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Herein, a deterministic solvothermal strategy was employed to synthesize an efficient anticancer agent ‘cis-dichlorobis(1,10-phenanthroline)manganese(II)’ (Mn(phen)2Cl2). A single-crystal X-ray diffraction analysis revealed that Mn(phen)2Cl2 crystallizes in a triclinic system with the space group P-1. Cyclic voltammetric studies of Mn(phen)2Cl2 indicated that the electrode process occurs only due to complex formation and has a diffusion-controlled mechanism. Density functional theory estimations showed that the Mn(phen)2Cl2 is quite stable and exists in sextet spin state (five unpaired electrons) as the most stable form and hence, Mn(phen)2Cl2 is a high spin complex. Mn(phen)2Cl2 demonstrated significant anticancer potential against HeLa and MCF-7 cancer cells and less toxic behaviour towards normal BHK-21 cells. Fluorescence imaging confirmed that the production of reactive oxygen species (ROS) in HeLa cells by Mn(phen)2Cl2 induces oxidized fluorescence of dichlorofluorescein which emitted fluorescence at 530 nm after excitation at 488 nm. The microscopic investigation of apoptotic effect of Mn(phen)2Cl2 using propidium iodide and 4′,6-diamidino-2-phenylindole staining indicated that nuclear condensation, cell detachment and shrinkage occur after treatment with IC50 values of Mn(phen)2Cl2. Furthermore, an assessment of caspase-9 and caspase-3 activity after exposure to Mn(phen)2Cl2 in HeLa cells indicated that at IC50 values of Mn(phen)2Cl2, 1.5 fold and 4.8 fold increase in caspase-9 and caspase-3 activity, respectively, occurs. The measurement of mitochondrial membrane potential of a cationic dye (JC-1) showed a decrease in mitochondrial membrane potential in both HeLa and MCF-7 cells depicting that compound might have adopted intrinsic pathway of apoptosis. Ability of Mn(phen)2Cl2 to interact with HS-DNA demonstrates hyperchromicity with slight blue shift from 269 nm to 265 nm showing a non-covalent interaction with Gibbs free energy of ΔG = −14.62 kJ/mol. Communicated by Ramaswamy H. Sarma

Metal doping has been used as an effective strategy to tune the energy levels of semiconductors. Herein, we dope NiTi layered double hydroxide (NiTi-LDH) with cobalt to prepare a ternary LDH, CoNiTi-LDH, to enhance its photocatalytic performance towards both water oxidation and hydrogen evolution. A CoNiTi-LDH with smaller plate sizes and a higher degree of order is obtained, which allows the band gap to shrink from 2.7 eV to 2.4 eV. CoNiTi-LDH exhibits a photocatalytic water oxidation activity of 366 μmol g−1 h−1, which is more than two times higher than NiTi-LDH (166 μmol g−1 h−1). We observed that appropriate energy levels of CoNiTi-LDH allow it to be an efficient photocatalyst also for hydrogen evolution. We performed detailed characterization studies to elucidate the effect of Co-doping on photocatalytic activity.

One of the most critical steps in the transition to carbon-free energy systems is sustainable hydrogen evolution from water. In this research, a cobalt borophosphate crystalline compound consisting of phosphate and borate anions was synthesized with a solid-state reaction. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and X-ray Photoelectron (XPS) was employed to investigate the structure, composition, and morphology of Co3BPO7. Electrocatalytic performances of the catalyst towards oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) have been investigated on nickel foam (NF) electrode in 1.0 M KOH (pH 13.6) by linear sweep voltammetry, chronopotentiometry, cyclic voltammetry, and electrochemical impedance spectroscopy. For OER, the catalyst exhibits an overpotential of 230 mV at 10 mA cm−2 with a Tafel slope of 130 mV dec−1, which is comparable to that of the benchmark RuO2 electrocatalyst, and 220 mV overpotential for a current density of 10 mA cm−2 with a Tafel slope of 147 mV dec−1 for HER process. Long-term chronoamperometry and multiple cyclic voltammetric experiments indicate the catalyst is stable throughout both HER and OER processes. Electrochemical experiments and characterization studies performed on the pristine and post-catalytic electrode indicate that the catalyst is robust under alkaline electrocatalytic conditions (pH 13.6).

A new composite from graphene quantum dots (GQDs) and NiFe layered double hydroxide was successfully prepared by the coprecipitation method under optimal conditions. The nanoparticles of the composite were analyzed by X‐ray diffraction (PXRD), Fourier transform infrared spectroscopy (FT‐IR), scanning electron microscopy (SEM), and thermal gravimetric analysis (TGA) to obtain the structure, composition and morphology information. Also, the electrochemical properties were investigated by cyclic voltammetry, galvanostatic charge/discharge measurements, and electrochemical impedance spectroscopy. The nanocomposite displays a specific capacitance of 712.7 F g−1 and excellent cycle life after 2500 cycles by applying 10 A g−1 of the current density in 1 M KOH electrolyte, which confirms that the nanocomposite has superb capacitance retention (∼94.8 %) and can be used as a capable supercapacitor. Furthermore, this study provides a desirable procedure for the preparation of novel nanocomposites based on graphene quantum dots, which can be used in energy storage/conversion devices.

A facile synthetic pathway using poly(4-vinylpyridine) as a polypyridyl platform is reported for the formation of a metallopolymer. Electrochemical studies indicate that the metallopolymer acts as an efficient H2 evolution catalyst similar to cobalt polypyridyl complexes. It is also observed that the metallopolymer is transformed to cobalt particles when a cathodic potential is applied in the presence of an acid. Electrochemical measurements indicate that an FTO electrode coated with these cobalt particles also acts as an efficient hydrogen evolution catalyst. Approximately 80 µmoles of H2 gas can be collected during 2 h of electrolysis at − 1.5 V (vs. Fc+/0) in the presence of 60 mM of acetic acid. A comprehensive study of the electrochemical and electrocatalytic behavior of cobalt-poly(4-vinylpyridine) is discussed in detail. Graphical Abstract: Poly(4-vinylpyridine) as a precursor for electrodeposited cobalt particles: a cobalt coat derived by a metallopolymer acts as an efficient H2 evolution catalyst. It can transform to a cobalt coat when a potential above − 1.1 V is applied in acid medium. Exchange current density of 10−2.67 mA cm−2 was observed from the Co-coat at − 1.5 V (vs. Fc+/0). Acknowledgements The authors thank the Science and Technology Council of Turkey, TUBITAK (Project No: 215Z249) for financial support. Emine Ülker thanks TUBITAK for support (Project No: 1929B011500059).

The Prussian Blue (PB) nanoparticles can be obtained by reacting the hexacyanometal center with metal ions in the existence of polymers such as polyethyleneglycol (PEG). In this study, a pentacyanometal complex, [Fe(CN)5NO]2-, was used in addition to hexacyanometal ion, [Fe(CN)6]3-, to obtain nanoparticles coated with PEG. PB nanoparticles have been prepared, characterized, and comprehensive electrochemical studies were performed to investigate their performance for water oxidation electrocatalysis. The effect the ratio of PEG to the morphology and the water oxidation electrocatalytic performance have also been interrogated. Overall, the study clearly indicates that Co-FeNO@PEG with 1:10 and 1:25 Co:PEG rate show the best electrocatalytic activity with an overpotential of 472 and 489 mV for current density of 1 mA cm-1, respectively.

Non-oxide cobalt based water oxidation electrocatalysts have received attention recently for their relative ease in preparation since they are easy to prepare, stable both in acidic & basic media, and they have higher turnover frequencies compared to cobalt oxides. Recent studies show that one of the main bottlenecks in implementing non-oxide systems to water splitting is the low number of active metal sites, which is in the order of nmol.cm−2. Herein a new series of non-oxide water oxidation catalysts have been introduced to the field. Cobalt dicyanamides are observed to have around four times higher surface active sites and better catalytic performances than cyanide based systems. Long term catalytic studies (70 h) at an applied potential of 1.2 V and electrochemical studies performed in solutions in pHs ranging from 3.0 to 12.0 indicate that the compounds are robust and retain their structures even under drastic conditions. Moreover, addition of nickel impurities to cobalt dicyanamides has been introduced as a feasible method to improve their catalytic activities.

This paper describes non-enzymatic phenol determination using poly(3-methylthiophene) coated Pt electrode. Modified electrode was prepared on Pt disc surface in dichloromethane medium containing 500 mM 3-methylthiophene (3MT) and 100 mM tetrabuthylammonium perchlorate (TBAP). This electrode was used for amperometric determination of phenol in NaHSO4 / Na2SO4 (SBS) solution at pH 2.0. For this purpose, 0.70, 0.80 and 0.90 V potentials were applied and results were compared. Limit of detection and linear range were found as 4.22x10-5 and 1.41x10-4 – 4.00 mM (with R2=0.9932) at 0.90 V working potential, respectively. Repeatability of method was tested by using at least three modified electrode for 0.5, 1.0 and 2.0 mM phenol concentrations and relative standard deviation (RSD were found as 2.49%, 1.92% and 2.75%, respectively. To test the accuracy of method and matrix effect, phenol determination was carried out for 1.0 and 2.0 mM phenol concentrations in artificially contaminated river water samples at optimum condition and recovery values were found as 96.44% and 99.60%, respectively. Proposed method was found as simple, rapid and economic for phenol determination. Keywords: Phenol; Poly(3-methylthiophene); Amperometric determination; Non-enzymatic DOI: 10.17350/HJSE19030000030 Full Text

The development of new water oxidation electrocatalysts that are both stable and efficient, particularly in neutral conditions, holds great promise for overall water splitting. In this study, the electrocatalytic water oxidation performance of a new cobalt-based catalyst, Co3(BO3)2, with a Kotoite-type crystal structure is investigated under neutral conditions. The catalyst is also hybridized with CNTs to enhance its electrocatalytic properties. A remarkable increase in catalytic current along with a significant shift in the onset overpotential is observed in Co3(BO3)2@CNT. Additionally, CNT addition also greatly influences the surface concentration of the catalyst: 12.7 nmol cm−2 for Co3(BO3)2@CNT compared with 3.9 nmol cm−2 for Co3(BO3)2. Co3(BO3)2@CNT demands overpotentials of 303 and 487 mV to attain current densities of 1 and 10 mA cm−2, respectively, at pH 7. Electrochemical and characterization studies performed over varying pH conditions reveal that the catalyst retains its stability over a pH range of 3-14. Multi-reference quantum chemical calculations are performed to study the nature of the active cobalt sites and the effect of boron atoms on the activity of the cobalt ions. The authors thank the Science and Technology Council of Turkey, TUBITAK (Project No: 214Z095) for financial support. E.U. thanks TUBITAK for support (Project No: 1929B011500059). Y.D. thanks BAGEP and TÜBA-GEBİP for young investigator awards and ECOSTBio (CM 1305) for support. TUBITAK TRGRID infrastructure is gratefully acknowledged for HPC resources.

Although several Prussian Blue analogues (PBAs) have been investigated as water oxidation catalysts, the field lacks a comprehensive study that focuses on the design of the ideal PBA for this purpose. Here, members of a series of PBAs with different cyanide precursors have been investigated to study the effect of hexacyanometal groups on their electrocatalytic water oxidation activities. Cyclic voltammetric, chronoamperometric, and chronopotentiometric measurements have revealed a close relationship between the electron density of electroactive cobalt sites and electrocatalytic activity, which has also been confirmed by infrared and XPS studies. Furthermore, pH-dependent cyclic voltammetry and computational studies have been performed to gain insight into the catalytic mechanism and electronic structure of cyanide-based systems to identify possible intermediates and to assign the rate-determining step of the target process. The authors thank the Science and Technology Council of Turkey, TUBITAK (Project No. 215Z249) for financial support. E.U. thanks TUBITAK for support (Project No. 1929B011500059). Y.D. acknowledges ECOSTBio (CM 1305) for support and thanks the M.N. Parlar Foundation, BAGEP, and TÜBA-GEBİP for young investigator awards. TUBITAK TRGRID infrastructure is gratefully acknowledged for HPC resources. We also thank Prof. Burak Ülgüt for helpful discussions on electrochemistry.

Research on H2 production has recently been directed to the development of cost-efficient and robust heterogeneous catalysts for hydrogen evolution reaction (HER). Given the promising catalytic activities of several cobalt-based systems and the robustness of Prussian blue analogues in harsh catalytic processes including water oxidation, a Co-Co Prussian blue analogue was investigated as a HER catalyst for the first time. Co-Co Prussian Blue modified fluorine doped tin oxide (FTO) electrode demonstrated a significant HER activity with an onset overpotential of 257 mV, a Tafel slope of 80 mV dec−1, and a turnover frequency of 0.090 s−1 at an overpotential of 250 mV. Comparative XPS, Infrared, and XRD studies performed on pristine and post-catalytic electrodes confirm the stability of the catalyst. Acknowledgements This work was suppoerted by the Grants from The Science and Technology Council of Turkey, TUBITAK (Project No: 215Z249). E. U. thanks TUBITAK for support (Project No: 1929B011500059).

A Pt electrode modified by polyaniline–poly(3-methylthiophene)–poly(3,3′-diaminobenzidine) was used for amperometric determination of epinephrine in a solution of NaHSO4/Na2SO4 (pH 2.0). For these studies, potentials between 0.40 and 0.50 V were applied, and the best response was obtained at 0.45 V. The limit of detection, limit of quantification, and the linear dynamic range were 1.23 × 10−4, 4.10 × 10−4, and 4.10 × 10−4 to 100.0 mmol L−1, respectively. These results were compared with determinations using Pt electrodes that were coated and uncoated with homopolymers. To check the accuracy of the developed method and the matrices interference, determination of epinephrine was performed in human serum samples using this modified electrode. The epinephrine concentrations were adjusted to 1.0 and 5.0 mmol L−1, and recovery values were calculated as 100.4% and 96.8%, respectively. It is significant that the determination of epinephrine was carried out at a lower potential (0.45 V) than the oxidation potential of epinephrine (0.65 V) without any matrix effect.

Although cobalt-based heterogeneous catalysts are the central focus in water oxidation research, interest in copper-based water oxidation catalysts has been growing thanks the great abundance of copper and its biological relevance. Several copper oxides have recently been reported to be active catalysts for water oxidation. In this study, a heterogeneous copper-based water oxidation catalyst that is not an oxide has been reported for the first time. Single-crystal XRD studies indicate that the compound is a one-dimensional coordination compound incorporating copper paddle-wheel units connected through phosphine dioxide ligands. The catalyst exhibits an onset potential of 372 mV at pH 10.2, whereas an overpotential of only 563 mV is required to produce a current density of 1 mA cm−2. In addition to cyclic voltammetric and chronoamperometric studies, an investigation into the effect of pH on the catalytic activity and the robustness of the catalyst using long-term bulk electrolysis (12 h) is presented.

A polyaniline–poly(3-methylthiophene)–poly(3,3′-diaminobenzidine) film was deposited on a platinum disc electrode in dichloromethane containing tetrabuthylammonium perchlorate supporting electrolyte and used for the amperometric determination of dopamine. At a pH of 2.0, this electrode allowed successful determination at a lower potential than the oxidation potential of dopamine. The limit of detection, limit of quantification, and the linear dynamic range were determined to be 1.63 × 10−5 mM, 5.43 × 10−5 mM and 5.43 × 10−5 to 100.0 mM (R2 = 0.997), respectively. The reproducibility was investigated by using three different films and good analytical results were obtained. In addition, the modified electrode was successfully employed to determine dopamine in human serum with good recoveries.

WOS: 000374187700008 PubMed: 26970788 Modified electrode based on combination of different conductive polymers (polyaniline -poly(3-methylthiophene) poly( 3,3'-diaminobenzidine) (PANI - P3MT - PDAB)) was previously synthesized in dichloromethane containing HClO4 and tetrabutylammoniumperchlorate (TBAP) as supporting electrolyte. Herein, the determination of hydroquinone (HQ) with amperometric I-t method over this modified and its homopolymers coated electrode was successfully carried out in river water as a real sample and in solution consisting of NaHSO4/Na2SO4 (pH 2.0). For this method, potentials between 0.45 V and 0.65 V were applied and the best analytical response was obtained at 0.55 V using this modified electrode when compared to its homopolymers. the limit of detection (LOD), limit of quantification (LOQ), the linear dynamic range and regression coefficient (R-2) were found as 1.31 x 10(-4) mM, 4.37 x 10(-4) mM, 4.37 x 10(-4)-95.0 mM and 0.998, respectively. These results were compared to homopolymers coated and uncoated Pt electrodes. For checking on the accuracy of the developed method and the matrices interference, determination of HQ was performed in artificially contaminated river water samples with HQ concentration of 5.0 mM and 10.0 mM using this modified electrode and recovery values were calculated as 100.6% and 100.1%, respectively. Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [111T445]; Recep Tayyip Erdogan University, Unit of Scientific ResearchRecep Tayyip Erdogan University [2013.102.02.3] This research was supported by the Scientific and Technological Research Council of Turkey (TUBITAK) (Project no: 111T445) and Recep Tayyip Erdogan University, Unit of Scientific Research (Project no: 2013.102.02.3). We thank to Dr. Selcuk Demir (Recep Tayyip Erdogan University, Faculty of Science & Arts, Department of Chemistry, Rize) for improving the language of this munucript.

WOS: 000361556500025 Poly(vinylferrocenium) perchlorate-poly(3,3'-diaminobenzidine) (PVF+ClO4--PDAB) composite film was synthesized electrochemically for the first time on Pt disc electrode in a dichloromethane solution containing poly(vinylferrocene) (PVF) polymer, 3,3'-diaminobenzidine (DAB) monomer and tetrabutylammonium perchlorate as supporting electrolyte. This modified electrode was characterized using cyclic voltammetry, Fourier transform infrared spectroscopy (FTIR), UV-Vis spectrophotometry, atomic absorption spectroscopy (AAS), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) methods and it was used for amperometric determination of hydroquinone (HQ) at potential ranges of 0.40 and 0.60 V. the best analytical results for HQ was obtained at 0.45 V in NaHSO4/Na2SO4 solution (pH 2.0) and limit of detection, limit of quantification and linear response range were found as 7.469 x 10(-5), 2.489 x 10(-4) and 2.489 x 10(-4)-65.0 mmol L-1 (R-2 = 0.996), respectively. These results were compared to poly(3,3'-diaminobenzidine) (PDAB) coated and uncoated Pt electrodes. the best analytical results were obtained with composite film because of behavior as electron transfer mediator of PVF. Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [111T445]; Recep Tayyip Erdogan University Scientific Research Projects UnitRecep Tayyip Erdogan University [2013.102.02.3] Support to this work by the Scientific and Technological Research Council of Turkey (TUBITAK) (Project No. 111T445) and Recep Tayyip Erdogan University Scientific Research Projects Unit (Project No. 2013.102.02.3) is greatly appreciated. We thank Associate Professor Dr Selcuk Demir (Recep Tayyip Erdogan University, Faculty of Sciences & Arts, Department of Chemistry, Rize, Turkey) for improving the language of this manuscript.

Poly(3-methylthiophene) (P3MT) film was synthesized by potentiodynamic method on Pt electrode in methylene chloride solution containing 0.10M tetrabuthlammonium perchlorate supporting electrolyte and used for the determination of hydroquinone (HQ) with amperometric I–t method in solution consisting of NaHSO4/Na2SO4 (SBS; pH 2.0). This modified electrode has a lower working potential and good operational stability due to reducing electrode fouling when compared with the direct oxidation of HQ at the bare Pt electrode. Limit of detection, limit of quantification, and the linear response range were found to be 1.32 × 10−5 mM, 4.41 × 10−5 mM, and between 4.41 × 10−5 – 50.0 mM (R2 = 0.997), at 0.50 V versus saturated calomel electrode, respectively. HQ determination in complex matrix was checked using real samples to demonstrate the applicability of modified electrode. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40859.

N aHSO4/Na2SO4 SBS pH 2.0 cozeltisi icerisinde amperometrik I-t yontemi kullanilarak polianilin-poli 3metiltiyofen -poli 3,3’-diaminobenzidin PANI - P3MT - PDAB kapli Pt disk elektrot uzerinden pirokatekol tayini basarili bir sekilde gerceklestirildi. 0,45 V–0,65 V araliginda potansiyel degerleri uygulandi ve 0.50 V optimum potansiyel olarak belirlendi. Analitik parametreler gozlenebilme siniri, alt tayin siniri ve dogrusal calisma araligi sirasiyla 7.37×10-5, 2.47×10-4 ve 2.47×10-4-25.0 mmol.L-1 olarak bulundu. Ayrica, matriks girisimini ve gelistirilen yontemin dogrulugunu test etmek icin, pirokatekol derisimi 5.0 ve 10.0 mmol.L-1 olacak sekilde yapay olarak kirletilmis nehir sularinda pirokatakol tayini gerceklestirildi. Geri kazanim degerleri sirasiyla % 101.1 ve % 101.2, olarak elde edildi. Pirokatekolun yukseltgenme potansiyelinden 0.62 V daha dusuk potansiyelde 0.50 V matriks etkisi olmaksizin pirokatakol tayini gerceklestirildi

Tez (yüksek lisans) - Anadolu Üniversitesi, Anadolu Üniversitesi, Eğitim Bilimleri Enstitüsü, Eğitim Bilimleri Anabilim Dalı, Kayıt no: 122028, Bu araştırmanın amacı Üniversitelerde çalışan Beden Eğitimi öğretim elemanları ile üniversite öğrencilerinin görüşlerine dayalı olarak Türk Üniversitelerinde uygulanabilecek bir Beden Eğitimi dersi program modeli geliştirmektir. Araştırma tarama modeli ile yapılmıştır. Araştırmanın örneklemi, farklı özelliklerdeki altı Üniversitenin 68 Beden Eğitimi öğretim elemanı ile bu derse kaydolmuş 567 öğrenciden oluşmuştur. Veriler iki gruba da anket uygulanarak toplanmıştır. Verilerin sayı ve yüzdeleri bulunmuş, yorumlar bunlara dayalı olarak yapılmıştır. Geliştirilen ''Türk Üniversiteleri için Beden Eğitimi Dersi Program Modeli''ne dayanarak oluşturan öğretim elemanları ile öğrencilerin görüşlerini yansıtan başlıca araştırma bulguları şunlardır : Üniversitelerde Beden Eğitimi dersinin amaçları öğrencilerin kişilik özelliklerini geliştirmeye, onları sağlıklı kılmaya ve onların yaratıcılık güçlerini geliştirmeye dönük olmalıdır. Beden Eğitimi dersleri üniversite merkezi bir örgüt tarafından planlanıp yürütülmelidir. Beden Eğitimi dersini yalnız isteyen öğrenciler katılmalıdır. Derse kaydolacak öğrencilerden sağlık raporu istenmelidir. Öğretim elemanlarının haftalık ders yükü en çok 12 saat olmalıdır. Derslerde serbest zaman etkinlikleri ve takım sporlarına daha çok yer verilmelidir. Beden Eğitimi dersi sekiz yarıyıl ve haftada iki saat olarak uygulanmalıdır. Dersler öğrencilerin oluşturdukları gruplarla uygulanmalıdır. Beden Eğitimi derslerinin gerçekleştirilmesi için sınıflar 15 öğrenciden oluşturulmalıdır. Dersler karma gruplarla yapılmalıdır. Derslerde oyunlar yoluyla, karma ve işbirliğine dayalı öğretim yöntemlerinden yararlanılmalıdır. Dersler için çok amaçlı açık spor alanları ile spor salonları yapılmalıdır. Başarı değerlendirmesi için derse devam yeterli sayılmalı yada sınav sonucuna göre başarılı-başarısız sistemi uygulanmalıdır. Araştırmada bulgulara bağlı olarak üniversitelerdeki Beden Eğitimi programının etkililiği artırmaya yönelik öneriler geliştirilmiştir.