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alkaline-conditions
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Biodegradation of cyanide by a new isolated strain under alkaline conditions and optimization by response surface methodology (RSM)
, Article Journal of Environmental Health Science and Engineering ; Vol. 12, issue. 1 , 2014 ; Yaghmaei, S ; Nejad, Z. G ; Sharif University of Technology
Abstract
Background: Biodegradation of free cyanide from industrial wastewaters has been proven as a viable and robust method for treatment of wastewaters containing cyanide. Results: Cyanide degrading bacteria were isolated from a wastewater treatment plant for coke-oven-gas condensate by enrichment culture technique. Five strains were able to use cyanide as the sole nitrogen source under alkaline conditions and among them; one strain (C2) was selected for further studies on the basis of the higher efficiency of cyanide degradation. The bacterium was able to tolerate free cyanide at concentrations of up to 500 ppm which makes it a good potentially candidate for the biological treatment of cyanide...
Melatonin as a powerful bio-antioxidant for reduction of graphene oxide
, Article Journal of Materials Chemistry ; Volume 21, Issue 29 , 2011 , Pages 10907-10914 ; 09599428 (ISSN) ; Akhavan, O ; Irajizad, A ; Sharif University of Technology
2011
Abstract
Graphene is usually synthesized through deoxygenation of graphene oxide (GO) by hydrazine as the most common and one of the strongest reducing agents. But, due to the high toxicity of hydrazine, it is not a promising reductant in large-scale production of graphene. Here, for the first time, we used melatonin (MLT), as a powerful antioxidant and a biocompatible competitor of hydrazine in reduction of GO suspension. X-ray photoelectron spectroscopy (XPS), current-voltage and optical characteristics of the sheets indicated that the deoxygenation efficiency of the GO suspensions by MLT and under heating in an alkaline condition for 3 h was comparable with the efficiency obtained by hydrazine in...
Simple and rapid detection of L-dopa based on in situ formation of polylevodopa nanoparticles
, Article Sensors and Actuators, B: Chemical ; Volume 243 , 2017 , Pages 715-720 ; 09254005 (ISSN) ; Moslehipour, A ; Bigdeli, A ; Sharif University of Technology
Elsevier B.V
2017
Abstract
Levodopa [L-3, 4-dihydroxyphenylalanine, or L-DOPA] is an important neurotransmitter used for the treatment of neural disorders such as Parkinson's disease. Abnormal L-Dopa concentrations in biological fluids can be used for the evaluation of such diseases. In this work, a rapid and sensitive method for L-DOPA detection has been reported which is based on in situ formation of polylevodopa nanoparticles. Under alkaline conditions, L-DOPA is spontaneously oxidized to its quinone derivative and shows fluorescence properties. The fluorescence signal of the oxidation product has been monitored and used for the determination of L-DOPA in the presence of dopamine, uric acid, ascorbic acid and other...
Biodegradation of cyanide under alkaline conditions by a strain of pseudomonas putida isolated from gold mine soil and optimization of process variables through response surface methodology (RSM)
, Article Periodica Polytechnica Chemical Engineering ; Volume 62, Issue 3 , May , 2018 , Pages 265-273 ; 03245853 (ISSN) ; Yaghmaei, S ; Ghobadi Nejad, Z ; Sharif University of Technology
Budapest University of Technology and Economics
2018
Abstract
In regard to highly poisonous effects of cyanide ion, concerns have been focused recently on treatment of such compounds in different ways. Four bacterial strains (C1-C4) capable of using cyanide as nitrogen source were isolated from contaminated gold mine soil samples under alkaline conditions at 30 °C, pH 9.5-10.5, and agitation speed 150 rpm. The gram-negative bacterium C3 (identified as Pseudomonas parafulva NBRC 16636(T) by 16S rRNA gene sequencing) was able to tolerate cyanide up to 500 ppm besides removing 93.5% of 200 ppm cyanide in 13 days which was confirmed by microorganisms growth. The addition of basal salts enhanced the removal efficiency of C3 by 16%. Cyanide removal...
Application of NaYF4:Yb/Er/Tm UCNPs in Array-Based Sensing of Neurotransmitters: From a Single Particle to a Multichannel Sensor Array
, Article ACS Applied Materials and Interfaces ; 2020 ; Bigdeli, A ; Hormozi Nezhad, M. R ; Sharif University of Technology
American Chemical Society
2020
Abstract
A novel multichannel sensor array has been designed using a single, yet multiemissive lanthanide-doped upconversion nanoparticle (UCNP). The energy levels of lanthanide ions gave rise to several emission bands which were exploited as individual sensor elements for the recognition of four important neurotransmitters (NTs): dopamine, norepinephrine, levodopa, and serotonin. At alkaline conditions, the oxidation products of these NTs quenched the fluorescence emissions of UCNPs with different quenching degrees. The resulting fingerprint multichannel emission profiles from NaYF4:Yb/Er/Tm UCNPs allowed the discrimination of NTs with excellent accuracy. The recognition was further verified in...
Copper oxide nanoflakes as highly sensitive and fast response self-sterilizing biosensors
, Article Journal of Materials Chemistry ; Volume 21, Issue 34 , Jul , 2011 , Pages 12935-12940 ; 09599428 (ISSN) ; Ghaderi, E ; Sharif University of Technology
2011
Abstract
Vertical copper oxide nanoflakes were synthesized on a Cu foil through oxidation in alkaline conditions. X-ray photoelectron spectroscopy showed that after exposing the nanoflakes to an Escherichia coli bacterial suspension, the outermost surface of the nanoflakes was chemically reduced through the glycolysis process of the bacteria. Current-voltage (I-V) characteristics of the nanoflakes (measured perpendicular to surface of the Cu foil by using conductive atomic force microscopy) indicated that electrical resistivity of the nanoflakes increased about one order of magnitude after exposure to the bacterial suspension. The nanoflakes reduced by the bacterial suspension could also be...
Identification of catecholamine neurotransmitters using fluorescence sensor array
, Article Analytica Chimica Acta ; Volume 917 , April , 2016 , Pages 85–92 ; 00032670 (ISSN) ; Hormozi Nezhad, M. R ; Mahmoudi, M ; Sharif University of Technology
Elsevier
2016
Abstract
A nano-based sensor array has been developed for identification and discrimination of catecholamine neurotransmitters based on optical properties of their oxidation products under alkaline conditions. To produce distinct fluorescence response patterns for individual catecholamine, quenching of thioglycolic acid functionalized cadmium telluride (CdTe) quantum dots, by oxidation products, were employed along with the variation of fluorescence spectra of oxidation products. The spectral changes were analyzed with hierarchical cluster analysis (HCA) and principal component analysis (PCA) to identify catecholamine patterns. The proposed sensor could efficiently discriminate the individual...
A wide-color-varying ratiometric nanoprobe for detection of norepinephrine in urine samples
, Article Analytica Chimica Acta ; Volume 1039 , 2018 , Pages 124-131 ; 00032670 (ISSN) ; Ghasemi, F ; Hormozi Nezhad, M. R ; Sharif University of Technology
Elsevier B.V
2018
Abstract
Owing to its dual role as a hormone and neurotransmitter, norepinephrine (NE) detection is of great significance to biomedical diagnosis. In the present work, we have explored intense green fluorescence of poly (norepinephrine) (PNE) nanoparticles synthesized by oxidizing NE in alkaline condition, in combination with red fluorescent bovine serum albumin-stabilized gold nanoclusters (BSA-AuNCs) for naked-eye detection of NE. The effect of sodium hydroxide on the emission behavior of NE was studied. The surface morphology and optical properties of PNE nanoparticles were characterized by UV–Vis, fluorescence, FTIR, Transmission Electron Microscopy (TEM) and Dynamic Light Scattering (DLS)...
Durability of epoxy polymer and ordinary cement concrete in aggressive environments
, Article Construction and Building Materials ; Volume 234 , 2020 ; Toufigh, V ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
Polymer concrete is well-known for quick repairing of concrete structures and pavement. However, there are relatively few studies on the durability of epoxy polymer concrete (EPC). This study aims to investigate the long-term environmental effects on the mechanical properties of EPC. Therefore, EPC and ordinary cement concrete (OCC) specimens were prepared and exposed to four chemical solutions with pH values of 2.5, 7, 12.5 and artificial seawater in intervals of 1, 3, 6, 9 and 12 months. Epoxy resin (10 and 12% by weight) and Portland cement were used as binder phase in EPC and OCC specimens, respectively. Scanning electron microscopy (SEM) was additionally applied to investigate the...
A ratiometric fluorescence nanoprobe using CdTe QDs for fast detection of carbaryl insecticide in apple
, Article Talanta ; Volume 221 , 2021 ; 00399140 (ISSN) ; Fahimi Kashani, N ; Hormozi nezhad, M. R ; Sharif University of Technology
Elsevier B.V
2021
Abstract
In this study, a novel, simple and sensitive ratiometric fluorescence method is presented for the detection of very low quantities of the carbaryl in Iranian apple using cadmium telluride quantum dots (CdTe QDs) nanoprobe. The principle of the proposed strategy relies on the rapid hydrolysis of the carbaryl under an alkaline condition and production of the 1-naphthol with a blue emission at 470 nm. Besides, using the CdTe QDs with a yellow emission at 580 nm, as a reference, improves the visual tracking of carbaryl through changes in color tonality. The herein described methodology is applied for enzyme-free visual detection of carbaryl with satisfactory results in the presence of other...
Degradation of humic acids through heterogeneous catalytic ozonation with bone charcoal
, Article Reaction Kinetics, Mechanisms and Catalysis ; Volume 100, Issue 2 , 2010 , Pages 471-485 ; 18785190 (ISSN) ; Asgari, Gh ; Hashemian, S. J ; Moussavi, G ; Sharif University of Technology
2010
Abstract
Catalytic ozonation has recently been used as a new means of contaminant removal from water and wastewater. In this study, bone charcoal (BC), a new catalyst prepared under laboratory conditions, was used to catalyze the ozonation of humic substances (HS) in aqueous solutions. The catalytic effect of bone charcoal and the relevant parameters of this ozonation process (solution pH, temperature, scavenger effect, humic acids concentration and BC dosage) were investigated. In the catalytic ozonation experiments, the degradation kinetics was investigated. The reaction rate and the rate constant were determined. The results showed that using a BC catalyst in the ozonation of HS produced a 1.43-...
Identification of catecholamine neurotransmitters using fluorescence sensor array
, Article Analytica Chimica Acta ; Volume 917 , 2016 , Pages 85-92 ; 00032670 (ISSN) ; Hormozi Nezhad, M. R ; Mahmoudi, M ; Sharif University of Technology
Elsevier B.V
2016
Abstract
A nano-based sensor array has been developed for identification and discrimination of catecholamine neurotransmitters based on optical properties of their oxidation products under alkaline conditions. To produce distinct fluorescence response patterns for individual catecholamine, quenching of thioglycolic acid functionalized cadmium telluride (CdTe) quantum dots, by oxidation products, were employed along with the variation of fluorescence spectra of oxidation products. The spectral changes were analyzed with hierarchical cluster analysis (HCA) and principal component analysis (PCA) to identify catecholamine patterns. The proposed sensor could efficiently discriminate the individual...