Yazar "Karimi-Maleh, Hassan" seçeneğine göre listele

Listeleniyor 1 - 8 / 8
  • [ X ]
    Öğe
    A Novel DNA Biosensor Based on a Pencil Graphite Electrode Modified with Polypyrrole/Functionalized Multiwalled Carbon Nanotubes for Determination of 6-Mercaptopurine Anticancer Drug
    (Amer Chemical Soc, 2015) Karimi-Maleh, Hassan; Tahernejad-Javazmi, Fahimeh; Atar, Necip; Lutfi, Mehmet; Gupta, Vinod Kumar; Ensafi, Ali A.
    A novel and sensitive biosensor employing immobilized DNA on a pencil graphite electrode modified with polypyrrole/functionalized multiwalled carbon nanotubes for the determination of 6-mercaptopurine (6-MP) is presented. In the first step, we modified the pencil graphite surface with polypyrrole and functionalized multiwalled carbon nanotubes (MWCNT/COOH). The developed electrode was characterized by scanning electron microscopy, atomic force microscopy, reflectionabsorption infrared spectroscopy, X-ray photoelectron spectroscopy, and electrochemical impedance spectroscopy. In the other step, we used decreases in the oxidation responses of guanine and adenine as a sign of the interaction of 6-MP with salmon sperm double-stranded DNA using differential pulse voltammetry. The signal of guanine oxidation was linear with respect to the 6-MP concentration in the range of 0.2-100 mu mol L-1 with a detection limit of 0.08 mu mol L-1. The modified electrode was utilized for the determination of 6-MP in real samples.
  • [ X ]
    Öğe
    A sensitive molecularly imprinted polymer based quartz crystal microbalance nanosensor for selective determination of lovastatin in red yeast rice
    (Elsevier Sci Ltd, 2015) Eren, Tanju; Atar, Necip; Yola, Mehmet Lutfi; Karimi-Maleh, Hassan
    Lovastatin (LOV) is a statin, used to lower cholesterol which has been found as a hypolipidemic agent in commercial red yeast rice. In present study, a sensitive molecular imprinted quartz crystal microbalance (QCM) sensor was prepared by fabricating a self-assembling monolayer formation of allylmercaptane on QCM chip surface for selective determination of lovastatin (LOV) in red yeast rice. To prepare molecular imprinted quartz crystal microbalance (QCM) nanosensor, LOV imprinted poly(2-hydroxyethyl methacrylate-methacryloylamidoaspartic acid) [p(HEMA-MAAsp)] nanofilm was attached on the modified gold surface of QCM chip. The non-modified and improved surfaces were characterized by using contact angle, atomic force microscopy (AFM) and Fourier transform infrared (FTIR) spectroscopy. The imprinted QCM sensor was validated according to the ICH guideline (International Conference on Harmonisation). The linearity range was obtained as 0.10-1.25 nM. The detection limit of the prepared material was calculated as 0.030 nM. The developed QCM nanosensor was successfully used to examine red yeast rice. Furthermore, the stability and repeatability of the prepared QCM nanosensor were studied. The spectacular long-term stability and repeatability of the prepared LOV-imprinted QCM nanosensor make them intriguing for use in QCM sensors. (C) 2015 Elsevier Ltd. All rights reserved.
  • [ X ]
    Öğe
    CoFe2O4@TiO2 decorated reduced graphene oxide nanocomposite for photocatalytic degradation of chlorpyrifos
    (Elsevier, 2015) Gupta, Vinod Kumar; Eren, Tanju; Atar, Necip; Yola, Mehmet Lutfi; Parlak, Cemal; Karimi-Maleh, Hassan
    Chlorpyrifos is widely used to control pest insects in residential, agricultural, and commercial applications. Its common use has led to the release of chlorpyrifos into sediments, wastewater and water sources. The presence of chlorpyrifos in wastewaters and water sources may affect ecosystem and human health due to its chronicle toxicity to aquatic organisms. In this study, magnetic recoverable CoFe2O4@TiO2 decorated reduced graphene oxide nanocomposite was prepared and used for investigating the photodegradation of chlorpyrifos. The nanocomposite was characterized by using transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction and scanning electron microscopy. In photocatalytic degradation of chlorpyrifos experiments, the effect of operating variables such as initial chlorpyrifos concentration, catalyst dosage and contact time was also investigated. The photocatalytic degradation of chlorpyrifos followed the pseudo-first-order kinetic model. The results indicated that the nanocomposite exhibited a high efficient photocatalytic activity on the photodegradation of chlorpyrifos. The nanocomposite was separated from the solution by a magnet and reused after the photodegradation of chlorpyrifos. The recyclable of the nanocomposite is economically significant in the industry. (C) 2015 Elsevier B.V. All rights reserved.
  • [ X ]
    Öğe
    Facile and green fabrication of silver nanoparticles on a polyoxometalate for Li-ion battery
    (Springer Heidelberg, 2015) Eren, Tanju; Atar, Necip; Yola, Mehmet Lutfi; Karimi-Maleh, Hassan; Colak, Alper Tolga; Olgun, Asim
    In the present study, we report the green and one-pot synthesis of silver nanoparticles (AgNPs) on as-prepared novel polyoxometalate {[Ni-2,Ni-5(Hpen)(4)(PW9O34)] center dot 5H(2)O} (POM) without any reducing agent and its application as improved anode material for lithium-ion batteries (LIBs). The structure of the AgNPs involved POM (AgNPs/POM) nanocomposite was characterized by transmission electron microscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy. The synthesized POM was also characterized by elemental analysis and thermal analysis. The electrochemical performances of the POM, AgNPs, and AgNPs/POM composites were measured for charge/discharge specific capacities at different current rates in CR2032 coin-type cells. The prepared AgNPs/POM composite showed a high specific gravimetric capacity of about 1760 mAh g(-1) and long-term cycle stability.
  • [ X ]
    Öğe
    Magnetic iron oxide and iron oxide@gold nanoparticle anchored nitrogen and sulfur-functionalized reduced graphene oxide electrocatalyst for methanol oxidation
    (Royal Soc Chemistry, 2015) Atar, Necip; Eren, Tanju; Yola, Mehmet Lutfi; Karimi-Maleh, Hassan; Demirdogen, Bermali
    Fuel cells have been attracting more and more attention in recent decades due to high-energy demands, fossil fuel depletions and environmental pollution throughout world. In this study, we report the synthesis of metallic and bimetallic nanoparticles such as spherical iron oxide nanoparticles [(sp)Fe3O4], rod iron oxide nanoparticles [(rd)Fe3O4] and iron@gold nanoparticles (Fe3O4@AuNPs) involving L-cysteine functionalized reduced graphene oxide nanohybrids [(sp) Fe3O4/cys/rGO, (rd)Fe3O4/cys/rGO and Fe3O4@AuNPs/cys/ rGO] and their application as an electrocatalyst for methanol electro-oxidation. The nanohybrids have been characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The experimental results have demonstrated that reduced graphene oxide-supported bimetallic nanoparticles enhanced the electrochemical efficiency for methanol electro-oxidation with regard to diffusion efficiency, oxidation potential and forward oxidation peak current. Fe3O4@AuNPs/cys/rGO, in comparison to (sp)Fe3O4/cys/rGO and (rd)Fe3O4/cys/rGO, showed the most efficiency for methanol electro-oxidation.
  • [ X ]
    Öğe
    Sensitive and selective determination of aqueous triclosan based on gold nanoparticles on polyoxometalate/reduced graphene oxide nanohybrid
    (Royal Soc Chemistry, 2015) Yola, Mehmet Lutfi; Atar, Necip; Eren, Tanju; Karimi-Maleh, Hassan; Wang, Shaobin
    The widespread use of triclosan (TCS) in household cleaning products, medical devices and personal care poses a potential risk to the ecological system and human health due to its release into sediments, surface water and ground water resources and chronicle toxicity to aquatic organisms. A novel molecular-imprinted electrochemical sensor based on gold nanoparticles decorating polyoxometalate (H3PW12O40)/reduced graphene oxide was developed for determination of trace TCS in wastewater. Reduced graphene oxide (rGO) was functionalized by polyoxometalate (POM) through electrostatic interaction between the POM and rGO nanosheets to produce a photocatalyst (POM/rGO) in aqueous solution. Gold nanoparticles (AuNPs) were further deposited on the POM/rGO without using any reducing agent and the prepared nanomaterial (AuNPs/POM/rGO) was employed to modify a glass carbon (GC) electrode (AuNPs/POM/rGO/GC) under infrared light. Several techniques, X-ray photoelectron spectroscopy (XPS), reflection-absorption infrared spectroscopy (RAIRS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), were used for electrode characterization. TCS imprinted film was generated on AuNPs/POM/rGO/GC via polymerization of phenol and TCS and characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The sensor was found to have a linear detection range and a limit of TCS at 0.5-50.0 nM and 0.15 nM, respectively. The molecular imprinted sensor was applied to wastewater and lakewater samples and demonstrated effective performance as compared to other complicated methods.
  • [ X ]
    Öğe
    Sensitive and selective determination of aqueous triclosan based on gold nanoparticles on polyoxometalate/reduced graphene oxide nanohybrid (vol 5, pg 65953, 2015)
    (Royal Soc Chemistry, 2015) Yola, Mehmet Lutfi; Atar, Necip; Eren, Tanju; Karimi-Maleh, Hassan; Wang, Shaobin
    [No abstract available]
  • [ X ]
    Öğe
    Voltammetric Determination of Hydroxylamine Using a Ferrocene Derivative and NiO/CNTs Nanocomposite Modified Carbon Paste Electrode
    (Esg, 2015) Golestanifar, Fereshteh; Karimi-Maleh, Hassan; Atar, Necip; Aydogdu, Ercan; Ertan, Bengu; Taghavi, Mehdi; Yola, Mehmet Lutfi
    The electrochemical activities of hydroxylamine (HX) as a pollutant compound at a 1,1-bis(phenylacetyl) ferrocenele/NiO/CNTs modified carbon paste electrode (1,1-BPF/NiO/CNTs/CPE) has been studied. 1,1-BPF was used as a suitable mediator for elecrocatalytic interaction with HX. The voltammetric properties of HX at the 1,1-BPF/NiO/CNTs/CPE was investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), chronoamperometry, and square wave voltammetry (SWV) methods. The oxidation peak current increases linearly with HX concentration in the range 0.5-250.0 mu M and the detection limit for HX was 0.2 mu M. The sensor was applied to wastewater samples with excellent performance.