Yazar "Durmus, Mahmut" seçeneğine göre listele

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    A BODIPY decorated multiple mode reusable paper-based colorimetric and fluorometric pH sensor
    (Elsevier, 2022) Ozturk, Dilek; Omeroglu, Ipek; Gol, Cem; Durmus, Mahmut
    In this study, two difluoroboradiazaindacene (BODIPY) compounds bearing diethylaminostyryl groups were synthesized in order to establish colorimetric and fluorometric paper-based pH sensors. The structures of these novel BODIPY compounds were identified by NMR (H-1, C-13, B-11, and F-19), elemental analysis, MALDI-TOF, FT-IR, UV-vis and fluorescence spectroscopies as well as single-crystal X-Ray data. The DFT study was also per-formed to optimize of these two novel BODIPY structures. Electrochemical measurements were applied to estimate their redox potentials. Photophysical properties such as fluorescence quantum yield and lifetimes were investigated to determine the effect of acid addition in both DMSO and 1,4-dioxane solutions of the studied BODIPY derivatives. Also, pKa values of the synthesized compounds (1a and 1b) were determined from absorbance and fluorescence measurements by acid titration studies. The paper-based pH sensor behavior of these BODIPY derivatives was investigated and their performances were determined on the lemon juice samples as a real sample analysis. A simple, cost-effective, rapid, portable, colorimetric, and fluorometric paper-based BODIPY sensing platform was developed in this study for the detection of the variety of pH changes in lemon juice.
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    Novel SWCNT-hybrid nanomaterial functionalized with subphthalocyanine substituted asymmetrical zinc (II) phthalocyanine conjugate: Design, synthesis, characterization and sensor properties for pesticides
    (Elsevier Science Sa, 2021) Köksoy, Baybars; Akyuz, Duygu; Senocak, Ahmet; Durmus, Mahmut; Demirbas, Erhan
    The novel asymmetric zinc (II) phthalocyanines containing one ethyloxy azido and three iodine (Iodo-Pc) or subphthalocyanine (SubPc-Pc) groups were designed and synthesized for the first time. These novel phthalocyanines were chemically characterized by common spectral methods such as FT-IR, UV-vis, H-1-NMR,C- 13-NMR and MALDI-TOF mass spectroscopy and elemental analyses as well. Furthermore, a novel hybrid carbon nanomaterial (SWCNT-SubPc-Pc) bearing subphthalocyanine substituted zinc (II) phthalocyanine conjugate on the single walled carbon nanotube (SWCNT) surface was also prepared via azide-alkyne Huisgen cycloaddition (click) reaction. This novel hybrid carbon nanomaterial was chemically characterized by UV-vis, FT-IR and Raman spectroscopies. The thermal behaviour of the prepared SWCNT-SubPc-Pc was characterized by thermogravimetric analysis. Surface morphologies of the hybrid material were also investigated by scanning and transmission electron microscopies. SWCNT-SubPc-Pc hybrid nanomaterial was successfully modified on glassy carbon electrode (GCE) by using drop cast method. Then, the GCE/SWCNT-SubPc-Pc electrode was tested as pesticide sensor via electrochemical methods. The electrochemical responses were recorded using differential pulse (DPV) and cyclic voltammetries. The modified electrode acted as selectively to methyl parathion among the used pesticides (methyl parathion, acetamiprid and chlorantraniliprole). The electrochemical sensor behaviour exhibited a broad linear range (2.5 nM and 3.75 x 10(-8) M) and low detection limit (1.78 nM) for methyl parathion. Moreover, high performance liquid chromatography was used to validate the results obtained from orange and cherry juice samples with respect to the DPV results.
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    Sensitive, simple and fast voltammetric determination of pesticides in juice samples by novel BODIPY-phthalocyanine-SWCNT hybrid platform
    (Pergamon-Elsevier Science Ltd, 2021) Köksoy, Baybars; Akyuz, Duygu; Senocak, Ahmet; Durmus, Mahmut; Demirbas, Erhan
    The present work describes the first synthesis of novel asymmetric zinc (II) phthalocyanine (ZnPc) including three boron dipyrromethene (BODIPY) and one ethyloxy azido moieties. Moreover, single walled carbon nanotube (SWCNT) surface was functionalized by this ZnPc containing BODIPY; using the azide-alkyne Huisgen cycloaddition (Click) reaction to obtain SWCNT-ZnPc hybrid material. Structural, thermal and morphological characterizations of both ZnPc and SWCNT-ZnPc hybrid were carried out in-depth by spectroscopic, thermal and microscopic techniques. In this study, the synthesized SWCNT-ZnPc material was decorated on composite glassy carbon electrode (GCE) by means of an easy and a practical drop cast method. The modified electrode was tested as a non-enzymatic electrochemical sensor in various common pesticides such as methyl parathion, deltamethrin, chlorpyrifos and spinosad. Electrochemical behavior of non-enzymatic electrode (GCE/SWCNT-ZnPc) was determined via cyclic voltammetry and differential pulse voltammetry. The non-enzymatic sensor demonstrated high selectivity for methyl parathion in a wide linear range (2.45 nM-4.0 x 10(-8) M), low limit of detection value (1.49 nM) and high sensitivity (0.1847 mu A nM(-1)). Also, the developing non-enzymatic sensor exhibited good repeatability (RSD = 2.3% for 10 electrodes) and stability (85.30% for 30 days). Validation guidelines by HPLC and statistical analysis showed that the proposed voltammetric method were precise, accurate, sensitive, and can be used for the routine quality control of methyl parathion determination in juice samples.
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    Synthesis and photovoltaic properties of novel ferrocene-substituted metallophthalocyanines
    (Royal Society of Chemistry, 2021) Özdemir, Mücahit; Köksoy, Baybars; Kuruca, Halid; Altindal, Ahmet; Durmus, Mahmut; Koyuncu, Sermet; Yalcin, Bahattin; Bulut, Mustafa
    In this paper, a series of new metallophthalocyanines, including ferrocene groups, were designed, synthesized and, characterized, and their photovoltaic properties were investigated as alternative electron-donor materials in bulk heterojunction (BHJ) solar cells. These products were synthesized by a Sonogashira cross-coupling reaction between tetraiodophthalocyanine and ethynyl ferrocene. The newly synthesized phthalocyanines (4-6) were characterized by FT-IR, UV-Vis, H-1 NMR, and MALDI-TOF spectroscopic methods and elemental analysis. The electrochemical characterizations were carried out by cyclic voltammetry as well as differential pulse voltammetry. Density functional theory calculations were realized to prove the charge separation between ferrocene as an electron-donor and the phthalocyanine ring as an acceptor. According to UV-Vis measurements, a 25 nm red-shift was observed for complex 4 compared with complexes 5 and 6. Finally, the photovoltaic performance of these compounds used as an electron-donor moiety in a BHJ device were investigated. A function of different blend ratios was tested by fabricating a series of BHJ devices with the architecture of FTO/PEDOT:PSS/4-6: PCBM blend/Ag with an identical thickness of the active layer. The results indicated that the photovoltaic conversion efficiency of BHJ devices exhibited a strong blend-ratio dependence. The maximum power conversion efficiency was obtained by 5-based devices, as 3.65%, with a blend ratio of 1.5 : 1.0 under standard AM 1.5 illumination.