322 results on '"Dilek Odaci"'
Search Results
2. Carbon-Based Nanomaterials Decorated Electrospun Nanofibers in Biosensors: A Review
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Nur Melis Kilic, Sultan Sacide Gelen, Simge Er Zeybekler, and Dilek Odaci
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Chemistry ,QD1-999 - Published
- 2023
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3. Electrospun Nanofibers including Organic/Inorganic Nanohybrids: Polystyrene- and Clay-Based Architectures in Immunosensor Preparation for Serum Amyloid A
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Gizem Evren, Eray Er, Esra Evrim Yalcinkaya, Nesrin Horzum, and Dilek Odaci
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nanobiotechnology ,serum amyloid A ,nanofiber ,clay ,dendrimer ,immunosensor ,Biotechnology ,TP248.13-248.65 - Abstract
Diagnostic techniques based on biomolecules have application potential that can be realized in many fields, such as disease diagnosis, bioprocess imaging, food/beverage industries, and environmental pollutant imaging. Successful surface immobilization of biomolecules is critical to increasing the stabilization, sensitivity, and selectivity of biomolecules used in bioassay systems. Nanofibers are good candidates for the immobilization of biomolecules owing to many advantages such as morphology and pore size. In this study, montmorillonite (MMT) clay is modified with poly(amidoamine) (PAMAM) generation 3 (PAMAMG3) and added to polystyrene (PS) solutions, following which PS/MMT-PAMAMG3 nanofibers are obtained using the electrospinning method. The nanofibers are obtained by testing PS% (wt%) and MMT-PAMAMG3% (wt%) ratios and characterized with scanning electron microscopy. Antiserum amyloid A antibody (Anti-SAA) is then conjugated to the nanofibers on the electrode surface via covalent bonds using a zero-length cross linker. Finally, the obtained selective surface is used for electrochemical determination of serum amyloid A (SAA) levels. The linear range of PS/MMT-PAMAM/Anti-SAA is between 1 and 200 ng/mL SAA, and the detection limit is 0.57 ng/mL SAA. The applicability of PS/MMT-PAMAMG3/Anti-SAA is investigated by taking measurements in synthetic saliva and serum both containing SAA.
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- 2023
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4. Novel Approaches to Enzyme-Based Electrochemical Nanobiosensors
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Nur Melis Kilic, Sima Singh, Gulsu Keles, Stefano Cinti, Sevinc Kurbanoglu, and Dilek Odaci
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nanobiosensors ,biosensors ,enzyme ,substrate ,electrochemistry ,Biotechnology ,TP248.13-248.65 - Abstract
Electrochemistry is a genuinely interdisciplinary science that may be used in various physical, chemical, and biological domains. Moreover, using biosensors to quantify biological or biochemical processes is critical in medical, biological, and biotechnological applications. Nowadays, there are several electrochemical biosensors for various healthcare applications, such as for the determination of glucose, lactate, catecholamines, nucleic acid, uric acid, and so on. Enzyme-based analytical techniques rely on detecting the co-substrate or, more precisely, the products of a catalyzed reaction. The glucose oxidase enzyme is generally used in enzyme-based biosensors to measure glucose in tears, blood, etc. Moreover, among all nanomaterials, carbon-based nanomaterials have generally been utilized thanks to the unique properties of carbon. The sensitivity can be up to pM levels using enzyme-based nanobiosensor, and these sensors are very selective, as all enzymes are specific for their substrates. Furthermore, enzyme-based biosensors frequently have fast reaction times, allowing for real-time monitoring and analyses. These biosensors, however, have several drawbacks. Changes in temperature, pH, and other environmental factors can influence the stability and activity of the enzymes, affecting the reliability and repeatability of the readings. Additionally, the cost of the enzymes and their immobilization onto appropriate transducer surfaces might be prohibitively expensive, impeding the large-scale commercialization and widespread use of biosensors. This review discusses the design, detection, and immobilization techniques for enzyme-based electrochemical nanobiosensors, and recent applications in enzyme-based electrochemical studies are evaluated and tabulated.
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- 2023
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5. Development of an Enzymatic Biosensor Using Glutamate Oxidase on Organic–Inorganic-Structured, Electrospun Nanofiber-Modified Electrodes for Monosodium Glutamate Detection
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Hamdiye Atilgan, Betul Unal, Esra Evrim Yalcinkaya, Gizem Evren, Gozde Atik, Fatma Ozturk Kirbay, Nur Melis Kilic, and Dilek Odaci
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nanobiotechnology ,electrochemical method ,nanomaterial ,nanofiber ,MSG ,montmorillonite ,Biotechnology ,TP248.13-248.65 - Abstract
Herein, dendrimer-modified montmorillonite (Mt)-decorated poly-Ɛ-caprolactone (PCL) and chitosan (CHIT)-based nanofibers were prepared. Mt was modified with a poly(amidoamine) generation 1 (PAMAMG1) dendrimer, and the obtained PAMAMG1–Mt was incorporated into the PCL–CHIT nanofiber’s structure. The PCL–CHIT/PAMAMG1–Mt nanofibers were conjugated with glutamate oxidase (GluOx) to design a bio-based detection system for monosodium glutamate (MSG). PAMAMG1–Mt was added to the PCL–CHIT backbone to provide a multipoint binding side to immobilize GluOx via covalent bonds. After the characterization of PCL–CHIT/PAMAMG1–Mt/GluOx, it was calibrated for MSG. The linear ranges were determined from 0.025 to 0.25 mM MSG using PCL–CHIT/Mt/GluOx and from 0.0025 to 0.175 mM MSG using PCL–CHIT/PAMAMG1–Mt/GluOx (with a detection limit of 7.019 µM for PCL–CHIT/Mt/GluOx and 1.045 µM for PCL–CHIT/PAMAMG1–Mt/GluOx). Finally, PCL–CHIT/PAMAMG1–Mt/GluOx was applied to analyze MSG content in tomato soup without interfering with the sample matrix, giving a recovery percentage of 103.125%. Hence, the nanofiber modification with dendrimer-intercalated Mt and GluOx conjugation onto the formed nanocomposite structures was performed, and the PCL–CHIT/PAMAMG1–Mt/GluOx system was successfully developed for MSG detection.
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- 2023
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6. Graphene Oxide-Magnetic Nanoparticles Loaded Polystyrene-Polydopamine Electrospun Nanofibers Based Nanocomposites for Immunosensing Application of C-Reactive Protein
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Simge Ketmen, Simge Er Zeybekler, Sultan Sacide Gelen, and Dilek Odaci
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nanobiotechnology ,nanotechnology ,graphene oxide ,magnetic nanoparticles ,polydopamine ,polystyrene ,Biotechnology ,TP248.13-248.65 - Abstract
The large surface area/volume ratio and controllable surface conformation of electrospun nanofibers (ENFs) make them highly attractive in applications where a large surface area is desired, such as sensors and affinity membranes. In this study, nanocomposite-based ENFs were produced and immobilization of Anti-CRP was carried out for the non-invasive detection of C-reactive protein (CRP). Initially, the synthesis of graphene oxide (GO) was carried out and it was modified with magnetic nanoparticles (MNP, Fe3O4) and polydopamine (PDA). Catechol-containing and quinone-containing functional groups were created on the nanocomposite surface for the immobilization of Anti-CRP. Polystyrene (PS) solution was mixed with rGO-MNP-PDA nanocomposite and PS/rGO-MNP-PDA ENFs were produced with bead-free, smooth, and uniform. The surface of the screen-printed carbon electrode (SPCE) was covered with PS/rGO-MNP-PDA ENFs by using the electrospinning technique under the determined optimum conditions. Next, Anti-CRP immobilization was carried out and the biofunctional surface was created on the PS/rGO-MNP-PDA ENFs coated SPCE. Moreover, PS/rGO-PDA/Anti-CRP and PS/MNP-PDA/Anti-CRP immunosensors were also prepared and the effect of each component in the nanocomposite-based electrospun nanofiber (MNP, rGO) on the sensor response was investigated. The analytic performance of the developed PS/rGO-MNP-PDA/Anti-CRP, PS/rGO-PDA/Anti-CRP, and PS/MNP-PDA/Anti-CRP immunosensors were examined by performing electrochemical measurements in the presence of CRP. The linear detection range of PS/rGO-MNP-PDA/Anti-CRP immunosensor was found to be from 0.5 to 60 ng/mL and the limit of detection (LOD) was calculated as 0.33 ng/mL for CRP. The PS/rGO-MNP-PDA/Anti-CRP immunosensor also exhibited good repeatability with a low coefficient of variation.
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- 2022
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7. Ferrocene-Functionalized 4-(2,5-Di(thiophen-2-yl)-1H-pyrrol-1-yl)aniline: A Novel Design in Conducting Polymer-Based Electrochemical Biosensors
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Rukiye Ayranci, Dilek Odaci Demirkol, Metin Ak, and Suna Timur
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ferrocenyldithiophosphonate ,conducting polymers ,biosensor ,glucose ,Chemical technology ,TP1-1185 - Abstract
Herein, we report a novel ferrocenyldithiophosphonate functional conducting polymer and its use as an immobilization matrix in amperometric biosensor applications. Initially, 4-(2,5-di(thiophen-2-yl)-1H-pyrrol-1-yl)amidoferrocenyldithiophosphonate was synthesized and copolymerized with 4-(2,5-di(thiophen-2-yl)-1H-pyrrol-1-yl)benzenamine at graphite electrodes. The amino groups on the polymer were utilized for covalent attachment of the enzyme glucose oxidase. Besides, ferrocene on the backbone was used as a redox mediator during the electrochemical measurements. Prior to the analytical characterization, optimization studies were carried out. The changes in current signals at +0.45 V were proportional to glucose concentration from 0.5 to 5.0 mM. Finally, the resulting biosensor was applied for glucose analysis in real samples and the data were compared with the spectrophotometric Trinder method.
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- 2015
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8. Comparison of direct and sandwich type immunoassays on electrospun nanofibers using of metal organic frameworks as a fluorescence probe
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Kirbay, Fatma Ozturk, Yazgan, İdris, and Demirkol, Dilek Odaci
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- 2022
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9. High generation dendrimer decorated poly-Ɛ-caprolactone/polyacrylic acid electrospun nanofibers for the design of a bioelectrochemical sensing surface
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Oner, Aylis, Tufek, Ensara, Yezer, Irem, Birol, Asli, Demir, Meltem, Er, Simge, and Demirkol, Dilek Odaci
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- 2021
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10. Catalase-conjugated surfaces: H2O2 detection based on quenching of tryptophan fluorescence on conducting polymers
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Gelen, Sultan Sacide, Munkhbat, Tuvshinjargal, Rexhepi, Zuale, Kirbay, Fatma Ozturk, Azak, Hacer, and Demirkol, Dilek Odaci
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- 2021
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11. 4-aminothiophenol-intercalated montmorillonite: Organic-inorganic hybrid material as an immobilization support for biosensors
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Yilmaz, Yahya Yasin, Yalcinkaya, Esra Evrim, Demirkol, Dilek Odaci, and Timur, Suna
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- 2020
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12. Cellulose acetate–chitosan based electrospun nanofibers for bio-functionalized surface design in biosensing
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Yezer, Irem and Demirkol, Dilek Odaci
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- 2020
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13. Cells-on-nanofibers: Effect of polyethyleneimine on hydrophobicity of poly-Ɛ-caprolacton electrospun nanofibers and immobilization of bacteria
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Gordegir, Meleknur, Oz, Sultan, Yezer, Irem, Buhur, Merve, Unal, Betul, and Demirkol, Dilek Odaci
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- 2019
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14. Laccase assay based on electrochemistry and fluorescence detection via anthracene sequestered poly(amic acid) films
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Esen, Elif, Yazgan, Idris, Demirkol, Dilek Odaci, and Timur, Suna
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- 2018
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15. Biofunctionalization of PAMAM-montmorillonite decorated poly (Ɛ-caprolactone)-chitosan electrospun nanofibers for cell adhesion and electrochemical cytosensing
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Kirbay, Fatma Ozturk, Yalcinkaya, Esra Evrim, Atik, Gozde, Evren, Gizem, Unal, Betul, Demirkol, Dilek Odaci, and Timur, Suna
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- 2018
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16. Brilliant green sequestered poly(amic) acid film for dual-mode detection: Fluorescence and electrochemical enzymatic biosensor
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Maiga, Mohomodou, Yazgan, Idris, Kariuki, Victor M., Demirkol, Dilek Odaci, Sadik, Omowunmi A., and Timur, Suna
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- 2018
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17. Carbon Nanotube-Incorporated Nanofibers for Immunosensor Preparation against CD36
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Simge Er Zeybekler and Dilek Odaci
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General Chemical Engineering ,General Chemistry - Published
- 2023
18. Electrospun Nanofibers: Functional and Attractive Materials for the Sensing and Separation Approaches in Analytical Chemistry
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Unal, Betul, primary, Kirbay, Fatma Ozturk, additional, Yezer, Irem, additional, Demirkol, Dilek Odaci, additional, and Timur, Suna, additional
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- 2019
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19. Biofunctional quantum dots as fluorescence probe for cell-specific targeting
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Ag, Didem, Bongartz, Rebecca, Dogan, Leyla Eral, Seleci, Muharrem, Walter, Johanna-G., Demirkol, Dilek Odaci, Stahl, Frank, Ozcelik, Serdar, Timur, Suna, and Scheper, Thomas
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- 2014
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20. List of Contributors
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Albuleţ, Delia, primary, Alves, André F., additional, Andreani, Tatiana, additional, Andronescu, Ecaterina, additional, Anton, Gabriel-Cristian, additional, Atyabi, Fatemeh, additional, Barick, Kanhu C., additional, Bastakoti, Bishnu P., additional, Benito, Marta, additional, Bhattacharjee, Jayita, additional, Blanco, María D., additional, Boarca, Bianca, additional, Bolocan, Alexandra, additional, Bontas, Denisa-Andreea, additional, Călugăreanu, Andreea, additional, Carvalho, Maria Deus, additional, Cerqueira, Nuno M.F.S.A., additional, Chandra, Ramesh, additional, Chavda, Vivek P., additional, Chifiriuc, Mariana C., additional, Choi, Young W., additional, Chow, James C.L., additional, Corvo, M. Luísa, additional, Cruz, Maria Margarida, additional, de Hollanda, Luciana M., additional, Demir, Bilal, additional, Demirkol, Dilek Odaci, additional, Ditu, Lia M., additional, Dorcioman, Gabriela, additional, Duran, Nelson, additional, Fernandes, Henrique S., additional, Fernandes, Pedro A., additional, Ferreira, Liliana P., additional, Ferreira, Paula, additional, Ficai, Anton, additional, Ficai, Denisa, additional, Florea, Denisa A., additional, Fufă, Oana, additional, Galal, Ahmed, additional, Gasar, Rogério, additional, Gheorghe, Irina, additional, Gherasim, Tudor G., additional, Godinho, Margarida, additional, Godiyal, Shilpa C., additional, Grumezescu, Alexandru M., additional, Grumezescu, Valentina, additional, Guler, Bahar, additional, Guler, Emine, additional, Silindir-Gunay, Mine, additional, Gupta, Indarchand, additional, Hassan, Puthusserickal A., additional, Hevus, Ivan, additional, Holban, Alina M., additional, Ingle, Avinash P., additional, Jadhav, Kisan R., additional, Jain, Upendra K., additional, Kadam, Vilasrao J., additional, Kang, Min H., additional, Kaur, Amanpreet, additional, Khonsari, Fatemeh, additional, Kohut, Ananiy, additional, Liu, Zongwen, additional, Madan, Jitender, additional, Maiti, Sabyasachi, additional, Maran, Avudaiappan, additional, Maricica, Hodorogea, additional, Marinho, H. Susana, additional, Martínez, Ana M., additional, Martins, M. Bárbara F., additional, Medina, Wanessa S.G., additional, Melinescu, Alina, additional, Mendes, Livia P., additional, Mendo, Sofia G., additional, Mihai, Mara M., additional, Mottaghitalab, Fatemeh, additional, Negut, Irina, additional, Oliveira, Mariana S., additional, Orzan, Olguţa A., additional, Ozer, A. Yekta, additional, Pandey, Ravi S., additional, Pantapasis, Konstantinos, additional, Pednekar, Priti P., additional, Pérez, Elena, additional, Plebanski, Magdalena, additional, Popescu, Roxana C., additional, Praça, Fabíola S.G., additional, Rai, Mahendra, additional, Rajagopalan, Rukkumani, additional, Raluca, Tudor, additional, Ramos, Maria J., additional, Rana, Suman, additional, Salahuddin, Nehal, additional, Santini, Antonello, additional, Sarghiuta, Daniela, additional, Selomulya, Cordelia, additional, Severino, Patrícia, additional, Shafiee, Akram, additional, Shah, Dhaval, additional, Sharma, Ankita, additional, Silva, Amélia M., additional, Souto, Eliana B., additional, Souto, Selma B., additional, Teixeira, Carla S. Silva, additional, Timur, Suna, additional, Torchilin, Vladmir P., additional, Tsirikis, Peter, additional, Varsha, Kumari, additional, Vazzana, Monica, additional, Verma, Gunjan, additional, Victor, Lamaru, additional, Vlad, Ologeanu, additional, Vlasceanu, George M., additional, Voronov, Andriy, additional, Voronov, Stanislav, additional, Wiwanitkit, Viroj, additional, Xiang, Sue D., additional, Yakhmi, Jatinder V., additional, Yaszemski, Michael J., additional, Yoon, Ho Y., additional, and Zahir, Forouhe, additional
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- 2017
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21. BiofuNctionalized nanomaterials for targeting cancer cells
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Guler, Emine, primary, Demir, Bilal, additional, Guler, Bahar, additional, Demirkol, Dilek Odaci, additional, and Timur, Suna, additional
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- 2017
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22. New class of 2,5-di(2-thienyl)pyrrole compounds and novel optical properties of its conducting polymer
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Söyleyici, Hakan Can, Ak, Metin, Şahin, Yüksel, Demikol, Dilek Odacı, and Timur, Suna
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- 2013
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23. Chitosan–ferrocene film as a platform for flow injection analysis applications of glucose oxidase and Gluconobacter oxydans biosensors
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Yılmaz, Övgü, Demirkol, Dilek Odacı, Gülcemal, Süleyman, Kılınç, Ali, Timur, Suna, and Çetinkaya, Bekir
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- 2012
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24. A conducting polymer with benzothiadiazole unit: Cell based biosensing applications and adhesion properties
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Başkurt, Eylül, Ekiz, Fulya, Demirkol, Dilek Odacı, Timur, Suna, and Toppare, Levent
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- 2012
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25. Virus detection using bio-based analysis systems: a review of biorecognition strategies
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NUR MELİS KILIÇ and DİLEK ODACI DEMİRKOL
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nanotechnology ,point-of-care ,biofunctional surface ,viruses ,General Chemistry ,nanobiotechnology ,Bio-based detection technologies ,nanomaterials - Abstract
Infectious illnesses are on the rise in today’s world, with serious consequences for animals, plants, and humans. Several infections, including the human immunodeficiency virus, affect a large number of individuals in various countries, particularly in the poorer portions of contemporary society, and continue to cause a variety of health problems. Viruses are tiny parasitic organisms. They are infectious agents that can only reproduce within a live cell of an organism. Viruses may infect any living organism. For clinical point- of-care applications, early detections for harmful agents such as bacteria, viruses are critical. The possibility of worldwide epidemics as a result of viral propagation emphasizes the importance of creating speedy, precise, and sensitive early detection systems. Furthermore, because certain viruses have a long latent phase and can evolve from one person to another, early detection during the incubation period is critical for improving recovery rates and avoiding pandemics. Nowadays, there has been various bio-based detection systems that have rapid reaction times, user-friendly, cost-effective, and repeatable. In this review, biological molecule-based detection technologies which focus on virus analysis are examined.
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- 2022
26. Graphene oxide incorporated polystyrene electrospun nanofibers for immunosensing of CD36 as a marker of diabetic plasma
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Simge Er and Dilek Odaci Demirkol
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Immunoassay ,Behavior ,Electrospun nanofibers ,Electrospinning ,Silanization ,Nanofibers ,Biophysics ,Biosensing Techniques ,General Medicine ,Carbon ,Orientation ,Immunosensing ,Diabetes Mellitus ,Electrochemistry ,Humans ,Polystyrenes ,Silane ,Graphite ,Physical and Theoretical Chemistry ,Polystyrene ,Stability ,Graphene oxide - Abstract
Electrospun nanofibers (ESNF) offer us a chance to obtain nanoscale building blocks by adding the desired modification agent to the polymer solution. Here, nanocomposite-based electrospun nanofibers designed for the recognition surface of the developed immunosensor were used for the first time in the determination of CD36. Firstly, graphene oxide (GO) was synthesized from graphite powder (GR), and GO sheets were silanized with different amounts of (3-Aminopropyl)triethoxysilane (APTES). Synthesized GO-APTES nanocomposite and polystyrene (PS) solution were mixed in different ratios to obtain uniform nanofibers without beads. As a result of the amino groups obtained on the surface of the nanofibers, the surface was made ready for covalent immobilization of the Anti-CD36 antibody. The nanofibers obtained under the optimum conditions determined were deposited on the surface of the screen-printed carbon electrode (SPCE) by the electrospinning technique. Then, Anti-CD36 was immobilized on the PS/GO-APTES modified SPCE through covalent bonding and used to prepare the biofunctional surface for the usage of bioelectrochemistry of CD36. The optimum Anti-CD36 con-centration decided to be used in experiments was determined as 10 mu g/mL. The linear detection range of CD36 was from 0.5 to 20 ng/mL, and the detection limit was 0.999 ng/mL. Finally, the developed PS/GO-APTES/Anti-CD36 immunosensor was used for the determination of CD36 in artificial blood serum without any interference effect., Council of Higher Education of Turkey [YOK 100/2000]; Ege University Scientific Research Projects Coordination Unit [FGA-2021-22688], S. ER who is supported in the special subject (Sensor Technologies) thanks The Council of Higher Education of Turkey 100/2000 PhD Project (YOK 100/2000 PhD Project). This study is supported by Ege University Scientific Research Projects Coordination Unit (Project Number: FGA-2021-22688).
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- 2022
27. Application of Biofunctionalized Magnetic Nanoparticles Based-Sensing in Abused Drugs Diagnostics
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Hichem Moulahoum, Zinar Pinar Gumus, Serdar Sanli, Suna Timur, Dilek Odaci Demirkol, Faezeh Ghorbanizamani, Hakan Coskunol, and Ege Üniversitesi
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Analyte ,Indoles ,Biosensing Techniques ,Naphthalenes ,010402 general chemistry ,Mass spectrometry ,01 natural sciences ,Analytical Chemistry ,Limit of Detection ,Magnetite Nanoparticles ,Electrodes ,Detection limit ,Psychotropic Drugs ,Chromatography ,Propylamines ,Illicit Drugs ,Immunomagnetic Separation ,Chemistry ,010401 analytical chemistry ,Reproducibility of Results ,Electrochemical Techniques ,Silanes ,0104 chemical sciences ,Electrode ,Magnetic nanoparticles ,Differential pulse voltammetry ,Cyclic voltammetry ,Antibodies, Immobilized ,Biosensor - Abstract
Real-time detection of substance use is an approach of high interest leading to the optimization of behavioral interventions and drug abuse intervention. the current methods in use suffer many limitations and need high logistical and laboratory requirements. Biosensors have shown a great potential in overcoming these limitations. in the present study, the electrochemical biosensor composed of a screen-printed electrode (SPE) was designed for the detection of synthetic cannabinoid (SC). Antibody-immobilized magnetic nanoparticles were also used to create a surface on the transducer with magnetic interactions in order to detect JWH-073 as a SC model. the use of immobilized magnetic nanoparticles to create working surfaces makes the electrode a reusable SPE which can be reutilized after the cleansing. To examine and observe any possible changes on the surface due to its interaction with the analyte, different electrochemical techniques such as differential pulse voltammetry, cyclic voltammetry, and electrochemical impedance spectrometry were applied. Based on the obtained results, the linearity of the biosensor was found between 5 and 400 ng/mL, and the detection limit was calculated as 22 ng/mL (n = 6) using the 3 Sb/m formula. the biosensor functionality was studied in the presence of some related interferents that showed lower responses than JWH-073, thus demonstrating the good selectivity of the prepared biosensor. Finally, the sensory platform was used to test synthetic urine sample, and the results were compared with obtained results from liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF/MS), which showed that the proposed method could be utilized to identify abuse drugs., Republic of Turkey, Ministry of DevelopmentTurkiye Cumhuriyeti Kalkinma Bakanligi [2016K121190]; Ege University, Aliye USTER FoundationEge University, This work was funded by Republic of Turkey, Ministry of Development (Project Grant No: 2016K121190). SEM and Chromatographic analyses were performed at EGE MATAL (Ege University/Izmir). Ege University, Aliye USTER Foundation is also acknowledged for the financial support.
- Published
- 2019
28. A new set up for multi-analyte sensing: At-line bio-process monitoring
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Akin, Mehriban, Prediger, Andreas, Yuksel, Merve, Höpfner, Tim, Demirkol, Dilek Odaci, Beutel, Sascha, Timur, Suna, and Scheper, Thomas
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- 2011
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29. Photochemically prepared polysulfone/poly(ethylene glycol) amphiphilic networks and their biomolecule adsorption properties
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Dizman, Cemil, Demirkol, Dilek Odaci, Ates, Sahin, Torun, Lokman, Sakarya, Serhan, Timur, Suna, and Yagci, Yusuf
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- 2011
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30. Virus detection using bio-based analysis systems: a review of biorecognition strategies
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KILIÇ, NUR MELİS, primary and DEMİRKOL, DİLEK ODACI, additional
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- 2022
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31. Novel fluorescence assay using µ-wells coated by BODIPY dye as an enzymatic sensing platform
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Dilek Odaci Demirkol, Mehri Akarsu, Bekir Çetinkaya, Rafet Kılınçarslan, Betül Aydoğan Ünal, and Suna Timur
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Analyte ,Biofunctional surface ,Glucose oxidases (GOx) ,chemistry.chemical_element ,02 engineering and technology ,Biofunctional ,01 natural sciences ,Oxygen ,Fluorescence ,µ-Well assays ,chemistry.chemical_compound ,Glucose concentration ,BODIPY ,0202 electrical engineering, electronic engineering, information engineering ,Glucose oxidase ,Phenols ,Electrical and Electronic Engineering ,Instrumentation ,Enzymatic sensing ,Chromatography ,biology ,Fluorescence sensors ,Applied Mathematics ,020208 electrical & electronic engineering ,010401 analytical chemistry ,Fluorescence intensities ,Substrate (chemistry) ,Condensed Matter Physics ,Ascorbic acid ,0104 chemical sciences ,Glucose ,chemistry ,Fluorescence sensing ,biology.protein ,Amino acids ,Glucose sensors - Abstract
BODIPY dyes are strongly fluorescent small molecules widely used in fluorescence sensing various analytes. In this study, 8-chloromethyl-2,6-diethyl-4,4-difluoro-1,3,5,7-tetramethyl-4-bora-3a,4a-diaza-s-indacene (BODIPY-CH2Cl) was successfully synthesized and used as a sensing platform in a 96-well microplate. After synthesis, commercial 96-well microplate surfaces covered with Poly-D-Lysine layer were modified with BODIPY. Glucose oxidase (GOx) was selected as a model enzyme to test the applicability of the BODIPY-coated surface as a fluorescence sensing platform. Since oxygen acts as a quencher for BODIPY, the addition of substrate to modified surfaces caused oxygen depletion and resulted in a quick increase fluorescence intensity. The increments were in proportion to the glucose concentration. Using these data, a linear graph was obtained between 0.0025 and 0.1 mM glucose with a LOD of 2.19 µM. There was no interference effect of some compounds, such as uric acid, ascorbic acid, phenols, and ethanol on sensing. Glucose detection in various complex matrices was carried out. © 2018 Elsevier Ltd
- Published
- 2019
32. Magnetic Nanofiber Layers as a Functional Surface for Biomolecule Immobilization and One-Use ‘Sensing in-a-Drop’ Applications
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Z. Pinar Gumus, Nur Aksuner, Bilal Demir, Dilek Odaci Demirkol, Raif İlktaç, Suna Timur, Serdar Sanli, and Emine Guler Celik
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chemistry.chemical_classification ,Surface (mathematics) ,Materials science ,Immobilized enzyme ,Biomolecule ,Nanotechnology ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,chemistry ,Nanofiber ,Surface modification ,Magnetic nanoparticles ,0210 nano-technology ,Biosensor - Abstract
Stabilization of biomolecules on matrices is critically important. Here we constructed composite nanofibers with magnetic features by electro-spinning of magnetic nanoparticles (MNP) in an appropriate polymer matrix on a collector surface for multiple uses. 'Poly(vinylalcohol)-polyethyleneimine/Fe3O4 magnetic nanoparticles' (PVA-PEI/MNP) composite nanofiber was used on the screen printed electrodes (SPE) to serve as a platform for the glucose oxidase (GOx) biofilm as the model biomolecule. To show the potential application of this material as a biosensor component, the resulted biofilm, called 'PVA-PEI/MNP/GOx', was fixed on SPE via a neodymium magnet for the electrochemical detection of glucose at -0.7 V where oxygen consumption due to enzymatic reaction was measured. The main advantage of the obtained magnetic biomembrane is that it allows analysis with a single drop. After step-by-step surface modifications, analytical characterization was performed using various techniques, such as voltammetry, electrochemical impedance spectroscopy, Fourier-transform infrared spectroscopy and X-Ray photoelectron spectroscopy as well as microscopic techniques. The linear range of the PVA-PEI/MNP/GOx surface was found as 0.0125 to 0.5 mM with a limit of detection of 11.5 mu M for glucose as analyte. The application of PVA-PEI/MNP/GOx for glucose detection in synthetic samples was carried out. Data proved the potential use of the 'PVA-PEI/MNP' surface as a biomolecule immobilization platform for disposable biosensor applications.
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- 2018
33. High generation dendrimer decorated poly-?-caprolactone/polyacrylic acid electrospun nanofibers for the design of a bioelectrochemical sensing surface
- Author
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Aylis Oner, Asli Birol, Meltem Demir, Irem Yezer, Ensara Tufek, Dilek Odaci Demirkol, Simge Er, and Ege Üniversitesi
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Dendrimers ,Materials science ,Polymers and Plastics ,Scanning electron microscope ,General Chemical Engineering ,Amidoamine ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Covalent immobilization ,Contact angle ,chemistry.chemical_compound ,Dendrimer ,Materials Chemistry ,Environmental Chemistry ,Poly-?-caprolactone (PCL) ,Electrospun nanofibers ,Polyacrylic acid ,General Chemistry ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Poly(acrylic) acid ,chemistry ,Chemical engineering ,Covalent bond ,Nanofiber ,Glutaraldehyde ,0210 nano-technology - Abstract
In this study, poly-?-caprolactone (PCL) and poly(acrylic) acid (PAA)-based electrospun nanofibers were prepared for the immobilization of pyranose oxidase (PyOx) to design a bioelectrochemical detection system. Different amounts of PAA were used to increase hydrophilicity (decreased contact angle) of the PCL electrospun nanofibers. To provide a multipoint attachment side to bind PyOx by covalent bonds, various amounts of high generation (G5) poly(amidoamine) (PAMAM) dendrimer with amino groups were added to the PCL:PAA backbone. To attach PyOx onto the PCL:PAA/PAMAM electrospun nanofibers, glutaraldehyde was used as a homobifunctional crosslinker. Firstly, PCL:PAA ratio was optimized to obtain the best electrospun nanofibers without beads and with decreased contact angle. Then, the effect of the PAMAM amount on the morphology of PCL:PAA and contact angle was tested. The obtained PCL:PAA/PAMAM electrospun nanofiber was characterized by scanning electron microscopy (SEM). Then, the presence of PAMAM in the structure and the success of PyOx immobilization onto PCL:PAA/PAMAM were proven by SEM and an energy dispersive X-ray analyzer (SEMEDX). Finally, PCL:PAA/PAMAM/PyOx was characterized, calibrated, and applied to analyze glucose in samples without any interfering effect of some chemicals. Briefly, the nanofibers modification with dendrimers and the conjugation of PyOx onto formed nanostructures was successfully performed, and a novel electrospun nanofiberbased sensor system was developed for target detection., BAGEP Award of the Science Academy; TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [215Z194]; TUBITAK 2209Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK), Acknowledgement This work is supported by the BAGEP Award of the Science Academy and TUBITAK (Project number: 215Z194) . A. Oner, E. Tufek, A. Birol and M. Demir thank to TUBITAK 2209 AProgram for the University Students at Undergraduate Level. Authors thank to Assoc. of Prof. Dr. Murat Yavuz for his valuable helps.
- Published
- 2021
34. Carbon dots and curcumin-loaded CD44-Targeted liposomes for imaging and tracking cancer chemotherapy: A multi-purpose tool for theranostics
- Author
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Z. Pinar Gumus, Faezeh Ghorbanizamani, Kadem Meral, F. Baris Barlas, Hichem Moulahoum, Bilal Demir, Suna Timur, Dilek Odaci Demirkol, Ozan Yesiltepe, and Ege Üniversitesi
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Cancer chemotherapy ,Materials science ,Curcumin ,Multifunctional nanoparticles ,Pharmaceutical Science ,Nanotechnology ,02 engineering and technology ,030226 pharmacology & pharmacy ,In vitro analysis ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Targeted liposomes ,Carbon dots ,CD44 ,Liposome ,biology ,Bioconjugation ,021001 nanoscience & nanotechnology ,Theranostics ,chemistry ,biology.protein ,Nanocarriers ,0210 nano-technology - Abstract
Growing needs in biomedical applications have driven the development of multifunctional nanoparticles towards theranostically-engineered multimodal platforms. Many strategies for point-effective cellular uptake of theranostics have been described. in this report, multifunctional nanostructures were designed and synthesized as a novel theranostic platform. Liposomes were loaded with curcumin as a therapeutic agent and carbon dots (CDs) as a contrast molecule. Anti-CD44 antibodies were bioconjugated on the liposomal surface to obtain an active targeting nanocarrier. After synthesis, the relative characterization of the vesicles was performed using DLS and TEM techniques. in vitro analysis was conducted to investigate the multimodal properties of the theranostic via testing its toxicity, cell uptake, bioimaging, and chemo/radiotherapy applications on two different cell lines. 3D holographic microscopy was employed to track the treatment effects during experimentation. Results indicated that these particles are efficient tools for clinical applications due to their fluorescent characteristic and increased bioperformance., Ege University, Scientific Research FoundationEge University [2017 FEN 007], Ege University, Scientific Research Foundation is acknowledged for the support (Project no: 2017 FEN 007) .
- Published
- 2021
35. Preparation of glutathione loaded nanoemulsions and testing of hepatoprotective activity on THLE-2 cells
- Author
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Caner Geyik, Zinar Pinar Gumus, Hakan Coskunol, Emine Guler Celik, Suna Timur, Ozan Yesiltepe, Dilek Odaci Demirkol, İstinye Üniversitesi, Tıp Fakültesi, Temel Tıp Bilimleri Bölümü, and Geyik, Caner
- Subjects
Chemistry, Multidisciplinary ,Nigella sativa ,nanoemulsion ,Antioxidant Properties ,010402 general chemistry ,01 natural sciences ,Article ,chemistry.chemical_compound ,Ethanol,Nigella sativa,glutathione,nanoemulsion,hepatoprotective activity ,Nigella-Sativa ,Gold Nanoparticles ,Viability assay ,glutathione ,hepatoprotective activity ,Colorimetric Assay ,Liver-Injury ,Aqueous solution ,Ethanol ,Chromatography ,Seed ,010405 organic chemistry ,food and beverages ,General Chemistry ,Glutathione ,Oil ,In vitro ,0104 chemical sciences ,Bioavailability ,Metabolism ,chemistry ,In-Vitro ,Toxicity ,Kimya, Ortak Disiplinler - Abstract
To improve bioavailability and stability of hydrophobic and hydrophilic compounds, nanoemulsions are good alternatives as delivery systems because of their nontoxic and nonirritant nature. Glutathione (GSH) suffers from low stability in water, where its encapsulation in nanoemulsions is a powerful strategy to its stability in aqueous systems. The aim of this study was to obtain nanoemulsions from the hydrophobic/hydrophilic contents of N. sativa seed oil so as to improve GSH stability along with bioavailability of N. sativa seed oil. Then, the prepared nanoemulsions were tested for in vitro hepatoprotective activity against ethanol toxicity. To the best of our knowledge, there is no study on the test of nanoemulsions by the combination of Nigella sativa seed oils and GSH in hepatoprotective activity. Here, nanoemulsions with different contents were prepared using Nigella sativa seed oils. Content analyses and characterisation studies of prepared nanoemulsions were carried out. In order to investigate the protective effects against to ethanol exposure, THLE-2 cells were pretreated with nanoemulsions for 2 h with the maximum benign dose (0.5 mg/mL of nanoemulsions). Ethanol (400 mM) was introduced to pretreated cells and nontreated cells for 48- or 72-h periods, followed by cell viability assay was carried out. Fluorescence microscopy tests revealed the introduction of the nanoemulsions into THLE-2 cells. The findings show that nanoformulations have promising in vitro hepatoprotective effects on the THLE-2 cell line against ethanol exposure. WOS:000644696500016 34104055 Q4
- Published
- 2021
36. Biosensing Applications of Modified Core–Shell Magnetic Nanoparticles
- Author
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Ozdemir, Caglar, Akca, Ozlet, Medine, E. Ilker, Demirkol, Dilek Odaci, Unak, Perihan, and Timur, Suna
- Published
- 2012
- Full Text
- View/download PDF
37. Sol–Gel/Chitosan/Gold Nanoparticle-Modified Electrode in Mediated Bacterial Biosensor
- Author
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Habib, Omer, Demirkol, Dilek Odaci, and Timur, Suna
- Published
- 2012
- Full Text
- View/download PDF
38. Caffeic Acid Detection Using an Inhibition-Based Lipoxygenase Sensor
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Demirkol, Dilek Odaci, Gulsunoglu, Baran, Ozdemir, Caglar, Dincer, Ayse, Zihnioglu, Figen, and Timur, Suna
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- 2012
- Full Text
- View/download PDF
39. Chitosan matrices modified with carbon nanotubes for use in mediated microbial biosensing
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Demirkol, Dilek Odaci and Timur, Suna
- Published
- 2011
- Full Text
- View/download PDF
40. 4-aminothiophenol-intercalated montmorillonite: Organic-inorganic hybrid material as an immobilization support for biosensors
- Author
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Yahya Yasin Yilmaz, Esra Evrim Yalcinkaya, Suna Timur, Dilek Odaci Demirkol, and Ege Üniversitesi
- Subjects
Thermogravimetric analysis ,Intercalation (chemistry) ,02 engineering and technology ,Glassy carbon ,010402 general chemistry ,01 natural sciences ,Materials Chemistry ,Electrical and Electronic Engineering ,Instrumentation ,Montmorillonite ,Chemistry ,Metals and Alloys ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Dielectric spectroscopy ,Pyranose oxidase ,Enzymatic biosensor ,Differential pulse voltammetry ,4-aminothiophenol ,Cyclic voltammetry ,0210 nano-technology ,Hybrid material ,Biosensor ,Nuclear chemistry - Abstract
Hybrid materials containing organic and inorganic structures are very important because they have the advantages of each of their components. Intercalation of the organic molecule to inorganic structures such as clay allows the preparation of multifunctional new immobilization matrices that contain both the strength properties of the clays and the properties of the organic molecule such as its functional groups (amine, carboxyl or hydroxyl etc.). in this study, 4-aminothiophenol intercalated montmorillonite (4ATP-Mt) was prepared and used as an immobilization layer for the pyranose oxidase (PyOx) enzyme on a glassy carbon (GC) electrode. Firstly, 4ATP intercalation of Mt was carried out, and the success of intercalation was proven using Fourier-Transform Infrared Spectroscopy (FTIR), X-ray Diffractometer (XRD), and Thermogravimetric Analysis (TGA) techniques. Then PyOx was immobilized using 4ATP-Mt, BSA and glutaraldehyde as a cross-linker on the surface of GC electrodes. To show the coating steps for the preparation of 4ATP-Mt/PyOx biosensors, cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) techniques were applied, and surface morphology was visualized by scanning electron microscopy (SEM). After optimization of working conditions, analytical performance parameters were determined for glucose detection. the 4ATP-Mt/PyOx biosensor exhibited a wide linear concentration range between 0.01 and 0.5 mM (LOD: 1.0 mu M) for glucose. Additionally, the fabricated 4ATP-Mt/PyOx was assayed for the analysis of glucose in artificial body fluids and drinks., Ege University Scientific Research Projects Coordination UnitEge University [16-FBE-023], This work was supported by Ege University Scientific Research Projects Coordination Unit. Project Number: 16-FBE-023.
- Published
- 2020
41. Aptamer konjuge edilmiş yarı iletken nanoparçacıkları temel alan patojen bir mikroorganizmanın elektrokimyasal belirlenmesi ve floresans görüntülenmesi
- Author
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Kadri Gulec, Dilek Odaci Demirkol, and Ege Üniversitesi
- Subjects
Fluorescence-lifetime imaging microscopy ,Jeokimya ve Jeofizik ,Electrochemical detection ,Fluorescence imaging ,Quantum dots ,Malzeme Bilimleri, Tekstil ,Bilgisayar Bilimleri, Yapay Zeka ,Ziraat, Toprak Bilimi ,Ekoloji ,Enerji ve Yakıtlar ,Nanoparticle ,Kimya, İnorganik ve Nükleer ,İnşaat Mühendisliği ,Photochemistry ,Kimya, Analitik ,Gıda Bilimi ve Teknolojisi ,lcsh:Technology (General) ,H7 sensing,Electrochemical detection ,Quantum dots [E. coli O157] ,Fluorescence microscope ,Telekomünikasyon ,Fizik, Akışkanlar ve Plazma ,Malzeme Bilimleri, Kompozitler ,Matematik ,Chemistry ,Bahçe Bitkileri ,Fizik, Uygulamalı ,Fizikokimya ,Entomoloji ,Zooloji ,Bilgisayar Bilimleri, Yazılım Mühendisliği ,Mühendislik, Makine ,Malzeme Bilimleri, Kâğıt ve Ahşap ,Kimya, Uygulamalı ,Fluorescence ,Bitki Bilimleri ,Bilgisayar Bilimleri, Sibernitik ,Biyoloji Çeşitliliğinin Korunması ,Genetik ve Kalıtım ,Mantar Bilimi ,Su Kaynakları ,Fizik, Nükleer ,Taşınım Bilimi ve Teknolojisi ,Nükleer Bilim ve Teknolojisi ,Hücre ve Doku Mühendisliği ,Orman Mühendisliği ,Tarımsal Ekonomi ve Politika ,Biyoloji ,Maden İşletme ve Cevher Hazırlama ,Bilgisayar Bilimleri, Donanım ve Mimari ,Fizik, Partiküller ve Alanlar ,E. coli O157:H7 sensing ,E. coli O157:H7 sensing,Electrochemical detection ,Aptamer ,Deniz ve Tatlı Su Biyolojisi ,Fizik, Atomik ve Moleküler Kimya ,Mühendislik, Elektrik ve Elektronik ,Jeoloji ,Conjugated system ,Mimarlık ,İmalat Mühendisliği ,Mühendislik, Kimya ,Kuş Bilimi ,lcsh:Agriculture ,Fizik, Katı Hal ,Monolayer ,Nanobilim ve Nanoteknoloji ,Robotik ,İstatistik ve Olasılık ,Malzeme Bilimleri, Biyomalzemeler ,lcsh:Agriculture (General) ,Kimya, Tıbbi ,Metalürji Mühendisliği ,Endüstri Mühendisliği ,Kimya, Organik ,Limnoloji ,İnşaat ve Yapı Teknolojisi ,Malzeme Bilimleri, Kaplamalar ve Filmler ,Mühendislik, Hava ve Uzay ,lcsh:S ,Ziraat Mühendisliği ,Savunma Bilimleri ,lcsh:S1-972 ,Çevre Bilimleri ,Çevre Mühendisliği ,Quantum dot ,Malzeme Bilimleri, Özellik ve Test ,Görüntüleme Bilimi ve Fotoğraf Teknolojisi ,Bilgisayar Bilimleri, Bilgi Sistemleri ,lcsh:T1-995 ,Mühendislik, Jeoloji ,Fizik, Matematik ,Malzeme Bilimleri, Seramik ,Bilgisayar Bilimleri, Teori ve Metotlar - Abstract
Aptamers are selective molecules against to various sizes of targets from small molecules to mammalian cells. Here, we reported QDs containing electrochemical aptasensor for the detection of E. coli O157:H7. the electrode surfaces were modified by cysteamine (CysN), which has amine and thiol groups, via self-assembled monolayer formation. the carboxyl-functionalized quantum dots (QD) and aptamers (Apt) were conjugated to cysteamine modified gold electrodes. Linear range for E. coli O157:H7 was from 1 to 102 CFU/mL after incubation on CysN/QD/Apt modified Au surfaces. QDs provide fluorescence surface, so that adhesion of cells was followed using fluorescence microscope. Adhered cells were also imaged by scanning electron microscopy. Finally, cell analysis was carried out in real samples., Aptamerler, küçük moleküllerden memeli hücrelerine kadar çeşitli boyutlardaki hedeflere karşı seçici moleküllerdir. Burada, E. coli O157:H7 dedeksiyonu için QD içeren elektrokimyasal aptasensör rapor edilmiştir. Yüzeyler, amino ve tiyol grupları içeren sisteamin (CysN) ile kendiliğinden oluşan tek tabaka meydana gelişi ile modifiye edildi. Karboksil ile fonksiyonelleştirilen quantum noktalar (QD) ve aptamerler (Apt), sisteaminle modifiye edilmiş altın elektrotlara konjuge edildi. CysN/QD/Apt modifiye edilen Au yüzeylerde inkübasyon sorasında, E. coli O157:H7 için doğrusal aralık 1 to 102 CFU/mL idi. QD floresans yüzeyler sağlar, böylece hücrelerin adezyonu floresans mikroskop kullanılarak takip edildi. Adezyon sonrası hücreler aynı zamanda taramalı electron mikroskobu ile görüntülendi. Son olarak, hücre analizi gerçek örneklerde gerçekleştirildi.
- Published
- 2018
42. Laccase assay based on electrochemistry and fluorescence detection via anthracene sequestered poly(amic acid) films
- Author
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Dilek Odaci Demirkol, Elif Esen, Suna Timur, and Idris Yazgan
- Subjects
Laccase ,Catechol ,Anthracene ,Chromatography ,Polymers and Plastics ,Hydroquinone ,General Chemical Engineering ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Biochemistry ,Fluorescence ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Materials Chemistry ,Environmental Chemistry ,Phenol ,Phenols ,Guaiacol ,0210 nano-technology - Abstract
Phenols are among the most problematic organic compounds, which manipulates metabolism of living organisms and pose threat to environment. Detection of total phenol at the lowest allowable concentration is critical, so development of sensitive and easy to use methods have been heavily investigated. Hereby, for the first time, anthracene (Ant) was sequestered into poly(amic acid) (PAA) to form fluorescent and conductive film support for laccase (Lac) immobilization to quantify total phenol content at high specificity and selectivity. Ant-PAA/Lac films were applied to fluorescent and electrochemical quantification of phenol, which provided high sensitivity (LOD 46 μM) and reproducibility (RSD, 0.5%) for the tested 10 phenolic compounds including phenol, catechol, 3-acetominophenol, hydroquinone, L-DOPA, 2,6-dimethylphenyl, syringalzadine, 3,5-dimethoxy-4-hydroxycinnamic acid, 2,5-dimethoxyaniline and guaiacol. The sensor system showed strong rejection to common organic interferent while real sample application revealed the applicability of the sensor. Therefore, the results can call the sensor system, particularly fluorescence-based quantification in 96-well plate, is an alternative approach for high-throughput screening of total phenolic compounds in waste-water at cost-effective manner.
- Published
- 2018
43. Surface Modification with a Catechol-Bearing Polypeptide and Sensing Applications
- Author
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Emine Guler Celik, Takeshi Endo, Shuhei Yamada, Dilek Odaci Demirkol, Eda Aydindogan, Suna Timur, and Yusuf Yagci
- Subjects
Polymers and Plastics ,Surface Properties ,Inorganic chemistry ,Catechols ,Bioengineering ,Biosensing Techniques ,02 engineering and technology ,01 natural sciences ,Biomaterials ,Glucose Oxidase ,chemistry.chemical_compound ,X-ray photoelectron spectroscopy ,Materials Chemistry ,Glucose oxidase ,Catechol ,biology ,010401 analytical chemistry ,021001 nanoscience & nanotechnology ,Amperometry ,Antibodies, Anti-Idiotypic ,0104 chemical sciences ,Glucose ,chemistry ,Immunoglobulin G ,biology.protein ,Surface modification ,Differential pulse voltammetry ,Cyclic voltammetry ,Peptides ,0210 nano-technology ,Biosensor - Abstract
A novel catechol-bearing polypeptide (CtP) was synthesized and used as a component of electrochemical biosensor involving both enzymatic activity and affinity-based sensing systems. Glucose oxidase (GOx) and anti-immunoglobulin G (Anti-IgG) were selected as model biorecognition elements for the selective analysis of glucose and IgG. Step-by-step surface modifications were followed using various techniques such as cyclic voltammetry (CV) and electrochemical impedance spectrometry (EIS) as well as X-ray photoelectron spectroscopy (XPS). Additionally, contact angles were measured in order to observe surface properties. Amperometric measurements using the GOx biosensor were performed at -0.7 V by following the oxygen consumption due to the enzymatic reaction in different glucose concentrations. Affinity-based interactions via IgG sensor were monitored using the differential pulse voltammetry (DPV) technique. As the "surface design with CtP" approach employed herein is generally applicable and easily adaptable to obtain functional matrices for biomolecule immobilization, CtP-coated surfaces can be promising platforms for the fabrication of various biobased sensing systems.
- Published
- 2018
44. Brilliant green sequestered poly(amic) acid film for dual-mode detection: Fluorescence and electrochemical enzymatic biosensor
- Author
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Victor M. Kariuki, Suna Timur, Idris Yazgan, Omowunmi A. Sadik, Dilek Odaci Demirkol, and Mohomodou Maiga
- Subjects
Analytical chemistry ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Materials Chemistry ,Fluorescence microscope ,Glucose oxidase ,Electrical and Electronic Engineering ,Instrumentation ,Quenching (fluorescence) ,biology ,Chemistry ,technology, industry, and agriculture ,Metals and Alloys ,biochemical phenomena, metabolism, and nutrition ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Fluorescence ,Amperometry ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,biology.protein ,Limiting oxygen concentration ,0210 nano-technology ,Fluorescent glucose biosensor ,Biosensor ,Nuclear chemistry - Abstract
Herein, we report a facile technique to fabricate fluorescent polymeric structure, brilliant-green sequestered poly(amic) acid film (BG-PAA), as enzyme support-material for biosensor applications. The structure and fluorescence properties of the fabricated BG-PAA membrane were investigated using 1 H NMR, scanning electron microscopy (SEM) and fluorescence microscopy. Glucose oxidase (GOx) was used as a model enzyme that immobilized on BG-PAA membrane using glutaraldehyde. The created BG-PAA/GOx membrane was utilized to fabricate dual-purpose as fluorescent and electrochemical biosensors for the determination of glucose in beverages. Utilization of the dissolved oxygen in GOx mediated glucose oxidation resulted in alteration of the measured fluorescence and current intensity. In the fluorescence assay, the decreased concentration of oxygen causes the increased fluorescence intensity due to the elimination of quenching effect of oxygen on BG fluorescence. In amperometric assay, decrease in oxygen concentration was followed at −0.7 V. After optimization of working conditions linearity, limit of detection and repeatability of system were determined. Finally, BG-PAA/GOx was tested to analyze glucose in beverages.
- Published
- 2018
45. pH responsive glycopolymer nanoparticles for targeted delivery of anti-cancer drugs
- Author
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Serdar Özçelik, Suna Timur, Caner Geyik, C. Remzi Becer, Emine Guler, Dilek Odaci Demirkol, Gokhan Yilmaz, Bilal Demir, Melek Ozkan, Özçelik, Serdar, Izmir Institute of Technology. Chemistry, and Izmir Institute of Technology
- Subjects
Gold nanoparticle ,Materials science ,Glycopolymer ,Biomedical Engineering ,Energy Engineering and Power Technology ,Nanoparticle ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,Glycopolymers ,01 natural sciences ,Industrial and Manufacturing Engineering ,chemistry.chemical_compound ,Materials Chemistry ,medicine ,Chemical Engineering (miscellaneous) ,Doxorubicin ,Process Chemistry and Technology ,021001 nanoscience & nanotechnology ,Drug delivery systems ,0104 chemical sciences ,Cancer drugs ,chemistry ,Chemistry (miscellaneous) ,Colloidal gold ,Drug delivery ,Surface modification ,Nanocarriers ,0210 nano-technology ,Conjugate ,medicine.drug - Abstract
Becer, C. Remzi/0000-0003-0968-6662; Ozcelik, Serdar/0000-0003-2029-0108; Geyik, Caner/0000-0002-8382-2186; Guler Celik, Emine/0000-0003-2381-9775; YILMAZ, GOKHAN/0000-0002-1803-5397; Odaci Demirkol, Dilek/0000-0002-7954-1381, WOS: 000424988400014, Over the past decade, there has been a great deal of interest in the integration of nanotechnology and carbohydrates. The advances in glyconanotechnology have allowed the creation of different bioactive glyconanostructures for different types of medical applications, especially for drug delivery and release systems. Therefore, the use of more efficient biocompatible nanocarriers with high loading capacity, low overall toxicity and receptor-mediated endocytosis specificity is still in focus for the enhancement of the therapeutic effect. Conjugation of sugar derivatives onto gold nanoparticles presents unique properties that include a wide array of assembling models and size-related electronic, magnetic and optical properties. Here, pH-responsive drug-conjugated glycopolymer-coated gold nanoparticles were prepared by functionalization of gold nanoparticles with thiol-terminated glycopolymers and then subsequent conjugation of doxorubicin (DOX). Among the four different glycopolymers, their drug release, physicochemical characterization (spectroscopy, particle size and surface charge) and in vitro bioapplications with four different cell lines were compared. As a result, pH-sensitive drug delivery via sugar-coated AuNPs was performed thanks to hydrazone linkages between glycopolymers and DOX. Comparative viability tests also demonstrated the efficiency of glycopolymer-DOX conjugates by fluorescence cell imaging. The obtained results reveal that AuNP homoglycopolymer DOX conjugates (P4D) have significant potential, especially in human neuroblastoma cells in comparison to cervical cancer cells and lung cancer cells.
- Published
- 2018
46. Preparation of Quantum Dot Bioconjugates as Fluorescence Probe for Targeting and Visualization of Cells
- Author
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Suna Timur and Dilek Odaci Demirkol
- Subjects
Materials science ,Quantum dot ,Kuantum noktalar,biyokonjugasyon,anti-c-ErbB2,hücre hedefleme ,Nanotechnology ,Fluorescence ,Quantum dots,bioconjugation,anti-c-ErbB2,cell targeting ,Visualization - Abstract
Here, the bioconjugation and application of water-soluble quantum dots QDs for targeted cellular imaging were investigated. Human Anti-c-ErbB2 antibodies were bound to QDs for the targeting of these nanostructures towards the cancer cells. QDs and Anti-c-ErbB2/QD bioconjugates were characterized by fluorescence and UV–Vis spectroscopy and hydrodynamic sizing. The effect of QDs and Anti-c-ErbB2/QD bioconjugates on cell viability was evaluated using an MTT assay. To observe targeting efficiency of Anti-c- ErbB2/QD bioconjugates, fluorescence microscopy and was performed. Higher cell affinities were obtained by Anti-c-ErbB2-conjugated QDs which is an evidence that these are well-suited for targeting and imaging of cells., B urada, hedeflenmiş hücresel görüntüleme için suda çözünür kuantum noktaların QD biyokonjugasyonu ve uygulamaları gerçekleştirilmiştir. Kanser hücrelerine nanoyapıların hedeflenmesi için anti-c-ErbB2 antikoru QD’lara bağlanmıştır. QD’lar ve anti-c-ErbB2/QD biyokonjugatları floresans/UV-Görünür bölge spektroskopisi ve hidrodinamik boyut ölçümleri ile karakterize edilmiştir. Hücre canlılığına QD’lar ve antic-ErbB2/QD biyokonjugatlarının etkisi MTT denemeleri kullanılarak gerçekleştirilmiştir. Anti-c-ErbB2/QD biyokonjugatlarının hedefleme etkinliğini gözlemlemek için, floresans mikroskopi kullanılmıştır. Hücreleri görüntüleme ve iyi gerçekleştirilmiş hedeflemenin ispatı olarak anti-c-ErbB2 konjuge edilen QD’lar ile daha yüksek hücre afiniteleri elde edilmiştir
- Published
- 2017
47. Offline Glucose Biomonitoring in Yeast Culture by Polyamidoamine/ Cysteamine-Modified Gold Electrodes
- Author
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Yuksel, Merve, Akin, Mehriban, Geyik, Caner, Demirkol, Dilek Odaci, Ozdemir, Caglar, Bluma, Arne, Höpfner, Tim, Beutel, Sascha, Timur, Suna, and Scheper, Thomas
- Published
- 2011
- Full Text
- View/download PDF
48. A novel ethanol biosensor on pulsed deposited MnOx-MoOx electrode decorated with Pt nanoparticles
- Author
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Buket Yılmaz, Süleyman Koçak, Dilek Odaci Demirkol, Bilal Demir, K. Volkan Özdokur, Alper Yalin Tatli, Suna Timur, Ece Atman, and F. Nil Ertaş
- Subjects
Materials science ,Inorganic chemistry ,Metals and Alloys ,Nanoparticle ,02 engineering and technology ,engineering.material ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Platinum nanoparticles ,01 natural sciences ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Catalysis ,Electrochromism ,Electrode ,Materials Chemistry ,engineering ,Mixed oxide ,Noble metal ,Electrical and Electronic Engineering ,0210 nano-technology ,Instrumentation ,Biosensor - Abstract
Transition metal oxides provide low cost alternatives to noble metals due to their unique electrocatalytic and electrochromic properties and display strong interactions with noble metal nanoparticles. Present study describes the use of mixed molybdenum and manganese oxide film electrode enriched with platinum nanoparticles to enhance the catalytic performance in the oxygen reduction reaction (ORR). The mixed oxide film, denominated as GCE/MnO x -MoO x /Pt, was co-deposited by pulsed potential deposition technique and then, it was used as an immobilization matrix for the intact bacterial cells. The resulted whole cell biosensor has served as a sensing platform for ethanol detection by monitoring of oxygen consumption as a result of the bacterial metabolism in the presence of the substrate. Following the optimization experiments, GCE/MnOx-MoOx/Pt/ Gluconobacter oxydans biofilm was applied to investigate the analytical characteristics and response time to ethanol as well as operational stability and substrate specificity for other carbon sources. The linear range was found as 0.075–5.0 mM with a response time of 63 s and the developed method was applied to the ethanol determination in alcoholic drinks. Satisfactory recovery figures were obtained in comparison to the standard method.
- Published
- 2016
49. CTAB modified dellite: A novel support for enzyme immobilization in bio-based electrochemical detection and its in vitro antimicrobial activity
- Author
-
Esra Evrim Yalcinkaya, Murat Yavuz, Dilek Odaci Demirkol, Debora Puglia, Burak Sonmez, Mohomodou Maiga, Jose Maria Kenny, and Suna Timur
- Subjects
Detection limit ,Chromatography ,Immobilized enzyme ,Glucose Measurement ,Intercalation (chemistry) ,Pyranose oxidase ,technology, industry, and agriculture ,Metals and Alloys ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,chemistry ,Bromide ,Materials Chemistry ,Glutaraldehyde ,Electrical and Electronic Engineering ,0210 nano-technology ,Instrumentation ,Biosensor - Abstract
A novel support material for enzyme immobilization based on cetyltrimethylammonium bromide modified Dellite (CTAB-Del) was successfully synthesized and used to manufacture pyranose oxidase (PyOx) biosensors (CTAB-Del/PyOx). The intercalation of CTAB into Dellite was confirmed by FTIR, XRD and TGA techniques. PyOx was immobilized onto the glassy carbon electrode, via glutaraldehyde crosslinking, by using CTAB-Del as a support. In order to test the analytical performance of CTAB-Del/PyOx biosensors, chronoamperometric measurements were carried out using three electrodes configurations, at a constant potential of −0.7 V in working buffer, under stirring, with successive addition of glucose. The linear response for CTAB-Del/PyOx biosensor ranged from 0.01 to 0.50 mM with an equation of y = 4.42x + 0.004 (R2 = 0.998), and the limit of detection for glucose was calculated to be 0.081 μM (S/N = 3). In order to confirm its practical use, the CTAB-Del/PyOx biosensor was also applied for glucose measurement in various beverages. In addition, the antimicrobial activities of Del and CTAB-Del were screened in vitro by means of the disc diffusion susceptibility test, selecting a yeast, three different Gram-positive, and five different Gram-negative bacteria. The obtained results showed a moderate antibacterial activity of CTAB-Del against Gram-positive bacteria.
- Published
- 2016
50. Electrospun Nanofibers: Functional and Attractive Materials for the Sensing and Separation Approaches in Analytical Chemistry
- Author
-
Betul Unal, Fatma Ozturk Kirbay, Irem Yezer, Dilek Odaci Demirkol, and Suna Timur
- Published
- 2019
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