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Functional properties of biodegradable corn starch nanocomposites for food packaging applications
, Article Materials and Design ; Volume 50 , 2013 , Pages 954-961 ; 02613069 (ISSN) ; Alemzadeh, I ; Vossoughi, M ; Sharif University of Technology
Elsevier Ltd
2013
Abstract
In this research, response surface methodology (RSM) was applied to study the effects of Na-Montmorillonite (Na-MMT) and glycerol on some functional properties of corn starch films. Films were prepared by casting method according to central composite design (CCD). Originally image processing technique was used in order to estimate transparency of the films. It was found that Na-MMT absorbed UV light from 216 to 266. nm. No antimicrobial activities were observed against Escherichia coli and Staphylococcus aureus. Contact angle analysis revealed hydrophilicity of starch films decreased utilizing nanoparticles and increased with plasticizer content. Increase in glycerol content decreased...
Functionalized carbon nanotubes in ZnO thin films for photoinactivation of bacteria
, Article Materials Chemistry and Physics ; Volume 130, Issue 1-2 , October , 2011 , Pages 598-602 ; 02540584 (ISSN) ; Azimirad, R ; Safa, S ; Sharif University of Technology
2011
Abstract
Two types of unfunctionalized and functionalized multi-wall carbon nanotubes (MWCNTs) were prepared to be applied in fabrication of MWCNT-ZnO nanocomposite thin films with various MWCNT contents. X-ray photoelectron spectroscopy indicated formation of functional groups on surface of the functionalized MWCNTs in the MWCNT-ZnO nanocomposite. Formation of the effective carbonaceous bonds between the ZnO and the MWCNTs was also investigated through photoinactivation of Escherichia coli bacteria on surface of the both unfunctionalized and functionalized MWCNT-ZnO nanocomposites. The functionalized MWCNT-ZnO nanocomposites showed significantly stronger photoinactivation of the bacteria than the...
Facile template-free synthesis of the CuO microflowers with enhanced photocatalytic properties
, Article Materials Research Innovations ; 2016 , Pages 1-5 ; 14328917 (ISSN) ; Padervand, M ; Vosoughi, M ; Roosta Azad, R ; Sharif University of Technology
Taylor and Francis Ltd
2016
Abstract
CuO flower-like microcrystals, prepared by a facile template-free thermal method, showed incredible photocatalytic activity towards degradation of Acid Blue 92 (AB92), an organic wastewater, Escherichia coli and Staphylococcus aureus pathogenic bacteria under visible light. The products were well characterised by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), scanning electron microscope (SEM), Fourier transform infrared (FTIR), photoluminescence spectroscopy (PL) and diffuse reflectance spectra (DRS) analysis methods. The XRD pattern of the products well confirmed the formation of copper oxide crystalline phase without any other impurities. The results of the photocatalytic...
Facile template-free synthesis of the CuO microflowers with enhanced photocatalytic properties
, Article Materials Research Innovations ; Volume 21, Issue 7 , 2017 , Pages 434-438 ; 14328917 (ISSN) ; Padervand, M ; Vosoughi, M ; Roosta Azad, R ; Sharif University of Technology
Abstract
CuO flower-like microcrystals, prepared by a facile template-free thermal method, showed incredible photocatalytic activity towards degradation of Acid Blue 92 (AB92), an organic wastewater, Escherichia coli and Staphylococcus aureus pathogenic bacteria under visible light. The products were well characterised by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), scanning electron microscope (SEM), Fourier transform infrared (FTIR), photoluminescence spectroscopy (PL) and diffuse reflectance spectra (DRS) analysis methods. The XRD pattern of the products well confirmed the formation of copper oxide crystalline phase without any other impurities. The results of the photocatalytic...
Fabrication and characterization of scaffolds containing different amounts of allantoin for skin tissue engineering
, Article Scientific Reports ; Volume 11, Issue 1 , 2021 ; 20452322 (ISSN) ; Shamloo, A ; Bahadoran, M ; Moravvej, H ; Sharif University of Technology
Nature Research
2021
Abstract
Using the skin tissue engineering approach is a way to help the body to recover its lost skin in cases that the spontaneous healing process is either impossible or inadequate, such as severe wounds or burns. In the present study, chitosan/gelatin-based scaffolds containing 0.25, 0.5, 0.75, and 1% allantoin were created to improve the wounds’ healing process. EDC and NHS were used to cross-link the samples, which were further freeze-dried. Different in-vitro methods were utilized to characterize the specimens, including SEM imaging, PBS absorption and degradation tests, mechanical experiments, allantoin release profile assessment, antibacterial assay, and cell viability and adhesion tests....
Examination of chondroitinase ABC I immobilization onto dextran-coated Fe3O4 nanoparticles and its in-vitro release
, Article Journal of Biotechnology ; Volume 309 , 2020 , Pages 131-141 ; Vossoughi, M ; Khajeh, K ; Alemzadeh, I ; Sharif University of Technology
Elsevier B.V
2020
Abstract
Chondroitinase ABC I (cABC I) has received notable attention in treatment of spinal cord injuries and its application as therapeutics has been limited due to low thermal stability at physiological temperature. In this study, cABC I enzyme was immobilized on the dextran-coated Fe3O4 nanoparticles through physical adsorption to improve the thermal stability. The nanoparticles were characterized using XRD, SEM, VSM, and FTIR analyses. Response surface methodology and central composite design were employed to assess factors affecting the activity of immobilized cABC I. Experimental results showed that pH 6.3, temperature 24 °C, enzyme/support mass ratio 1.27, and incubation time 5.7 h were the...
Evaluation of antibacterial behavior of in situ grown CuO-GO nanocomposites
, Article Materials Today Communications ; Volume 28 , 2021 ; 23524928 (ISSN) ; Fattahi Nafchi Fatahi, R ; Sangpour, P ; Bagheri, M ; Rahimi, T ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
The growth of harmful microorganisms is a severe threat to human life. Nowadays, it is necessary to prepare antimicrobials materials with high biocompatibility properties. Hence, the use of nanomaterials and their nanocomposites has been proposed as a suitable way to obtain safe and potent antibacterial materials. Recently, several studies have been conducted on the antibacterial properties of metal oxide and graphene oxide (GO) nanomaterials individually. This study investigated the synergistic effect of GO and copper oxide (CuO) as a nanocomposite. CuO-GO nanocomposite containing 5%, 15%, 25%, 50%, and 75% of GO were synthesized to study antibacterial properties. X-ray diffraction (XRD)...
Evaluation of antibacterial behavior of in situ grown CuO-GO nanocomposites
, Article Materials Today Communications ; Volume 28 , 2021 ; 23524928 (ISSN) ; Fattahi Nafchi Fatahi, R ; Sangpour, P ; Bagheri, M ; Rahimi, T ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
The growth of harmful microorganisms is a severe threat to human life. Nowadays, it is necessary to prepare antimicrobials materials with high biocompatibility properties. Hence, the use of nanomaterials and their nanocomposites has been proposed as a suitable way to obtain safe and potent antibacterial materials. Recently, several studies have been conducted on the antibacterial properties of metal oxide and graphene oxide (GO) nanomaterials individually. This study investigated the synergistic effect of GO and copper oxide (CuO) as a nanocomposite. CuO-GO nanocomposite containing 5%, 15%, 25%, 50%, and 75% of GO were synthesized to study antibacterial properties. X-ray diffraction (XRD)...
Evaluating the toxic effect of an antimicrobial agent on single bacterial cells with optical tweezers
, Article Biomedical Optics Express ; Volume 6, Issue 1 , 2015 , Pages 112-117 ; 21567085 (ISSN) ; Zhang, C ; Chen, J ; Reihani, S. N. S ; Chen, Z ; Sharif University of Technology
OSA - The Optical Society
2015
Abstract
We implement an optical tweezers technique to assess the effects of chemical agents on single bacterial cells. As a proof of principle, the viability of a trapped Escherichia coli bacterium is determined by monitoring its flagellar motility in the presence of varying concentrations of ethyl alcohol. We show that the “killing time” of the bacterium can be effectively identified from the correlation statistics of the positional time series recorded from the trap, while direct quantification from the time series or associated power spectra is intractable. Our results, which minimize the lethal effects of bacterial photodamage, are consistent with previous reports of ethanol toxicity that used...
Escherichia coli bacteria reduce graphene oxide to bactericidal graphene in a self-limiting manner
, Article Carbon ; Volume 50, Issue 5 , 2012 , Pages 1853-1860 ; 00086223 (ISSN) ; Ghaderi, E ; Sharif University of Technology
2012
Abstract
Interactions of chemically exfoliated graphene oxide (GO) nanosheets and Escherichia coli bacteria living in mixed-acid fermentation with an anaerobic condition were investigated for different exposure times. X-ray photoelectron spectroscopy showed that as the exposure time increased (from 0 to 48 h), the oxygen-containing functional groups of the GO decreased by ∼60%, indicating a relative chemical reduction of the sheets by interaction with the bacteria. Raman spectroscopy and current-voltage measurement confirmed the reduction of the GO exposed to the bacteria. The reduction was believed to be due to the metabolic activity of the surviving bacteria through their glycolysis process. It was...
Enhancement of antibacterial properties of Ag nanorods by electric field
, Article Science and Technology of Advanced Materials ; Volume 10, Issue 1 , 2009 ; 14686996 (ISSN) ; Ghaderi, E ; Sharif University of Technology
2009
Abstract
The effect of an electric field on the antibacterial activity of columnar aligned silver nanorods was investigated. Silver nanorods with a polygonal cross section, a width of 20-60 nm and a length of 260-550 nm, were grown on a titanium interlayer by applying an electric field perpendicular to the surface of a Ag/Ti/Si(100) thin film during its heat treatment at 700 °C in an Ar+H2 environment. The optical absorption spectrum of the silver nanorods exhibited two peaks at wavelengths of 350 and 395 nm corresponding to the main surface plasmon resonance bands of the one-dimensional silver nanostructures. It was found that the silver nanorods with an fcc structure were bounded mainly by {100}...
Enhanced electricity generation from whey wastewater using combinational cathodic electron acceptor in a two-chamber microbial fuel cell
, Article International Journal of Environmental Science and Technology ; Volume 9, Issue 3 , 2012 , Pages 473-478 ; 17351472 (ISSN) ; Safekordi, A. A ; Sharif University of Technology
2012
Abstract
While energy consumption is increasing worldwide due to population growth, the fossil fuels are unstable and exhaustible resources for establishing sustainable life. Using biodegradable compounds present in the wastewater produced in industrial process as a renewable source is an enchanting approach followed by scientists for maintaining a sustainable energy production to vanquish this problem for ulterior generations. In this research, bioelectricity generation with whey degradation was investigated in a two-chamber microbial fuel cell with humic acid as anodic electron mediator and a cathode compartment including combinational electron acceptor. Escherichia coli was able to use the...
Electrospun Ag-decorated reduced GO-graft-chitosan composite nanofibers with visible light photocatalytic activity for antibacterial performance
, Article Chemosphere ; Volume 299 , 2022 ; 00456535 (ISSN) ; Mohammadi Ziarani, G ; Badiei, A ; Setayeshmehr, M ; Kiani, M ; Pourjavadi, A ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
The treatment of water contaminated by bacteria is becoming a necessity. The nanomaterials possessing both intrinsic antibacterial properties and photocatalytic activity are excellent candidates for water disinfection. The powdered form of nanomaterials can be aggregated while embedding the nanomaterials into the NFs can overcome the limitation and enhance the photocatalytic activity and transition from UV-light to visiblelight. Here, graphene oxide (GO) was synthesized, grafted to chitosan, and decorated with silver nanoparticles (Ag NPs) to produce Ag-decorated reduced GO-graft-Chitosan (AGC) NPs. The blends of polyacrylonitrile (PAN) and AGC NPs were prepared in various concentrations of...
Electrochemical and computational studies of bio-mimicked Ti3C2Tx MXene-based sensor with multivalent interface
, Article Journal of Colloid and Interface Science ; Volume 623 , 2022 , Pages 1063-1074 ; 00219797 (ISSN) ; Ashari Astani, N ; Atabay, M ; Naseri, N ; Esfandiar, A ; Reza Ejtehadi, M ; Sharif University of Technology
Academic Press Inc
2022
Abstract
Two-dimensional MXenes are the newly emerging family of nanomaterials with competitive performance for nano-device development. Surface functional groups and abundant binding sites make these materials ideal candidates for sensor applications. Herein, we report the successful fabrication of a MXene-based nano-bio device for capturing, sensing, and filtering the Escherichia coli (E. coli) bacteria. Mannose carbohydrate, which binds strongly to E.coli's fimH protein via glucan multivalent interactions, is used as the bio-receptor element. MXene's structure was engineered to guarantee efficient E. coli capturing without mannose detachment. Electrochemical impedance spectroscopy (EIS) and cyclic...
Effects of temperature shifts and oscillations on recombinant protein production expressed in Escherichia coli
, Article Bioprocess and Biosystems Engineering ; Volume 36, Issue 11 , 2013 , Pages 1571-1577 ; 16157591 (ISSN) ; Herwig, C ; Sharif University of Technology
2013
Abstract
Escherichia coli is widely used host for the intracellular expression of many proteins. However, in some cases also secretion of protein from periplasm was observed. Improvement of both intracellular and extracellular production of recombinant protein in E. coli is an attractive goal in order to reduce production cost and increase process efficiency and economics. Since heat shock proteins in E. coli were reported to be helpful for protein refolding and hindering aggregation, in this work different types of single and periodic heat shocks were tested on lab scale to enhance intracellular and extracellular protein production. A single heat shock prior to induction and different oscillatory...
Effects of SiC nanoparticles on synthesis and antimicrobial activity of TiCu nanocrystalline powder
, Article Ceramics International ; Volume 46, Issue 1 , January , 2020 , Pages 114-120 ; Alipour, S ; Akbarpour, M. R ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
Effects of SiC nanoparticles addition on synthesis and antibacterial properties of TiCu nanocrystalline powder prepared through high energy mechanical milling were studied. The results showed that the synthesis of TiCu powder in the presence of the nanoparticles was accelerated and after mechanical alloying for 20 h, a TiCu/SiC nanocrystalline powder with the crystallite size <5 nm, and 3.3% lattice micro-strain obtained. Further milling resulted in fully amorphous TiCu intermetallic alloy with more uniform distribution of SiC nanoparticles. The antibacterial activity of the synthesized powders was investigated by disk diffusion test. The TiCu/SiC nanocomposites showed enhanced antibacterial...
Effect of graphene oxide nanosheets on visible light-assisted antibacterial activity of vertically-aligned copper oxide nanowire arrays
, Article Journal of Colloid and Interface Science ; Volume 521 , 2018 , Pages 119-131 ; 00219797 (ISSN) ; Ashari Astani, N ; Rahighi, R ; Tayyebi, A ; Tayebi, M ; Khezri, J ; Hashemi, E ; Rothlisberger, U ; Simchi, A ; Sharif University of Technology
Academic Press Inc
2018
Abstract
In the present work, the effect of graphene oxide (GO) nanosheets on the antibacterial activity of CuO nanowire arrays under visible light irradiation is shown. A combined thermal oxidation/electrophoretic deposition technique was employed to prepare three-dimensional networks of graphene oxide nanosheets hybridized with vertically aligned CuO nanowires. With the help of standard antibacterial assays and X-ray photoelectron spectroscopy, it is shown that the light-activated antibacterial response of the hybrid material against gram-negative Escherichia coli is significantly improved as the oxide functional groups of the GO nanosheets are reduced. In order to explore the physicochemical...
Dynamical analysis of microfluidic microbial electrolysis cell via integrated experimental investigation and mathematical modeling
, Article Electrochimica Acta ; Volume 227 , 2017 , Pages 317-329 ; 00134686 (ISSN) ; Yaghmaei, S ; Sharif University of Technology
Elsevier Ltd
2017
Abstract
The present study deals with the feasibility of a microfluidic microbial electrolysis cell (MEC) as an efficient biohydrogen generator for medical usage for the first time. The evaluation of nickel in microfluidic MEC as an alternative for conventional electrodes indicates successful performance in the improvement of bioenergy production. The maximum biohydrogen production rate and produced power density of 2.2 μW cm−2 and 1.4 μl H2 μl substrate−1 day−1 were obtained, respectively. It is considered a promising technology for medical usage due to the following factors: significant biohydrogen generation, low consumption of expensive materials, simple construction, and utilization of human...
DNA and RNA extractions from eukaryotic and prokaryotic cells by graphene nanoplatelets
, Article RSC Advances ; Vol. 4, issue. 105 , 2014 , p. 60720-60728 ; Akhavan, O ; Shamsara, M ; Valimehr, S ; Rahighi, R ; Sharif University of Technology
Abstract
Graphene nanoplatelets with lateral dimensions of ∼50-200 nm and thicknesses <2 nm were utilized for the extraction of nucleic acids (NAs) from eukaryotic and prokaryotic cells. The graphene nanoplatelets (both chemically exfoliated graphene oxide nanoplatelets and hydrazine-reduced graphene oxide nanoplatelets) successfully extracted plasmid DNA (pDNA) from Escherichia coli bacteria, comparable to a conventional phenol-chloroform (PC) method. Furthermore, it was found that the yield of graphene nanoplatelets in genomic DNA (gDNA) and RNA extractions from embryonic stem cells (ESCs) was also comparable to the yield of the conventional methods. The effects of the graphene nanoplatelets on...
Dextran-graft-poly(hydroxyethyl methacrylate) gels: A new biosorbent for fluoride removal of water
, Article Designed Monomers and Polymers ; Volume 16, Issue 2 , 2013 , Pages 127-136 ; 1385772X (ISSN) ; Mousavi, S. A ; Amini Fazl, A ; Amini Fazl, M. S ; Ahmari, R ; Sharif University of Technology
2013
Abstract
Synthesis of dextran-graft-poly(hydroxyethyl methacrylate) gels as a new fluoride biosorbent was considered in this work. For this propose, the Taguchi experimental design method was used for optimizing the synthetic conditions of the gels to reach high level of fluoride absorbency. The effects of three main parameters including concentrations of monomer (hydroxyethyl methacrylate), crosslinking agent (ethylene glycol dimethacrylate), and initiator (ammonium persulfate) on the final properties of the prepared gels were investigated. The proposed mechanism for grafting and chemically crosslinking reactions was proved with equilibrium water absorption, Fourier-transformed infrared, scanning...