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Öğe Affinity binding of proteins to the modified bacterial cellulose nanofibers(Elsevier B.V., 2017) Bakhshpour, Monireh; Tamahkar Irmak, Emel; Andaç, Müge; Denizli, AdilThe potential of the modified bacterial cellulose (BC) nanofibers was determined bearing metal ion coordination interactions to enhance the protein adsorption and binding capacity. Thus, a household synthesized metal chelating monomer, namely N-methacryloyl-L-histidine methylester (MAH), and a commercial metal chelating monomer, namely 4-vinylimidazole (VIm), were used to complex with metal ions Cu(II) and Ni(II) respectively for the synthesis of the modified BC nanofibers. The modified nanofibers were characterized by FT-IR, SEM and EDX measurements. The protein adsorption tests were carried out using hemoglobin as a model protein and it was determined that the maximum adsorption capacity of hemoglobin onto the modified BC nanofibers was found as 47.40 mg/g. The novel strategy for the preparation of metal chelated nanofibers was developed. © 2017 Elsevier B.V.Öğe Bacterial cellulose nanofibers for efficient removal of Hg2+ from aqueous solutions(Wiley Blackwell, 2018) Tamahkar Irmak, Emel; Türkmen, Deniz; Akgönüllü, Semra; Qureshi, Tahira; Denizli, Adil; Mishra, Ajay Kumar; Hussain, Chaudhery MustansarThe removal of mercury from wastewater is gaining much attention because of being one of the common heavy metal pollutants found in water source affecting human health and environment. Dye affinity chromatography is a general method for heavy metal removal having high reactivity, stability, easiness, and cost effectiveness. In this study, modified bacterial cellulose nanofibers (BC) were prepared using a dye namely Cibacron Blue F3GA (CB). The covalently attached Cibacron Blue F3GA (17.8 × 104 nmol/g) to the bacterial cellulose nanofibers was successfully applied to remove Hg2+ from aqueous solutions. Cibacron Blue F3GA attachment onto the bacterial cellulose nanofibers significantly increased the Hg2+ adsorption (928.0 mg/g), while the adsorption of Hg2+ onto the unmodified bacterial cellulose nanofibers was obtained very low (0.62 mg/g polymer). The competitive adsorption of heavy metals on BC-CB nanofibers was performed to examine the efficiency of BC-CB nanofibers for Hg2+ in comparison with other divalent metal ions. The adsorption capacities were observed as 322.4 mg/g for Hg2+; 48.5 mg/g for Cd2+; and 41.9 mg/g for Pb2+ indicating higher specificity for Hg2+ adsorption onto BC-CB nanofibers for the mercury ions comparing to other ions. The successive adsorption experiments and elution process demonstrated the efficient repeated workability of modified BC nanofibers. The results show that the preparation of cheap, effective, and eco-friendly nanofibers for mercury removal was performed successfully indicating the potential of BC-CB nanofibers for metal ion removal applications. © 2018 Scrivener Publishing LLC. All rights reserved.Öğe Determination of pKa values of some sulfonamides by LC and LC-PDA methods in acetonitrile-water binary mixtures(2010) Şanlı, Nurullah; Şanlı, Senem; Özkan, Güleren; Denizli, AdilAs constantes de dissociação de sete sulfonamidas antibióticas, sulfadiazina, sulfatiazol, sulfamerazina, sulfametazina, sulfamonometoxina, sulfadoxina e sulfametoxazol, foram determinadas em diferentes misturas binárias acetonitrila-água (15, 30, 40, 50% (v/v)) usando cromatografia líquida de fase reversa. Um método usando espectros de absorbância no máximo dos picos cromatográficos previamente obtidos foi também aplicado para determinar os valores de pKa . Este método pode ser aplicado a dados oriundos de equipamentos LC-UV (com detecção por arranjo de diodos, PAD) retendo todas as vantagens dos métodos LC e espectrofotométricos. Correlações lineares foram observadas quando os valores calculados de pKa das sulfonamidas em diferentes misturas de solventes foram comparados com a fração molar da acetonitrila.Öğe Ion imprinted cryogels for selective removal of Ni(II) ions from aqueous solutions(Elsevier B.V., 2017) Tamahkar Irmak, Emel; Bakhshpour, Monireh; Andaç, Müge; Denizli, AdilIn this article, ion imprinted poly(hydroxyethyl methacrylate) (PHEMA) based supermacroporous cryogels were synthesized in the presence of a functional monomer, namely N-methacryloyl-histidine methyl ester (MAH), to be complexed with Ni(II) ions. Two types of cryogels (MIP1 and MIP2) were synthesized according to functional monomer/template [MAH/Ni(II)] complexing molar ratios. These cryogels were then characterized by swelling tests, FT-IR and SEM measurements and used for selective binding of Ni(II) ions from aqueous solutions and a certified material. The maximum adsorption capacities of MIP1 and MIP2 cryogels were found as 1.89 and 5.54 mg/g, respectively. Ni(II) imprinted cryogels exhibited excellent selectivity toward competitive metal ions [Fe(III), Cu(II) and Zn(II)] indicating important potential for selective removal of Ni(II) ions from aqueous solutions. In addition, Ni(II) imprinted cryogels were used repeatedly without a decrement in the binding capacity. © 2016 Elsevier B.V.Öğe Molecularly imprinted composite bacterial cellulose nanofibers for antibiotic release(Taylor and Francis Inc., 2019) Tamahkar Irmak, Emel; Bakhshpour, Monireh; Denizli, AdilThe aim of this work is to develop drug carrier system with high loading capacity and controlled drug release profile for antibiotic release. For this purpose, composite molecularly imprinted nanofibers were prepared via in-situ graft polymerization of methacrylic acid as a monomer, N,N’-methylene bisacrylamide as a crosslinker and gentamicin sulfate as a template molecule onto surface-modified bacterial cellulose nanofibers. Gentamicin imprinted microparticles were fabricated onto bacterial cellulose nanofibers resulting in the formation of composite BC nanofibers. Thus, the composite nanofibers incorporated with gentamicin imprinted microparticles were achieved to fabricated. The in-vitro drug release tests were performed to evaluate the release performance of the resultant composite nanofibers at 37 °C. Also, kinetic models were applied to the drug release data. It was determined that the drug release from the composite molecularly imprinted nanofibers fit well in the Korsmeyer-Peppas model. © 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group.Öğe Molecularly imprinted smart cryogels for selective nickel recognition in aqueous solutions(Wiley, 2021) Andac, Muge; Tamahkar, Emel; Denizli, AdilSmart polymers with fast response to slight changes show high practicability in separation and removal applications, such as water and wastewater treatment. Molecular imprinted polymers (MIPs) are designed to possess specific binding sites enabling the recognition of the target analytes. In this article, the newly synthesized smart adsorbents were used for the selective removal of nickel [Ni(II)] ions from aqueous solutions, which have dual (pH and temperature) memory for the recognition of Ni(II) ions due to the self-assembled recognition sites in MIP structure. The Ni(II)-MIP smart cryogels were prepared by cryopolymerization ofN-isopropylacrylamide (NIPAm) andN-methacryloyl-l-histidine (MAH) monomers to incorporate their smart features for removal of Ni(II) ions in a selective and temperature-modulated way. The maximum binding capacity of Ni(II) ions onto MIP smart cryogel was determined at pH 6 as 414 mu g g(-1)at 20 degrees C and only 104.5 mu g g(-1)at 40 degrees C, respectively. The adsorption reached an equilibrium within 30 min, while 85% of the bound amount of Ni(II) ions was achieved in only 15 min. This unique MIP cryogel as a smart and selective adsorbent was able to remove Ni(II) ions immediately by a significant temperature and pH change as an alternative application for water and wastewater treatment.Öğe Phenol removal from wastewater by surface imprinted bacterial cellulose nanofibres(Taylor & Francis Ltd, 2020) Derazshamshir, Ali; Gokturk, Ilgim; Tamahkar, Emel; Yilmaz, Fatma; Saglam, Necdet; Denizli, AdilIn this study, we have reported a novel wastewater treatment technique by phenol imprinted bacterial cellulose (BC-MIP) nanofibres with high specificity and adsorption capacity. N-methacryloyl-(L) phenylalanine methyl ester (MAPA) functional monomer was used to create specific binding sites for the template molecule phenol via electrostatic and hydrophobic interactions. BC-MIP nanofibres were synthesized by surface imprinting approach in the presence of different amounts of total monomer (% weight), monomer/template ratio and polymerization time. Then, the nanofibres were characterized by FTIR-ATR, surface area analysis (BET), elemental analysis, scanning electron microscopy (SEM) and contact angle measurements. Adsorption studies were performed with respect to pH, temperature and ionic strength, and the adsorption capacity was calculated by using the spectrophotometer. In order to desorb the adsorbed phenol from BC-MIP nanofibres, 0.1 M NaCl solution was used. Besides, BC-MIP nanofibres were applied to real wastewater samples from Ergene basin in Turkey. The suitable equilibrium isotherm was determined as Langmuir isotherm. To evaluate the selectivity of the BC-MIP nanofibres, similar molecules were utilized as competitor molecules, which were 2-chlorophenol, 4-chlorophenol and 2,4-dichlorophenol. Electrostatic interactions were found to contribute to the generation of specific recognition binding sites. The results have shown that imprinting of phenol was achieved successfully with high adsorption capacity. The phenol removal efficiency was reported up to 97%. BC-MIP nanofibres were used 10 times with a negligible decrease in adsorption capacity. [GRAPHICS] .Öğe PolyAdenine cryogels for fast and effective RNA purification(Elsevier B.V., 2016) Köse, Kazım; Erol, Kadir; Özgür, Erdoğan; Uzun, Lokman; Denizli, AdilCryogels are used effectively for many diverse applications in a variety of fields. The isolation or purification of RNA, one of the potential utilizations for cryogels, is crucial due to their vital roles such as encoding, decoding, transcription and translation, and gene expression. RNA principally exists within every living thing, but their tendency to denaturation easily is still the most challenging issue. Herein, we aimed to develop adenine incorporated polymeric cryogels as an alternative sorbent for cost-friendly and fast RNA purification with high capacity. For this goal, we synthesized the polymerizable derivative of adenine called as adenine methacrylate (AdeM) through the substitution reaction between adenine and methacryloyl chloride. Then, 2-hydroxyethyl methacrylate (HEMA)-based cryogels were prepared in a partially frozen aqueous medium by copolymerization of monomers, AdeM, and HEMA. The cryogels were characterized by using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), surface area measurements, thermogravimetric analysis (TGA), and swelling tests. RNA adsorption experiments were performed via batch system while varying different conditions including pH, initial RNA concentration, temperature, and interaction time. We achieved high RNA adsorption capacity of cryogels, with the swelling ratio around 510%, as 11.86 mg/g. The cryogels might be reused at least five times without significant decrease in adsorption capacity. © 2016 Elsevier B.V.Öğe Polyethyleneimine assisted-two-step polymerization to develop surface imprinted cryogels for lysozyme purification(Elsevier B.V., 2016) Erol, Kadir; Köse, Kazım; Uzun, Lokman; Say, Rıdvan; Denizli, AdilSurface imprinting strategy is one of the promising approaches to synthesize plastic antibodies while overcoming the problems in the protein imprinting research. In this study, we focused our attentions on developing two-step polymerization to imprint on the bare surface employing polyethyleneimine (PEI) assisted-coordination of template molecules, lysozyme. For this aim, we firstly synthesized poly(2-hydroxyethyl methacrylate-glycidyl methacrylate), poly(HEMA-GMA) cryogels as a bare structure. Then, we immobilized PEI onto the cryogels through the addition reaction between GMA and PEI molecules. After that, we determined the amount of free amine (NH2) groups of PEI molecules, subsequently immobilized methacrylate functionalities onto the half of them and another half was used to chelate Cu(II) ions as a mediator between template, lysozyme and PEI groups. After the characterization of the materials developed by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and the micro-computed tomography (?CT), we optimized the lysozyme adsorption conditions from aqueous solution. Before performing lysozyme purification from chicken egg white, we evaluated the effects of pH, interaction time, the initial lysozyme concentration, temperature and ionic strength on the lysozyme adsorption. Moreover, the selectivity of surface imprinted cryogels was examined against cytochrome c and bovine serum albumin (BSA) as the competitors. Finally, the mathematical modeling, which was applied to describe the adsorption process, showed that the experimental data is very well-fitted to the Langmuir adsorption isotherm. © 2016 Elsevier B.V.Öğe Protein depletion with bacterial cellulose nanofibers(Elsevier B.V., 2018) Göktürk, İlgim; Tamahkar Irmak, Emel; Yılmaz, Fatma; Denizli, AdilIn this study, we have reported a novel fabrication technique for human serum albumin (HSA) imprinted composite bacterial cellulose nanofibers (MIP-cBCNFs) used for the depletion of HSA selectively from artificial blood plasma for proteomic applications. Molecular imprinting was achieved by using metal ion coordination interactions of N?methacryloyl?(L)?histidinemethylester (MAH) monomer and Cu(II) ions. MAH-Cu(II)-HSA complex was polymerized with bacterial cellulose nanofibers (BCNFs) under constant stirring at room temperature. The characterization of the MIP-cBCNFs was carried out by FTIR-ATR, SEM, contact angle measurements and surface area measurements. The adsorption experiments of HSA onto the MIP-BCNFs and NIP-BCNFs from aqueous HSA solutions were investigated in a batch system. The selectivity of the MIP-cBCNFs was investigated by using non-template human transferrin (HTR), and myoglobin (Myo). The relative selectivity coefficients of the MIP-cBCNFs were calculated as 4.73 and 3.02 for HSA/HTR and HSA/Myo molecules, respectively. In addition, the depletion of HSA from artificial human plasma was confirmed by SDS-PAGE and 2-D gel electrophoresis. As a result, it has been shown that metal ion coordination interactions contribute to specific binding of template when preparing MIP-cBCNFs for the depletion of HSA with a high adsorption capacity, significant selectivity and reusability. © 2018Öğe Recognition of lysozyme using surface imprinted bacterial cellulose nanofibers(Taylor and Francis Inc., 2017) Saylan, Yeşeren; Tamahkar Irmak, Emel; Denizli, AdilHere, we developed the lysozyme imprinted bacterial cellulose (Lyz-MIP/BC) nanofibers via the surface imprinting strategy that was designed to recognize lysozyme. This study includes the molecular imprinting method onto the surface of bacterial cellulose nanofibers in the presence of lysozyme by metal ion coordination, as well as further characterizations methods FTIR, SEM and contact angle measurements. The maximum lysozyme adsorption capacity of Lyz-MIP/BC nanofibers was found to be 71 mg/g. The Lyz-MIP/BC nanofibers showed high selectivity for lysozyme towards bovine serum albumin and cytochrome c. Overall, the Lyz-MIP/BC nanofibers hold great potential for lysozyme recognition due to the high binding capacity, significant selectivity and excellent reusability. © 2017 Informa UK Limited, trading as Taylor & Francis Group.Öğe Surface imprinted bacterial cellulose nanofibers for hemoglobin purification(Elsevier B.V., 2017) Bakhshpour, Monireh; Tamahkar Irmak, Emel; Andaç, Müge; Denizli, AdilThere is a significant need for the development of the novel adsorbents in the field of protein purification. In this study, thin hemoglobin imprinted film (MIP) was fabricated onto the bacterial cellulose nanofibers’ (BCNFs) by surface imprinting method using metal ion coordination interactions with N-methacryloyl–(L)-histidinemethylester (MAH) and copper ions. The hemoglobin surface imprinted bacterial cellulose nanofibers (MIP-BCNFs) was applied to selective recognition of hemoglobin and purification from hemolysate. The characterization of the MIP-BCNFs was carried out by the Fourier Transformed Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), micro-Computerized Tomography (?CT), atomic force microscopy (AFM) and surface area measurements. The adsorption experiments of hemoglobin onto the MIP-BCNFs and NIP-BCNFs from aqueous hemoglobin solutions were investigated in a batch system. The results showed that MIP-BCNFs are promising materials for purification of hemoglobin with high adsorption capacity, significant selectivity and reusability. © 2017 Elsevier B.V.
