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Öğe Antibody purification from human plasma by metal-chelated affinity membranes(Wiley, 2012) Yavuz, Handan; Bereli, Nilay; Armutçu, Canan; Yılmaz, Fatma; Denizli, AdilThe aim of this study is to investigate in detail the feasibility of poly(2-hydroxyethyl methacrylate-N-methacryloyl-(L)-histidine methyl ester), PHEMAH membranes for purification of immunoglobulin G (IgG) from human plasma. PHEMAH membranes were prepared by photo-polymerization technique. Then, Zn2+, Ni2+, Co2+, and Cu2+ ions were chelated directly on the PHEMAH membranes. Elemental analysis assay was performed to determine the nitrogen content and polymerized MAH was calculated as 168.5 mu mol/g. The nonspecific IgG adsorption onto the plain PHEMA membranes was negligible (about 0.25 mg/mL). A remarkable increase in the IgG adsorption capacities were achieved from human plasma with PHEMAH membranes (up to 68.4 mg/mL). Further increase was observed with the metal-chelated PHEMAH membranes (up to 118 mg/mL). The metal-chelate affinity membranes allowed the one-step separation of IgG from human plasma. The binding range of metal ions for surface histidines from human plasma followed the order: Cu2+ > Ni2+ > Zn2+ > Co2+. Adsorbed IgG was eluted using 250 mM EDTA with a purity of 94.1%. IgG molecules could be repeatedly adsorbed and eluted with the metal-chelated PHEMAH membranes without noticeable loss in their IgG adsorption capacity. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 123: 3476-3484, 2012Öğe Antibody Purification from Human Plasma by Metal-Chelated Affinity Membranes(Humana Press Inc, 2015) Yavuz, Handan; Bereli, Nilay; Yilmaz, Fatma; Armutcu, Canan; Denizli, AdilImmobilized metal ion affinity chromatography (IMAC) has been used for purification of proteins. IMAC introduces a new approach for selectively interacting biomolecules on the basis of their affinities for metal ions. The separation is based on different binding abilities of the proteins to the chelated metal ions on support. Here, N-methacryloyl-(L)-histidine methyl ester (MAH) is used as the metal-chelating ligand. Poly(hydroxyethyl methacrylate) Poly(HEMA) based membranes were prepared by photo-polymerization technique. Then, Zn2+, Ni2+, Co2+, and Cu2+ ions were chelated directly on the poly(HEMA-MAH) membranes for purification of immunoglobulin G (IgG) from human plasma.Öğe Development of surface plasmon resonance sensors based on molecularly imprinted nanofilms for sensitive and selective detection of pesticides(Elsevier Science Sa, 2017) Saylan, Yeşeren; Akgönüllü, Semra; Çimen, Duygu; Derazshamshir, Ali; Bereli, Nilay; Yılmaz, FatmaPesticides have been utilized in agriculture for decades. However, their widespread use has increased multiple concerns due to their known and suspected toxicities on long-term human health risks in scientific and industrial communities. Thus, detecting pesticides will have a great impact on their management, as well as improve their toxicity effects over humans. Here, we fabricate molecularly imprinted nanofilms and integrate them with surface plasmon resonance (SPR) sensors for sensitive, selective, fast and real-time detection of multiple pesticides, including cyanazine (SNZ), simazine (SMZ) and atrazine (ATZ). The molecularly imprinted nanofilms onto the SPR gold surfaces are prepared via UV polymerization reactions, which consist of N-methacryloyl-L-phenylalanine methyl ester (MAPA) as a functional monomer, 1-vinylimidazole (VIM) as a co-monomer, and ethylene glycol dimethacrylate (EGDMA) as a cross-linker. The real-time measurements on SPR sensor provide a detection range from 0.10 to 6.64 nM, as well as denote a limit of detection (LOD) values of 0.095, 0.031 and 0.091 nM for SNZ, SMZ and ATZ, respectively. Furthermore, we perform selectivity test, where SNZ, SMZ and ATZ are examined as competitor agents. Overall, the pesticide imprinted SPR sensors have been found to be highly selective and sensitive. These SPR sensors also hold great potential to be used an alternative method for the existing pesticide monitoring approaches due to their reusability, fast response, and easy-to-use properties, as well as can be tailored to detect and real-time monitor of other pesticides. (C) 2016 Elsevier B.V. All rights reserved.Öğe Megaporous poly(hydroxy ethylmethacrylate) based poly(glycidylmethacrylate-N-methacryloly-(L)-tryptophan) embedded composite cryogel(Elsevier Science Bv, 2015) Türkmen, Deniz; Bereli, Nilay; Derazshamshir, Ali; Perçin, Işık; Shaikh, Huma; Yılmaz, FatmaOne-step activation, purification, and stabilization of lipase enzyme were performed by using composite hydrophobic support at low ionic strength with increased surface area during embedding process. A novel hydrophobic poly(hydroxyethylmethacrylate) [PHEMA] based, poly(glycidyl methacrylate-N-methacryloly-(L)-tryptophan) [PGMATrp] bead embedded composite cryogel membrane having specific surface area of 195 m(2)/g was used as hydrophobic matrix for adsorption of commercial Candida Rugosa lipase in a continuous system. PGMATrp embedded PHEMA cryogel membrane with 60-100 mu m pore size was obtained by dispersion polymerization of GMA and MATrp to form PGMATrp beads followed by embedding of PGMATrp to HEMA via APS and TEMED redox pair. The introduction of hydrophobic MATrp monomer into bead structure aiming to increase interaction between lipase and composite membrane was estimated using nitrogen stoichiometry of elemental analysis and found to be 239 mu mol/g of polymer. Hydophobicity increment due to embedding process was confirmed by measuring contact angle, it was found 42 degrees and 48.4 degrees for the PHEMA and PHEMA/PGMATrp composite cryogel respectively. Some parameters i.e. pH, flow-rate, protein concentration, temperature, salt type and ionic intensity were evaluated on the adsorption capacity in a continuous system. Fast protein liquid chromatography (FPLC) studies were performed for specific adsorption of lipase onto the PHEMA/PGMATrp embedded composite cryogel membrane. (C) 2015 Elsevier B.V. All rights reserved.Öğe Preparation of cryogel columns for depletion of hemoglobin from human blood(Taylor & Francis Ltd, 2016) Derazshamshir, Ali; Baydemir, Gözde; Yılmaz, Fatma; Bereli, Nilay; Denizli, AdilIn this study, we aimed to prepare the metal chelate affinity cryogels for the hemoglobin (Hb) depletion. Poly(2-hydroxyethyl methacrylate) (PHEMA) cryogels were selected as base matrix because of their blood compatibility, osmotic, chemical, and mechanical stability. Cryogels are also useful when working with the viscous samples such as blood, because of their interconnected macroporous structure. Iminodiacetic acid (IDA), the chelating agent, was covalently coupled with PHEMA cryogels after activation with the epichlorohydrin and then the Ni(II) ions were chelated to the IDA-bound cryogels. The depletion of the Hb from hemolysate was shown by SDS-PAGE.Öğe Real time monitoring and label free creatinine detection with artificial receptors(Elsevier Science Bv, 2019) Topçu, Aykut Arif; Özgür, Erdoğan; Yılmaz, Fatma; Bereli, Nilay; Denizli, AdilMolecular imprinting technique is used to design artificial creatinine receptor on the gold surface of surface plasmon resonance (SPR) chip using N-methacryloyl-(L)-histidine methyl ester (MAH), as a functional monomer. Surface characterization of SPR sensor chip is performed with atomic force microscope (AFM), ellipsometry and contact angle measurements. Creatinine imprinted SPR sensor is characterized with a linear range between 1 and 100 mM and limit of detection (LOD) and limit of quantification (LOQ) of creatinine are found 57 mu M and 190 mu M, respectively. N-hydroxysuccinimide (NHS) and creatine molecules are selected to examine the selectivity of creatinine imprinted SPR sensor. Reusability studies of SPR sensor is determined in urine mimic samples.Öğe Selective detection of penicillin g antibiotic in milk by molecularly imprinted polymer-based plasmonic SPR sensor(MDPI, 2021) Bakhshpour, Monireh; Göktürk, Ilgım; Bereli, Nilay; Yılmaz, Fatma; Denizli, AdilMolecularly imprinted polymer-based surface plasmon resonance sensor prepared using silver nanoparticles was designed for the selective recognition of Penicillin G (PEN-G) antibiotic from both aqueous solution and milk sample. PEN-G imprinted sensors (NpMIPs) SPR sensor was fabricated using poly (2-hydroxyethyl methacrylate-N-methacroyl-(L)-cysteine methyl ester)-silver nanoparticles-N-methacryloyl-L-phenylalanine methyl ester polymer by embedding silver nanoparticles (AgNPs) into the polymeric film structure. In addition, a non-imprinted (NpNIPs) SPR sensor was prepared by utilizing the same polymerization recipe without addition of the PEN-G template molecule to evaluate the imprinting effect. FTIR-ATR spectrophotometer, ellipsometer, contact angle measurements were used for the characterization of NpMIPs SPR sensors. The linear concentration range of 0.01-10 ng/mL PEN-G was studied for kinetic analyses. The augmenting effect of AgNPs used to increase the surface plasmon resonance signal response was examined using polymer-based PEN-G imprinted (MIPs) sensor without the addition of AgNPs. The antibiotic amount present in milk chosen as a real sample was measured by spiking PEN-G into the milk. According to the Scatchard, Langmuir, Freundlich and Langmuir-Freundlich adsorption models, the interaction mechanism was estimated to be compatible with the Langmuir model.Öğe SPR signal enhancement with silver nanoparticle-assisted plasmonic sensor for selective adenosine detection(IEEE-Inst Electrical Electronics Engineers Inc, 2022) Göktürk, Ilgım; Yücel, Monireh Bakhshpour; Çimen, Duygu; Yılmaz, Fatma; Bereli, Nilay; Denizli, AdilIn this study, we fabricated adenosine imprinted poly(hydroxyethyl methacrylate-N-methacryloyl-L-cysteine methyl ester-silver nanoparticles (AgNPs)-N-methacryloyl-L-phenylalanine methyl ester) (MIP-Ag) sensor. It is a sensitive, simple, low-cost, and label-free adenosine determination in an aqueous solution without the need for any complicated coupling processes. The sensor without the addition of AgNPs (MIP) was prepared for control experiments to examine the effect of incorporated AgNPs to increase the signal response of surface plasmon resonance. Also, non-imprinted (NIP-Ag) sensor were designed using the same polymerization recipe without adding adenosine to evaluate the imprinting efficiency. The characterization studies of MIP-Ag, NIP-Ag and MIP sensors were carried out by atomic force microscopy and contact angle measurements. It was determined that the MIP-Ag sensor detected the target adenosine molecule 5.10 times more selectively than the competitor guanosine and 3.92 times more than thymidine. Imprinting efficiency was determined by comparing the signal response of MIP-Ag and NIP-Ag sensors. Repeatability studies of the MIP-Ag sensor were statistically analyzed for the 1.0 ppm adenosine, and the percent relative standard deviation of the intraday assays of less than 1.0% showed an insignificant decrease in the detection of adenosine after four adsorption-desorption cycles.Öğe Surface plasmon resonance based nanosensors for detection of triazinic pesticides in agricultural foods(Elsevier, 2017) Yılmaz, Fatma; Saylan, Yeşeren; Akgönüllü, Semra; Çimen, Duygu; Derazshamshir, Ali; Bereli, Nilay; Denizli, AdilHerein, we have focused on the preparation of triazinic pesticide imprinted SPR nanosensors for detection of herbicides. Triazinic pesticides are weedkillers that are related with possible carcinogenic effects, birth defects, and menstrual problems when uptake by humans. Although there are restrictions and bans on their use in some countries they are still one of the most widely used pesticides in the world. The development of rapid, sensitive, and inexpensive diagnosis tools for environmental and biological monitoring is currently a research area of great interest. Surface plasmon resonance (SPR) nanosensors have been used widely for the detection of triazinic pesticides because of their simplicity, lack of requirement for labeling and ease of miniaturization, low cost, high specificity and sensitivity, and real-time measurement. Molecularly imprinted polymers that have molecular recognition talent, are easy to prepare, less expensive, stable, and can be manufactured with good reproducibility, are used for the creation of biorecognitive surfaces on the SPR nanosensors. Herein, we have focused on the production of triazinic pesticide-imprinted SPR nanosensors. © 2017 Elsevier Inc. All rights reserved.Öğe Surface plasmon resonance sensors for medical diagnosis(Springer Berlin Heidelberg, 2018) Saylan, Yeşeren; Yılmaz, Fatma; Özgür, Erdogan; Derazshamshir, Ali; Bereli, Nilay; Yavuz, Handan; Denizli, AdilSurface plasmon resonance (SPR) sensors have fascinated impressive attention to detect clinically related analytes in recent years. SPR sensors have also multiple advantages over existing conventional diagnostic tools such as easy preparation, no requirement of labeling, and high specificity and sensitivity with low cost, and they provide real-time detection capability. There are some articles and reviews in literature focusing on the applications of SPR-based sensors for the diagnosis of medically important entities such as proteins, cells, viruses, disease biomarkers, etc. These articles generally give information on the determination of such structures merely, whereas this presented manuscript combines recent literature for most of the medically important structures together including proteins, hormones, nucleic acids, whole cells, and drugs that especially the latest applications of SPR sensors for medical diagnosis to follow up new strategies and discuss how SPR strategy is brought to solve the medical problems.
