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    Biosorption of Diclofenac by Magnetic Biosorbent (M-EColi)
    (Jihad Daneshgahi, 2024) Ertas, Erdal; Tural, Bilsen; Tural, Servet
    Diclofenac sodium (DCF), 2-[(2,6-dichlorophenyl)amino] benzene acetic acid, monosodium salt is widely used as a non-steroidal anti-inflammatory drug with high consumption. It therefore presents a serious risk to both human health and the environment and is among the pharmaceuticals that are most commonly found in aqueous effluents. In this study, a novel magnetic biosorbent (M-EColi) was successfully prepared by immobilizing Escherichia coli (E.coli) on nano- sized magnetic iron oxides, and its efficacy in DCF biosorption was investigated. To determine the characterization of the synthesized M-EColi biosorbents, Vibrational Sample Magnetometry (VSM), Scanning Electron Microscope (SEM), Energy Dispersive X-ray (EDX) spectroscopy Fourier Transform & Idot;nfraRed Red (FT-IR) spectroscopy analyses were performed and the effects of contact time, temperature, biosorbent dose and initial DCF concentration on the biosorption process were investigated. Isothermal, kinetic, and thermodynamic calculations were performed to determine which mechanism is consistent with biosorption. It was found that the DCF biosorption on M-EColi corresponded to the Langmuir isotherm and the biosorption kinetics corresponded to the pseudo-second-order kinetic model. The thermodynamic analyses indicate that the biosorption of DCF on the M-EColi nano-sorbent is physical. The maximum biosorption capacity was found to be 46.01 +/- 0.12 mg/g.
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    Biosorption of phenolic compounds from aqueous solutions onto magnetic chitosan nanoparticles
    (Amer Chemical Soc, 2014) Tural, Bilsen; Ertas, Erdal; Tural, Servet
    [Abstract Not Available]
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    Electrochromic properties of poly(diphenyldithieno[3,2-b;: 2?,3?-d]thiophene)
    (Elsevier Science Sa, 2006) Mert, Olcay; Sahin, Elif; Ertas, Erdal; Ozturk, Turan; Aydin, Engin A.; Toppare, Levent
    A conducting polymer of diphenyldithieno[3,2-b;2',3'-d]thiophene (DPhDTT) was synthesized via potentiodynamic method in dichloromethane (DCM)/acetonitrile (AN) (1:9(v/v))-NaClO4/LiClO4 (0.1:0.1 M) solvent-electrolyte couple. Characterizations of the resulting homopolymer were performed by cyclic voltarnmetry (CV), Fourier transform infrared (FTIR) and UV-Vis spectroscopy. Moreover, the spectroelectrochemical and electrochromic properties of the homopolymer films were investigated. Consequently, P(DPhDTT)/PEDOT device was constructed and their characteristics were examined in detail. A potential range of 0.0-2.0 V was found to be suitable for operating the P(DPhDTT)/PEDOT device between yellow and blue colors. The device reveals good open circuit memory and stability. (c) 2006 Elsevier B.V. All rights reserved.
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    The Impact of Pistacia khinjuk plant gender on silver nanoparticle synthesis: Are extracts of root obtained from female plants preferentially used?
    (Academic Press Inc Elsevier Science, 2025) Tural, Bilsen; Ertas, Erdal; Batibay, Hayri; Tural, Servet
    Pistacia khinjuk, a dioecious plant native to Southeast Anatolia, Turkey, features distinct male and female individuals with varying bioactive compound profiles. This study investigates the gender-specific phytochemical composition of root extracts from male and female Pistacia khinjuk plants and their influence on the green synthesis of silver nanoparticles. Using natural bioactive compounds such as polyphenols, flavonoids, alkaloids, and terpenoids as reducing and stabilizing agents, the study demonstrates significant differences between the nanoparticles synthesized from male and female root extracts. Female root extracts, with their higher poly- phenolic content, produced silver nanoparticles that were smaller in size (150.1 nm) and more stable, as indicated by a zeta potential of-32.5 mV. In comparison, the silver nanoparticles synthesized from male root extracts were larger in size (213.8 nm) and exhibited a less negative zeta potential of-21.36 mV. Additionally, silver nanoparticles derived from female root extracts showed superior antioxidant activity and greater antibacterial efficacy against Staphylococcus aureus and Escherichia coli, as reflected in larger inhibition zones. These findings highlight the potential of Pistacia khinjuk root extracts for sustainable nanoparticle synthesis and underscore the value of gender-specific bioactive compounds in advancing green technologies and biomedical applications.
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    Preparation and characterization of a novel magnetic biosorbent functionalized with biomass of Bacillus Subtilis: Kinetic and isotherm studies of biosorption processes in the removal of Methylene Blue
    (Elsevier Sci Ltd, 2017) Tural, Bilsen; Ertas, Erdal; Enez, Baris; Fincan, Sema Aguloglu; Tural, Servet
    A novel magnetic biosorbent (M-BSub) was successfully prepared by the immobilization of Bacillus subtilis (B. subtilis) with nano-sized magnetic silica which was confirmed by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), vibrating sample magnetometry (VSM), scanning electron microscope (SEM). Optimum biosorption conditions were determined as a function of pH, contact time and initial concentration of Methylene Blue (MB). The maximum biosorption efficiency of MB was obtained at pH 6.8 and 30 degrees C. The uptake of dye was very fast initially, and achieved equilibrium after 3 h. The isotherm models like Langmuir, Freundlich, Dubinin-Radushkevich (D-R) were used to analyze the equilibrium data. The equilibrium data fit better to the Freundlich model compared to the Langmuir model in concentration range studied (50-300 mg/L). The maximum biosorption capacity of biosorbent reached up to 59 +/- 0.6 mg g(-1) at pH value of 6.8 and 30 degrees C. The kinetics data were analyzed using adsorption kinetic models like the pseudo-first order, pseudo-second order and intraparticle diffusion equation. Kinetic data showed good agreement with the pseudo-second order kinetic model. In addition, biosorbent can be easily regenerated and reused for five cycles with high biosorption capacity. This study indicated that M-BSub is a reusable biosorbent for rapid, convenient, and efficient removal of MB from contaminated aquatic systems.
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    Purification and covalent immobilization of benzaldehyde lyase with heterofunctional chelate-epoxy modified magnetic nanoparticles and its carboligation reactivity
    (Elsevier Science Bv, 2013) Tural, Bilsen; Tural, Servet; Ertas, Erdal; Yalinkilic, Ibrahim; Demir, Ayhan S.
    In this work, histidine-tagged recombinant benzaldehyde lyase from Pseudomonas fluorescens Biovar I (BAL, EC 4.1.2.38) was immobilized on the magnetically responsive epoxy-chelate magnetic support following a two-step mechanism; that is, the protein is physically adsorbed and then the covalent bonding takes place. This mechanism has been exploited to combine the selectivity of metal chelate affinity chromatography with the covalent immobilization capacity of epoxy supports. In this way, it has been possible to accomplish, in a simple manner, the purification, immobilization, and stabilization of a histidine-tagged recombinant benzaldehyde lyase. To fulfill this objective we prepared and characterized a multifunctional Co2+-IDA-epoxy functionalized the silica coated magnetic nanoparticles (SCMPs) which are modified with glycidyloxypropyltrimethoxysilane (GPTMS) and iminodiacetic acid (IDA). To test immobilized BAL, benzoin condensation reaction was performed with this magnetically responsive biocatalyst. The results obtained from the carboligation reaction that was performed with this simple and convenient heterogeneous biocatalyst were comparable to that of free-enzyme-catalyzed reaction. Additional advantages are its reusability and it is easy to work with. (c) 2013 Elsevier B.V. All rights reserved.
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    Removal of phenolic pollutants from aqueous solutions by a simple magnetic separation
    (Desalination Publ, 2016) Tural, Bilsen; Ertas, Erdal; Tural, Servet
    The removal efficiencies of phenol, 2-chlorophenol (2-CPh), and 4-chlorophenol (4-CPh) from aqueous solution with magnetic chitosan nanoparticles were investigated in this work. Chitosan-coated magnetite nanoparticles were successfully synthesized, characterizated, and applied as an effective magnetic biosorbent for the removal of phenol, 2-CPh, and 4-CPh from aqueous solutions. The characterization of synthesized magnetic chitosan nanoparticles was performed by Fourier transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, dynamic light scattering, vibrating sample magnetometry analyses, and thermogravimetric analysis. Adsorption characteristics of phenolic compounds from aqueous solution on to magnetic chitosan have been studied and results indicated that the adsorption capacities were affected by initial pH values, initial concentration of adsorbates, dosage of adsorbent, and contact time. The adsorption of adsorbates followed with the pseudo-second-order reaction and equilibrium experiments were well fitted with the Freundlich isotherm model. Furthermore, it was found that the magnetic biosorbent can be regenerated and reused for five repeated cycles for the removal of phenol, 2-CPh, and 4-CPh and avoided secondary pollution of biosorbent to water.