38 research outputs found

    Epidermal Growth Factor Receptor Imaging of A431 Cancer Cells Using Gold Nanorods

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    In this study, we report the synthetic processing of gold nanorods and a method for the molecular imaging of epidermal growth factor receptors (EGFRs) on A431 cancer cells using synthesized gold nanorods and confocal laser scanning microscopy. Through this study, we confirm the potential of this imaging method instead of using fluorophores and quantum dots

    Sensitivity maximized near-field scanning optical microscope with dithering sample stage

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    We developed a new scheme for a higher sensitivity near-field scanning optical microscope (NSOM) by using a dithering sample stage rather than a dithering probe for the constant gap control between probe and sample. In a conventional NSOM, which use tip dithering feedback mechanism, the Q factor drastically decreases from 7783 to 1000 (13%) or even to 100 (1%) because harmonic oscillating characteristic is deteriorated owing to the large change of stiffness and mass of one prong of tuning fork when a probe is attached to it. In our proposed scheme, on the other hand, we use sample dithering feedback mechanism, where the probe is not attached to the tuning fork and the sample is loaded directly onto the surface of dithering tuning fork. Thus, the Q factor does not decrease significantly, from only 7783 to 7480 (96%), because the loaded sample hardly changes the stiffness and mass of tuning fork. Accordingly, gap control between the immobile fiber probe and the dithering sample is performed precisely by detecting the shear force with high sensitivity. Consequently, the extremely high Q factor enables clear observation of graphene sheets with sub-nanometer vertical resolution, which is not possible with a conventional NSOM setup

    Ultrafine PMMA(QDs)/PVDF core-shell fibers for nanophotonic applications

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    Ultrafine fibers of poly(methyl methacrylate) (PMMA)/poly(vinylidene fluoride) (PVDF) with unique core-shell structure were fabricated via facile electrospinning method, and were adopted as waveguide materials. PMMA, into which CdSe/ZnS quantum dots (QDs) were incorporated for efficient mode excitation, was employed as the core material, and PVDF was used as the cladding material for PMMA. These core-shell structured PMMA(QDs)/PVDF ultrafine fibers were electrospun in a one-step process by using two concentric syringes. The morphology of the PMMA(QDs)/PVDF ultrafine fibers was examined by field emission-scanning electron microscopy and transmission electron microscopy. The fluorescence of QDs dispersed in the PMMA/PVDF ultrafine fibers was measured via confocal laser scanning microscopy. The characterization of the light propagation by NSOM indicated that the electrospun PMMA/PVDF fibers containing CdSe/ZnS QDs functioned as an effective optical waveguide

    A new method of Q factor optimization by introducing two nodal wedges in a tuning-fork/fiber probe distance sensor

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    We report on a new method of achieving and optimizing a high Q factor in a near-field scanning optical microscope (NSOM) by introducing two nodal wedges to a tuning-fork/fiber probe distance sensor and by selecting a vibrational mode of the dithering sensor. The effect of the nodal wedges on the dynamical properties of the sensor is theoretically analyzed and experimentally confirmed. The optimization achieved by the proposed method is understood from the vibration isolation and the subsequent formation of a local vibration cavity. The optimal condition is found to be less susceptible to the variation of the fiber tip length. This method allows effective NSOM measurement of samples placed even in aqueous solution

    Observation of a CdSe/ZnS Quantum dot-incorporated PMMA Nanofiber with NSOM,

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    A CdSe/ZnS quantum dot-incorporated PMMA nanofiber is measured with a collection-mode NSOM having an exceptionally high Q value. Its topography, the propagtion of light, and the light emission from quantum dots are observed and analyzed. © 2010 Optical Society of America.11Nscopu

    Observation of a CdSe/ZnS Quantum dot-incorporated PMMA Nanofiber with NSOM

    No full text
    A CdSe/ZnS quantum dot-incorporated PMMA nanofiber is measured with a collection-mode NSOM having an exceptionally high Q value. Its topography, the propagtion of light, and the light emission from quantum dots are observed and analyzed. © 2010 Optical Society of America.11Nscopu
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