have high photostability and display light emission, in particular simultaneous fluorescence and phosphorescence emission in solution at room temperature, in the biologically relevant 700-850 nm red and near-infrared (NIR) spectral region, making them excellent materials for biological imaging. The simultaneous presence of fluorescence and phosphorescence emission at room temperature, with the phosphorescence strongly quenched by oxygen whereas fluorescence remains unaffected, allows these compounds to be used as ratiometric oxygen sensors in chemical and biological media...
March 9, 2017: ACS Medicinal Chemistry Letters
Noor-Ul-Ain, Martin O Eriksson, Susann Schmidt, M Asghar, Pin-Cheng Lin, Per Olof Holtz, Mikael Syväjärvi, G Reza Yazdi
Tuning the emission energy of graphene quantum dots (GQDs) and understanding the reason of tunability is essential for the GOD function in optoelectronic devices. Besides material-based challenges, the way to realize chemical doping and band gap tuning also pose a serious challenge. In this study, we tuned the emission energy of GQDs by substitutional doping using chlorine, nitrogen, boron, sodium, and potassium dopants in solution form. Photoluminescence data obtained from (Cl- and N-doped) GQDs and (B-, Na-, and K-doped) GQDs, respectively exhibited red- and blue-shift with respect to the photoluminescence of the undoped GQDs...
November 3, 2016: Nanomaterials
Robin G Geitenbeek, P Tim Prins, Wiebke Albrecht, Alfons van Blaaderen, Bert M Weckhuysen, Andries Meijerink
The rapid development of nanomaterials with unique size-tunable properties forms the basis for a variety of new applications, including temperature sensing. Luminescent nanoparticles (NPs) have demonstrated potential as sensitive nanothermometers, especially in biological systems. Their small size offers the possibility of mapping temperature profiles with high spatial resolution. The temperature range is however limited, which prevents use in high-temperature applications such as, for example, nanoelectronics, thermal barrier coatings, and chemical reactors...
February 16, 2017: Journal of Physical Chemistry. C, Nanomaterials and Interfaces
Sharmistha Dutta Choudhury, Jiddhu M Chethodil, Poojan Milan Gharat, Praseetha P K, Haridas Pal
Remarkable and systematic pH-dependent changes are observed in the absorption and emission spectra of carbon dots derived for the first time from lemon juice, a natural bioresource. Detailed photophysical studies of these novel carbon dots (henceforth termed LD), in conjunction with Fourier transform infrared spectra, reveal that among the two possible prototropic equilibria, phenol ↔ phenolate and carboxylic ↔ carboxylate, that occur at the surface of LD, it is the former that is actually coupled with the emissive moiety and directly involved in determining the nature of the electronic energy levels and the associated optical transitions...
March 15, 2017: Journal of Physical Chemistry Letters
F G M Mauricio, A Z Pralon, M Talhavini, M O Rodrigues, I T Weber
This work describes the incorporation of luminescent taggants in cartridges of ammonium nitrate-fuel oil (ANFO) to allow easy identification and collection of post-blast residues. Metal-Organic Frameworks taggants proved to be appropriate for explosive marking when ANFO proportions were above 3.0wt.%. Lanthanide-based light emission enabled in situ retrieval of explosive residues as well as chemical identification, allowing the creation of a coding system using Energy Dispersive Spectroscopy (EDS). The proposed method will accelerate laboratory analysis and support forensic investigations, connecting evidence to suspects and/or to the explosive origin...
March 6, 2017: Forensic Science International
Alexis Rossignol, Véronique Bonnaudet, Béatrice Clémenceau, Henri Vié, Laurent Bretaudeau
Standardized and biologically relevant potency assays are required by the regulatory authorities for the characterization and quality control of therapeutic antibodies. As critical mechanisms of action (MoA) of antibodies, the antibody-dependent cell-meditated cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) must be characterized by appropriate potency assays. The current reference method for measuring cytotoxicity is the (51)Cr-release method. However, radioactivity handling is difficult to implement in an industrial context because of environmental and operator protection constraints...
April 2017: MAbs
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