Sürdürülebilir Kalkınma Amaçları
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- ArticleYalnız künye2026Removal of Malachite Green from Aqueous Solutions by Using Bi4V2O11 Nanosheet
Yavuz, Emre; Dundar, Ozan Ali; Yavuz, Sevtap Caglar; Yilmaz, Erkan; Ozdokur, Kemal Volkan; Cirak, Burcu Bozkurt; Caglar, Bulent; Cirak, Cagri; Arar, Özgür
Introduction: Transition metal oxides are highly effective for dye removal due to their adaptable surface chemistry, availability, and robust mechanical and thermal properties. Among them, Bi4V2O11 nanosheets offer potential due to their morphology and high surface area. To synthesize Bi4V2O11 nanosheets and evaluate their performance in removing malachite green, focusing on the impact of adsorbent amount, contact time, and interfering ions on dye removal efficiency. This study aims to evaluate the performance of Bi4V2O11 nanosheets in removing malachite green dye from aqueous solutions and to examine the effects of adsorbent dosage, contact time, and the presence of coexisting ions on the sorption process. Methods: Bi4V2O11 nanosheets were synthesized and used to remove the malachite green dye. Batch experiments were conducted to study the effects of adsorbent dose, contact time, and coexisting ions (Na+, Ca2+, and tannic acid). Equilibrium data were fitted to the Langmuir isotherm model to determine the maximum sorption capacity. Results: Malachite green sorption using Bi4V2O11 nanosheets reached equilibrium within 240 minutes, demonstrating efficient dye removal under the tested conditions. The sorption process conformed to the Langmuir isotherm model, indicating monolayer adsorption with a maximum capacity of 47.27 mg/g. While the presence of Na+ and tannic acid had negligible effects on dye removal efficiency, the coexistence of Ca2+ significantly reduced the removal efficiency from 95% to 58%, highlighting the potential impact of divalent ions on the adsorption process. Discussion: Bi4V2O11 nanosheets are effective adsorbents for malachite green removal, demonstrating high sorption capacity and resilience to Na+ and tannic acid interference. However, the presence of Ca2+ significantly reduces removal efficiency, highlighting the need for further optimization in practical applications. Conclusion: Bi4V2O11 nanosheets offer high sorption capacity and structural stability, environment friendly synthesis procedure, making them feasible for small-scale or pre-treatment applications. 2026, Bentham Science Publishers
RDL Kalıcı Kaydıİncele - ArticleAçık Erişim2026Experimental and theoretical investigation of a benzazole-2-carboxamide derivative: Crystal structure, spectroscopic characterization, antiproliferative evaluation, and molecular docking studies
Kılıç, Selçuk; Aktekin, Mine Buga; Turkmenoglu, Burcin; Sert, Yusuf; Caglar, Bulent; Çırak, Çağrı; Algul, Oztekin
In this study, the structural, spectroscopic, and biological properties of a benzazole-2-carboxamide derivatives, N-(1H-benzo[d]imidazole-2-yl)-4-chlorobenzamide, were comprehensively investigated through both experimental and theoretical approaches. First, the crystal structure of the compound was revealed with the help of single-crystal X-ray diffraction (XRD). Subsequently, density functional theory (DFT) calculations were performed using Gaussian 09 W to optimize the molecular geometry, simulate vibrational spectra, predict nuclear magnetic resonance (NMR) parameters, analyze frontier molecular orbitals HOMO (Highest Occupied Molecular Orbital) - LUMO (Lowest Unoccupied Molecular Orbital), and generate molecular electrostatic potential (MEP) surface maps. To enhance the accuracy of vibrational assignments, potential energy distribution (PED) analysis was conducted via the VEDA4 software. Furthermore, theoretical infrared (IR) and NMR data were compared with experimental results, with results from FT-IR, ¹H-NMR, and ¹³CNMR spectra demonstrating strong agreement and validating the computational models. In addition to spectroscopic characterization, the antiproliferative activity of the synthesized compound against human breast cancer cell line MCF7 and a normal mouse fibroblast cell line (L929) was evaluated. Among the tested compounds, those exhibiting the highest inhibitory activity against MCF7 cells were selected for further analysis. In order to explain the underlying molecular interactions, molecular placement studies were carried out with the help of the Schrödinger Maestro software program, which targets the basic protein binding sites to predict binding affinity and interaction patterns. Collectively, this integrated study provides valuable insights into the structural, spectroscopic, and biological behavior of benzazole-based derivatives, highlighting the synergy between experimental techniques and computational modeling in modern drug discovery research.
RDL Kalıcı Kaydıİncele - ArticleAçık Erişim2024Photocatalytic Performances of ZnS/g-C3N4 Nanocomposites with Different Mass Ratios
Caglar, Bulent; Güner, Eda Keles; Doğan, Bilge; Özdemir, Agah Oktay
In this study, we prepared a series of ZnS/graphitic-C3N4 nanocomposites in various mass percentages and morphological properties of all the nanocomposites were examined by utilizing SEM/EDX technique. The photocatalytic performances of ZnS/graphitic-C3N4 nanocomposites were evaluated by degradation of Rhodamine B molecules under visible light. The photocatalytic performances of all nanocomposites under various photocatalyst dosages and initial Rhodamine B concentrations were further investigated for determination of optimal conditions.the obtained results indicated that ZnS/graphitic-C3N4 nanocomposites show almost 2 times higher photocatalaytic performances than pure graphitic-C3N4 and ZnS nanoparticles. The scavenger studies showed that the superoxide radicals had a major role in the photodegradation and the photodegradation of Rhodamine B follows the pseudo-first-order kinetic.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2024Photocatalytic application of nickel oxide/zinc oxide nanoparticles decorated kaolinite nanocomposite for the degradation of crystal violet
Keles Güner, Eda; Ertugay, Nese; Ozdemir, Agah Oktay; Doğan, Bilge; Caglar, Bulent
The photocatalysis process, which is effective, economical, and environmentally friendly can overcome rapidly increasing environmental problems, has shown rapid development in recent years. Nontoxic, low-cost natural minerals are often used in photocatalysis processes that remove organic pollution from wastewater. In this study, a selective method for the removal of crystal violet (CV) from aqueous solutions using nanocomposite of nickel oxide/zinc oxide nanoparticles (NiO/ZnO) supported on kaolinite photocatalyst was investigated. The raw kaolinite, bare NiO, bare ZnO and nanocomposite samples were characterized by the XRD, TEM, SEM-EDX, XPS and FTIR techniques. The photocatalytic performances of kaolinite-NiOZnO (K-NiO/ZnO) nanocomposite and bare samples were also investigated and comparatively evaluated by the photodegradation of CV (cationic dye) dye under visible light irradiation. The effects of various parameters such as the dosage of photocatalysis, contact time, and initial dye concentration on the rate of removal of dye were investigated and optimized. The kinetics of decolorization by samples can be well described by the pseudo-first-order model. Finally, it can be used in advanced oxidative processes for the degradation of organic pollutants.
RDL Kalıcı Kaydıİncele - ArticleAçık Erişim2024Development of a Composite Cu(II)-Selective Potentiometric Sensor Based on a Thiourea Derivative Symmetric Schiff Base
Yildirim, Ozden; Coldur, Fatih; Topcu, Cihan; Caglar, Bulent
In the present study, initially, a thiourea derivative symmetric Schiff base, (1E,3E)-1,3-bis(5-bromo-2-hydroxybenzylidene)thiourea, was synthesized and characterized by FTIR and SEM-EDX analysis. In addition, an all-solid-state composite Cu(II)-selective potentiometric sensor based on this synthesized compound as an electroactive substance was constructed. Optimization studies indicated that the composition of the optimum sensing composite exhibiting the best potentiometric characteristics was 3.0% Schiff base, 5.0 % multi-walled carbon nanotube (MWCNT), 20.0 % paraffin oil and 72.0% graphite by mass. The proposed sensor displayed a linear response in the concentration range of 5.0×10-6-1.0×10-1 M with a slope of 31.1 mV/decade and a detection limit of 5.0×10-7 M. The proposed sensor exhibited a fairly selective, stable (potential drift: 1.85 mV/h), and rapid (<10 s) response towards Cu(II) ions. Because of the magnitude of its potential drift, the sensor should be recalibrated along the analysis time at least half an hour apart. The sensor can employed safely in the samples with pHs in the range of 2.0-6.5. The lifetime of the fresh sensor surface was determined as 2 weeks. The most important advantage of the sensor is that the sensing composite surface is renewable (at least 10 times) and thus the sensor can be used many times for a long period of time. The analytical applications of the sensor were executed successfully by using the electrode in the potentiometric titration of Cu(II) ions with EDTA as an indicator electrode, in the direct determination of Cu(II) contents of spiked water samples, and in the determination of (w/w) Cu% content of a Turkish coin.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2024Highly selective and sensitive potentiometric determination of favipiravir in COVID-19 antiviral drug formulations
Topcu, Cihan; Aydin, Senanur; Atasoy, Betul Hilal; Yilmaz, Rabia Rana; Coldur, Fatih; Caglar, Bulent
In this study, a novel all-solid-state electrochemical sensor based on favipiravir-tetraphenylborate (FAV-TPB) electroactive material was developed and reported for FAV's highly selective and sensitive potentiometric determination in COVID-19 antiviral drug formulations. All-solid-state FAV selective sensor was fabricated by mixing and properly pressing FAV-TPB, graphite (G), multi-walled carbon nanotube (MWCNT), and paraffin oil (PO). In order to obtain the best sensor response, the sensor component ratios were optimized. The most satisfying response characteristics was obtained with the sensor composition FAV-TPB:G:MWCNT:PO in the ratio 32.5:42.5:5:20 (w/w %). The developed sensor displayed a wide linear near-Nernstian response to FAV over the concentration of 1.0 × 10−6 − 1.0 × 10−1 molL−1 with a slope of 53.6 ± 1.4 mV (R2 = 0.9997). The detection limits of the sensor was calculated as 6.0 × 10−7 molL−1, respectively. The dynamic response time of the sensor was 7 s, and the sensor exhibited fairly reproducible potentiometric responses. In the pH range of 6.0–8.0, the sensor's potential response was not affected by the pH change of the test solutions. The improved sensor had a wide temperature tolerance, and its response remained unchanged in the 10–40 ℃ temperature range. The interference effect of some chemical and biological species was evaluated by the matched potential method and separate solution method. The sensor worked stable for 12 weeks without any considerable change in its potential response. The analytical applications of the sensor were successfully carried out with the potentiometric titration of FAV with sodium tetraphenylborate solution and also the direct determination of favipiravir in COVID-19 antiviral drug formulations.
RDL Kalıcı Kaydıİncele - ArticleAçık Erişim2023Kaolin Yüzeyine Dekore Edilmiş Bakır Katkılı Çinko Oksit Nanokompoziti Kullanılarak Reaktif Mavi 21 Tekstil Boyar Maddesinin Adsorpsiyonu, Kinetiği ve Termodinamiği
Caglar, Bulent; Güner, Eda Keles; Doğan, Bilge; Özdemir, Agah Oktay
Bu çalışmanın amacı; tekstil endüstrisinde yaygın olarak kullanılan bir boyarmadde olan Reaktif Mavi 21 (RM21)’in atık sulardan adsorpsiyon yöntemiyle uzaklaştırılmasında kaolin yüzeyine dekore edilmiş bakır katkılı çinko oksit nanokompozitinin adsorban olarak kullanılabilirliğinin araştırılmasıdır. Adsorpsiyon üzerine, başlangıç RM21 konsantrasyonu, adsorban miktarı, sıcaklık ve denge süresi gibi çeşitli deneysel parametrelerin etkileri incelenmiştir. Adsorpsiyon hızının ikinci mertebeden hız ifadesine uyduğu ve kaolin yüzeyine dekore edilmiş bakır katkılı çinko oksit nanokompozitinin RM21 üzerine adsorpsiyonunun Redlich-Peterson izoterm modeliyle uyum sağladığı görülmüştür. Bu çalışmanın sonuçları, RM21’nin sulu çözeltilerden uzaklaştırılmasında kaolin yüzeyine dekore edilmiş bakır katkılı çinko oksit nanokompozitinin etkili bir adsorban olarak kullanılabileceğini göstermiştir.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2023Construction of a novel Cu(II)-selective electrode with long life span based on 8-aminoquinoline functionalized bentonite
Dogan, Bilge; Coldur, Fatih; Caglar, Bulent; Ozdemir, Agah Oktay; Guner, Eda Keles; Ozdokur, Kemal Volkan
A novel 8-aminoquinoline-functionalized bentonite was utilized as an electroactive sensing element in the construction of a potentiometric carboxylated-PVC-based polymeric membrane electrode. The electrode exhibited a linear response for copper(II) ions in the concentration range of 1.0 × 10–5−1.0 × 10–2 mol/dm3 with a slope of 28.24 mV/decade. While the response time of the electrode determined as about 20 s, its detection limit and long life time was determined as 5.0 × 10–6 mol/dm3 and 5 months, respectively. The proposed electrode was applied for the potentiometric detection of Cu(II) contents of some spiked water samples and satisfied results were attained. Graphical abstract: [Figure not available: see fulltext.]
RDL Kalıcı Kaydıİncele - ArticleAçık Erişim2023A PVC-Membrane Cationic Surfactant Sensitive Potentiometric Sensor: Potentiometric Determination of Dodecyltrimethyl Ammonium Ion
Yalcin, Belgin; Coldur, Fatih; Caglar, Bulent; Topcu, Cihan
A potentiometric poly (vinyl chloride) (PVC) membrane cationic surfactant-selective sensor based on a dodecyltrimethylammonium-phosphotungstate ion pair as an electroactive material was suggested for the determination of dodecyltrimethylammonium bromide. Membrane optimization studies revealed that the PVC membrane in the composition of 0.5 % dodecyltrimethylammonium-phosphotungstate ion pair, 69.5 % o-nitrophenyloctylether and 30.0 % PVC displayed the best potentiometric performance properties. The sensor exhibited a linear response to dodecyltrimethylammonium ions in the concentration range of 1.0×10−6–1.0×10−2 mol L−1 with a detection limit and sensitivity of 5.0×10−7 mol L−1 and 56.6 mV/decade, respectively. The response of the sensor to dodecyltrimethylammonium cation was quite stable, sensitive, selective and rapid (<10 s). The life span of the sensor was found to be about 3 months. The analytical applications of the sensor were successfully carried out with the developed sensor as an indicator electrode for the determination of the end-point of dodecyltrimethylammonium ions titration and dodecyltrimethylammonium contents of synthetic water samples.
RDL Kalıcı Kaydıİncele - ArticleAçık Erişim2022Kil Esaslı Bütünüyle-Katı-Hal Kompozit Kurşun (II)-Seçici Potansiyometrik Elektrot
Caglar, Bulent; Topcu, Cihan; Güner, Eda Keles; Ozdokur, Kemal Volkan; Cubuk, Osman; Çoldur, Fatih; Doğan, Bilge; Özdemir, Agah Oktay
Bentonit kili XRD, FTIR ve SEM-EDX teknikleriyle karakterize edildi. Karakterize edilen kil bütünüyle katı hal kompozit potansiyometrik elektrot yapımında iyonofor madde olarak kullanılmış ve kilin potansiyometrik uygulaması gerçekleştirilmiştir. Elektrodun Pb2+ iyonuna karşı, diğer yaygın inorganik katyonlarla karşılaştırıldığında oldukça duyarlı ve seçici potansiyometrik bir cevap sergilediği gözlemlenmiştir. Membran optimizasyon çalışmaları neticesinde en iyi potansiyometrik performans özellikleri sergileyen bileşimin kütlece %65.0 grafit, %5.0 çok duvarlı karbon nanotüp, %20.0 iyonofor (bentonit) ve %10.0 parafin yağı olduğu belirlenmiştir. Pb2+ seçici kompozit elektrodun 1.0×10-5 ˗ 1.0×10-1 M konsantrasyon aralığında doğrusal cevap sergilediği, doğrusal çalışma aralığında standart Pb2+ çözeltilerine karşı her 10 katlık konsantrasyon değişiminde ortalama 31 mV potansiyel fark sergilediği gözlenmiştir. Elektrodun tayin sınırı 9.0×10-6 M olarak hesaplanmıştır. Elektrodun cevap zamanının oldukça kısa olduğu (~5 s) potansiyometrik cevabın ve tekrarlanabilirliğinin de oldukça yüksek olduğu ortaya konmuştur.
RDL Kalıcı Kaydıİncele - ArticleAçık Erişim2022TiO2 Nanoparçacık Kaplı Pamuklu Kumaşın Fotokatalitik ve Antibakteriyel Özelliklerinin İncelenmesi
Kuzucu, Mehmet; Caglar, Bulent; Güner, Eda Keles; Doğan, Bilge; Özdemir, Agah Oktay
Bu çalışmada, fotokatalitik ve antibakteriyel özelliklere sahip, TiCl4'ün hidroliziyle sentezlenen farklı miktarlarda TiO2 nanoparçacıklar ile yüzey modifiye edilmiş pamuklu kumaşlar hazırlandı. Hazırlanan bu TiO2 nanoparçacıkları kaplı pamuklu kumaşların fotokatalitik aktiviteleri UVA ışınları altında Kristal Viyolet (KV) boyar maddesinin bozunmasında incelendi. KV’nin, TiO2 nanoparçacıkları kaplı pamuklu kumaşlar üzerindeki fotokatalitik bozunması için en uygun şartlar 0,625 mgL-1 başlangıç KV konsantrasyonu ve 57 mgL-1 TiO2 nanoparçacık yükleme miktarı olarak belirlendi. Bu en uygun şartlar altında, ilgili fotokatalizör varlığında 40 dakika içerisinde UVA ışınları altında KV’nin % 89,31’inin bozunmaya uğradığı tespit edildi ve bozunma reaksiyonunun birinci dereceden kinetiği takip ettiği belirlendi. Reaktif tür deneyleri, hidroksil radikallerinin diğer radikal türlere nispeten daha önemli bir rol oynadığını ortaya çıkardı ve elde edilen bu verilere göre olası bozunma mekanizması önerildi. Ayrıca TiO2 kaplanmış pamuklu kumaşların antibakteriyel aktivitesinin incelenmesi için disk difüzyon metodu kullanıldı. Antibakteriyel aktivite tayininde Gram pozitif bakteri olarak Staphylococcus aureus (ATCC 6538), Gram negatif bakteri olarak Escherichia coli (ATCC 25922) üzerinde denemeler gerçekleştirildi. Disk difüzyon deneyi sonuçlarına göre; 38 ve 57 mgL-1 konsantrasyonlarında TiO2 ile kaplanmış pamuklu kumaşlarda, antibiyotik referansların oluşturduğu inhibisyon zonu çapına kıyasla relatif olarak E. coli’ye karşı sırasıyla % 40,9 ve % 60,2 oranlarında antibakteriyel etki görülmüştür.
RDL Kalıcı Kaydıİncele - ArticleAçık Erişim2022In Vitro Cytotoxic Evaluation of a Silver(I) Complex Including Non-Steroidal Anti-Inflammatory Drug Niflumic Acid and 3-Picoline on Human-Derived Cancer Cell Lines
Caglar, Bulent; Altay, Ahmet; Yeniçeri, Esma Kübra Kağan; Caglar, Sema; Harurluoğlu, Betül
Burada, steroidal olmayan anti-enflamatuar ilaç niflumik asit ve 3-pikolin içeren yeni bir gümüş(I) kompleksi sentezlendi ve FT-IR, 1H NMR, elemental ve termik analiz teknikleri ile karakterize edildi. Bu teknikler, sentezlenen kompleksin formülünün [Ag(nif)(3-pic)] olduğunu gösterdi. Kompleks, ligand (niflumik asit) ve gümüş iyonlarının tek başına sitotoksik yeteneği, insan meme adenokarsinomu (MDA-MB-453), akciğer adenokarsinomu (A-549), kolorektal adenokarsinom (HT-29) ve fare fibroblast hücre hatlarına (3T3-L1) karşı test edildi. XTT sonuçları, AgNO3 ve niflumik asidin tek başına kanser ve sağlıklı hücre hatları üzerinde orta düzeyde sitotoksisite sergilemesine rağmen, kompleksin kanser hücreleri üzerinde doza bağlı bir şekilde güçlü sitotoksik aktivite gösterdiğini gösterdi. Kompleksin en güçlü sitotoksisitesi ve en yüksek seçiciliği HT-29 hücrelerinde belirlendi. Bu bulgular, gelişmiş antikanser çalışmalarında yeni gümüş(I) kompleksinin değerlendirilmesi için temel çıktılar sağlar.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2022Solid-state Electrochemical Sensor Based on a Cross-linked Copper(II)-doped Copolymer and Carbon Nanotube Material for Selective and Sensitive Detection of Monohydrogen Phosphate
Topcu, Cihan; Coldur, Fatih; Caglar, Bulent; Ozdokur, K. Volkan; Cubuk, Osman
A novel solid-state electrochemical sensor based on a newly synthesized cross-linked copper(II) doped-copolymer and carbon nanotube material was developed for the direct determination of monohydrogen phosphate ions (HPO42−). The synthesized copolymers were characterized by FTIR, XPS, TG/DTG-DTA and SEM techniques. The sensor had a Nernstian slope:-30.7±0.4 mV/decade, linear concentrations range: 1.0×10−6 - 1.0×10−1 M, detection limit: 6.5×10−7 M, response time: 4 s and life time: 17 weeks. The sensor displayed constant potentials in the pH range 7.0-9.5. The sensor was successfully used as an indicator electrode in potentiometric titration and the direct determination of HPO42− in water samples.
RDL Kalıcı Kaydıİncele - ArticleAçık Erişim2022Synthesis, structural characterization and evaluation of anticancer activity of polymeric silver(I) complexes based on niflumic acid/naproxen and picoline derivatives
Caglar, Sema; Altay, Ahmet; Harurluoglu, Betul; Yeniceri, Esma K. K.; Caglar, Bulent; Şahin, Onur
Two polymeric mixed-ligand silver(I) complexes, [Ag(µ-nif)(4-pic)]n (1) and [Ag4(µ-nap)4(2-pic)2]n (2), where Hnif: niflumic acid, Hnap: naproxen, 4-pic: 4-picoline and 2-pic: 2-picoline, were synthesized and characterized by single-crystal X-ray diffraction, FT-IR and 1H NMR spectroscopies, elemental and thermal analysis techniques. In 1, nif ligand behaves as a µ3-N,O,O' bridge connecting three silver(I) ions and each silver(I) ion exhibits a seesaw geometry. In 2, nap ligands act as a µ-carboxylato-(O,O') bridge between two silver(I) ions and µ3-carboxylato-(O,O,O') bridge linking three silver(I) ions. Each silver(I) ion occurs in trigonal geometry. To uncover the anticancer properties of the complexes, first, their cytotoxic abilities were tested against three cancer cell lines, HT-29 (human colorectal adenocarcinoma), A-549 (human lung carcinoma), and MDA-MB-453 (human breast adenocarcinoma), and normal 3T3-L1 (mouse fibroblast) cell line by XTT tests. Afterwards, the anticancer mechanism of the complexes was tried to be elucidated through the flow cytometry analyzes. XTT assay results showed that the complexes exhibited the highest cytotoxic activity and selectivity on HT-29 cells among all the cell lines. Flow cytometry analyses revealed that both complexes induced the apoptosis through the mitochondrial membrane depolarization and activation of the caspase cascade in HT-29 cells.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2022Facile synthesis of TiO2-coated cotton fabric and its versatile applications in photocatalysis, pH sensor and antibacterial activities
Özdemir, Agah Oktay; Caglar, Bulent; Çubuk, Osman; Coldur, Fatih; Kuzucu, Mehmet; Guner, Eda Keles; Doğan, Bilge; Caglar, Sema; Özdokur, Kemal Volkan
TiO2 nanoparticles-coated cotton fabric was readily prepared by the hydrolysis of TiCl4 solution over cotton fabric and characterized various techniques in comparison with pristine cotton fabric. Initially, the photocatalytic application of the obtained fabric was carried out by using it as a catalyst for the photodegradation of rhodamine B. A higher degradation ratio for rhodamine B in the presence of TiO2-coated cotton fabric as photocatalyst was observed under visible light compared to the one performed under UVA. The reactive species trapping experiments revealed that the superoxide radicals played a major role than other radical species and two different degradation mechanisms were proposed according the trapping results. Subsequently, considering that the fabricated TiO2-coated cotton fabric is a very suitable sensor material for the development of a wearable flexible pH sensor, a potentiometric solid state pH sensor prototype was constructed and tested for pH measurements. The proposed prototype exhibited a linear potentiometric response in the pH range from 2.0 to 9.0 with a slope of −23.9 mV/decade. The pH accuracies (as relative error %) calculated for the current electrode with respect to the commercial electrode in the studied buffer solutions were ranged between −1.8% and 1.9%. The presently proposed pH electrode allowed pH measurements highly coherent with commercially available pH electrode. Finally, the antibacterial activity of the TiO2 nanoparticles was evaluated by minimum bactericidal concentration (MBC), minimum inhibitory concentration (MIC) testing and also antibacterial property of the TiO2 nanoparticles-coated cotton fabric was demonstrated by GB/T 20944.3–2008 method using Staphylococcus aureus (ATCC 6538) and Escherichia coli (ATCC 25922) as representative strains of Gram-positive and Gram-negative bacteria, respectively. This study would be indicative to design of nano metal oxide-coated cotton fabrics in the application of photocatalyst, pH sensor and antibacterial agent against bacteria.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2022Silver(I) complexes containing diclofenac and niflumic acid induce apoptosis in human-derived cancer cell lines
Altay, Ahmet; Caglar, Sema; Caglar, Bulent
We investigated the anti-cancer activity of [Ag(μ-dicl)] n 1 and [AgH(nif)2] 2 complexes against human cancer cell lines (MCF-7, HT-29, and HepG2) and mouse fibroblast (3T3-L1) cell line. Anti-proliferative activity was monitored by XTT cell viability and LDH leakage assays. Cell death mode was evaluated by multi-caspase activity, annexin V cytofluorimetric, MMP, cell cycle arrest, and ROS generation assays. Antioxidant capacity was evaluated on SOD, GPx, GR, and CAT enzymes. The XTT and LDH assay results showed that both complexes exhibited strong cytotoxicity against the tested cancer cell lines. The apoptotic mechanisms of the complexes were demonstrated by loss of MMP and increase in phosphatidylserine translocation, sub-G1 phase, and multi-caspase activity. Besides, both complexes induced the oxidative stress in MCF-7 cells by decreasing the activity of GPx, GR, and CAT enzymes. In conclusion, both Ag(I) complexes, especially 1, warrant for further in vivo evaluation as a new alternative in cancer treatment.Highlights Ag(I) complexes inhibited cell proliferation and induced LDH leakage in human cancer cell lines. Ag(I) complexes induced apoptosis through MMP disruption and ROS generation. Ag(I) complexes mimicked the multi-caspase activity. Ag(I) complexes increased the accumulation of sub-G1 phase. Ag(I) complexes inhibited the activity of antioxidant system enzymes.
RDL Kalıcı Kaydıİncele - ArticleAçık Erişim2021Farklı ışık kaynakları altında kristal viyole boyar maddesinin kaolin-$BiFeO_3$ nanokompozit üzerinde fotobozunması
Caglar, Bulent; Güner, Eda Keles; Özdemir, Agah Oktay; İçer, Fatih
Kaolin yüzeyine perovskit yapılı $BiFeO_3$ (BFO) nanoparçacıklarının yerleştirilmesiyle kaolin-$BiFeO_3$ (KBFO) nanokompoziti hazırlandı. Saf kaolin (K), saf BFO ve hazırlanan KBFO nanokompozitin fotokatalitik aktiviteleri UVA ve görünür bölge ışımaları altında katyonik bir boyar madde olan kristal viyole (KV)’nin fotokatalitik bozunması incelenerek değerlendirildi. KBFO nanokompozitinin diğer katalizörlere nispeten daha yüksek fotokatalitik aktivite sergilediği ve fotobozunmanın yalancı birinci dereceden kinetik izlediği belirlendi. Ayrıca pH, başlangıç boya konsantrasyonu ve katalizör miktarı gibi deneysel parametrelerin fotokataliz reaksiyonuna etkileri incelenerek en uygun değerleri tespit edildi. pH 9’da $10mgL^{-1}$ başlangıç boya konsantrasyonunda ve 100 mg katalizör varlığında KV’nin KBFO katalizörü üzerindeki fotokatalitik bozunma verimleri UVA ve GB ışınları altında sırasıyla %84 ve %89 olarak belirlendi. KV'nin KBFO nanokompozit üzerindeki fotokatalitik bozunmasından sorumlu olan reaktif türlerinin katkısını belirlemek için radikal süpürücü deneyler yapıldı ve olası mekanizma önerildi. Yapılan radikal süpürücü deneylerine göre hidroksil radikallerinin KV’nin fotokatalitik bozunmasında başlıca role sahip olduğu tespit edildi.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2021Bi2S3 nanorods decorated on bentonite nanocomposite for enhanced visible-light-driven photocatalytic performance towards degradation of organic dyes
Caglar, Bulent; Guner, Eda Keles; Ersoy, Selin; Caglar, Sema; Özdemir, Agah Oktay; Özdokur, Kemal Volkan; Doğan, Bilge; İçer, Fatih; Çırak, Çağrı
In this study, we prepared bentonite-Bi2S3 nanocomposite via decoration of Bi2S3 nanorods on bentonite for the first time to enhance the photocatalytic performance of Bi2S3 nanorods under visible light irradiation. XRD, TEM, SEM-EDX, XPS, UV-DRS, PL, electrochemical impedance spectroscopy, chronoamperometry, zeta potential, and BET techniques were used to compare analysis of structural, morphological, optical, electrochemical and textural properties of raw bentonite, bare Bi2S3 nanorods and bentonite-Bi2S3 nanocomposite. The photocatalytic performances of bentonite-Bi2S3 nanocomposite and bare samples were also investigated and comparatively evaluated by photodegradations of crystal violet and rhodamine B dyes under visible light irradiation. The photocatalytic degradation efficiencies of fabricated bentonite-Bi2S3 nanocomposite for crystal violet and rhodamine B were determined as 100% and 85% after the periods of 30 min and 90 min, respectively, which were more superior compared with those of bare Bi2S3 nanorods. The enhanced photodegradation activity of bentonite-Bi2S3 nanocomposite was assigned to the good visible light absorption ability, enlarged surface area, increased adsorption capability and decreased aggregation of Bi2S3 nanorods with the inclusion of bentonite platform as well as suppressed hole-electron recombination process due to electrostatic interaction between negatively charged bentonite surface and positively charged holes. The reactive species trapping revealed that hydroxyl radicals played a major role on the photodegradation and a plausible mechanism for photodegradation of dye molecules on bentonite-Bi2S3 nanocomposite was suggested. The photodegradation of dyes was found to follow the pseudo-first-order kinetic model. The prepared photocatalyst exhibited good reusability and stability after 4 cycles.
RDL Kalıcı Kaydıİncele - ArticleYayıncıda açık erişim2021In Vitro Anticancer Activity of Novel Co(II) and Ni(II) Complexes of Non-steroidal Anti-inflammatory Drug Niflumic Acid Against Human Breast Adenocarcinoma MCF-7 Cells
Caglar, Sema; Altay, Ahmet; Kuzucu, Mehmet; Caglar, Bulent
Herein, we report the synthesis, characterization and anticancer activity of six novel complexes of non-steroidal anti-inflammatory drug niflumic acid with Co(II) and Ni(II). In vitro cytotoxicity screening in MCF-7, HepG2 and HT-29 cancer cell lines showed that the complex 3 [Co(nif)2(met)(4-pic)] and complex 6 [Ni(nif)2(met)(4-pic)] among all the complexes exhibited the highest cytotoxicity against MCF-7 cells with IC50 values of 11.14 µM and, 41.47 µM, respectively. Besides, all the complexes exhibited significantly higher selectivity towards mouse fibroblast 3T3L1 cells. Further mechanistic studies with both complexes on MCF-7 cells revealed their cytotoxic action through the mitochondrial-dependent apoptotic pathway causing an increase oxidative/nitrosative stress, decrease in mitochondrial membrane potential (ΔΨm), inducing the multicaspase activation and arresting the cell cycle at S phase. q-PCR analysis resulted in an increase in the expression of the apoptotic marker proteins bax, p53 and caspase-3 and -8 in MCF-7 cells, but a decrease in the expression of antiapoptotic bcl-2 gene. Moreover, both complexes induced the apoptosis through the inhibition of PI3K/Akt signaling pathway by decreasing the expression of PI3K and increasing dephosphorylation form of Akt protein. These results provide a significant contribution to the explanation of the anticancer mechanisms of these complexes in MCF-7 cells. [Figure not available: see fulltext.]
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2021Binuclear silver(I) complexes with the non-steroidal anti-inflammatory drug tolfenamic acid: Synthesis, characterization, cytotoxic activity and evaluation of cellular mechanism of action
Harurluoglu, Betul; Altay, Ahmet; Caglar, Sema; Kubra Kagan Yeniceri, Esma; Caglar, Bulent; Sibel Şahin, Zarife
In this study, two new binuclear silver(I)-tolfenamic acid complexes including picoline derivative ligands, [Ag2(μ-tolf)2(2-pic)2] 1 and [Ag2(μ-tolf)2(4-pic)2] 2, were synthesized and identified by elemental analysis, FT-IR, 1H NMR and thermal analysis techniques. The in vitro cytotoxicity of the complexes was investigated against human breast cancer cell lines by XTT, flow cytometry, enzyme activity and western blot studies. The structures of 1 and 2 were clarified by single-crystal X-ray diffraction determination. The data clearly indicated that the Ag(I) ion is coordinated to one auxiliary ligand (2-pic or 4-pic), two tolfenamato ligands and another Ag(I) ion, demonstrating a distorted tetrahedral geometry. The tolfenamato ligands act as a bridging bidentate ligands. The chains are stabilized by intramolecular Ag(I)⋯π and π···π interactions. The 1H NMR and thermal analyses displayed the presence of picoline and tolfenamato ligands in the coordination sphere and the purity of the complexes. Both complexes exhibited potent cytotoxicity against cancer cell lines with higher selectivity than carboplatin. Flow cytometry and enzyme activity studies indicated that both complexes caused an increase in apoptosis, ROS and NO levels, cell cycle arrest, mitochondrial membrane damage and caspase activity, as well as inhibiting PI3K/Akt phosphorylation and modulating the oxidant/antioxidant balance system. Western blot analyses revealed the up-regulation of bax, caspase-3, caspase-9 and p53 proteins, but the down-regulation of bcl-2. These results demonstrate the vigorous apoptotic potential of the novel Ag(I) complexes in human breast cancer MDA-MB-453 cells.
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