Yazar "Babur, Esra" seçeneğine göre listele

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    Fabrication of Plasmonic Nanorod-Embedded Dipeptide Microspheres via the Freeze-Quenching Method for Near-Infrared Laser-Triggered Drug-Delivery Applications
    (Amer Chemical Soc, 2016) Erdogan, Hakan; Yilmaz, Mehmet; Babur, Esra; Duman, Memed; Aydin, Halil M.; Demirel, Gokhan
    Control of drug release by an external stimulus may provide remote controllability, low toxicity, and reduced side effects. In this context, varying physical external stimuli, including magnetic and electric fields, ultrasound, light, and pharmacological stimuli, have been employed to control the release rate of drug molecules in a diseased region. However, the design and development of alternative on-demand drug-delivery systems that permit control of the dosage of drug released via an external stimulus are still required. Here, we developed near-infrared laser-activatable microspheres based on Fmoc-diphenylalanine (Phe-Phe) dipeptides and plasmonic gold nanorods (AuNRs) via a simple freeze-quenching approach. These plasmonic nanoparticle-embedded microspheres were then employed as a smart drug-delivery platform for native, continuous, and pulsatile doxorubicin (DOX) release. Remarkable sustained, burst, and on-demand DOX release from the fabricated microspheres were achieved by manipulating the laser exposure time. Our results demonstrate that AuNR-embedded dipeptide microspheres have great potential for controlled drug delivery systems.
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    Nanostructured organic semiconductor films for molecular detection with surface-enhanced Raman spectroscopy
    (Nature Publishing Group, 2017) Yilmaz, Mehmet; Babur, Esra; Ozdemir, Mehmet; Gieseking, Rebecca L.; Dede, Yavuz; Tamer, Ugur; Schatz, George C.
    pi-Conjugated organic semiconductors have been explored in several optoelectronic devices, yet their use in molecular detection as surface-enhanced Raman spectroscopy (SERS)-active platforms is unknown. Herein, we demonstrate that SERS-active, superhydrophobic and ivy-like nanostructured films of a molecular semiconductor, alpha,omega-diperfluorohexylquaterthiophene (DFH-4T), can be easily fabricated by vapour deposition. DFH-4T films without any additional plasmonic layer exhibit unprecedented Raman signal enhancements up to 3.4 x 10(3) for the probe molecule methylene blue. The combination of quantum mechanical computations, comparative experiments with a fluorocarbon-free alpha,omega-dihexylquaterthiophene (DH-4T), and thin-film microstructural analysis demonstrates the fundamental roles of the pi-conjugated core fluorocarbon substitution and the unique DFH-4T film morphology governing the SERS response. Furthermore, Raman signal enhancements up to similar to 10(10) and sub-zeptomole (< 10(-21) mole) analyte detection were accomplished by coating the DFH-4T films with a thin gold layer. Our results offer important guidance for the molecular design of SERS-active organic semiconductors and easily fabricable SERS platforms for ultrasensitive trace analysis.
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    Öğe
    Understanding the effect of polydopamine coating on catalytic reduction reactions
    (Elsevier Science Bv, 2017) Bakirci, Gizem; Yilmaz, Mehmet; Babur, Esra; Ozden, Dilek; Demirel, Gokhan
    The polydopamine (PDOP) layer with varying thicknesses has been deposited on the vertical aligned silicon nanowire (SiNW) arrays by manipulating the PDOP deposition time. It is interestingly found that catalysis ability of PDOP layer does not only depend on its thickness but also the morphology of the support material. In addition to these, by growing gold nanoparticles on PDOP coated SiNWs, catalytic reduction reactions were investigated in the presence of laser illumination having different wavelengths. We observed that, in the presence of laser illumination with a proper wavelength, catalytic conversion is about 12-fold faster than that of the catalytic process which was carried out in the absence of laser illumination. (C) 2016 Elsevier B.V. All rights reserved.