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https://www.readbyqxmd.com/read/27914330/synergistic-effect-of-p-n-heterojunction-supporting-and-zeolite-nanoparticles-in-enhanced-photocatalytic-activity-of-nio-and-sno2
#1
Hadis Derikvandi, Alireza Nezamzadeh-Ejhieh
Increased photocatalytic activity of NiO and SnO2 was achieved by coupling and supporting of them onto clinoptilolite nanoparticles (NC) via calcination of Ni(II)-Sn(IV) - exchanged NC in photocatalytic degradation of metronidazole (MZ) aqueous solution. XRD, XRF, FTIR, SEM, X-ray mapping, DRS, TEM, BET Cyclic voltammetry and electrochemical impedance spectroscopy techniques (EIS) were used for characterization of samples. Red shift occurred in bang gap energies of the coupled semiconductors with respect to monocomponent one...
November 21, 2016: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/27909862/combined-characterization-of-bovine-polyhemoglobin-microcapsules-by-uv-vis-absorption-spectroscopy-and-cyclic-voltammetry
#2
Marcos Camargo Knirsch, Filippo Dell'Anno, Marco Salerno, Claudio Larosa, Bronislaw Polakiewicz, Roberto Eggenhöffner, Attilio Converti
Polyhemoglobin produced from pure bovine hemoglobin by reaction with PEG bis(N-succynimidil succinate) as a cross-linking agent was encapsulated in gelatin and dehydrated by freeze-drying. Free carboxyhemoglobin and polyhemoglobin microcapsules were characterized by UV-Vis spectroscopy in the absorption range 450-650 nm and cyclic voltammetry in the voltage range from -0.8 to 0.6 mV to evaluate the ability to break the bond with carbon monoxide and to study the carrier's affinity for oxygen, respectively...
December 1, 2016: Bioprocess and Biosystems Engineering
https://www.readbyqxmd.com/read/27907873/excellent-storage-stability-and-sensitive-detection-of-neurotoxin-quinolinic-acid
#3
Ranjana Singh, Sunayana Kashyap, Suveen Kumar, Shiju Abraham, Tejendra K Gupta, Arvind M Kayastha, Bansi D Malhotra, Preeti Suman Saxena, Anchal Srivastava, Ranjan K Singh
Quinolinic acid (QA) is a metabolite of tryptophan degradation obtained through kynurenine pathway, produced naturally in the mammalian brain as well as in the human cerebrospinal fluid. The presence of QA ~10-40µM is a clear indicator of many neurological disorders as well as deficiency of vitamin B6 in human being. In the present work; rapid, sensitive and cost-effective bio-electrodes were prepared to detect the trace amount of endogenous neurotoxin (QA). Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) studies were carried out to measure the electrochemical response of the fabricated bio-electrodes as a function of QA concentrations...
November 23, 2016: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/27907865/biophysical-characterization-and-antineoplastic-activity-of-new-bis-thiosemicarbazonato-cu-ii-complexes
#4
Elisa Palma, Filipa Mendes, Goreti Ribeiro Morais, Inês Rodrigues, Isabel Cordeiro Santos, Maria Paula C Campello, Paula Raposinho, Isabel Correia, Sofia Gama, Dulce Belo, Vítor Alves, Antero J Abrunhosa, Isabel Santos, António Paulo
Aiming to explore alternative mechanisms of cellular uptake and cytotoxicity, we have studied a new family of copper(II) complexes (CuL(1)-CuL(4)) with bis(thiosemicarbazone) (BTSC) ligands containing pendant protonable cyclic amines (morpholine and piperidine). Herein, we report on the synthesis and characterization of these new complexes, as well as on their biological performance (cytotoxic activity, cellular uptake, protein and DNA binding), in comparison with the parental Cu(II)ATSM (ATSM=diacetyl-bis(N4-methylthiosemicarbazonate) complex without pendant cyclic amines...
November 23, 2016: Journal of Inorganic Biochemistry
https://www.readbyqxmd.com/read/27902920/an-ultrasensitive-aptasensor-for-hemin-and-hemoglobin-based-on-signal-amplification-via-electrocatalytic-oxygen-reduction
#5
Zahra Shekari, Hamid R Zare, Ali Falahati
The present study aims at the fabrication of a novel electrochemical aptasensor, Ap-GA-AMSN-G, for the label-free determination of hemin and hemoglobin (Hb). Basically, the electrochemical reduction current of hemin or Hb incubated on Ap-GA-AMSN-GCE in the presence of oxygen serves as an excellent signal for quantitative determination of these analytes. By differential pulse voltammetry, the calibration plot was linear in the concentration range of 1.0 × 10(-19)-1.0 × 10(-6) M of hemin and Hb. Also, the detection limits, DL, of hemin and Hb were found to be 7...
November 27, 2016: Analytical Biochemistry
https://www.readbyqxmd.com/read/27901542/redox-trends-in-cyclometalated-palladium-ii-complexes
#6
Yulia B Dudkina, Kirill V Kholin, Tatyana V Gryaznova, Daut R Islamov, Olga N Kataeva, Ildar Kh Rizvanov, Alina I Levitskaya, Olga D Fominykh, Marina Yu Balakina, Oleg G Sinyashin, Yulia H Budnikova
A series of diverse binuclear and mononuclear cyclometalated palladium(ii) complexes of different structure was investigated by electrochemical techniques combined with density functional theory (DFT) calculations. The studies including cyclic and differential pulse voltammetry, X-ray structure analysis and quantum chemical calculations revealed a regularity of the complexes oxidation potential on the metal-metal distance in the complexes: the larger Pd-Pd distance, the higher oxidation potentials. The reduction potentials feature unusually high negative values while no correlation depending on the structure could be observed...
November 30, 2016: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/27900618/3d-carbon-nanofiber-microelectrode-arrays-fabricated-by-plasma-assisted-pyrolysis-to-enhance-sensitivity-and-stability-of-real-time-dopamine-detection
#7
Wenwen Yi, Yuanyuan Yang, Parastoo Hashemi, Mark Ming-Cheng Cheng
In this paper, we have fabricated 3D carbon nanofiber microelectrode arrays (MEAs) with highly reproducible and rich chemical surface areas for fast scan cyclic voltammetry (FSCV). Carbon nanofibers are created from negative photoresist by a new process called dual O2 plasma-assisted pyrolysis. The proposed approach significantly improves film adhesion and increases surface reactivity. We showcase our sensor's compatibility with FSCV analysis by demonstrating highly sensitive and stable FSCV dopamine measurements on a prototype 4-channel array...
December 2016: Biomedical Microdevices
https://www.readbyqxmd.com/read/27898333/chemical-synthesis-and-supercapacitive-properties-of-lanthanum-telluride-thin-film
#8
S J Patil, A C Lokhande, D-W Lee, J H Kim, C D Lokhande
Lanthanum telluride (La2Te3) thin films are synthesized via a successive ionic layer adsorption and reaction (SILAR) method. The crystal structure, surface morphology and surface wettability properties are investigated using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Field emission scanning electron microscopy (FE-SEM) and contact angle goniometer techniques, respectively. The La2Te3 material exhibits a specific surface area of 51m(2)g(-1) determined by Brunauer-Emmett-Teller (BET) method...
November 9, 2016: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/27898046/pro-and-antioxidant-activity-of-three-selected-flavan-type-flavonoids-catechin-eriodictyol-and-taxifolin
#9
Vladimir Chobot, Franz Hadacek, Gert Bachmann, Wolfram Weckwerth, Lenka Kubicova
The flavanol (±)-catechin shows an OH group but no 4-keto group on ring C (C3), and no conjugation between ring A and B. The related flavanone (+)-eriodictyol has a keto group on C4 but no 3-OH group on ring C. (+)-Taxifolin, another flavanone, has an OH on C3 and a keto group on C4 of the C ring. Deoxyribose degradation assay systems, with hydrogen peroxide and ascorbic acid either added or omitted, were performed in variants in which Fe(III) was added in a complex with ethylenediaminetetraacetic acid (EDTA)...
November 26, 2016: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/27897238/synergetic-signal-amplification-of-multi-walled-carbon-nanotubes-fe3o4-hybrid-and-trimethyloctadecylammonium-bromide-as-a-highly-sensitive-detection-platform-for-tetrabromobisphenol-a
#10
Feng Zhou, Yue Wang, Wei Wu, Tao Jing, Surong Mei, Yikai Zhou
In this work, we fabricated an electrochemical sensor based on trimethyloctadecylammonium bromide and multi-walled carbon nanotubes-Fe3O4 hybrid (TOAB/MWCNTs-Fe3O4) for sensitive detection of tetrabromobisphenol A (TBBPA). The nanocomposite was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FT-IR) techniques. The electrochemical behaviors of TBBPA on TOAB/MWCNTs-Fe3O4 composite film modified glassy carbon electrode (GCE) were investigated by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) method...
November 29, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27896338/electrochemical-investigation-of-co4-%C3%AE-3-o-4-%C3%AE-oac-4-py-4-and-peroxides-by-cyclic-voltammetry
#11
Edwin B Clatworthy, Xiaobo Li, Anthony F Masters, Thomas Maschmeyer
Two oxidative redox processes of the neutral cobalt(iii) cubane, [Co4(μ3-O)4(μ-OAc)4(py)4], were investigated by cyclic voltammetry at a glassy carbon electrode in acetonitrile. In addition to the first quasi-reversible one-electron oxidation at E1/2 = 0.283 V vs. Fc(0/+), a second quasi-reversible one-electron oxidation was observed at E1/2 = 1.44 V vs. Fc(0/+). Oxidation at this potential does not facilitate water oxidation. In the presence of tert-butylhydroperoxide the peak current of this second oxidation increases, suggesting oxidation of the peroxide by the doubly oxidised cubane...
November 29, 2016: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/27894754/composite-of-cu-metal-nanoparticles-multiwall-carbon-nanotubes-reduced-graphene-oxide-as-a-novel-and-high-performance-platform-of-the-electrochemical-sensor-for-simultaneous-determination-of-nitrite-and-nitrate
#12
Hasan Bagheri, Ali Hajian, Mosayeb Rezaei, Ali Shirzadmehr
In the present research, we aimed to fabricate a novel electrochemical sensor based on Cu metal nanoparticles on the multiwall carbon nanotubes-reduced graphene oxide nanosheets (Cu/MWCNT/RGO) for individual and simultaneous determination of nitrite and nitrate ions. The morphology of the prepared nanocomposite on the surface of glassy carbon electrode (GCE) was characterized using various methods including scanning electron microscopy (SEM), atomic force microscopy (AFM), and electrochemical impedance spectroscopy...
November 21, 2016: Journal of Hazardous Materials
https://www.readbyqxmd.com/read/27890676/combined-in-vitro-and-in-silico-approaches-to-the-assessment-of-stimulant-properties-of-novel-psychoactive-substances-the-case-of-the-benzofuran-5-mapb
#13
Michelle A Sahai, Colin Davidson, George Khelashvili, Vincenzo Barrese, Neelakshi Dutta, Harel Weinstein, Jolanta Opacka-Juffry
Novel psychoactive substances (NPS) are increasingly prevalent world-wide although their pharmacological characteristics are largely unknown; those with stimulant properties, due to interactions with the dopamine transporter (DAT), have addictive potential which their users may not realise. We evaluated the binding of 1-(1-benzofuran-5-yl)-N-methylpropan-2-amine (5-MAPB) to rat striatal DAT by means of quantitative autoradiography with [(125)I]RTI-121, and the effects of 5-MAPB on electrically-evoked dopamine efflux by fast-cyclic voltammetry in rat brain slices...
November 24, 2016: Progress in Neuro-psychopharmacology & Biological Psychiatry
https://www.readbyqxmd.com/read/27888684/ultrasensitive-non-enzymatic-multiple-immunosensor-for-tumor-markers-detection-by-coupling-dna-hybridization-chain-reaction-with-intercalated-molecules
#14
Jinjin Guo, Junchun Wang, Junjun Zhang, Wenjuan Zhang, Yuzhong Zhang
In this study, we tried coupling the small signal molecules that could intercalate into DNA double helix with hybridization chain reaction (HCR) technique to fabricate a multiple immunosensor. Doxorubicin hydrochloride (DXH) and methylene blue (MB) were used as signal molecules and alpha-fetoprotein (AFP) and carcinoembryonic antigen (CEA) were selected as model biomarkers. The immunosensor mainly consists of three parts as follows: First, two different primary antibodies (Ab1) immobilized on the surface of gold nanoparticles (Au NPs); Second, secondary antibodies (Ab2) conjugated with DNA primer; Third, long DNA concatemers from HCR were used as a carrier to intercalate amounts of signal molecules (DXH or MB)...
November 21, 2016: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/27887815/recycled-hierarchical-tripod-like-cucl-from-cu-pcb-waste-etchant-for-lithium-ion-battery-anode
#15
Song Liu, Hongying Hou, Xianxi Liu, Jixiang Duan, Yuan Yao, Qishu Liao, Jing Li, Yunzhen Yang
Hierarchical CuCl with high economic value added (EVA) was successfully recycled with 85% recovery from the acid Cu printed circuit board (Cu-PCB) waste etchant via facile liquid chemical reduction. The micro-structure and morphology of the recycled hierarchical CuCl were systematically characterized in terms of scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET). Furthermore, the corresponding electrochemical performances as lithium ion battery (LIB) anode were also investigated in terms of galvanostatic charge/discharge, cyclic voltammetry (CV) and AC impedance...
October 29, 2016: Journal of Hazardous Materials
https://www.readbyqxmd.com/read/27886594/proposed-binding-mechanism-of-galbanic-acid-extracted-from-ferula-assa-foetida-to-dna
#16
F Ahmadi, Y Shokoohinia, Sh Javaheri, H Azizian
Recently, galbanic acid (GA), a sesquiterpenoid coumarin, has been introduced as an apoptotic and geno/cytotoxicity agent. In the present study, GA has been extracted from Ferula assa-foetida, a native medicinal plant in Iran, and characterized by (1)H NMR, mass spectroscopy. Additionally, spectroscopic studies have been performed in order to investigate its DNA-interaction mode. The electrochemical behavior of GA has been studied by cyclic voltammetry (CV) in various scan rates. In neutral media (pH=7.3) one irreversible cathodic peak was obtained at -1...
November 16, 2016: Journal of Photochemistry and Photobiology. B, Biology
https://www.readbyqxmd.com/read/27886072/peroxynitrite-sensor-based-on-a-screen-printed-carbon-electrode-modified-with-a-poly-2-6-dihydroxynaphthalene-film
#17
Ioana Silvia Hosu, Diana Constantinescu-Aruxandei, Maria-Luiza Jecu, Florin Oancea, Mihaela Badea Doni
For the first time the electropolymerization of 2,6-dihydroxynaphthalene (2,6-DHN) on a screen printed carbon electrode (SPCE) was investigated and evaluated for peroxynitrite (PON) detection. Cyclic voltammetry was used to electrodeposit the poly(2,6-DHN) on the carbon electrode surface. The surface morphology and structure of poly(2,6-DHN) film were investigated by SEM and FTIR analysis, and the electrochemical features by cyclic voltammetry. The poly(2,6-DHN)/SPCE sensor showed excellent electrocatalytic activity for PON oxidation in alkaline solutions at very low potentials (0-100 mV vs...
November 23, 2016: Sensors
https://www.readbyqxmd.com/read/27885779/explaining-the-cyclic-voltammetry-of-a-poly-1-4-phenylene-ethynylene-alt-poly-1-4-phenylene-vinylene-copolymer-upon-oxidation-by-using-spectroscopic-techniques
#18
Christina Enengl, Sandra Enengl, Nassima Bouguerra, Marek Havlicek, Helmut Neugebauer, Daniel A M Egbe
Poly(1,4-phenylene-ethynylene)-alt-poly(1,4-phenylene-vinylene) (PPE-PPV) copolymers have attracted quite a lot of attention in the last few years for electronic device applications owing to their enhanced fluorescence. In this work, we focus on one particular PPE-PPV copolymer with dissymmetrically substituted 1,4-phenylene-ethynylene and symmetrically substituted 1,4-phenylene-vinylene building units. Six successively performed cyclic voltammograms are presented, measured during the oxidation reactions. As the oxidation onset of the electrochemical reaction shifts to lower potentials in each cycle, this behavior is elucidated by using spectroscopic techniques ranging from UV/Vis/near-IR to mid-IR including spin-resonance techniques...
November 4, 2016: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
https://www.readbyqxmd.com/read/27883244/a-redox-switchable-germylene-and-its-ligating-properties-in-selected-transition-metal-complexes
#19
Florian Walz, Eric Moos, Delphine Garnier, Ralf Köppe, Christopher E Anson, Frank Breher
The synthesis, structure, and full characterization of a redox-switchable germylene based on a [3]ferrocenophane ligand arrangement, [Fc(NMes)2Ge] (4), is presented. The title compound is readily available from Fc(NHMes)2 (2) and Ge{N(SiMe3)2}2, or from the dilithiated compound Fc(NLiMes)2 · 3 Et2O (3) and GeCl2. Cyclic voltammetry studies are provided for 4 confirming the above mentioned view of a redox-switchable germylene metalloligand. Although several 1:1 Rh(I) and Ir(I) complexes of 4 (5 - 7) are cleanly formed in solution, all attempts to isolate them in pure form failed due to stability problems...
November 24, 2016: Chemistry: a European Journal
https://www.readbyqxmd.com/read/27882263/electrochemical-study-of-carbon-nanotubes-nanohybrids-for-determination-of-metal-species-cu-2-and-pb-2-in-water-samples
#20
Andréa Claudia Oliveira Silva, Luis Carlos Ferreira de Oliveira, Angladis Vieira Delfino, Mario Roberto Meneghetti, Fabiane Caxico de Abreu
The use of nanomaterials, such as nanoparticles and nanotubes, for electrochemical detection of metal species has been investigated as a way of modifying electrodes by electrochemical stripping analysis. The present study develops a new methodology based on a comparative study of nanoparticles and nanotubes with differential pulse anodic stripping voltammetry (DPASV) and examines the simultaneous determination of copper and lead. The glassy carbon electrode modified by gold nanoparticles demonstrated increased sensitivity and decreased detection limits, among other improvements in analytical performance data...
2016: Journal of Analytical Methods in Chemistry
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