Yazar "Gokturk, Ilgim" seçeneğine göre listele
Listeleniyor 1 - 8 / 8
Sayfa Başına Sonuç
Sıralama seçenekleri
Öğe Development of Molecularly Imprinted Magnetic Amino Acid-Based Nanoparticles for Voltammetric Analysis of Lead Ions in Honey(Mdpi, 2024) Karagozlu, Mehmet; Asir, Suleyman; Abu Shama, Nemah; Gokturk, Ilgim; Yilmaz, Fatma; Turkmen, Deniz; Denizli, AdilLead (Pb) is a hazardous metal that poses a significant threat to both the environment and human health. The presence of Pb in food products such as honey can pose a significant risk to human health and is therefore important to detect and monitor. In this study, we propose a voltammetric detection method using molecularly imprinted polymer (MIP) electrodes to detect Pb (II) ions in honey. Pb (II) ion-imprinted amino acid-based nanoparticles with magnetic properties on a carbon paste electrode (MIP-CPE) were designed to have high sensitivity and selectivity towards Pb (II) ions in the honey sample. Zetasizer measurements, electron spin resonance, and scanning electron microscopy were used to characterize magnetic polymeric nanoparticles. The results showed that the voltammetric detection method using MIP-CPE was able to accurately detect Pb (II) ions in honey samples with a low detection limit. The proposed method offers a simple, rapid, cost-effective solution for detecting Pb (II) ions in honey. It could potentially be applied to other food products to ensure their safety for human consumption. The MIP-CPE sensor was designed to have high sensitivity and selectivity towards Pb (II) ions in the honey sample. The results showed that the technique was able to deliver highly sensitive results since seven different concentrations were prepared and detected to obtain an R2 of 0.9954, in addition to a low detection limit (LOD) of 0.0912 mu M and a low quantification limit (LOQ) of 0.276 mu M. Importantly, the analysis revealed no trace of Pb (II) ions in the honey samples obtained from Cyprus.Öğe Nano-biosorbents for contaminant removal: An introduction(Elsevier, 2022) Cimen, Duygu; Gokturk, Ilgim; Calisir, Merve; Yilmaz, Fatma; Denizli, AdilIn recent years, nanobiopolymers such as nanochitin, nanocellulose, nanostarch, nanosilk, and microbial produced by living organisms have received a wide range of attention in different fields of science and engineering. Nanobiopolymers are sustainable and biodegradable compared to petroleum-based synthetic polymers. While synthetic polymer materials are the most used materials in recent times, they have brought serious problems affecting human health, environment and nature. Nanobiopolymers with unique structural properties resulting from nano-dimensional effects such as ultra-high aspect ratio and length-to-diameter ratio are produced by a variety of mechanical, chemical and synthetic biology techniques. These properties ensure their machinability. Nanobiopolymers, which are successfully produced from agriculture, nature, and forestry products such as cotton, wood, silk fibers, coconut, shrimp/crab shell, wheat, rice and potatoes, are used in a wide range of high-tech areas such as transparent display panels, while ultrafiltration membranes, energy storage devices and catalytic as supports. This section demonstrates the manufacturing techniques for producing nano biopolymers and then summarizes the most recently reported applications of nanobiopolymers for decontamination of environmental pollutants. © 2022 Elsevier Inc. All rights reserved.Öğe Phenylalanine functionalized cryogels for selective cholesterol removal from milk(Springer Int Publ Ag, 2024) Gokturk, Ilgim; Saylan, Yeseren; Yilmaz, Fatma; Kartal, Fatma; Denizli, AdilHigh cholesterol grades are a significant threat factor for coronary heart disease, which leads to heart attacks. General practices focus on lowering cholesterol and saturated fatty acids in the diet to decrease the incidence of cardiovascular diseases. Milk is a primary food with high nutritional value and high consumption. Molecularly imprinted cryogels are an excellent alternative according to non-selective methods such as liquid-liquid and/or solid-phase extraction to elute cholesterol selectively from milk. Because the cryogels are low cost, they can be synthesized easily, and the sample can be applied directly to the cryogel without needing any pre-treatment. In this study, we synthesized cholesterol-imprinted (Chl-MIP) cryogel membranes employing aminoacid-based hydrophobic functional comonomer N-methacryloyl-L-phenylalanine to be used as a selective adsorbent to remove cholesterol from milk samples. Chl-MIP cryogel exhibited a maximum Chl adsorption capacity of 12.01 mg/g at 25 degrees C with an interaction time of 60 min. The selectivity of the cryogel was 2.89 times greater for estradiol molecules and 4.99 times greater for progesterone molecules. Chl-MIP cryogel provides a rapid mass transfer by a short diffusion path without any diffusion restrictions. This process is simple to implement, efficient, affordable, and feasible for use on modern manufacturing lines.Öğe Plasmonic sensing platform for C-reactive protein recognition via synthetic receptors decorated on graphene oxide and gold nanoparticles(Elsevier, 2024) Ovezova, Mamajan; Yilmaz, Fatma; Gokturk, Ilgim; Denizli, AdilC-reactive protein (CRP) level provides important information about the health status of the individual in predicting many diseases such as cardiovascular, chronic inflammatory, and neurodegenerative diseases. Therefore, determining CRP levels is important for correct health intervention and treatment follow-up. For the selective detection of CRP, we developed a (GO/Au-MIP) SPR sensor containing CRP-imprinted polymer modified with graphene oxide and gold nanoparticles. To prove the enhanced sensitivity of the sensor resulting from the presence of graphene oxide (GO) and gold nanoparticles (AuNPs), a CRP-imprinted (MIP) SPR sensor was prepared using the same method, excluding the incorporation of GO and AuNPs. In addition, a non-imprinted GO/Au-NIP SPR sensor was also prepared to evaluate the imprinting efficiency. In detecting CRP in PBS buffer, the GO/Au-MIP SPR sensor exhibited linearity in the concentration ranges of 0.1-2 ppm (R-2 = 0.9721) and 5-100 ppm (R-2 = 0.9740). The detection limit of the prepared sensor was calculated as 0.0082 ppm. In the study, the imprinting process efficiency was also evaluated by calculating the imprinting factor value (I.F=13.84). In the selectivity studies, the GO/Au-MIP SPR sensor was determined to be 9.23 times more selective against CRP protein than bovine serum albumin and 29.53 times more selective than hemoglobin. When the repeatability of the GO/Au-MIP SPR sensor was examined, it was determined that the GO/Au-MIP SPR sensor was able to detect CRP without any deterioration in performance in five consecutive reuses (RSD<1.5). Finally, CRP detection studies from the serum and urine solutions, which were selected as real samples, were carried out by the GO/Au-MIP SPR sensor to evaluate the matrix effect. CRP spiked serum sample was analyzed by the other standard method to validate the analytical results using CRP analyser.Öğe Poly(vinyl alcohol)/polyethyleneimine (PVA/PEI) blended monolithic cryogel columns for the depletion of haemoglobin from human blood(Taylor & Francis Inc, 2016) Gokturk, Ilgim; Derazshamshir, Ali; Yilmaz, Fatma; Denizli, AdilWe have synthesized PVA/PEI monolithic cryogel columns chelated with Cu2+ ions as a model adsorbent, which is capable of binding haemoglobin (Hb) from human blood. The goal of this study is to perform the depletion of Hb via a single and easy process to be useful in proteomic studies. PVA/PEI-Cu2+ cryogel columns were subjected to adsorption studies of Hb from both aqueous solution and human plasma to evaluate the extent of interaction between cryogel columns and Hb. The effects of experimental parameters, such as pH, Hb equilibrium concentration, adsorption time, temperature, and ionic strength, on Hb adsorption capacity were investigated.Öğe Protein depletion with bacterial cellulose nanofibers(Elsevier Science Bv, 2018) Gokturk, Ilgim; Tamahkar, Emel; Yilmaz, 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 center dot Cu(II)center dot 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.Öğe Recent advances and applications in drug analysis by nano-scale separation techniques(Elsevier, 2024) Aydogan, Cemil; Cakan, Busra Beltekin; Alharthi, Sarah; Ali, Ashraf; Gokturk, Ilgim; Yilmaz, Fatma; Denizli, AdilNano-scale separation techniques (NSTs) offer significant advantages in relation to drug analysis in a wide range of samples. NSTs, including low flow rate LC systems or capillary or chip based electrophoresis/electrochromatography systems, have become the primary tool for advanced drug analysis, and indispensable technology for sensitive and selective drug analysis. In recent decades, significant advances have been achieved using NSTs for drug analysis. In this review, sample preparation strategies, new advances and applications in NSTs and the contribution toward forensic science applications were reported. In addition, some recent and selected applications with or without mass spectrometry (e.g., low resolution/high resolution -MS) are summarized.Öğe Removal of iron by chelation with molecularly imprinted supermacroporous cryogel(Taylor & Francis Ltd, 2016) Cimen, Duygu; Gokturk, Ilgim; Yilmaz, FatmaIron chelation therapy can be used for the selective removal of Fe3+ ions from spiked human plasma by ion imprinting. N-Methacryloyl-(L)-glutamic acid (MAGA) was chosen as the chelating monomer. In the first step, MAGA was complexed with the Fe3+ ions to prepare the precomplex, and then the ion-imprinted poly(hydroxyethyl methacrylate-N-methacryloyl-(L)-glutamic acid) [PHEMAGA-Fe3+] cryogel column was prepared by cryo-polymerization under a semi-frozen temperature of -12 degrees C for 24 h. Subsequently, the template, of Fe3+ ions was removed from the matrix by using 0.1 M EDTA solution. The values for the specific surface area of the imprinted PHEMAGA-Fe3+ and non-imprinted PHEMAGA cryogel were 45.74 and 7.52 m(2)/g respectively, with a pore size in the range of 50-200 mm in diameter. The maximum Fe3+ adsorption capacity was 19.8 mmol Fe3+/g cryogel from aqueous solutions and 12.28 mmol Fe3+/g cryogel from spiked human plasma. The relative selectivity coefficients of ion-imprinted cryogel for Fe3+/Ni2+ and Fe3+/Cd2+ were 1.6 and 4.2-fold greater than the non-imprinted matrix, respectively. It means that the PHEMAGA-Fe3+ cryogel possesses high selectivity to Fe3+ ions, and could be used many times without significantly decreasing the adsorption capacity.
