Yazar "Yalcinkaya, Esra E." seçeneğine göre listele

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    Amino acid intercalated montmorillonite: electrochemical biosensing applications
    (Royal Soc Chemistry, 2014) Demir, Filiz; Demir, Bilal; Yalcinkaya, Esra E.; Cevik, Serdar; Demirkol, Dilek Odaci; Anik, Ulku; Timur, Suna
    The present work is the first that includes the use of glycine (Gly), lysine (Lys) and glutamic acid (Glu) modified clay mineral matrices in the biosensors. For this purpose, initially, Gly, Lys and Glu were intercalated with montmorillonite (Mt), thus, various modified Mts were obtained. These modified materials were then characterized via X-ray diffraction, Fourier transform infrared spectroscopy, zeta potential and thermal gravimetric analysis (TGA/DTG) and scanning electron microscopy (SEM). In order to investigate the applicability of amino acid modified clay minerals in biosensor areas, glucose oxidase (GOx) was selected as the model enzyme and a GOx based biosensor was prepared. After immobilizing the enzyme with amino acid modified Mt onto a glassy carbon electrode, working conditions like pH and modifier type were optimized. Among the modified Mts, Gly-Mt was the optimum clay mineral type and pH 4.0 was the optimum pH value. Then analytical characteristics were examined under optimum experimental conditions. The linear range of optimum sensor design was 0.1-1.0 mM within the kinetic parameters of an immobilized enzyme K-m(app) m = 0.7 mM, I-max = 107.8 nA. Finally, the developed biosensor was applied to real samples where the results were compared with a spectrophotometric reference method.
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    Folic acid-modified clay: targeted surface design for cell culture applications
    (Royal Soc Chemistry, 2013) Bongartz, Rebecca; Ag, Didem; Seleci, Muharrem; Walter, Johanna-G.; Yalcinkaya, Esra E.; Demirkol, Dilek Odaci; Stahl, Frank; Timur, Suna; Scheper, Thomas
    Here we report the preparation, characterization and application of folic acid modified Montmorillonite clay (FA-Mont) as a cell culture material. Clays exhibit unique properties such as good mechanical and chemical stabilities, high surface area, low toxicity and easy combination with functional organic groups. FA was used as a modifier to facilitate adhesion of folate positive cells on the clay surface. FA-Mont was characterized using FT-IR, XRD, zeta potential measurements as well as thermogravimetric analyses. Finally, the usage potential of FA-Mont as a receptor mediated cell adhesion material was successfully proved by using folate receptor (FR) rich HeLa and FR poor A-549 cells. The cell adhesion studies were monitored and imaged by fluorescence and scanning electron microscopy techniques.
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    Folic acid-modified clay: targeted surface design for cell culture applications
    (Royal Soc Chemistry, 2013) Bongartz, Rebecca; Ag, Didem; Seleci, Muharrem; Walter, Johanna-G.; Yalcinkaya, Esra E.; Demirkol, Dilek Odaci; Stahl, Frank; Timur, Suna; Scheper, Thomas
    Here we report the preparation, characterization and application of folic acid modified Montmorillonite clay (FA-Mont) as a cell culture material. Clays exhibit unique properties such as good mechanical and chemical stabilities, high surface area, low toxicity and easy combination with functional organic groups. FA was used as a modifier to facilitate adhesion of folate positive cells on the clay surface. FA-Mont was characterized using FT-IR, XRD, zeta potential measurements as well as thermogravimetric analyses. Finally, the usage potential of FA-Mont as a receptor mediated cell adhesion material was successfully proved by using folate receptor (FR) rich HeLa and FR poor A-549 cells. The cell adhesion studies were monitored and imaged by fluorescence and scanning electron microscopy techniques.