Yazar "Baycan, Fatma" seçeneğine göre listele

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    A new donor-acceptor conjugated polymer-gold nanoparticles biocomposite materials for enzymatic determination of glucose
    (Elsevier Sci Ltd, 2020) Tan, Burcu; Baycan, Fatma
    In this study, the monomer 3-(5,8-bis (2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl) -3-(9hexyl-9H-carbazole-3-yl) quinoxalin-2-yl)-9-hexyl9H-carbazole (HCQE) was electropolymerized on the graphite pencil electrode for the first time and used as a glucose biosensor. After electropolymerization, enrichment with Au nanoparticles was performed to amplify the signal (PHCQE/AuNPs). Following the electropolymerization step, glucose oxidase (GOx) immobilization was performed on the conjugated polymer coated graphite pencil electrode (GPE) surface using glutaraldehyde (GA) as crosslinking reagent due to strong pi-pi* conjugation on the polymer backbone (PHCQE/AuNPs/GOx). Voltammetric determination was also performed by monitoring the oxygen consumption against Ag/AgCl reference electrode at-0.7 V in phosphate buffer solution (0.10 mM; pH 7.4). The new PHCQE/ AuNPs/GOx biosensor showed a linear response for glucose in the concentration range between 0.75 and 3.125 mM (LOD: 0.017 mM) along with a good sensitivity (0.13 mu A/mM(-1)). To examine the selectivity of the PHCQE/ AuNPs/GOx biosensor, citric acid, fructose, sucrose, galactose, L-ascorbic acid, mannose, dopamine and salicylic acid were studied in the same buffer solution. The conjugated polymer PHCQE enriched with Au nano particles provides enzyme immobilization effectively. The applicability of the biosensor in the commercial samples has been also investigated and we have found that the conjugated polymer PHCQE enriched with Au nano particles is very effective for the determination of glucose in commercial samples.
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    A novel PEDOT-derived electroactive polymer-based enzymatic glucose biosensor enriched with gold nanoparticles
    (Springer Science and Business Media Deutschland GmbH, 2023) Tan, Burcu; Baycan, Fatma
    In this study, 3,4-ethylenedioxythiophene derivative conjugated monomer 4-(dihexylamino)-9,12-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-7H-benzo [de]benzo[4,5]imidazo[2,1-a]isoquinolin-7-one (EDOTBN) was synthesized and electropolymerized on pencil graphite electrode (PGE) to fabricate a highly stable and sensitive sensor for glucose detection for the first time. The structurally high conjugation of the monomer and the effect of increasing the conductivity of the gold nanoparticles increased the covalent bonding ability of the enzyme to the modified electrode surface and provided an excellent immobilization. PGE/p(EDOTBN)/AuNPs/GOx designed biosensor was characterized by a wide linear glucose determination range between 1.169 x 10-2 and 10 mM with a limit of detection of 0.008461 mM and a sensitivity of 38.365 mu A/mMcm2. Furthermore, the prepared bioelectrode showed storage stability for 4 weeks. Recovery studies were also carried out to check the accuracy of the developed bioelectrode and the glucose concentration in commercial samples was determined accurately.
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    An Enzymatic Glucose Biosensor Based on a Pencil Graphite Electrode Modified with Naphthalenedimide/3,4-Ethylenedioxythiophene Conjugated Polymer and Enriched with Au Nanoparticles
    (Wiley-V C H Verlag Gmbh, 2022) Tan, Burcu; Baycan, Fatma
    N,N '-bis(2-hexyl)-2,6-(3,4 ethylenedioxythiophene)-1,4,5,8-naphthalenimide (ENDI) monomer was electropolymerized on pencil graphite electrode (PGE) and used as a biosensor for glucose immobilization for the first time. After electropolymerization of ENDI monomer on PGE (AuNPs/PENDI/PGE), the intensity of the current signal was improved by using gold nanoparticles (AuNPs). The immobilization of the glucose oxidase (GOx) enzyme was carried out by using the cross-linking reagent glutaraldehyde (GA) due to the strong pi-pi* interaction of the poly- N,N '-bis(2-hexyl)-2,6-(3,4 ethylenedioxythiophene)-1,4,5,8-naphthalenimide (PENDI) polymer. GOx/AuNPs/PENDI/PGE designed biosensor, was characterized by a wide linear glucose determination range between 0.0009-0.33 mM with a limit of detection of 0.0407 mM and a sensitivity of 0.172 mu A/mMcm(2). Herein we have shown that GOx/AuNPs/PENDI/PGE biosensor effectively provides the enzyme immobilization and very effective for glucose determination in commercial samples.
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    Fabricating a new immobilization matrix based on a conjugated polymer and application as a glucose biosensor
    (John Wiley and Sons Inc, 2023) Tan, Burcu; Baycan, Fatma
    A new monomer named 4-(dihexylamino)9,12-di(thiophen-2-yl)-7H-benzo[de]benzo[4,5]imidazo[2,1-a]isoquinolin-7-one (ThBN) is synthesized and used as a potential glucose biosensor after electropolymerization of the ThBN on the graphite pencil electrode. The amount of glucose is determined according to the decrease in the amount of oxygen by using cyclic voltammetry technique. Herein, conjugated polymer of ThBN is used as a immobilization matrix. The synthesized PThBN is found to be effective enzymatic biosensor having wide linear glucose determination range between 2.975 × 10−3 and 2.087 mM with a limit of detection of 0.0304 mM and a sensitivity of 0.1326 μA/mM cm2. This potential enzymatic biosensor has been also tested in commercial samples and found to be useful to detect the glucose concentration.
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    Fabrication of AuNPs/PHCQE/GPE electrochemical sensor for the determination of isoniazid
    (Elsevier Inc., 2025) Baycan, Fatma; Saglikoglu, Gulsen
    In this study, we have developed an electrochemical sensor based conjugated polymer to determine the compound isoniazid. Isoniazid is a drug-active substance widely used in the treatment of tuberculosis. To determine isoniazid electrochemically, 3-(5,8-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-3-9-hexyl-9H-carbazole-3-yl)quinoxalin-2-yl)-9-hexyl-9H-carbazole monomer was first electropolymerized on a graphite pencil electrode and then gold nanoparticles were doped on it. The prepared electrode showed excellent electrocatalytic activity for the oxidation of isoniazid. The electrochemical behavior of isoniazid was examined, and oxidation of isoniazid was determined by the Cyclic Voltammetry technique as a diffusion controlled. The linearity range of isoniazid was calculated 3–100 µM and the detection limit was 0.310 ?M by using differential pulse voltammetry. An electrochemical sensor was successfully applied to the determination of isoniazid in tablet dosage forms. The suggested method provides good recovery, wide linearity range and low detection limit. In addition, interference, repeatability, reproducibility and stability studies were carried out. © 2025 Elsevier B.V.
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    Side chain functional carbazole-fluorene electroactive polymers: Optical, electrochemical properties, antimicrobial activity and thin film morphologies
    (John Wiley and Sons Inc, 2021) Meriç, Çağla; Kanbur, Savaş; Baycan, Fatma
    A new electroactive polymer based on fluorene and carbazole moieties with double bond side chain (MP25) was synthesized and then double bond at the side chain was functionalized with -COOH and -Si(OEt)3 as ITO/glass compatible groups. Electrochemical and optical properties of the polymers were elucidated with cyclic voltammetry (CV), ultraviolet–visible absorption (UV–Vis), and photoluminescence (PL) spectroscopy. It was observed that all polymers absorbed only the UV region and emitted blue light. By using CV, HOMO values were found as approximately 5.45 eV. According to AFM results, when the rough MP25 polymer thin film was modified with ITO/glass compatible groups, more uniform and smoother polymer thin films were obtained. Thermogravimetry analyses (TGA) shown that the MP25-Si and MP25-COOH were stable against thermo-oxidative decomposition. The weight loss of MP-25-Si was found to be only %23 at 700°C. Additionally, antimicrobial activity of MP25 polymers was also investigated. According to test results, all polymers were found to have antimicrobial activity against C.albicans.
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    Synthesis, characterization, conductivity, band gap and thermal analysis of poly-2-[(4-mercaptophenyl) imino methyl] phenol and some of its polymer-metal complexes
    (Elsevier Science Sa, 2007) Kaya, İsmet; Baycan, Fatma
    The oxidative polycondensation reaction conditions of 2-[(4-mercaptophenyl) imino methyl] phenol (4-MPIMP) was studied in an aqueous alkaline medium between 30 and 90 degrees C by using oxidants such as air O-2, NaOCl and H2O2. Polymer-metal complex compounds were synthesized from the reactions of poly-2-[(4-mercaptophenyl) imino methyl] phenol (P-4-MPIMP) with Cr3+, Co2+, Ni2+, Cu2+, Mn2+, Zn2+, Pb2+, Cd2+ and Zr4+ ions. The structures of these monomer and polymer were identified from UV-vis, Fr-IR, H-1 NMR, C-13 NMR and elemental analysis. While thermal analysis of P-4-MPIMP and polymer-metal complexes were made by TGA-DTA, the number-average molecular weight (M-n), weight-average molecular weight (M-w) and polydispersity index (PDI) values of this polymer were determined by size exclusion chromatography (SEC). According to TG-DTA analyses, P-4-MPIMP-Cu was found to be higher stable than other synthesized polymer and polymer-metal complexes. While conductivity measurements of polymer and polymer-metal complexes were done by electrometer using four point probe techniques, electrochemical and optical band gap values of 4-MPIMP, P-4-MPIMP and polymer-metal complexes were determined by using cyclic voltammetry and UV-vis measurements. Conductivity and band gap values show that this polymer and polymer-metal complexes are a typical semiconductor. (c) 2007 Elsevier B.V. All rights reserved.
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    Synthesis, Characterization, Conductivity, Band Gap, and Kinetic of Thermal Degradation of Poly-4-[(2-Mercaptophenyl) Imino Methyl] Phenol
    (John Wiley & Sons Inc, 2009) Kaya, İsmet; Baycan, Fatma; Doğan, Fatih
    The oxidative polycondensation reaction conditions of 4-[(2-mercaptophenyl) imino methyl] phenol (2-MPIMP) were studied in an aqueous acidic medium between 40 and 90 degrees C by using oxidants such as air, H(2)O(2), and NaOCl. The structures of the synthesized monomer and polymer were confirmed by FTIR, (1)H NMR, (13)C NMR, and elemental analysis. The characterization was made by TGA-DTA, size exclusion chromatography (SEC) and solubility tests. At the optimum reaction conditions, the yield of poly-4-[(2-mercaptophenyl) imino methyl]phenol (P-2-MPIMP) was found to be 92% for NaOCl oxidant, 84% for H(2)O(2) oxidant 54% for air oxidant. According to the SEC analysis, the number-average molecular weight (M(w)), weight-average molecular weight (M(w)), and polydispersity index values of P-2-MPIMP were found to be 1700 mol(-1) 1900 g mol(-1), and 1.118, using H(2)O(2); 3100 g mol(-1), 3400 g mol(-1), and 1.097, using air; and 6750 g mol(-1), 6900 g mol(-1), and 1.022, using NaOCl, respectively. According to TG analysis, the weight losses of 2-MPIMP and P-2-MPIMP were found to be 95.93% and 76.41% at 1000 degrees C, respectively. P-2-MPIMP showed higher stability against thermal decomposition. Also, electrical conductivity of the P-2-MPIMP was measured, showing that the polymer is a typical semiconductor. The highest occupied molecular orbital, the lowest unoccupied molecular orbital, and the electrochemical energy gaps (E'(g),) of 2-MPIMP and P-2-MPIMP were found to be -6.1.3, -6.09; -2.65, -2.67; and 3.48, 3.42 eV, respectively. Kinetic Q thermodynamic parameters of these compounds investigated by MacCallum-Tanner and van Krevelen methods. The values of the apparent activation energies of thermal decomposition (E(a)), the reaction order (n), pre-exponential factor (A), the entropy change (Delta S*), enthalpy change (Delta H*), and free energy change (Delta G*) were calculated from the TGA curves of compounds. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 112: 1234-1243, 2009
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    Thiophene-benzimidazolium Polymer Salts: Synthesis, Characterization, Antimicrobial Activities, and Evaluation in Terms of Occupational Health
    (Polymer Society of Korea, 2021) Kanbur, Savaş; Ateş, Gülçin Özcan; Altınışık, Sinem; Çınar, Ulaş; Baycan, Fatma
    A new thiophene benzimidazole based polymer (TBIP) was synthesized and then the TBIP-Br, TBIP-BF4 and TBIP-ClO4 polymer salts were obtained in water. All polymer salts can be dissolved in environmentally friendly solvents such as water or ethanol. Electrochemical and optical properties of the polymers were elucidated with cyclic voltammetry (CV) and ultraviolet-visible absorption (UV-Vis) spectroscopy. By using CV, the highest occupied molecular orbital (HOMO) values were found as approximately 1.70 eV. According to the atomic force microscopy (AFM) images of the thin film of TBIP, there are homogeneously distributed and smaller particles on the film surface, while the surface of TBIP-Br and TBIP-ClO4 thin films is rougher due to -Br and -ClO4 counter ions being bigger than -BF4. Additionally, the antimicrobial activity of TBIP polymers was also investigated. All TBIP and its salts were showed antimicrobial activity against S. aureus ATCC 6538 and no antimicrobial activity against E. coli ATCC 1301 and ATCC 25922.
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    Zopiklon'un voltametrik metotlar ile elektrokimyasal davranışının incelenmesi ve ilaçlarda kantitatif tayini
    (Çanakkale Onsekiz Mart Üniversitesi, 2006) Baycan, Fatma; Yılmaz, Selahattin
    ÖZETBu çalışmada, zopiklon adlı ilaç etken maddesinin elektrokimyasal özelliğivoltametrik yöntemler ile camsı karbon elektrot kullanılarak incelendi. Optimumşartları belirlemek için farklı destek elektrolitlerde adsortif sıyırma diferansiyel pulsvoltametrisi ve adsorptif sıyırma osteryoung kare dalga voltametrisi ile yükseltgenmeözelliği çalışıldı. Zopiklon için camsı karbon elektrotda keskin pikin ve maksimumakımın gözlendiği pH=7,08 BRT çözeltisi destek elektrolit olarak seçildi.Zopiklonun pik akımına ve pik potansiyeline pH' ın etkisi adsorptif sıyırmadiferansiyel puls voltametrisi (AdSDPV) ve adsorptif sıyırma osteryoung kare dalgavoltametrisi (AdSOSW) ile, tarama hızının pik akımına etkisi ise dönüşümlüvoltametri tekniği (CV) ile incelendi. AdSDPV ve AdSOSW teknikleri ile eldeedilen pik akımı-konsantrasyon grafiklerinden doğrusallık aralığı (AdSDPV için6x10-7-2x10-5 mol L-1 ve AdSOSW için 8x10-7-2x10-5 mol L-1) belirlendi. Bugrafiklerden yararlanılarak belirleme sınırı ve kantitatif tayin alt sınırı hesaplandı.Uygulanan voltametrik yöntemin doğruluk ve kesinliğini kontrol etmek amacıile ilaç tabletlerinden zopiklonun geri kazanım çalışmaları yapıldı. Ayrıca, ilaçtabletlerindeki zopiklon miktarı da belirlendi.Anahtar Kelimeler: Zopiklon, Adsorptif sıyırma diferansiyel pulsvoltametrisi, Adsorptif sıyırma osteryoung kara dalga voltametrisi, Camsı karbonelektrot, Ticari ilaç tabletleriVI