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Öğe A Comparative Study of Electrochemical Behaviors of 1-nitroso-2-naphthol on Glassy Carbon and Platinum Electrode Surfaces by Cyclic Voltammetry(Univ Tehran, Fac Chemistry, Center Excellence Electrochemistry, 2012) Mulazimoglu, Aysen Demir; Yilmaz, Ecir; Mercimek, Bedrettin; Mulazimoglu, Ibrahim EnderIn the present work, electrochemical and spectroelectrochemical behaviors of 1-nitroso-2-naphthol has been studied by cyclic voltammetry and electrochemical impedance spectroscopy techniques in non-aqueous media. Cyclic voltammetric studies of 1-nitroso-2-naphthol in acetonitrile containing 100 mM tetrabutylammonium tetrafluoroborate on glassy carbon and platinum electrodes were performed between 0.0 mV and +2600 mV potential range at 100 mV s(-1) scan rate with 10 cycles. Anodic peaks were observed at 475.3 mV, 958.9 mV, 1395 mV and 2103 mV for 1-nitroso-2-naphthol on the glassy carbon electrode surface vs. Ag/Ag+ reference electrode. The surface characterizations were carried out by using cyclic voltammetry and electrochemical impedance spectroscopy techniques in both aqueous and non-aqueous media. Electrochemical behaviors of 1-nitroso-2-naphthol on glassy carbon and platinum electrode surfaces were compared.Öğe Determination of copper ions based on newly developed poly-chrysin modified glassy carbon sensor electrode(Walter De Gruyter Gmbh, 2012) Mulazimoglu, Aysen Demir; Mulazimoglu, Ibrahim Ender; Yilmaz, EcirIn this paper, glassy carbon (GC) was modified through the electrochemical polymerization of chrysin (PolyChr/GC) on the surface in media where the electrode surface was aqueous and non-aqueous. Electrochemical polymerization was performed between +800 mV and +2600 mV in aqueous medium, and from +500 mV to +1800 mV in non-aqueous medium in 100 mV s(-1) sweep rate with 30 cycles. Modified electrode surface characterization was done by cyclic voltammetry and electrochemical impedance spectroscopy. In the study, the interaction between the PolyChr/GC electrode surface and Cu(II), Zn(II), Cd(II), Pb(II), Co(II) and Ni(II) ions was investigated by using the square wave voltammetry technique. The PolyChr/GC electrode surface was found to be sensitive and selective towards Cu(II), Pb(II) and Cd(II) ions.Öğe Determination of copper ions based on newly developed poly-chrysin modified glassy carbon sensor electrode(Walter De Gruyter Gmbh, 2012) Mulazimoglu, Aysen Demir; Mulazimoglu, Ibrahim Ender; Yilmaz, EcirIn this paper, glassy carbon (GC) was modified through the electrochemical polymerization of chrysin (PolyChr/GC) on the surface in media where the electrode surface was aqueous and non-aqueous. Electrochemical polymerization was performed between +800 mV and +2600 mV in aqueous medium, and from +500 mV to +1800 mV in non-aqueous medium in 100 mV s(-1) sweep rate with 30 cycles. Modified electrode surface characterization was done by cyclic voltammetry and electrochemical impedance spectroscopy. In the study, the interaction between the PolyChr/GC electrode surface and Cu(II), Zn(II), Cd(II), Pb(II), Co(II) and Ni(II) ions was investigated by using the square wave voltammetry technique. The PolyChr/GC electrode surface was found to be sensitive and selective towards Cu(II), Pb(II) and Cd(II) ions.Öğe Dithiooxamide Modified Glassy Carbon Electrode for the Studies of Non-Aqueous Media: Electrochemical Behaviors of Quercetin on the Electrode Surface(Mdpi Ag, 2012) Mulazimoglu, Aysen Demir; Yilmaz, Ecir; Mulazimoglu, Ibrahim EnderElectrochemical oxidation of quercetin, as an important biological molecule, has been studied in non-aqueous media using cyclic voltammetry, electrochemical impedance spectroscopy and scanning electron microscopy. To investigate the electrochemical properties of quercetin, an important flavonoid derivative, on a different surface, a new glassy carbon electrode has been developed using dithiooxamide as modifier in non-aqueous media. The surface modification of glassy carbon electrode has been performed within the 0.0 mV and +800 mV potential range with 20 cycles using 1 mM dithioxamide solution in acetonitrile. However, the modification of quercetin to both bare glassy carbon and dithiooxamide modified glassy carbon electrode surface was carried out in a wide +300 mV and +2,800 mV potential range with 10 cycles. Following the modification process, cyclic voltammetry has been used for the surface characterization in aqueous and non-aqueous media whereas electrochemical impedance spectroscopy has been used in aqueous media. Scanning electron microscopy has also been used to support the surface analysis. The obtained data from the characterization and modification studies of dithioxamide modified and quercetin grafted glassy carbon electrode showed that the developed electrode can be used for the quantitative determination of quercetin and antioxidant capacity determination as a chemical sensor electrode.Öğe Electrochemical Behaviors of 2-Amino-3-Hydroxypyridine onto the Glassy Carbon Sensor Electrode: Simultaneous and Independent Determinations of Quercetin, Galangin, 3-Hydroxyflavone, and Chrysin(Springer, 2013) Mulazimoglu, Aysen Demir; Mulazimoglu, Ibrahim EnderFlavonoids, with high antioxidant activity in fruits and vegetables, are natural vegetable dyes synthesized from phenylalanine. They are very essential for human health due to their activity as free radical acceptors. In this paper, the availability in the determination of quercetin (Que), galangin (Gal), 3-hydroxyflavone (3HF), and chrysin (Chr) of a modified glassy carbon (GC) sensor electrode using 2-amino-3-hydroxypyridine (AHP) was examined separately and simultaneously by cyclic voltammetry (CV). Surface characterization of modified electrodes was performed using CV, electrochemical impedance spectroscopy, and scanning electron microscopy techniques. The modification of AHP onto the GC electrode surface was carried out between -150 and +600 mV potential range using 100 mV s(-1) scanning rate with 30 cycles. The binding of flavonoid derivatives onto the modified surface was performed between +300 and +1,700 mV potential range using 100 mV s(-1) scanning rate with 10 cycles. The usability of the modified electrode was examined in the determination of some flavonoids by square wave voltammetry. From the experimental results, it was found out that Que, 3HF, and Chr; Gal, 3HF, and Chr; and 3HF and Chr can be determined simultaneously by using an AHP-modified GC sensor electrode. Also, these molecules can easily be determined separately by using the modified electrode.Öğe Electrochemical Behaviours of 4,4?-Methylenedianiline in Non-Aqueous Media on a Platinum Electrode Surface(Asian Journal Of Chemistry, 2012) Mulazimoglu, Aysen Demir; Yilmaz, EcirElectrochemical behaviours of 4,4'-methylenedianiline were investigated by cyclic voltammetry, differential pulse voltammetry and electrochemical impedance spectroscopy on a platinum electrode surface. The platinum working electrode surface was modified with 4,4'-methylenedianiline in acetonitrile containing 100 mM tetrabutylammonium tetrafluoroborate using 100 mV s(-1) scan rate from 0.0 mV to +1600 mV potential range with 30 cycles. In differential pulse voltammetry experiments, the potential range was from 0.0 mV to +1000 mV. The presence of 4,4'-methylenedianiline at the platinum electrode surface was characterized by cyclic voltammetry and electrochemical impedance spectroscopy.Öğe Electrochemical Grafting by Reduction of 4-Methylaminobenzenediazonium Salt at GC, Au and Pt Electrode: Investigation of Sensitivity Against Phenol by Cyclic Voltammetry(Univ Tehran, Fac Chemistry, Center Excellence Electrochemistry, 2012) Mulazimoglu, Aysen Demir; Mulazimoglu, Ibrahim Ender; Mercimek, BedrettinThe aim of this study is to modify a glassy cabon, gold and platinum electrode with 4-methylaminobenzenediazonium salt (MABDAS) to evaluate the possible application on the detection of phenol by cyclic voltammetry (CV). Diazonium salt was reduced electrochemically and covalently electro-grafted onto GC, Au and Pt electrodes surface to form modified electrodes in non-aqueous media. The electrode surfaces were modified with MABDAS in acetonitrile (CH3CN). MAB modified GC (MAB/GC) electrode was used for the phenol determination in aqueous media. The effect of pH on the electrochemical behavior of the modified GC electrode was investigated for the phenol detection.Öğe Electrochemical Properties of MDA/GC Electrode and Investigation of Usability as Sensor Electrode for Determination of Que, Kae, Lut and Gal Using CV, DPV and SWV(Springer, 2013) Mulazimoglu, Aysen Demir; Mulazimoglu, Ibrahim EnderFlavonoids, natural vegetable dyes synthesized from phenylalanine, are responsible for the colour of blooming portions of plants. They are very essential for human health due to their activity as free radical acceptors. In this study, electrochemical modification of a glassy carbon (GC) electrode with 4,4'-methylenedianiline (MDA) was carried out, and the modified electrode was investigated separately and simultaneously for the availability in determination of quercetin, kaempferol, luteolin and galangin. The surface modification of the GC electrode was performed with MDA using cyclic voltammetry (CV), whereas the characterization of this sensor electrode was performed using CV, electrochemical impedance spectroscopy and scanning electron microscopy. The usability of the modified electrode has been examined in the determination of some flavonoids using CV, differential pulse voltammetry and square wave voltammetry. Consequently, flavonoid derivatives can easily be determined separately and simultaneously by using an MDA-modified GC sensor electrode.Öğe Electrochemically grafted poly-chrysin to glassy carbon electrode for Cu(II) determination in lake water sample(Sila Science, 2012) Yilmaz, Ecir; Mulazimoglu, Aysen DemirThe electrochemical polymerization of chrysin (Chr) on the glassy carbon (GC) electrode surface was performed in non-aqueous media by potential cycling. Surface modification was performed by 30 cycles within the potential range from +500 mV to +1800 mV at 100 mV s(-1) sweep rate. The oxidation peak potential of PolyChr/GC during the first potential cycle was 1403 mV. Presence of grafted PolyChr/GC on the GC electrode surface was verified by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The sensitivity of GC electrode modified in described way towards copper(H) (Cu(II)) was investigated in Britton-Robinson (BR) buffer solution, pH 5, by differential pulse voltammetry (DPV) and square wave voltammetry (SWV). SWV was found to be more sensitive in comparison with DPV. For the calibration curve, a series of standard Cu(II) solution from 1.0x10(-11) M to 1.0x10(-3) M was prepared. In present study, the modified electrode was successfully applied for the determination of Cu(II) ions in Egirdir lake(in Isparta, Turkey) water sample by SWV.Öğe Electropolymerization of 4,4?-Methylenedianiline onto the Gold Electrode in Non-Aqueous Medium and Investigation of Electrochemical and Spectroelectrochemical Behaviours(Asian Journal Of Chemistry, 2012) Yilmaz, Ecir; Mulazimoglu, Aysen DemirIn this work, electrochemical and spectroelectrochemical behaviours of 4,4'-methylenedianiline have been studied by using cyclic voltammetry, electrochemical impedance spectroscopy and differential pulse voltammetry technique. In cyclic voltammetry surface characterization performed study, the grafting process of 4,4'-methylenedianiline on the electrode surface has been performed using 1 mM 4,4'-methylenedianiline solution in 100 mM tetrabutylammonium tetrafluoroborate in the range from 0.0 mV to +1600 mV potential range at 100 mV s(-1) sweeping rate with 30 cycles. The surface characterization process has been carried out by using cyclic voltammetry and electrochemical impedance spectroscopy technique in both aqueous and non-aqueous media. Differential pulse voltammetry technique has been used to support the clear binding of molecule to the electrode surface. A polymerization mechanism for the binding process has also been suggested.Öğe Investigation of Sensitivity Against Different Flavonoid Derivatives of Aminophenyl-Modified Glassy Carbon Sensor Electrode and Antioxidant Activities(Springer, 2012) Mulazimoglu, Ibrahim Ender; Mulazimoglu, Aysen DemirThe electrochemical behaviors of 10 structurally different flavonoids (quercetin, galangin, chrysin, 3-hydroxyflavone, naringenin, luteolin, apigenin, flavone, kaempferol, and naringin) on a glassy carbon electrode were studied by cyclic voltammetry. In the current study, nitrophenyl diazonium salt has been synthesized from p-nitrophenylamine. One millimolar prepared nitrophenyl diazonium salt (in 100 mM tetrabutylammonium tetrafluoroborate) in acetonitrile was used to modify the glassy carbon electrode. Nitro groups have been reduced to amine groups in 100 mM HCl medium on the nitrophenyl-modified glassy carbon electrode surface. Although nitrophenyl-modified glassy carbon electrode surface was electro-inactive, it is activated by reducing the nitro group into amine group. And then, aminophenyl-modified glassy carbon electrode surface has been used for the determination of antioxidant activities of 10 flavonoid derivatives with cyclic voltammetry technique. The activity sequence of the investigated, structurally different, flavonoids follows the sequence: quercetin > galangin > chrysin > 3-hydroxyflavone > naringenin > luteolin > apigenin > flavone > kaempferol > naringin.Öğe A novel highly sensitive carbon-based HMPD/GC sensor electrode: copper ions analysis in flour and water samples(Desalination Publ, 2018) Durmus, Nagihan; Yilmaz, Ecir; Mulazimoglu, Aysen Demir; Mercimek, Bedrettin; Cukurovali, Alaaddin; Yilmaz, Ibrahim; Solak, Ali OsmanIn this research, (Z)-2-(2-(hydroxyimino)-2-(3-methyl-3-phenylcyclobutyl) ethyl)-3a,7a-dihy-dro-1H-isoindole-1,3(2H)-dione, HMPD molecule has been grafted to the glassy carbon (GC) electrode surface. The HMPD-modified GC electrode has been originally developed and it used for the quantitative determination of Cu(II) in flour and water samples. The modification steps have been performed using cyclic voltammetry (CV). CV, electrochemical impedance spectroscopy and scanning electron microscopy have been employed for the characterization processes. Cu(II) standard solutions changing from 1.0 x 10(-9) to 1.0 x 10(-3) M have been prepared and the corresponding peak currents have been measured. From the obtained data calibration equation has been calculated I-p = -1.555C(cu) + 15.86 which is having a 0.9974 correlation coefficient. 10.0 mL of flour and water samples have been mixed with 10.0 mL Britton-Robinson (BR) buffer solution (pH = 5.00) and HMPD/GC sensor electrode has been kept in these mixed solutions for 90 min. Differential pulse voltammetric (DPV) technique has been applied for the measurement of the peak currents. After the application of the developed sensor electrode for Cu(II) detection in flour and water samples, Cu(II) ion concentrations have been calculated from the obtained peak current values, 1.97 and 2.46 mu A. The Cu(II) ion concentrations have been calculated as 1.17 x 10(-9) and 2.41 x 10(-9) M, respectively.Öğe Sensitive and selective determination of paracetamol in antipyretic children's syrup with a polyglycine modified glassy carbon electrode(Royal Soc Chemistry, 2023) Islamoglu, Nesim; Mulazimoglu, Ibrahim Ender; Mulazimoglu, Aysen DemirA sensitive and selective electrochemical sensor for the determination of paracetamol (acetaminophen) is proposed based on a polyglycine-coated glassy carbon electrode. The electrochemical behavior of paracetamol was studied by cyclic voltammetry and differential pulse voltammetry. Under optimal experimental conditions, the peak oxidation current of paracetamol increases linearly in the range of 0.5-75 & mu;M. The limit of detection of paracetamol was 0.03 & mu;M and the limit of quantitation was 0.09 & mu;M. In addition, modified glassy carbon with polyglycine as the sensor was successfully used for the determination of paracetamol in antipyretic children's syrup samples, with a recovery rate of over 95.3%, showing its great application potential in drug analysis.Öğe The synthesis of a novel DDPHC diazonium salt: Investigation of its usability in the determination of phenol and chlorophenols using CV, SWV and DPV techniques(Elsevier, 2020) Celik, Haci Hasan; Ozcan, Saniye; Mulazimoglu, Aysen Demir; Yilmaz, Ecir; Mercimek, Bedrettin; Cukurovali, Alaaddin; Yilmaz, IbrahimElectrochemical and spectroelectrochemical properties of newly synthesized diazonium salt of 2-(2-(1,3-dioxo- 3,3a-dihydro-1H-isoindol-2(7aH)-yl)-1-(3 methyl-3-phenylcyclobutyl)ethylidene) hydrazinecarboxamide (DDPHC-DAS) were studied using glassy carbon (GC) electrode. In the current study, surface characterization was performed by cyclic voltammetry (CV). Besides electrochemical impedance spectroscopy (EIS) was used for the electrochemical and spectroelectrochemical characterization. Surface images were obtained using scanning electron microscopy (SEM). After completion of modification and characterization process, DDPHC-DAS surface was examined for the usability for the quantitative determination of phenol and chlorophenol derivatives by using CV, square wave voltammetry (SWV) and differential pulse voltammetry (DPV). Phenol and chlorophenol solutions that were prepared in Britton-Robinson (BR) buffer solution (pH 8-12) were employed in this research. The presented study proves that all of compounds can be quantitatively determined not only simultaneously but also independently.Öğe Utilizing of 2-Amino-3-hydroxypyridine Modified Glassy Carbon Electrode to Detect Copper(II) Ions(Asian Journal Of Chemistry, 2013) Mulazimoglu, Aysen DemirIn this paper 2-amino-3-hydroxypyridine modified glassy carbon electrode was used for the electrochemical analysis of trace copper(II) ions by square wave voltammetry technique. The modification of the glassy carbon electrode by 2-amino-3-hydroxypyridine soution was performed in the potential range between -150 mV and +600 mV by 30 cycles at 100 mV s(-1) potential scan rate in non-aqueous media by cyclic voltammetry. The surface characterizations of this sensor electrode were performed by cyclic voltammetry. A lower detection limit would be reached in the presence of Britton-Robinson buffer solutin at pH 5 for determination of Cu(II) ions by square wave voltammetry. The voltammetric response of the electrode was linear within the Ci(II) ion concentration range from 1.0 x 10(-12) M to 1.0 x 10(-6) M and the detection limit of 1.0 x 10(-12) M. The modified electrode offered and excellent way, with a high stability, simple, rapid, low cost and reusability, for selective determination of Cu(II) ions in Acigol lake (in Afyonkarahisar, Turkey) water sample.Öğe Utilizing of 2-Amino-3-hydroxypyridine Modified Glassy Carbon Electrode to Detect Copper(II) Ions(Asian Journal Of Chemistry, 2013) Mulazimoglu, Aysen DemirIn this paper 2-amino-3-hydroxypyridine modified glassy carbon electrode was used for the electrochemical analysis of trace copper(II) ions by square wave voltammetry technique. The modification of the glassy carbon electrode by 2-amino-3-hydroxypyridine soution was performed in the potential range between -150 mV and +600 mV by 30 cycles at 100 mV s(-1) potential scan rate in non-aqueous media by cyclic voltammetry. The surface characterizations of this sensor electrode were performed by cyclic voltammetry. A lower detection limit would be reached in the presence of Britton-Robinson buffer solutin at pH 5 for determination of Cu(II) ions by square wave voltammetry. The voltammetric response of the electrode was linear within the Ci(II) ion concentration range from 1.0 x 10(-12) M to 1.0 x 10(-6) M and the detection limit of 1.0 x 10(-12) M. The modified electrode offered and excellent way, with a high stability, simple, rapid, low cost and reusability, for selective determination of Cu(II) ions in Acigol lake (in Afyonkarahisar, Turkey) water sample.Öğe Voltammetric Determination of Acrylamide Using Coal Tar Pitch Modified Pencil Graphite Electrode by SWV(Springer, 2023) Korkmaz, Seyma; Bosnali, Wael; Mulazimoglu, Ibrahim Ender; Mulazimoglu, Aysen DemirThe adverse effects of acrylamide (AA) on humans are becoming clear, especially after a series of related investigations reported the dependence on consuming foods prepared by exposure to high temperatures for a long-time and cancer risk. Accurate determination of AA in food samples at trace amount is considered the first step to overcome this significant problem. The determination of AA using coal tar pitch modified pencil graphite (PGE/CTP) electrode was reported. The bare PGE and PGE/CTP electrodes were characterized using microscopic imaging technique scanning electron microscopy (SEM). The electrochemical behavior of AA was studied on PGE/CTP electrode in different medium acidities (pH) of phosphate and Briton-Robinson (BR) buffer solutions by employing square wave voltammetry (SWV). Linear sweep voltammetry (LSV) technique was applied to determine the mass transfer mode of AA from bulk solution to the PGE/CTP electrode surface. The optimum conditions were using phosphate buffer solution (PBS) at pH 7.0. The detectability of AA on the surfaces of bare PGE and PGE/CTP electrodes was compared, and the suitability of PGE/CTP electrode usage was determined. The linear relationship between peak current and AA concentration was in the range of 1000.0 to 0.5 nM. The limit of detection of AA was 0.2094 nM, and the limit of quantitation was 0.6912 nM. In addition, the PGE/CTP electrode as a sensor was successfully used for the determination of AA in the instant coffee sample.
