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Öğe Adsorption behaviours of lysozyme onto poly-hydroxyethyl methacrylate cryogels containing methacryloyl antipyrine-Ce(III)(Taylor & Francis As, 2018) Baysal, Zubeyde; Aksoy, Eyyup; Dolak, Ibrahim; Ersoz, Arzu; Say, RidvanIn this study, Ce3+-based cryogel with methacryloyl antipyrine (MAAP) and 2-hydroxyethyl methacrylic acid (HEMA) [p(HEMA-MAAP-Ce3+] was prepared. MAAP-Ce3+ complex was characterized by UV-near infrared and energy-dispersive X-ray spectroscopy. Cryogel was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and swelling test. Pore size of the cryogel was found to be about 30-50 mu m. The effects of flow rate, pH, temperature, and initial enzyme concentration have been investigated. Maximum adsorption capacity was found to be 57.84 mg g(-1) cryogel at pH 6.0. After seven times of adsorption-desorption cycles of same cryogel, it was observed that there is negligible decrease in the adsorption capacity. [GRAPHICS] .Öğe Cadmium removal out of human plasma using ion-imprinted beads in a magnetic column(Elsevier, 2009) Candan, Nilgun; Tuzmen, Nalan; Andac, Muge; Andac, Cenk A.; Say, Ridvan; Denizli, AdilThe aim of this study is to utilize ion-imprinted magnetic beads in the selective removal of Cd2+ ions out of human plasma overdosed with Cd2+ ions. The Cd (2+) imprinted magnetic poly(HEMA-MAC) (mPHEMAC-Cd2+) beads were produced by suspension polymerization in the presence of magnetite Fe3O4 in a nano-powder form. The template Cd2+ ions could be reversibly detached from the matrix to form mPHEMAC-Cd2+ beads using 0.1 M thiourea solution. The specific surface area of the mPHEMAC-Cd2+ beads was found to be 24.7 m(2)/g. The MAC and Fe3O4 contents of the mPHEMAC-Cd2+ beads were found to be 41.8 mu mol/g polymer and 8.2% on the average. The Cd2+ adsorption capacity of mPHEMAC-Cd2+ columns decreased drastically from 48.8 mu mol/g to 20.0 mu mol/g as the flow rate is increased from 0.50 ml/min to 3.0 ml/min. The maximum adsorption capacity of the mPHEMAC-Cd2+ beads was determined to be 48.8 mu mol Cd2+/g on the average. The relative selectivity coefficients of the mPHEMAC beads for Cd2+/Pb2+ and Cd2+/Zn2+ were 22.6 and 160.7 times greater than those of the non-imprinted magnetic PHEMAC (mPHEMAC) beads, respectively. The mPHEMAC-Cd2+ beads are reusable for many times with no significant decrease in their adsorption capacities. (C) 2008 Elsevier B.V. All rights reserved.Öğe Ferritin based bionanocages as novel biomemory device concept(Elsevier Advanced Technology, 2018) Elmas, Sukriye Nihan Karuk; Guzel, Remziye; Say, Mehmet Girayhan; Ersoz, Arzu; Say, RidvanFerritin is an iron cage having protein, capable of extracting metal ions in their cages and a consequence of the electron transfer of metal ions in their cage by reduction and oxidation processes, electrochemical information storage devices can be designed. In this work, ferritin based protein biomemory substrate has been synthesized by using Amino Acid (monomer) Decorated and Light Underpinning Conjugation Approach (ANADOLUCA) method, which utilizes photosensitive electron transfer based microemulsion co-polymerization as nanobead form of ferritin. Protein substrate contains metal ions such as silver and copper or metal ion pairs namely, silver copper (Janus bionanocage) and co-polymeric shell of the photosensitive crosslinker protein. The redox behavior of bionanocages differentiates electrochemical writing and erase states depending on these metal ions (silver or copper) or metal ion pairs. The bionanocages based biomemory substrates have been immobilized using graphene modified glassy carbon electrodes and the memory functions of ferritin based bionanocages have been confirmed by chronoamperometry (CA) and open circuit potential amperometry (OCPA). The stability and durability of multi-state memory devices represent promising properties for future bioelectronic information technologies.Öğe Ion imprinted cryogel-based supermacroporous traps for selective separation of cerium(III) in real samples(Elsevier, 2018) Kecili, Rustem; Dolak, Ibrahim; Ziyadanogullari, Berrin; Ersoz, Arzu; Say, RidvanThis study demonstrates the preparation and characterization of a novel ion imprinted cryogel which exhibits high affinity and selectivity towards Ce(III) ions in aqueous solutions and bastnasite ore samples. 2-Hydroxyethyl methacrylate (HEMA) and N-methacryloylamido antipyrine (MAAP) were used as functional monomers for the preparation of Ce(III) imprinted cryogel. The effects of various factors such as initial Ce(III) concentration, flow rate, pH, interaction time and ionic strength on the Ce(III) binding to the prepared ion imprinted cryogels were also studied. The binding equilibrium for Ce(III) is obtained in 30 min at the flow rate of 0.5 mL/min. The maximum binding capacity of the prepared ion imprinted cryogel towards Ce(III) is obtained as 36.58 mg/g at optimum conditions. The selectivity of the prepared ion imprinted cryogel towards Ce(III) in the presence of other possible interfering lanthanide ions such as La(III) and Nd(III) were also performed. The obtained results showed that the prepared ion imprinted cryogel exhibits high selectivity and sensitivity towards Ce(III) ions. The limit of detection (LOD) was found as 50 mu g/L. (C) 2018 Published by Elsevier B.V. on behalf of Chinese Society of Rare Earths.Öğe An Ion-Imprinted Monolith for in Vitro Removal of Iron out of Human Plasma with Beta Thalassemia(Amer Chemical Soc, 2008) Ozkara, Serpil; Say, Ridvan; Andac, Cenk; Denizli, AdilThe aim of this study is to prepare an ion-imprinted monolith which can be utilized to remove Fe3+ from beta thalassemia patient plasma. Fe, as a template, was initially complexed with N-methacryloyl-(L)-cysteine methyl ester (MAC) to form MAC-Fe3+ (the complex monomer), which was then polymerized with hydroxyethyl methacrylate (HEMA) to constitude a Fe3+-imprinted poly(HEMA-MAC) monolith (PHEMAC-Fe3+) by bulk polymerization method. The template (FC3+) was removed from the polymer by 0.1 M EDTA solution. The specific surface area of PHEMAC-Fe3+ was found to be 35.2 m(2)/g, with a swelling ratio of 60.2%. A maximum adsorption capacity of 150 mu g Fe3+/g was observed with PHEMAC-Fe3+. It was determined that PHEMAC-Fe3+ possesses relative selectivity coefficients for Fe3+/Cd2+ and Fe3+/ Ni2+, which are 42.6 and 36. 1, respectively, times greater than nonimprinted monolith (produced in the absence of Fe3+, PHEMAC). The PHEMAC-Fe3+ monolith has been recovered and reused many times without a significant decrease in its adsorption capacity.Öğe Ion-Imprinted Polymers for Selective Recognition of Neodymium(III) in Environmental Samples(Amer Chemical Soc, 2015) Dolak, Ibrahim; Kecili, Rustem; Hur, Deniz; Ersoz, Arzu; Say, RidvanThis study describes the selective recognition of Nd(III) in aqueous, solutions in the presence of various lanthanide ions by molecularly imprinted polymers. Molecularly imprinted polymers (MIPs) were prepared by suspension polymerization. N-methacryloylamido folic acid (MAFol) was used as the functional monomer. The effects of different variables such as pH, time, and initial Nd(III) concentration on binding characteristics were investigated. Binding, equilibrium time was achieved in 30 min. The maximum binding capacity was found to be 14.6 mg Nd(III) g(-1) polymer. Binding studies of W(III) in the presence of Ce(III), La(III), and Eu(III),ions were also carried out using Nd(III)-imprinted polymers. The imprinted polymers displayed high selectivity toward Nd(III) ions. The obtained binding order under competitive conditions was Nd(III) > La(III) > Ce(III) > Eu(III).Öğe Light harvesting and photo-induced electrochemical devices based on bionanocage proteins(Elsevier, 2019) Guzel, Remziye; Ocak, Yusuf Selim; Karuk, Sukriye Nihan; Ersoz, Arzu; Say, RidvanIn this study, bionanoferritin based Fe and Mn having nanocages, FeMnFBNC's, have adsorbed onto the immobilized graphene surface by electrostatic bonding. This immobilization enhances the capability of electron transfer between the bionanoferritin layer and graphene surface owing to the well-designed robust bionanocage structure. FeMnFBNCs have electronic bridges that consist of some tyrosine and ferritin amino acid residues with visible light photocrosslinking system between iron and manganese metals, which are capable of electron transfer that allows designing electrochemical and energy harvesting devices. Additionally, a novel hybrid and self-assembly bio-dye-approach as a new generation of dye-sensitized solar cells has been developed. Bio-nanoferritin/graphene/TiO2 based Bio-N-DSSC molecules can provide an intriguing alternative to traditional materials utilized in dye-sensitized solar cells.Öğe Metal chelate based site recognition of ceruloplasmin using molecularly imprinted polymer/cryogel system(Taylor & Francis Inc, 2020) Dolak, Ibrahim; Canpolat, Gurbet; Ersoz, Arzu; Say, RidvanIn the present study, N-Acetylneuraminic acid (NANA)-imprinted poly(2-hydroxyethyl methacrylate-N-methacryloyl-(L)-histidin-Cu(II)) p(HEMA-(MAH)(2)-Cu(II)) has been synthesized by radical polymerization for site recognition of ceruloplasmin. Prepared imprinted cryogel has been characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). When the binding capacity of NANA-imprinted cryogel (MIP) was compared with non-imprinted cryogel (NIP), it was found that MIP has higher adsorption capacity. The maximum amount of binding NANA has found as 83.20 mgg(-1) at pH 7.0 with flow rate of 1 mLmin(-1) at 25 degrees C. Selectivity experiments for MIP and NIP cryogel have been carried out via the NANA/D-mannose and ceruloplasmin/immunoglobulin G (IgG) pair separately and the relative selectivity coefficient (k') has found as 77.46 and 17.97, respectively. Applicable of the MIP in human serum has been studied and resulted successfully.Öğe Molecular Recognition-Based Detoxification of Aluminum in Human Plasma(Taylor & Francis Ltd, 2009) Demircelik, Ahmet H.; Andac, Muge; Andac, Cenk A.; Say, Ridvan; Denizli, AdilMolecular recognition-based Al3+-imprinted poly(hydroxyethyl methacrylate-N-methacryloyl-L-glutamic acid) (PHEMAGA-Al3+) beads were prepared to be used in selective removal of Al3+ out of human plasma overdosed with Al3+ cations. The PHEMAGA-Al3+ beads were synthesized by suspension polymerization in the presence of a template-monomer complex (MAGA-Al3+). The specific surface area of PHEMAGA-Al3+ beads was found to be 55.6 m(2)/g on the average. The MAGA content in the PHEMAGA-Al3+ beads were found to be 640 mu mol/g polymer. The template Al3+ cations could be reversibly detached from the matrix to form PHEMAGA-Al3+ using a 50 mM solution of EDTA. The Al3+-free PHEMAGA-Al3+ beads were then exposed to a selective separation procedure of Al3+ out of human plasma, which was implemented in a continuous system by packing the beads into a separation column (10 cm long with an inner diameter of 0.9 cm) equipped with a water jacket to control the temperature. The Al3+ adsorption capacity of the PHEMAGA-Al3+ beads decreased drastically from 0.76 mg/g polymer to 0.22 mg/g polymer as the flow rate was increased from 0.3 ml/min to 1.5 ml/min. The relative selectivity coefficients of the PHEMAGA-Al3+ beads for Al3+/Fe3+, Al3+/Cu2+ and Al3+/Zn2+ were found to be 4.49, 8.95 and 32.44 times greater than those of the non-imprinted PHEMAGA beads, respectively. FT-IR analyses on the synthesized PHEMAGA-Al3+ beads reveals monodentate and bidentate binding modes of Al3+ in complex with the carboxylate groups of the glutamate residues. Density functional theory computations at the B3LYP/6-31G(d,p) basis set suggests that structured water molecules play essential role in the stability of the monodentate binding mode in 1:1 PHEMAGA-Al3+ complexes. The PHEMAGA-Al3+ beads were recovered and reused many times, with no significant decrease in their adsorption capacities. (C) Koninklijke Brill NV, Leiden, 2009Öğe Molecularly imprinted affinity cryogels for the selective recognition of myoglobin in blood serum(Elsevier Science Bv, 2018) Dolak, Ibrahim; Kecili, Rustem; Onat, Ruken; Ziyadanogullari, Berrin; Ersoz, Arzu; Say, RidvanThe present work demonstrates the selective recognition of myoglobin in human serum in the presence of various competitive proteins such as lysozyme, cytochrome c and hemoglobin by using molecularly imprinted affinity cryogels. The imprinted affinity cryogels towards myoglobin were prepared by using cryopolymerization technique. For this purpose, N-methacryloylamido antipyrine (MAAP)-Ce(III) and myoglobin were used as the complex functional monomer and template molecule, respectively. (MAAP)-Ce(III) complex functional in the imprinted cryogel provided a luminescence feature to the cryogel and the detection of the myoglobin was successfully achieved by UV-VIS-Near Infrared (UV-VIS-NIR) Spectroscopy. The effects of some variables such as initial myoglobin concentration, temperature, pH and ionic strength on myoglobin binding to the prepared cryogels were studied. The myoglobin binding capacity of the prepared cryogels was determined to be 68 mgg(-1). Myoglobin binding to the cryogels in the presence of competitive proteins lysozyme, cytochrome c and hemoglobin were also performed. The imprinted cryogels exhibited high selectivity towards myoglobin and the obtained binding order under competitive conditions was myoglobin > lysozyme > cytochrome c > hemoglobin. (C) 2018 Elsevier B.V. All rights reserved.Öğe Multistate proteinous biomemory device based on redox controllable hapten cross-linker(Elsevier, 2017) Guzel, Remziye; Ersoz, Arzu; Dolak, Ibrahim; Say, RidvanA multistate biomemory device consisting of cytochrome c (Cyt-c) photosensitively cross-linked by MACysRu(bipyr)(2)-MACys hapten molecules, which have memory effect through a charge transfer mechanism, has been developed. In this study, it has suggested a highly resolute surface-confined switch composed a signal-enhanced electro-active protein (Cyt-c) co-polymerized on the gold substrates that can be controlled by redox property through Ruthenium based cysteine monomer hapten, MACys-Ru(bipyr)(2)-MACys as an ANADOLUCA photosensitive cross-linker. The photosensitive cross-linking of the Cyt-c protein on the gold surface topography has been determined by the scanning electron microscopy (SEM). Two state memory functions, writing and erasing of the developed biomemory device, have been investigated by the chronoamperometry (CA) and open-circuit potential amperometry (OCPA). The polymeric proteinous memory device, p(MACys-Ru(bipyr)(2)-MACys-coCyt-c) layer, on the gold electrode is stable and repeatable up to with 10(4) times continuous cycle. (C) 2017 Elsevier B.V. All rights reserved.Öğe Nano-hemoglobin film based sextet state biomemory device by cross-linked photosensitive hapten monomer(Elsevier Science Bv, 2018) Guzel, Remziye; Ersoz, Arzu; Ziyadanogullari, Recep; Say, RidvanIn this study, a biomemory device, consisting of hemoglobin (Hb) cross-linked by MACys-Ru(bipyr)(2)-MACys) photosensitive monomer cross-linkers, which have memory effect through both Ru3+/2+ in hapten monomer and Fe3+/2+ in redox active center of Hb through multi-charge transfer mechanism, has been improved. Cyclic voltammetry (CV) has been used to determine the redox property of the Hb cross-linked MACys-Ru(bipyr)(2)-MACys) hapten. Three memory functions, writing, reading and erasing of the fabricated biomemory device, have been accomplished by chronoamperometry (CA) and open-circuit potential amperometry (OCPA). The reliability and repeatability of the biodevice consisting of the p(Hb-co-MACys-Ru(bipyr)(2)-MACys) sextet state bio-memory layer have been analysed. The Hb film based biodevice on gold electrodes has shown >= 2 months the retention time and switched until 10(6) times continuous cycling without degradation in efficiency. Other hand, the topography of p(Hb-co-MACys-Ru(bipyr)(2)-MACys) layer on the gold surface has investigated by scanning electron microscopy (SEM) and EDX data.Öğe Photosystem (PSII)-based hybrid nanococktails for the fabrication of BIO-DSSC and photo-induced memory device(Elsevier Science Sa, 2020) Guzel, Remziye; Yediyildiz, Fatma; Ocak, Yusuf Selim; Yilmaz, Filiz; Ersoz, Arzu; Say, RidvanChromophore-containing complexes and proteins in nature are widespread use in the area of photochemistry and as models for photosynthesis. However, when they are removed from their biological environment, the proteins undergo denaturation and are unstable. In addition, cofactors such as NADH need to be released for continuous use in the system. In order to make PSII composed of protein mixtures, chromoforms and different cofactors stable and sustainable, the use of the ANADOLUCA (Amino Acid monomer Decorated and Light Underpinning Conjugation Approach) method to combine multicomponent photo-active bio-complexes has been used for energy and bio-inspired devices. The fabricated PSII-BNC based bio-nanodevice has boosted excellently photo-induced memory functions. To determine the stability of the particles, oxidation, reduction and OCPA potentials behavior of the PSII-BNC having a film under the light has been repeated continuously up to 10(9) cycles. In addition, we have developed a novel, bio-inspired and hybrid bio-dye-approach (BIO-H-DSSC) as a new generation of dye-sensitized solar cells. The bio-nanoenergetic layer formed by PSII-BNC with TiO2 has resulted in 0.22 % level of power conversion efficiency with open circuit voltage of 0.50 V, short circuit current of 888 mu Acm(-2) and fill factor of 0.50.
