Extremely fast and highly selective detection of nitroaromatic explosive vapours using fluorescent polymer thin films

Cataloged from PDF version of article.A novel sensing material based on pyrene doped polyethersulfone worm-like structured thin film is developed using a facile technique for detection of nitroaromatic explosive vapours. The formation of pi-pi stacking in the thin fluorescent film allows a highly sensitive fluorescence quenching which is detectable by the naked eye in a response time of a few seconds

Soft biomimetic tapered babostructures for large-area antireflective surfaces and SERS sensing

Cataloged from PDF version of article.We report a facile fabrication method for the fabrication of functional large area nanostructured polymer films using a drop casting technique. Reusable and tapered silicon molds were utilized in the production of functional polymers providing rapid fabrication of the paraboloid nanostructures at the desired structural heights without the requirement of any complex production conditions, such as high temperature or pressure. The fabricated polymer films demonstrate promising qualities in terms of antireflective, hydrophobic and surface enhanced Raman spectroscopy (SERS) features. We achieved up to 92% transmission from the single-side nanostructured polymer films by implementing optimized nanostructure parameters which were determined using a finite difference time domain (FDTD) method prior to production. Large-area nanostructured films were observed to enhance the Raman signal with an enhancement factor of 4.9 x 10(6) compared to bare film, making them potentially suitable as freestanding SERS substrates. The utilized fabrication method with its demonstrated performances and reliable material properties, paves the way for further possibilities in biological, optical, and electronic applications

Fluorescent Paper Strips for Highly Sensitive and Selective Detection of Nitroaromatic Analytes in Water Samples

A portable, low-cost, flexible, sensitive and selective paper-based sensor was proposed for nitroaromatic explosive detection in water samples. The sensor was designed to achieve π-π stacking formation between emaraldine base polyaniline (PANI) and pyrene (Py) molecules. This π-π stacking formation enables a sensitive turn-off fluorescence quenching under the principle of photo-induced electron transfer (PET) mechanism. PANI−Py absorbed paper strips were immersed into the aqueous mediums of analytes and the fluorescence quenching was observed under a simple UV lamp by naked-eye. Paper strips exhibited∼ 96 % quenching efficiency and the limit of detection was calculated about 9.59 ng/ml. Self-quenching efficiency test showed that the sensor can be used for several weeks under the adequate storing conditions. In addition, experimental findings revealed that the paper-based PANI−Py strips work with high precision in real-samples such as tap water with∼ 85 % quenching efficiency. Moreover the reusability investigations showed that PANI−Py paper-based sensor can be reused 5 times with 54 % sensitivity. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinhei

Plasmonically enhanced hot electron based photovoltaic device

Cataloged from PDF version of article.Hot electron photovoltaics is emerging as a candidate for low cost and ultra thin solar cells. Plasmonic means can be utilized to significantly boost device efficiency. We separately form the tunneling metal-insulator-metal (MIM) junction for electron collection and the plasmon exciting MIM structure on top of each other, which provides high flexibility in plasmonic design and tunneling MIM design separately. We demonstrate close to one order of magnitude enhancement in the short circuit current at the resonance wavelengths. (C) 2013 Optical Society of Americ

Superhydrophobic and Omnidirectional Antifreflective Surfaces from Nanostructured Ormosil Colloids

Cataloged from PDF version of article.A large-area superhydrophobic and omnidirectional antireflective nanostructured organically modified silica coating has been designed and prepared. The coating mimics the self-cleaning property of superhydrophobic lotus leaves and omnidirectional broad band antireflectivity of moth compound eyes, simultaneously. Water contact and sliding angles of the coating are around 160 and 10, respectively. Coating improves the transmittance of the glass substrate around 4%, when coated on a single side of a glass, in visible and near-infrared region at normal incidence angles. At oblique incidence angles (up to 60) improvement in transmission reaches to around 8%. In addition, coatings are mechanically stable against impact of water droplets from considerable heights. We believe that our inexpensive and durable multifunctional coatings are suitable for stepping out of the laboratory to practical outdoor applications

A Motion- and Sound-Activated, 3D-Printed, Chalcogenide-Based Triboelectric Nanogenerator

Cataloged from PDF version of article.A multilayered triboelectric nanogenerator (MULTENG) that can be actuated by acoustic waves, vibration of a moving car, and tapping motion is built using a 3D-printing technique. The MULTENG can generate an open-circuit voltage of up to 396 V and a short-circuit current of up to 1.62 mA, and can power 38 LEDs. The layers of the triboelectric generator are made of polyetherimide nanopillars and chalcogenide core-shell nanofibers. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Plasmonically enhanced hot electron based photovoltaic device

Hot electron photovoltaics is emerging as a candidate for low cost and ultra thin solar cells. Plasmonic means can be utilized to significantly boost device efficiency. We separately form the tunneling metal-insulator-metal (MIM) junction for electron collection and the plasmon exciting MIM structure on top of each other, which provides high flexibility in plasmonic design and tunneling MIM design separately. We demonstrate close to one order of magnitude enhancement in the short circuit current at the resonance wavelengths. © 2013 Optical Society of America

Semiconductor-less photovoltaic device

We demonstrate a novel semiconductor-less photovoltaic device and investigate the plasmonic effects on this device structure. The device is made of metal and dielectric layers and the operation is based on hot carrier collection. We present the use of surface plasmons to improve energy conversion efficiency. The field localization provided by surface plasmons confine the incident light in the metal layer, increasing the optical absorption and hot electron generation rate inside the metal layer. The device consists of two tandem MIM (metal-insulator-metal) junctions. Bottom MIM junction acts as a rectifying diode and top MIM junction is used to excite surface plasmons. The device operation principle as well as the topology will be discussed in detail. © 2013 IEEE

Enhanced performance of dye-sensitized solar cells by omnidirectional antireflective coatings

Organically modified silica (ORMOSIL)-coated dye-sensitized solar cells (DSSCs) with improved energy conversion efficiency are demonstrated. ORMOSIL-coated DSSC surfaces exhibit omnidirectional low reflectivity over a broad range of wavelengths (400-800 nm). The short-circuit current density (JSC) is enhanced up to 23% at normal incidence (θ=0 deg) as a result of ORMOSIL coating. In addition, JSC enhancement is even higher at larger angles of incidence; 84% enhancement was observed at θ=30 deg. Moreover, ORMOSIL coating is superhydrophobic with a contact angle of 155 deg. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its

Leukotriene biosynthesis inhibition ameliorates acute lung injury following hemorrhagic shock in rats

<p>Abstract</p> <p>Background</p> <p>Hemorrhagic shock followed by resuscitation is conceived as an insult frequently induces a systemic inflammatory response syndrome and oxidative stress that results in multiple-organ dysfunction syndrome including acute lung injury. MK-886 is a leukotriene biosynthesis inhibitor exerts an anti inflammatory and antioxidant activity.</p> <p>Objectives</p> <p>The objective of present study was to assess the possible protective effect of MK-886 against hemorrhagic shock-induced acute lung injury via interfering with inflammatory and oxidative pathways.</p> <p>Materials and methods</p> <p>Eighteen adult Albino rats were assigned to three groups each containing six rats: group I, sham group, rats underwent all surgical instrumentation but neither hemorrhagic shock nor resuscitation was done; group II, Rats underwent hemorrhagic shock (HS) for 1 hr then resuscitated with Ringer's lactate (1 hr) (induced untreated group, HS); group III, HS + MK-886 (0.6 mg/kg i.p. injection 30 min before the induction of HS, and the same dose was repeated just before reperfusion period). At the end of experiment (2 hr after completion of resuscitation), blood samples were collected for measurement of serum tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). The trachea was then isolated and bronchoalveolar lavage fluid (BALF) was carried out for measurement of leukotriene B₄(LTB₄), leukotriene C₄(LTC₄) and total protein. The lungs were harvested, excised and the left lung was homogenized for measurement of malondialdehyde (MDA) and reduced glutathione (GSH) and the right lung was fixed in 10% formalin for histological examination.</p> <p>Results</p> <p>MK-886 treatment significantly reduced the total lung injury score compared with the HS group (<it>P </it>< 0.05). MK-886 also significantly decreased serum TNF-α & IL-6; lung MDA; BALF LTB₄, LTC₄& total protein compared with the HS group (<it>P </it>< 0.05). MK-886 treatment significantly prevented the decrease in the lung GSH levels compared with the HS group (<it>P </it>< 0.05).</p> <p>Conclusions</p> <p>The results of the present study reveal that MK-886 may ameliorate lung injury in shocked rats via interfering with inflammatory and oxidative pathways implicating the role of leukotrienes in the pathogenesis of hemorrhagic shock-induced lung inflammation.</p