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Adsorptive removal of Co(II), Ni(II), and Cu(II) ions from aqueous media using chemically modified sporopollenin of Lycopodium clavatum as novel biosorbent
(DESALINATION PUBL, 2014) Cimen, Aysel; Bilgic, Ali; Kursunlu, Ahmed Nuri; Gubbuk, Ilkay Hilal; Ucan, Halil Ismet
In this study, sporopollenin of Lycopodium clavatum spores was used for sorption experiments. (E)-4-((2-hydroxyphenylimino) methyl) benzoic acid (HPBA) immobilized sporopollenin (Sp) was employed as a sorbent in sorption of selected heavy metal ions in aqueous solutions. The sorbent material was prepared with sequential treatment of sporopollenin with silanazing compound and HPBA. Experimental conditions for effective sorption of heavy metal ions were optimized with respect to different experimental parameters using the batch method in detail. pHs for maximum sorption of Cu(II) Ni(II) and Co(II) ions were found in six and five, respectively. Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) isotherm equations were applied to the experimental data. Thermodynamic parameters such as free energy (Delta G degrees), entropy (Delta S degrees), and enthalpy (Delta H degrees) were also calculated from the sorption results and were used to explain the mechanism of the sorption. The results indicated that this sorbent is successfully employed in the separation of trace Cu(II), Ni(II), and Co(II) from the aqueous solutions.
A Bodipy-bearing pillar[5]arene for mimicking photosynthesis: Multi-fluorophoric light harvesting system
(PERGAMON-ELSEVIER SCIENCE LTD, 2018) Kursunlu, Ahmed Nuri; Baslak, Canan
Herein, we submitted to the original synthesis, characterization, energy transfer mechanism of the Bodipy-bearing pillar[5]arene Bodipy and its reactants by employing of infrared, H-1, B-11, C-13, F-19- NMRs, UV-vis, fluorescence spectroscopy, melting point apparatus, CHN elemental analysis and mass spectroscopy. Preliminary UV-vis, fluorescence and excitation measurements were carried out in CH2Cl2 and the results revealed an effective fluorescence resonance energy transfer (FRET) system based on the interaction of pillar[5]arene and Bodipy derivative. epsilon(max) of target molecule reached to a maximum value and it was found as 955 000 M-1 cm(-1). This fluorescent macromolecule worked well for mimicking a light harvesting system with an energy transfer efficiency up to 92%. (C) 2018 Elsevier Ltd. All rights reserved.
Bodipy/dipyridylamino-based "turn-on" fluorescent chemosensor for trivalent chromium cations: characterization and photophysical properties
(ROYAL SOC CHEMISTRY, 2015) Kursunlu, Ahmed Nuri; Sahin, Emel; Guler, Ersin
{{3,5-Bis[4,4-difluoro, 8-(2,6-diethyl,1,3,5,7-tetramethyl-4-bora-3a, 4a-diaza-s-indacene)]}}phenyl-N,N-di( pyridin-2-yl) benzamide (Bodipy-DPy) was designed as an efficient fluorescent chemosensor for Cr(III). The structure of Bodipy-DPy was confirmed by UV-vis spectroscopy, fluorometry, melting point analysis, H-1-NMR, C-13-NMR, elemental analysis and ESI-TOF-MS. Its photophysical properties was investigated by absorption, emission and excitation techniques. Based on chelation assisted fluorescence enhancement, a fluorometric method was developed for trace level detection, selectivity and concentration studies of chromium(III) in EtOH-H2O. The fluorescent ligand behaved as a chemosensor for Cr(III) cations and showed a strong red fluorescence upon coordination with Cr(III), whereas almost no fluorescence was observed for the other metal cations studied. The Bodipy-DPy has absorption and emission maxima at 528 nm and 535 nm, respectively. The equilibrium binding constant of Bodipy-DPy with Cr(III) was calculated as 1.17 x 10(6) from the Stern-Volmer equation.
Chemical modification of silica gel with synthesized new Schiff base derivatives and sorption studies of cobalt (II) and nickel (II)
(ELSEVIER SCIENCE BV, 2009) Kursunlu, Ahmed Nuri; Guler, Ersin; Dumrul, Hakan; Kocyigit, Ozcan; Gubbuk, Ilkay Hilal
In this study, three Schiff base ligands and their complexes were synthesized and characterized by infrared spectroscopy (IR), thermogravimetric analyses (TGA), nuclear magnetic resonance (NMR), elemental analysis and magnetic susceptibility apparatuses. Silica gel was respectively modified with Schiff base derivatives, (E)-2-[(2-chloroethylimino)methyl]phenol, (E)-4-[(2-chloroethylimino) methyl]phenol and N,N'-[1,4-phenilendi(E)methylidene]bis(2-chloroethanamine), after silanization of silica gel by (3-aminopropyl)trimethoxysilane (APTS) by using a suitable method. Characterization of the surface modi. cation was also performed with IR, TGA and elemental analysis. The immobilized surfaces were used for Co(II) and Ni(II) sorption from aqueous solutions and values of sorption were detected by atomic absorption spectrometer (AAS). (C) 2009 Elsevier B.V. All rights reserved.
Cu (II) Chemosensor Based on a Fluorogenic Bodipy-Salophen Combination: Sensitivity and Selectivity Studies
(SPRINGER/PLENUM PUBLISHERS, 2016) Kursunlu, Ahmed Nuri; Sahin, Emel; Guler, Ersin
A new fluorescent chemosensor (Bodipy-S) derived from Bodipy and Salophen was developed. After the characterization of all compounds, the behavior of the chemosensor Bodipy-S toward p, d and f block-metal ions was investigated by UV-vis and fluorescence spectroscopy. This chemosensor can selectively detect to Cu (II) in methanol-aqueous solution based on chelation enhanced fluorescence (CHEF) and it almost exhibit to a fluorescence quenching effect with 20-fold. The binding constant of the fluorophore was interpreted by using of the Stern-Volmer method and the complex stoichiometry was defined by using Job's plot. Moreover, the effect of pH was performed by the fluorescence intensities of Bodipy-S in presence of Cu(II) ions. The chemosensor can be successfully used to the detection of Cu(II) in most areas.
The example of calix[4]pyrrole derivative containing Bodipy unit: Fluorometric and colorimetric sensor for F- ion
(PERGAMON-ELSEVIER SCIENCE LTD, 2014) Taner, Bilge; Kursunlu, Ahmed Nuri; Guler, Ersin
A novel chemosensor based on calix[4]pyrrole derivative modified by Bodipy unit has been synthesized, and its complexes with various anions were investigated. The results show that the receptors can selectively recognize biologically important fluoride ions. The binding affinity for fluoride ions was investigated by naked-eye color change, absorption, emission, proton nuclear magnetic resonance spectroscopy. The addition of fluoride ions to an acetonitrile solution of chemosensor can result in an obvious color change (brownish yellow color to straw yellow). The stoichiometries between the receptor and fluoride were determined from the molar ratio plots using the UV-visible spectra, which showed evident 1:1. The proton nuclear magnetic resonance spectral data supported the fluoride anion recognition with the disappearance of the amino proton peaks. Published by Elsevier B.V.
Facile assembly of Bodipy-based metal ion sensor using click chemistry
(TAYLOR & FRANCIS LTD, 2013) Kursunlu, Ahmed Nuri; Guler, Ersin
In this study, two novel 4,4-difluoro-4-bora-3a,4a-diaza-s-indacenes (BODIPY)-based metal ion sensors were synthesised using click' chemistry. The coordination modes and binding constants of the complexes formed with a range of metal ions were calculated. Results indicate that both BODIPY molecules can potentially serve as fluorescent sensors for the studied metal cations. The results also show that the BODIPY-based sensors have more selectivity for Zn (II) ions in the presence of other metal ions.
Fe (III), Co(II), Ni(II), Cu(II) and Zn(II) complexes of schiff bases based-on glycine and phenylalanine: Synthesis, magnetic/thermal properties and antimicrobial activity
(ELSEVIER SCIENCE BV, 2018) Sevgi, Fatih; Bagkesici, Ugur; Kursunlu, Ahmed Nuri; Guler, Ersin
Zinc (II), copper (II), nickel (II), cobalt (II) and iron (III) complexes of Schiff bases (L-G, L-P) derived from 2-hydroxynaphthaldehyde with glycine and phenylalanine were reported and characterized by H-1 NMR, C-13 NMR, elemental analyses, melting point, FT-IR, magnetic susceptibility and thermal analyses (TGA). TGA data show that iron and cobalt include to the coordinated water and metal:ligand ratio is 1:2 while the complex stoichiometry for Ni (II), Cu (II) and Zn (II) complexes is 1:1. As expected, Ni (II) and Zn (II) complexes are diamagnetic; Cu (II), Co (II) and Fe (III) complexes are paramagnetic character due to a strong ligand of L-G and L-P. The L-G, L-P and their metal complexes were screened for their antimicrobial activities against five Gram-positive (Staphylococcus aureus, Methicillin resistant Staphylococcus aureus (MRSA), Bacillus cereus, Streptococcus mutans and Enterococcus faecalis) and three Gram-negative (Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa) and one fungi (Candida albicans) by using broth microdilution techniques. The activity data show that ligands and their metal complexes exhibited moderate to good activity against Gram-positive bacteria and fungi. (C) 2017 Elsevier B.V. All rights reserved.
A fluorescent "turn on" chemosensor based on Bodipy-anthraquinone for Al(III) ions: synthesis and complexation/spectroscopic studies
(ROYAL SOC CHEMISTRY, 2015) Kursunlu, Ahmed Nuri
A novel triazole-linked Bodipy-anthraquinone compound (Bodipy-A) was easily prepared through one step click chemistry. Bodipy-A displayed a remarkable increase in fluorescence intensity in the presence of trace amounts of Al(III). These changes could be attributed to intramolecular charge transfer (ICT), and Bodipy-A also showed high selectivity over a series of other metal ions in methanol/water (9/1). The results obtained from an absorption spectroscopy titration (Job's plot) suggested a 2 : 1 ligand-to-metal complex, which was further demonstrated by FT-IR spectroscopy. The binding constant K of the target complex was then calculated using the Benesi-Hildebrand equation. All fluorescence experiments have shown that the compound Bodipy-A has a good selectivity for Al(III) ions. The results show that this system could be used in semi-aqueous systems.
A highly selective fluorescent sensor for mercury (II) ion based on Bodipy and Calix[4]arene bearing triazolenaphthylene groups; synthesis and photophysical investigations
(ELSEVIER SCIENCE SA, 2017) Sulak, Mine; Kursunlu, Ahmed Nuri; Girgin, Burcu; Karakus, Ozlem Ozen; Guler, Ersin
A highly selective and sensitive fluorescent sensor for mercury ion has been obtained from a combination of Bodipy and Calix[4]arene derived by click chemistry. The structural characterization of all compounds had been carried out by FT-IR, H-1 NMR, C-13 NMR, MS, elemental analysis or melting point. Calix[4]-B including a calix[4]arene and two Bodipy units is a good fluorescent sensor for Hg(II). It can be explained by the coordination between mercury and the triazole rings. In a co-solvent of methanol and water, the complexation ratio for Calix[4]-B/Hg(II) was determined as 1:1 and the binding constant was found to be 3.42 x 10 (7) M-1. The detection of Hg(II) by Calix[4]-B works selectively in aqueous methanol mixture. (C) 2017 Elsevier B.V. All rights reserved.
A new BODIPY/nanoparticle/Ni affinity system for binding of cytochrome c
(ELSEVIER SCIENCE BV, 2015) Maltas, Esra; Kursunlu, Ahmed Nuri; Arslan, Gulsin; Ozmen, Mustafa
In this study, 3,5-{Bis[4,4-difluoro, 8-(2,6-diethyl, 1,3,5,7-tetramethy1-4-bora-3a,4a-diaza-sindacene)]}benzoylchloride (BODIPY) was synthesized for the improving of a new immobilized metal affinity supporting material. Firstly, the synthesized BODIPY was immobilized on iron oxide superparamagnetic nanoparticles (SPIONs) and then, Ni(II) ions were chelated with the active terminals of BODIPY on nanoparticles surfaces to prepare an immobilized metal affinity (IMA) adsorbent for protein adsorption. The amount of BODIPY coated on SPIONs was about 29.7 mu M at 10 mg nanoparticles. 738 mu mol of Ni(II) ions were loaded to 10 mg of the SPIONs/BODIPY. The binding amount of cytochrome c was found to be 170 mu g to the SPIONs/BODIPY/Ni at pH 7.4. The binding amount of the molecules on SPIONs was analyzed by using UV-vis, fluorescence and atomic absorption spectroscopy. The characterization of the prepared surfaces was performed by FT-IR, SEM and TEM. (C) 2015 Elsevier B.V. All rights reserved.
A new calix[4]azacrown ether based boradiazaindacene (Bodipy): Selective fluorescence changes towards trivalent lanthanide ions
(ELSEVIER SCI LTD, 2013) Bayrakci, Mevlut; Kursunlu, Ahmed Nuri; Guler, Ersin; Ertul, Seref
We report on the synthesis and photophysical properties of a new calix[4]azacrown derivative, capped with two amide bridges, in the cone conformation bearing two boradiazaindacene (Bodipy) groups at the narrow rim. Its binding properties towards trivalent lanthanide ions such as La3+, Gd3+, Tb3+, Dy3+, Er3+ and Yb3+ were investigated by using spectroscopic techniques. With respect to fluorescence intensity changes upon trivalent lanthanide ion complexation, calix[4]azacrown ether based Bodipy showed higher selectivity towards Yb3+ ion over other ions. Presence of proximal two amide groups in calix[4] azacrown ether based Bodipy were observed to play an important role in exhibiting its lanthanide ion binding. (C) 2013 Elsevier Ltd. All rights reserved.
A novel Bodipy-Dipyrrin fluorescent probe: Synthesis and recognition behaviour towards Fe (II) and Zn (II)
(ELSEVIER SCI LTD, 2012) Kursunlu, Ahmed Nuri; Guler, Ersin; Ucan, Halil Ismet; Boyle, Ross W.
We present the design, synthesis, characterization and spectral studies for a new Zn (II) and Fe (II) selective fluorescent probe, 4,4-Difluoro-8-{3-[(4-phenoxy-dipyrromethene)propoxy]}-4-bora-3a,4a-diazaindacene (DPYBODPY). DPBODPY consists of a terminal fluorophore and a selective ligand and was designed to detect significant changes in absorbance and/or fluorescence on metal ion binding. The fluorophore is based on the Bodipy unit due to its excellent photophysical properties, while the dipyrrin unit has specific recognition abilities for Fe2+ and Zn2+ ions. The combination of these two structures is optimised to achieve significant spectral changes in the presence of Fe2+ and Zn2+ ions. (C) 2012 Elsevier Ltd. All rights reserved.
Novel fluorescent sensor for silver (I) based on the 3,4-bis-triazole Bodipy via dual-click chemistry
(ELSEVIER SCIENCE BV, 2017) Kursunlu, Ahmed Nuri; Guler, Ersin
This investigation paper relates with a novel dual-Bodipy derivative obtained by using 'click' chemistry. The synthesized compounds were characterized by some techniques as H-1 NMR, C-13 NMR, B-11-NMR, F-19 NMR, FT-IR, Uv vis, spectrofluorimetry, mass, elemental analysis, melting point. The photophysical measurements were conducted on 4,4-difluoro-8-(443-(843,4-Bis(1,2,3 triazolomethoxy)benzaldehyde)}propoxy))phenyl-4-bora-3a,4a, diaza-s-indacene (Bodipy-T) in presence of different metal ions. General trends were performed for emission, absorption, excitation, complex stoichiometry, different concentrations, competing ion, binding constants etc. in methanolic medium. Bodipy-T can be potentially served as a sensitive and selective ratiometric sensor for Ag (1) ion, moreover, it includes a modifiable group (aldehyde) for the preparing of its new derivatives. (C) 2017 Elsevier B.V. All rights reserved.
Novel magnetite nanoparticle based on BODIPY as fluorescent hybrid material for Ag(I) detection in aqueous medium
(ELSEVIER, 2016) Kursunlu, Ahmed Nuri; Ozmen, Mustafa; Guler, Ersin
This manuscript describes a highly selective and ultra-sensitive detection of Ag(l) in aqueous solution using amine coated magnetite nanoparticles modified boron-dipyrromethene by spectrofluorometer. Fe3O4 nanoparticles were synthesized by co-precipitation of Fe2+ and Fe(3+)in an ammonia solution. Amine modified Fe3O4 was prepared by using (3-aminopropyl)triethoxysilane as silanization agent. The covalent binding of boron-dipyrromethene to amine modified Fe3O4 was confirmed by means of Fourier Transform infrared spectroscopy, transmission electron microscopy, dynamic light scattering, UV-vis and fluorimeter measurements and obtained nanoparticle-boron dipyrromethene structure. The binding abilities of nanoparticle-boron dipyrromethene towards different metal ions have been investigated by some spectroscopic methods as UV-vis, fluorescence spectroscopy, Job plot, etc. and the novel surface displayed high selectivity and sensitivity for Ag(I) among all tested metals. (C) 2016 Elsevier B.V. All rights reserved.
Porphyrin-Bodipy combination: synthesis, characterization and antenna effect
(ROYAL SOC CHEMISTRY, 2014) Kursunlu, Ahmed Nuri
This paper described the synthesis of multichromophoric and pi-conjugated macromolecules consisting of two equal Bodipy units and one porphyrin unit (free base). Then, a zinc(II) complex of this macromolecule based on Bodipy and porphyrin was prepared by a classical complex reaction. The formation of nitroporphyrin, aminoporphyrin, Bodipy-porphyrin (PB) and Bodipy-metalloporphyrin (Zn-PB) was confirmed by H-1-NMR, C-13-NMR, elemental analysis, UV-vis/fluorescence spectra, melting point and ESI-TOF-MS techniques. Moreover, the photophysical properties of chromophoric groups such as absorption, emission and quantum yields were investigated for the photoinduced energy transfer in three different organic solvents. The result indicated that the emission of Bodipy in the Bodipy-porphyrin combination was significantly quenched with the formation of the free base and zinc(II) complex of porphyrin. Efficient energy transfer from the Bodipy unit to the porphyrins (free base or Zn-chelate) was observed between 88% and 96% due to high pi-conjugation. The energy transfer also occurred from Bodipy to porphyrin though the high polarity of acetonitrile.
Preparation of pillar[5]arene immobilized trypsin and its application in microwave-assisted digestion of Cytochrome c
(ELSEVIER SCIENCE BV, 2019) Atacan, Keziban; Kursunlu, Ahmed Nuri; Ozmen, Mustafa
This work presents the immobilization of trypsin on the synthesized pillar[5]arene derivative (P5) containing ten iodo-terminals. The characterization has been carried out by Thermogravimetric Analysis (TGA), Fourier Transform Infrared (FTIR) and Raman spectra, Scanning Electron Microscopy (SEM) and Zeta Potential. Furthermore, Cytochrome c (Cyt c) was chosen as a model protein for evaluation of the performance of the pillar [5]arene-immobilized trypsin (P5-T), and its microwave-assisted digestion conditions were investigated by using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) for 15 second. The peptide numbers of 10 and sequence coverage of 93% for 15 second microwave-assisted digestion were obtained for P5-T. The results can be further applied in future proteomics studies due to high efficiency, good reproducibility and stability of the pillar[5]arene-immobilized trypsin.
The sensitivity and selectivity properties of a fluorescence sensor based on quinoline-Bodipy
(ELSEVIER SCIENCE BV, 2014) Kursunlu, Ahmed Nuri; Guler, Ersin
A novel florescence sensor (Q-BODIPY) based on quinoline-Bodipy (quinoline-boradiazaindacene) was prepared by 'click chemistry' in several stages. The sensing actions of Q-BODIPY were confirmed by UV-vis titration, emission and excitation spectroscopic studies in presence of Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Sn2+, Hg2+, Pb2+, La3+, Ga3+, Er3+ and Yb3+ ions in methanol:H2O (1:1) medium. Whereas some metal ions can only cause quenching effect on the fluorescence intensity of Q-BODIPY, some of them show an increase in fluorescence intensity. The stoichiometry of host-guest complexes formed was determined by Job's plot method. The binding constants were calculated by Stern-Volmer method. As a fluorescence sensor, Q-BODIPY shows the best selectivity performance against Zn2+ ions in according to all spectroscopic data. Published by Elsevier B.V.
A symmetric and selective fluorescent Cu (II) sensor based on bodipy and s-triazine
(ELSEVIER SCIENCE BV, 2014) Kursunlu, Ahmed Nuri; Koc, Ziya Erdem; Obali, Aslihan Yilmaz; Guler, Ersin
A symmetric fluorescent sensor based on Bodipy for Cu (II) ion was designed according to binding site-signaling subunit approach. This sensor was prepared by reaction of 2,4-diamino-6-methyl-1,3,5-triazine with a 8-{4-(chloromethyl)phenyl}-2,6-diethyl-4,4-difluoro-1,3,5,7-tetramethyl-4-bora-3a,4a-diaza-s-indacene in dimethyl formamide. The synthesis and the photophysical properties of Bodipy-triazine derivative were investigated in presence of some metal ion. The results show that this symmetrical fluorescent sensor has a high selectivity for Cu (II) ion. Published by Elsevier B.V.
The Synthesis and Characterization of Star Shaped Metal Complexes of Triazine Cored Schiff Bases: Their Thermal Decompositions and Magnetic Moment Values
(SPRINGER, 2011) Uysal, Saban; Kursunlu, Ahmed Nuri
Tripodal ligand III, 2,4,6-tris(4-hydroxybenzimino)-1,3,5-triazine, was synthesized by reacting melamine with 4-hydroxybenzaldehyde. (E)-4-Bromo-2-((2-bromoethylimino)-methyl)phenol VI was obtained by reaction of 5-bromo-2-hydroxybenzaldehyde and 2-bromoethanamine hydrochloride. Melamine cored tripodal Schiff base VII (H(3)L) was synthesized by reacting III with VI. Tripodal metal complexes were obtained by reacting H(3)L and transition metal salts. The complexes were characterized by elemental analyses, FT-IR, (1)H NMR and LC-MS spectroscopy, thermal analyses and magnetic measurements. Finally, metal ratios of the complexes were determined by atomic absorption spectroscopy. The complexes are square-planar low-spin (S = 1/2) Co(II), diamagnetic square-planar Ni(II), square-planar (S = 1/2) Cu(II) and diamagnetic tetrahedral Zn(II).

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