MF研究者総覧

研究者データベース

詳細
三浦　篤志(ミウラ　アツシ)
理学研究院　化学部門　無機・分析化学分野
准教授
researchmap個人ページ
Last Updated :2024/05/09

基本情報

所属

  • 理学研究院　化学部門　無機・分析化学分野

職名

  • 准教授

学位

  • 博士(理学)（関西学院大学）

ホームページURL

J-Global ID

研究キーワード

  • ナノバイオテクノロジー   一分子抽出・分析   エアロゾル   タンパク質結晶   顕微分光   レーザートラッピング   

研究分野

  • ナノテク・材料 / 分析化学
  • ナノテク・材料 / 基礎物理化学
  • ナノテク・材料 / ナノマイクロシステム
  • ナノテク・材料 / ナノバイオサイエンス

担当教育組織

職歴

  • 2014年05月 - 現在 北海道大学 大学院理学研究院 化学部門 准教授
  • 2009年08月 - 2014年04月 國立台湾交通大学 應用化學系 助理教授
  • 2008年04月 - 2011年09月 奈良先端科学技術大学院大学 客員研究員（兼任）
  • 2008年04月 - 2009年07月 國立台湾交通大学 應用化學系 副研究員
  • 2004年02月 - 2008年03月 奈良先端科学技術大学院大学 物質創成科学研究科 博士研究員
  • 2001年05月 - 2004年01月 ルーベンカトリック大学 化学科 博士研究員

学歴

  • 1997年 - 2001年   関西学院大学   理学研究科
  • 1995年 - 1997年   北海道大学   地球環境科学研究科
  • 1991年 - 1995年   北海道大学   理学部   化学科

所属学協会

  • 日本化学会   応用物理学会   光化学協会   日本分析化学会   高分子学会   

研究活動情報

論文

  • Takashi Matsumura, Atsushi Miura, Takio Hikono, Yukiharu Uraoka
    AIP ADVANCES 12 5 2022年05月 [査読有り]
     
    To fabricate metal nanocrystal (NC) memories based on iron ferritin proteins, we propose a method for embedding ferritin cores in SiO2 and performing a reduction process by rapid thermal annealing (RTA) in a hydrogen atmosphere. An iron oxide core biochemically synthesized by ferritin was used to fabricate a high-density memory node array of 7.7 x 10(11) dots/cm(2). Reduction intermediates and metallic iron NCs were obtained in a short time by using a hydrogen atmosphere RTA with the iron oxide core embedded in SiO2. Metal-oxide-semiconductor memory structures were fabricated, capacitance-voltage (C-V) measurements were performed, and hysteresis (memory window) suggesting charging and discharging of NCs was observed. Furthermore, the memory window and the charge injection threshold tended to vary depending on the reduction temperature. Since these values are proportional to the magnitude of the dot work function (or electron affinity), it is assumed that the formation of reduced intermediates NCs with varying work functions depending on the treatment temperature affects the electrical properties. The results suggest that the work function of the charge retention node can be controlled by reducing the metal oxide, enabling a new approach to memory design that actively employs the reduction process. (c) 2022 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license(http://creativecommons.org/licenses/by/4.0/).
  • Ryosuke Nakajima, Atsushi Miura, Sayaka Abe, Noboru Kitamura
    Analytical Chemistry 93 12 5218 - 5224 2021年03月16日 [査読有り][通常論文]
     
    Optical trapping-polarized Raman microspectroscopy of single ethanol (EtOH) microdroplets with a diameter (d) of 6.1-16.5 mu m levitated in an EtOH vapor-saturated air/N-2 gas atmosphere has been explored to elucidate the vibrational and rotational motions of EtOH in the droplets at 22.0 degrees C. The Raman spectral bandwidth of the C-C stretching vibrational mode observed for an aerosol EtOH microdroplet was narrower than that of bulk EtOH, suggesting that the vibrational/rotational motions of EtOH in the aerosol system were restricted compared to those in the bulk system. In practice, polarized Raman microspectroscopy demonstrated that the rotational relaxation time (tau(rot)) of EtOH in an aerosol microdroplet with d = 16.5 mu m was slower (2.33 ps) than that in a bulk EtOH (1.65 ps), while the vibrational relaxation times (tau(vib)) in the aerosol and bulk EtOH systems were almost comparable with one another: 0.86-0.98 ps. Furthermore, although the tau(vib) value of an aerosol EtOH microdroplet was almost unchanged irrespective of d as described above, the tau(rot) value increased from 2.33 to 3.57 ps with a decrease in d from 16.5 to 6.1 mu m, which corresponded to the increase in EtOH viscosity (eta) from 1.33 to 2.04 cP with the decrease in d. The droplet size dependences of tau(rot) and. in an aerosol EtOH microdroplet were discussed in terms of the gas/droplet interfacial molecular arrangements of EtOH and Laplace pressure experienced by a spherical EtOH microdroplet in the gas phase.
  • Atsushi Miura, Riku Nohara, Azumi Nojima, Noboru Kitamura
    Analytical Chemistry 93 6 3202 - 3208 2021年02月04日 [査読有り][通常論文]
     
    We report photothermal phase separation of aqueous poly(N-isopropylacrylamide) (PNIPAM)/1-butanol (BuOH) solutions by focused 1064 nm laser irradiation and subsequent single microparticle formation in the solution. The single microparticle [diameter = similar to 10 mu m and volume = similar to picoliter (pL)] produced by laser irradiation was optically trapped by the incident 1064 nm laser beam, and this enabled us in situ Raman/fluorescence microspectroscopies of the particle. Raman spectroscopy demonstrated that the particle produced by laser irradiation was composed of PNIPAM and BuOH. In the presence of rhodamine B (RhB) in the solution, RhB was distributed from the water phase to the PNIPAM/BuOH microparticle produced by laser irradiation, as confirmed by fluorescence microspectroscopy. Laser-induced distribution/extraction of RhB to a single PNIPAM/BuOH microparticle was shown to be possible at the RhB concentration as low as 10(-14) mol/dm(3), where the RhB fluorescence intensity from the particle showed a step-by-step increase by every similar to 3 min laser irradiation. This is the first demonstration of laser-induced simultaneous extraction and detection of single RhB molecules in solution.
  • Atsushi Miura, Ryosuke Nakajima, Sayaka Abe, Noboru Kitamura
    The Journal of Physical Chemistry A 124 43 9035 - 9043 2020年10月15日 [査読有り][通常論文]
     
    We report temperature (T = +22.5 similar to -57.0 degrees C)-controlled optical trapping of single dimethylsulfoxide (DMSO) droplets with the diameter (d) of 7-15 mu m in air. Optically levitated DMSO microdroplets containing 0.1 mol/dm(3) (=M) potassium iodide (KI) as an additive for reducing the vapor pressure of DMSO in air have been suggested to take supercooled liquid states even below the freezing temperature (f(p)) of the bulk DMSO liquid (f(p) = +18.4 degrees C in the presence of 0.1 M KI) as seen in bright-field microscopic observations of the droplet. Clear evidence for supercooling of an aerosol DMSO microdroplet below f(p) has been obtained by in situ optical trapping-polarized Raman microspectroscopy of the droplet down to -14.9 degrees C. Analysis of the polarized Raman spectral data of an aerosol DMSO droplet (d = similar to 10 mu m) has demonstrated that the droplet at +22.5, +0.2, or -14.9 degrees C is characterized by the rotational relaxation time (tau(rot)) of a DMSO molecule in the droplet being 1.95, 2.58, or 3.90 ps, respectively. On the basis of the tau(rot) values and the Stokes-Einstein equation (tau(rot) = 8 pi a(3) eta/k(B)T where a, eta, k(B) are the radius (1.883 angstrom) of a DMSO molecule, the viscosity in DMSO, and the Boltzmann constant, respectively), the eta values in the DMSO microdroplet in air at +22.5, +0.2, or -14.9 degrees C have been estimated to be 2.39, 2.94, or 4.20 cP, respectively, while that of bulk DMSO liquid at +20.5 degrees C is 1.98 cP. We also report the T-dependence (+22.5 > T > -14.9 degrees C) of the viscosity in a single aerosol DMSO microdroplet (d = similar to 10 mu m) and the effects of aerosolization in air on the viscosity in DMSO.
  • Mari Kimura, Masaki Yoshida, Sho Fujii, Atsushi Miura, Kosei Ueno, Yasuhiro Shigeta, Atsushi Kobayashi, Masako Kato
    Chemical Communications 56 85 12989 - 12992 2020年09月 [査読有り][通常論文]
     

    A Pt(ii)-based luminescent porous molecular crystal was selectively crystallised at the liquid–liquid interface, allowing control of porosity and luminescence.

  • Kizuku Shibata, Sho Fujii, Quan Sun, Atsushi Miura, Kosei Ueno
    The Journal of Chemical Physics 152 10 104706 - 104706 2020年03月09日 [査読有り][通常論文]
     
    Metallic nanogap dimers are extremely useful for enhancing surface-enhanced Raman scattering and various nonlinear optical effects employing near-field enhancement effects induced by the localized surface plasmon resonance. However, the metallic nanogap dimers exhibit an intense light scattering due to the strong dipole-dipole interaction between two metallic nanostructures and, therefore, are not necessarily a structural design that exhibits the highest near-field enhancement due to the radiation loss. Here, we propose further enhancement of the near-field on metallic nanogap dimers using quasi-dark plasmon modes. By coupling with gold (Au) nanorods having the same plasmon resonant wavelength, but completely different sizes, a quasi-dark plasmon mode, which reduces the radiation loss slightly, is induced, resulting in the elongation of the plasmon dephasing time. As a result, the signal of surface-enhanced Raman scattering of crystal violet molecules adsorbed on the Au nanogap dimer is enhanced up to about three times as compared to that measured using the Au nanogap dimer without the Au nanorods. Scattering spectrum measurements as well as electromagnetic simulations were performed to clarify the mechanism for further enhancement of the near-field. The proposed coupled plasmonic system is expected to be advantageous, especially in enhancing nonlinear optical effects using plasmonic enhancement effects.
  • Jun Harada, Naho Yoneyama, Seiya Yokokura, Yukihiro Takahashi, Atsushi Miura, Noboru Kitamura, Tamotsu Inabe
    Journal of the American Chemical Society 140 1 346 - 354 2018年01月10日 [査読有り][通常論文]
     
    Plastic crystals represent a unique compound class that is often encountered in molecules with globular structures. The highly symmetric cubic crystal structure of plastic crystals endows these materials with multiaxial ferroelectricity that allows a three-dimensional realignment of the polarization axes of the crystals, which cannot be achieved using conventional molecular ferroelectric crystals with low crystal symmetry. In this work, we focused our attention on malleability as another characteristic feature of plastic crystals. We have synthesized the new plastic/ferroelectric ionic crystals tetramethylammonium tetrachloroferrate(III) and tetramethylammonium bromotrichloroferrate(III), and discovered that free-standing translucent films can be easily prepared by pressing powdered samples of these compounds. The thus obtained polycrystalline films exhibit ferroelectric polarization switching and a relatively large piezoelectric response at room temperature. The ready availability of functional films demonstrates the practical utility of such plastic/ferroelectric crystals, and considering the vast variety of possible constituent cations and anions, a wide range of applications should be expected for these unique and attractive functional materials.
  • Kai-Jen Chen, Ya-Ching Tsai, Yuji Suzaki, Kohtaro Osakada, Atsushi Miura, Masaki Horie
    Nature Communications 7 1 13321  2016年12月03日 [査読有り][通常論文]
     
    Crystalline phase transitions caused by external stimuli have been used to detect physical changes in the solid-state properties. This study presents the mechanical switching of crystals of ferrocene-containing rotaxane controlled by focused laser light. The expansion and contraction of the crystals can be driven by turning on and off laser light at 445 nm. The irradiation-induced expansion of the crystal involves elongation along the a, b and c axes at 30 degrees C, whereas heating of the crystal at 105 degrees C causes the shortening of c axis. The expansions reversibly occur and have the advantage of a rapid relaxation (reverse) process. Single-crystal X-ray crystallography reveals the detailed structural changes of the molecules, corresponding to a change in the size of the crystals on laser irradiation. This molecular crystal behaviour induced by laser irradiation, is demonstrated for the remote control of objects, namely, microparticle transport and microswitching in an electric circuit.
  • Jing-Ru Tu, Atsushi Miura, Ken-ichi Yuyama, Hiroshi Masuhara, Teruki Sugiyama
    CRYSTAL GROWTH & DESIGN 14 6 3153 - 3153 2014年06月
  • Tu, Jing-Ru, Miura, Atsushi, Yuyama, Ken-ichi, Masuhara, Hiroshi, Sugiyama, Teruki
    Crystal Growth & Design 14 1 15 - 22 2014年 [査読有り][通常論文]
     
    We demonstrate the growth of a tetragonal crystal of hen egg-white lysozyme (HEWL) in D2O buffer solution controlled by laser trapping with a focused continuous-wave (CW) near-infrared (NIR) laser beam. The focal spot was located at 10 mu m away from the edge of the target crystal that was generated spontaneously, and the crystal growth was observed although the focal spot size was much smaller than the distance. The growth rate of (101) and {110} faces of the tetragonal crystal was examined with various laser powers and polarizations. The rate observed under the irradiation was much different from those in spontaneous growth, namely, the growth rate of the {1 10} face showed a large decrease or increase depending on the irradiation time. The dynamics and mechanism of this unusual crystal growth behavior is discussed from the viewpoint of a large stable domain formation of the HEWL liquidlike clusters through liquid nucleation and growth and by considering the anisotropy of the cluster domain.
  • Ping-Yu Hee, Takayuki Uwada, Kazunori Okano, Atsushi Miura, Hiroshi Masuhara
    OPTICAL TRAPPING AND OPTICAL MICROMANIPULATION X 8810 88102T-1  2013年 [査読有り][通常論文]
     
    Rayleigh scattering correlation microspectroscopy is developed and applied to study diffusion dynamics of some nanospheres in water. It was clearly found that the diffusion constant of gold nanoparticles decreased with increasing excitation laser power at the excitation wavelength of higher absorption cross section. This behavior was explained in terms of a coupling between laser trapping by the scattering excitation laser itself and laser heating of the particle. In the case of non-absorbing nanospheres such as silica and polystyrene, the excitation power dependence can be ascribed only to the laser trapping. Experimental setup is introduced, theoretical formulation is described, and future development of this measurement is considered.
  • Miura, Atsushi, Huang, Yan-Hua, Masuhara, Hiroshi
    Applied Physics B-Lasers and Optics 112 4 473 - 477 2013年 [査読有り][通常論文]
     
    We investigated laser trapping crystallization of glycine by using femtosecond (fs) laser as a trapping light source. Impulsively exerted fs laser pulses crystallized glycine more effectively than that induced by continuous wave (CW) laser trapping. Highly efficient crystallization and crystal growth behavior indicates fs laser irradiation increased the concentration not only at the focal spot, but also around the laser focus. Furthermore, we found that irradiation of fs pulses to CW laser-induced locally high supersaturation region enables immediate crystallization. Spatiotemporally controlled triggering of a single crystal formation with sub-second time resolution has achieved by integrating fs and CW laser trapping techniques.
  • Tojo, Y., Miura, A., Ishikawa, Y., Yamashita, I., Uraoka, Y.
    Thin Solid Films 540 266 - 270 2013年 [査読有り][通常論文]
     
    Crystallization employing an N-(2-aminoethyl)-3-aminopropyltrimethoxysilane self-assembled monolayer (AEAPS-SAM) to coordinate Ni metal catalyst was found to produce large grain poly-Si. A small concentration of Ni could be deposited controllably onto an AEAPS-SAM covered with Si by immersing it in Ni solution for 1-60 min. Larger grains and a lower Ni concentration in the poly-Si could be obtained by shorter immersion. Immersion for 1 min produced grains, as large as 47 mu m and a Ni concentration as low as 7.4 x 10(18) atoms/cm(3). A poly-Si thin-film transistor fabricated with AEAPS-SAMpoly-Si of 1 min immersion had a field-effect mobility of 98 cm(2)/(V s), which is one order of magnitude higher than that of a thin-film transistor fabricated without the AEAPS-SAM treatment. (C) 2013 Elsevier B. V. All rights reserved.
  • Sano, Ken-Ichi, Miura, Atsushi, Yoshii, Shigeo, Okuda, Mitsuhiro, Fukuta, Megumi, Uraoka, Yukiharu, Fuyuki, Takashi, Yamashita, Ichiro, Shiba, Kiyotaka
    Langmuir 29 40 12483 - 12489 2013年 [査読有り][通常論文]
     
    The first six peptides of multifunctional titanium binding peptide-1 bestowed recombinant L-ferritin, minT1-LF, was genetically engineered and used to fabricate multilayered nanoparticle architecture. The multifunctionality of minT1-LF enables specific binding of nanoparticle-accommodated minT1-LF to the silicon substrate surface and wet biochemical fabrication of gate oxide layer by its biomineralization activity. Three-dimensional (3D) nanoparticle architecture with multilayered structure was fabricated by the biological layer-by-layer method and embedded in a metal oxide-semiconductor device structure as a charge storage node of a flash memory device. The 3D-integrated multilayered nanoparticle architecture successfully worked as a charge storage node in flash memory devices that exhibited improved charge storage capacity compared with that of a conventional monolayer structure device.
  • Inoue, H., Katayama, K., Iwai, K., Miura, A., Masuhara, H.
    Physical Chemistry Chemical Physics 14 16 5620 - 5627 2012年 [査読有り][通常論文]
     
    We observed phase transition and phase relaxation processes of a poly(N-isopropylacrylamide) (PNIPAM) aqueous solution using the heterodyne transient grating (HD-TG) method combined with the laser temperature jump technique. The sample temperature was instantaneously raised by about 1.0 K after irradiation of a pump pulse to crystal violet (CV) molecules for heating, and the phase transition was induced for the sample with an initial temperature just below the lower critical solution temperature (LCST); the following phase relaxation dynamics was observed. Turbidity relaxation was observed in both the turbidity and HD-TG responses, while another relaxation process was observed only in the HD-TG response, namely via the refractive index change. It is suggested that this response is due to formation of globule molecules or their assemblies since they would have nothing to do with turbidity change but would affect the refractive index, which is dependent on the molar volume of a chemical species. Furthermore, the grating spacing dependence of the HD-TG responses suggests that the response was caused by the counter propagating diffusion of the coil molecules as a reactant species and the globule molecules as a product species and the lifetime of the globule molecules ranged from 1.5 to 5 seconds. Thus, we conclude that the turbidity reflects the dynamics of aggregate conditions, not molecular conditions. The coil and globule sizes were estimated from the obtained diffusion coefficient. The sizes of the coil molecules did not change at the initial temperatures below the LCST but increased sharply as it approaches LCST. We propose that the coil-state molecules associate due to hydrophobic interaction when the initial temperature was higher than LCST minus 0.5 K and that the globule-state molecules generated from the coil-state molecules showed a similar trend in temperature. The phase transition was also induced by heating under a microscope, and the relaxation process was followed using the fluorescence peak shift of a fluorescent molecule-labeled PNIPAM. The result also supports the existence of a globule molecule or its assembly remains for several seconds in the phase relaxation.
  • Uwada, T., Fujii, S., Sugiyama, T., Usman, A., Miura, A., Masuhara, H., Kanaizuka, K., Haga, M.
    Acs Applied Materials & Interfaces 4 3 1158 - 1163 2012年 [査読有り][通常論文]
     
    We have developed a novel laser-induced crystallization method utilizing local heat-induced bubble/water interface. Continuous laser beam of 1064 nm is focused on a gold nanoparticles thin film surface covered with glycine supersaturated aqueous solution. Light absorption of the film due to localized plasmon resonance caused local heating at the focal position and produced a single thermal vapor microbubble, which generated thermal gradient followed by convection flow around the bubble and eventually induced glycine crystallization and growth. The crystallization mechanism is discussed by considering gathering and accumulating molecules around the bubble/water interface assisted by convection flow and temperature jump.
  • Masuhara, H., Sugiyama, T., Rungsimanon, T., Yuyama, K., Miura, A., Tu, J. R.
    Pure and Applied Chemistry 83 4 869 - 883 2011年 [査読有り][通常論文]
     
    Laser trapping of molecules and proteins in solution at room temperature is made possible by irradiating 1064-nm continuous-wave (CW) laser with power around 1 W. Although conventional small molecules are not trapped at the focal point, molecules that can form clusters upon assembling and proteins whose size is close to 10 nm are gathered, giving unique assembly structure. Glycine in H2O shows crystallization, urea in D2O gives a millimeter-sized giant droplet, and cobalt oxide-filled ferritin protein confirms assembly followed by precipitation. Solute concentration, solvent, and laser power are important factors for determining trapping and assembling phenomena, and the laser focal position is very critical. These unique behaviors are realized by setting the irradiation at the air/solution surface, inside the solution, and at the glass/solution interface. Laser trapping-induced crystallization, liquid/liquid phase separation, and precipitation are compared with the previous results and considered. After summarizing the results, we describe our future perspective and plans.
  • Tojo, Yosuke, Miura, Atsushi, Yamashita, Ichiro, Uraoka, Yukiharu
    Japanese Journal of Applied Physics 50 4 04DL12 - 04DL12-4 2011年 [査読有り][通常論文]
     
    We have proposed a new crystallization method for silicon thin films utilizing a cage-shaped protein (ferritin), called "bio-nano crystallization", which combines semiconductor processing technology and biotechnology. We utilized nickel nanoparticle-accommodated ferritins as metal catalysts, and succeeded in performing the crystallization. When the ferritin was adsorbed randomly onto the film, crystal nuclei were formed at random places, thus grain position was randomly distributed. In this study, we performed the positional controlled deposition of ferritin by electrostatic interaction for location control of crystal grains. Positively charged areas were formed on negatively charged SiO2 using 3-amino-propyltriethoxysilane (APTES) as the electrostatic pattern. As a result, we could optimize Ni ferritin concentration to make a large adsorption difference between APTES and amorphous silicon. Therefore, nickel nanoparticles adsorption areas were controlled using APTES patterns. Furthermore, the location control of crystallized areas was achieved by optimizing the concentration of Ni ferritin and the APTES pattern. (C) 2011 The Japan Society of Applied Physics
  • Masuhara, H., Sugiyama, T., Yuyama, K., Uwada, T., Miura, A.
    Abstracts of Papers of the American Chemical Society 242 1 - 1 2011年 [査読有り][通常論文]
  • Masanobu Naito, Kenji Iwahori, Atsushi Miura, Midori Yamane, Ichiro Yamashita
    Angewandte Chemie 122 39 7160 - 7163 2010年09月17日
  • Uwada, T., Sugiyama, T., Miura, A., Masuhara, H.
    Optical Trapping and Optical Micromanipulation Vii 7762 2010年 [査読有り][通常論文]
     
    We present direct observation of particle transfer and assembling upon laser irradiation under a microscope. We employed gold nanoparticles (60 nm) dispersed in water as optical markers and studied laser trapping and accompanying phenomenon by wide-field Rayleigh scattering microscopy. At the focal spot of the near IR laser, laser trapping of gold was observed. Simultaneously, we observed that the particle migration toward the focal spot from all the directions within several tens micrometer. We consider that thermocapillary effect due to laser heating can assist the particle migration from far away, resulting in concentration increase not only at the focal point but also near the surrounding area.
  • Naito, Masanobu, Iwahori, Kenji, Miura, Atsushi, Yamane, Midori, Yamashita, Ichiro
    Angewandte Chemie-International Edition 49 39 7006 - 7009 2010年 [査読有り][通常論文]
  • Atsushi Miura, Ryota Tanaka, Yukiharu Uraoka, Nozomu Matsukawa, Ichiro Yamashita, Takashi Fuyuki
    NANOTECHNOLOGY 20 12 9  2009年03月 [査読有り][通常論文]
     
    We investigated electronic properties of a biochemically synthesized cobalt oxide bionanodot (Co-BND) by means of scanning tunneling microscopy/spectroscopy (STM/STS) and Kelvin-probe force microscopy (KFM). Experimentally obtained I-V characteristics and numerically obtained dI/dV and (dI/dV)/(I/V) from I-V revealed the band gap energy, band position of valence and conduction band of the Co-BND. KFM observation shows that bias polarity dependent surface potential change after charge injection. The observed surface potential change indicates that the Co-BND has a charge storage capability. We demonstrated the application of Co-BNDs for electronic devices by choosing flash memory as the example device. The fabricated Co-BND embedded MOS memory showed clear memory operation due to the charge confinement in the embedded Co-BNDs.
  • Miura, A., Tanaka, R., Uraoka, Y., Matsukawa, N., Yamashita, I., Fuyuki, T.
    Nanotechnology 20 12 9 - 9 2009年 [査読有り][通常論文]
     
    We investigated electronic properties of a biochemically synthesized cobalt oxide bionanodot (Co-BND) by means of scanning tunneling microscopy/spectroscopy (STM/STS) and Kelvin-probe force microscopy (KFM). Experimentally obtained I-V characteristics and numerically obtained dI/dV and (dI/dV)/(I/V) from I-V revealed the band gap energy, band position of valence and conduction band of the Co-BND. KFM observation shows that bias polarity dependent surface potential change after charge injection. The observed surface potential change indicates that the Co-BND has a charge storage capability. We demonstrated the application of Co-BNDs for electronic devices by choosing flash memory as the example device. The fabricated Co-BND embedded MOS memory showed clear memory operation due to the charge confinement in the embedded Co-BNDs.
  • Tojo, Y., Miura, A., Uraoka, Y., Fuyuki, T., Yamashita, I.
    Japanese Journal of Applied Physics 48 4 5 - 5 2009年 [査読有り][通常論文]
     
    We proposed a new process technology, named the "bio-nano-process", in which semiconductor processing technology and biotechnology are conbined. We utilized a ferritin protein cobalt core as a memory node, and succeeded in performing the operation of floating gate memory. In this study, we undertook the reduction control of a cobalt core embedded in silicon oxide by thermal annealing. We also fabricated metal-oxide-semiconductor (MOS) capacitors with using the cobalt core and evaluated their electronic properties. As a result, we could elucidate the contribution of the metallic cobalt in the core by controlling of the ambient and temperature. We found that memory windows become large with increasing contribution of metallic cobalt. (C) 2009 The Japan Society of Applied Physics
  • Miura, A., Tsukamoto, R., Yoshii, S., Yamashita, I., Uraoka, Y., Fuyuki, T.
    Nanotechnology 19 25 6 - 6 2008年 [査読有り][通常論文]
     
    We demonstrated non-volatile flash memory fabrication by utilizing uniformly sized cobalt oxide (Co3O4) bionanodot (Co-BND) architecture assembled by a cage-shaped supramolecular protein template. A fabricated high-density Co-BND array was buried in a metal-oxide-semiconductor field-effect-transistor (MOSFET) structure to use as the charge storage node of a floating nanodot gate memory. We observed a clockwise hysteresis in the drain current-gate voltage characteristics of fabricated BND-embedded MOSFETs. Observed hysteresis obviously indicates a memory operation of Co-BND-embedded MOSFETs due to the charge confinement in the embedded BND and successful functioning of embedded BNDs as the charge storage nodes of the non-volatile flash memory. Fabricated Co-BND-embedded MOSFETs showed good memory properties such as wide memory windows, long charge retention and high tolerance to repeated write/erase operations. A new pathway for device fabrication by utilizing the versatile functionality of biomolecules is presented.
  • Miura, A., Uraoka, Y., Fuyuki, T., Yoshii, S., Yamashita, I.
    Journal of Applied Physics 103 7 10 - 10 2008年 [査読有り][通常論文]
     
    We have demonstrated floating nanodot gate memory (FNGM) fabrication by utilizing uniform biomineralized cobalt oxide (Co3O4) nanodots (Co-BNDs) which are biochemically synthesized in the vacant cavity of supramolecular protein, ferritin. High-density Co-BND array (>6.5x10(11) cm(-2)) formed on Si substrate with 3-nm-thick tunnel SiO2 is embedded in metal-oxide-semiconductor (MOS) stacked structure and used as the floating gate of FNGM. Fabricated Co-BND MOS capacitors and metal-oxide-semiconductor field effect transistors show the hysteresis loop due to the electron and hole confinement in the embedded Co-BND. Fabricated MOS memories show wide memory window size of 3-4 V under 10 V operation, good charge retention characteristics until 10(4) s after charge programming, and stress endurance until 10(5) write/erase operation. Observed charge injection thresholds suggest that charge injection through the direct tunneling from Si to the energy levels in the conduction and valence bands of Co3O4 and long charge retention characteristics implies prompt charge confinement to the deeper energy level of metal Co which is formed during the annealing in the device processing. (C) 2008 American Institute of Physics.
  • Atsushi Miura, Yutaka Shibata, Haik Chosrowjan, Noboru Mataga, Naoto Tamai
    JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY 188 1 140 - 140 2007年04月 [査読無し][通常論文]
  • Boens, N., Qin, W. W., Basaric, N., Hofkens, J., Ameloot, M., Pouget, J., Lefevre, J. P., Valeur, B., Gratton, E., Vandeven, M., Silva, N. D., Engelborghs, Y., Willaert, K., Sillen, A., Rumbles, G., Phillips, D., Visser, Ajwg, van Hoek, A., Lakowicz, J. R., Malak, H., Gryczynski, I., Szabo, A. G., Krajcarski, D. T., Tamai, N., Miura, A.
    Analytical Chemistry 79 5 2137 - 2149 2007年 [査読有り][通常論文]
     
    A series of fluorophores with single-exponential fluorescence decays in liquid solution at 20 degrees C were measured independently by nine laboratories using single-photon timing and multifrequency phase and modulation fluorometry instruments with lasers as excitation source. The dyes that can serve as fluorescence lifetime standards for time-domain and frequency-domain measurements are all commercially available, are photostable under the conditions of the measurements, and are soluble in solvents of spectroscopic quality (methanol, cyclohexane, water). These lifetime standards are anthracene, 9-cyanoanthracene, 9,10-diphenylanthracene, N-methylcarbazole, coumarin 153, erythrosin B, N-acetyl-L-tryptophanamide, 1,4-bis(5-phenyloxazol-2-yl)benzene, 2,5-diphenyloxazole, rhodamine B, rubrene, N-(3-sulfopropyl)acridinium, and 1,4-diphenylbenzene. At 20 degrees C, the fluorescence lifetimes vary from 89 ps to 31.2 ns, depending on fluorescent dye and solvent, which is a useful range for modern pico- and nanosecond time-domain or mega- to gigahertz frequency-domain instrumentation. The decay times are independent of the excitation and emission wavelengths. Dependent on the structure of the dye and the solvent, the excitation wavelengths used range from 284 to 575 nm, the emission from 330 to 630 nm. These lifetime standards may be used to either calibrate or test the resolution of time- and frequency-domain instrumentation or as reference compounds to eliminate the color effect in photomultiplier tubes. Statistical analyses by means of two-sample charts indicate that there is no laboratory bias in the lifetime determinations. Moreover, statistical tests show that there is an excellent correlation between the lifetimes estimated by the time-domain and frequency-domain fluorometries. Comprehensive tables compiling the results for 20 (fluorescence lifetime standard/solvent) combinations are given.
  • De Feyter, S., Miura, A., Uji-I, H., Jonkheijm, P., Schenning, Aphj, Meijer, E. W., Chen, Z., Wurthner, F., Schuurmans, N., van Esch, J., Feringa, B., De Schryver, F. C.
    Nanoscience and Technology, Pts 1 and 2 121-123 396 - 372 2007年 [査読無し][通常論文]
     
    With scanning tunneling microscopy (STM), the intramolecular conformational and intermolecular ordering aspects have been investigated of a variety of organic molecules physisorbed at the liquid-solid interface. By balancing the interplay between intramolecular and intermolecular interactions (hydrogen bonding), leading to control of the molecular conformation, foldamers were created which order into well-defined two-dimensional crystals. The nature of the hydrogen bonding groups in conjugated oligomers leads to the formation of infinite stacks and cyclic multimers, expressing the chiral nature of the molecules.
  • Yamada, K., Yoshii, S., Kumagai, S., Miura, A., Uraoka, Y., Fuyuki, T., Yamashita, I.
    Japanese Journal of Applied Physics Part 1-Regular Papers Brief Communications & Review Papers 46 11 7549 - 7553 2007年 [査読有り][通常論文]
     
    The charge injection characteristics of nanodot arrays for floating nanodot gate memories (FNGMs) were studied using a metal-oxide-semiconductor (MOS) capacitor having density-controlled arrays of homogenous nanodots in a SiO2 layer. Nanodot arrays were prepared using cage-shaped proteins, Listeria ferritin and ferritin with a nanodot core, the diameters of which are 4.5 and 7nm, respectively. Dot densities are from 3.3 x 10(9) to 1.8 X 10(12) cm(-2) for Listeria ferritin and from 3.8 x 10(9) to 7.9 x 10(11) cm(-2) for ferritin. The capacitance-voltage (C-V) characteristics of the obtained MOS capacitors were measured at 1 MHz by applying a DC bias voltage from -10 to + 10 V. The flat-band voltage shift was found to depend on both dot density and dot size, and to be numerically proportional to the sum of the upper hemisphere surface areas of nanodots. It is important to balance dot density and dot size in order to fabricate advanced FNGMs, and the appropriate design of the array is necessary.
  • Iwahori, K., Enomoto, T., Furusho, H., Miura, A., Nishio, K., Mishima, Y., Yamashita, I.
    Chemistry of Materials 19 13 3105 - 3111 2007年 [査読有り][通常論文]
     
    Cadmium sulfide (CdS) nanoparticles (NPs) were synthesized in the cavity of the recombinant Dps cage-shaped protein from Listeria innocua (rLiDps) modifying the slow chemical reaction synthesis (SCRY) and two-step synthesis protocol (TSSP). The SCRY is realized by stabilizing cadmium ions as tetraamminecadmium and employing thioacetic acid (which is added in the final stage of the TSSP). The optimized condition produced cubic CdS NPs in the rLiDps cavity with an average diameter of 4.2 nm and small size dispersion. These CdS NPs showed photoluminescence. It was also found that the pH of the reaction solution affects the elemental composition CdS NPs. At pH 4.5 and 6.5, CdxSy (x < y) NPs were obtained, and at pH 8.5, cubic CdS NPs were synthesized at pH 8.5.
  • Miura, A., Uraoka, Y., Fuyuki, T., Kumagai, S., Yoshii, S., Matsukawa, N., Yamashita, I.
    Surface Science 601 15 L81 - L85 2007年 [査読有り][通常論文]
     
    A polyelectrolyte thin film which was simply spin-coated on a substrate showed the high-density adsorption of bionanodot-accommodated ferritins through electrostatic interaction. Solution pH adjustment facilitated the control of adsorption density to a value grater than 80% of the theoretical maximum density. The formed polyelectrolyte film was very thin and vulnerable like protein, therefore, only the array with densely adsorbed bionanodot was left on the substrate after organic component removal. The floating nanodot gate type MOS capacitor fabricated with this bionanodot array showed a memory effect, and no negative influences of polymer such as carrier trapping on the capacitance-voltage characteristics was observed. (c) 2007 Elsevier B.V. All rights reserved.
  • Tomohiro Kubota, Takeshi Hashimoto, Yasushi Ishikawa, Seiji Samukawa, Atsushi Miura, Yukiharu Uraoka, Takashi Fuyuki, Masaki Takeguchi, Kensuke Nishioka, Ichiro Yamashita
    APPLIED PHYSICS LETTERS 89 23 3  2006年12月 [査読有り][通常論文]
     
    A defect-free nanometer-scale silicon disk (nanodisk) on thin SiO2 film was precisely fabricated by using Cl neutral beam etching of a 3.5-4-nm-thick polycrystalline silicon on 1.4-3-nm-thick underlying SiO2 with a 7-nm-diameter ferritin iron core mask. Kelvin force microscope observations revealed that nanodisks could maintain injected positive and negative charges. Additionally, Coulomb staircases were observed by I-V measurement of a nanodisk at a temperature of 25 K. These results indicate that the nanodisk fabricated in this research had a precise quantum effect structure and attained the single electron property. This process has great potential in the development of future quantum effect devices. (c) 2006 American Institute of Physics.
  • T Hikono, T Matsumura, A Miura, Y Uraoka, T Fuyuki, M Takeguchi, S Yoshii, Yamashita, I
    APPLIED PHYSICS LETTERS 88 2 3  2006年01月 [査読有り][通常論文]
     
    A metal-oxide-semiconductor (MOS) structure with a buried monolayer of ferritin cores in the SiO2 layer was fabricated and the electron confinement in the cores was confirmed. A monolayer of ferritin molecule was adsorbed on the thermal silicon oxide layer. After the protein of the monolayer was eliminated, the ferrihydrite cores were buried in the silicon dioxide layer. We reduced the cores to conductive iron metal nanodots by low-temperature annealing. X-ray photoelectron spectroscopy and electron-energy-loss spectroscopy measurements confirmed the reduction of the cores. The MOS capacitance with the iron nanodots showed hysteresis in the capacitance-voltage measurement, indicating the charging and discharging behavior in iron nanodots.
  • Miura, A., Hikono, T., Matsumura, T., Yano, H., Hatayama, T., Uraoka, Y., Fuyuki, T., Yoshii, S., Yamashita, I.
    Japanese Journal of Applied Physics Part 2-Letters & Express Letters 45 1-3 L1 - L3 2006年 [査読有り][通常論文]
     
    The memory effect in floating nanodot gate field-effect-transistor (FET) was investigated by fabricating biomineralized inorganic nanodot embedded metal-oxide-semiconductor (MOS) devices. Artificially biomineralized cobalt (Co) oxide cores accommodated in ferritins were utilized as a charge storage node of floating gate memory. Two dimensional array of Co oxide core accommodated ferritin were, after selective protein elimination, buried into the stacked dielectric layers of MOS capacitors and MOSFETs. Fabricated MOS capacitors and MOSFETs presented a clear hysteresis in capacitance-voltage (C-V) characteristics and drain current-oate voltage (ID-VG) characteristics, respectively. The observed hysteresis in C-V and ID-VG are attributed to the electron and hole confinement within the embedded ferritin cores. These results clearly support the biologically synthesized cores work as charge storage nodes. This work proved the feasibility of the biological path for fabrication of electronic device components.
  • Yamada, K., Yoshii, S., Kumagai, S., Miura, A., Uraoka, Y., Fuyuki, T., Yamashita, I.
    Japanese Journal of Applied Physics Part 1-Regular Papers Brief Communications & Review Papers 45 11 8946 - 8951 2006年 [査読有り][通常論文]
     
    An array of high-density 1.8 x 10(12) cm(-2) floating nanodots was embedded within a metal-oxide-semi conductor (MOS) capacitor using a cage-shaped protein supramolecule, Listeria ferritin (Lis-fer). A monolayer of Lis-fer with a 4.5 nm ferrihydrite core was adsorbed on a 3 nm tunneling SiO2 layer on a p-Si substrate by 3-aminopropyl-triethoxysilane (APTES) surface modification. The outer protein was selectively removed and the obtained cores were covered with a 20-nm-thick control SiO2 layer and an aluminum electrode. The MOS capacitor was annealed in reducing gas (H-2 : N-2 = 10 : 90%), and the embedded cores were reduced to conductive nanodots. The capacitance-voltage characteristics of the MOS capacitor measured at I MHz by applying a DC bias voltage from -5 to +5 V showed a clear hysteresis. This result indicates that the array of nanodots produced and positioned by Lis-fer has the ability for electron confinement.
  • De Feyter, S., Uji-i, H., Mamdouh, W., Miura, A., Zhang, J., Jonkheijm, P., Schenning, Aphj, Meijer, E. W., Chen, Z., Wurthner, F., Schuurmans, N., van Esch, J., Feringa, B. L., Dulcey, A. E., Percec, V., De Schryver, F. C.
    International Journal of Nanotechnology 3 4 462 - 479 2006年 [査読有り][通常論文]
     
    The liquid/solid interface provides an ideal environment to investigate self-assembly phenomena, and scanning tunnelling microscopy (STM) is one of the preferred methodologies to probe the structure and the properties of physisorbed monolayers on the nanoscale. Physisorbed monolayers are of relevance in areas such as lubrication, patterning of surfaces on the nanoscale, and thin film based organic electronic devices, to name a few. It's important to gain insight in the factors which control the ordering of molecules at the liquid/solid interface in view of the targeted properties. STM provides detailed insight into the importance of molecule-substrate (epitaxy) and molecule-molecule interactions to direct the ordering of both achiral and chiral molecules on the atomically flat surface. The electronic properties of the self-assembled physisorbed molecules can be probed by taking advantage of the operation principle of STM, revealing spatially resolved intramolecular differences within these physisorbed molecules.
  • Miura, A., Shibata, Y., Chosrowjan, H., Mataga, N., Tamai, N.
    Journal of Photochemistry and Photobiology a-Chemistry 178 2-3 192 - 200 2006年 [査読有り][通常論文]
     
    Fluorescence dynamics of tetra(4-sulfonatophenyl) porphyrin (TPPS) in aqueous solution and mesoscopic structures of TPPS in thin films have been investigated by femtosecond fluorescence up-conversion spectroscopy and scanning probe microscopy (AFM/SNOM), respectively. We observed very short lifetime in B-state fluorescence of J-aggregate (140 +/- 10 fs) which was shorter than that of monomer (200 +/- 10 fs) and protonated monomer (530 +/- 10 fs). In addition to the very short lifetime component in B state, we found very weak and short lifetime component in Q state of monomer TPPS. Fluorescence observed at the shorter wavelength edge of the monomer Q band has a comparable short lifetime of 240 +/- 20 fs as well as B-state component which has been assigned to the fluorescence from Q(y)(0, 0) state. TPPS J-aggregate prepared by spin coating on the substrate shows quasi-2D nano-rod structures originated from the interaction between I D J-aggregate. Large microcrystalline structures were observed in drop cast film. Near-field absorption and fluorescence images suggest the structural inhomogencities of J-aggregate microcrystals. (c) 2005 Elsevier B.V. All rights reserved.
  • Hikono, T., Matsumura, T., Miura, A., Uraoka, Y., Fuyuki, T., Takeguchi, M., Yoshii, S., Yamashita, I.
    Applied Physics Letters 88 2 3 - 3 2006年 [査読有り][通常論文]
     
    A metal-oxide-semiconductor (MOS) structure with a buried monolayer of ferritin cores in the SiO2 layer was fabricated and the electron confinement in the cores was confirmed. A monolayer of ferritin molecule was adsorbed on the thermal silicon oxide layer. After the protein of the monolayer was eliminated, the ferrihydrite cores were buried in the silicon dioxide layer. We reduced the cores to conductive iron metal nanodots by low-temperature annealing. X-ray photoelectron spectroscopy and electron-energy-loss spectroscopy measurements confirmed the reduction of the cores. The MOS capacitance with the iron nanodots showed hysteresis in the capacitance-voltage measurement, indicating the charging and discharging behavior in iron nanodots.
  • Kubota, T., Hashimoto, T., Ishikawa, Y., Samukawa, S., Miura, A., Uraoka, Y., Fuyuki, T., Takeguchi, M., Nishioka, K., Yamashita, I.
    Applied Physics Letters 89 23 3 - 3 2006年 [査読有り][通常論文]
     
    A defect-free nanometer-scale silicon disk (nanodisk) on thin SiO2 film was precisely fabricated by using Cl neutral beam etching of a 3.5-4-nm-thick polycrystalline silicon on 1.4-3-nm-thick underlying SiO2 with a 7-nm-diameter ferritin iron core mask. Kelvin force microscope observations revealed that nanodisks could maintain injected positive and negative charges. Additionally, Coulomb staircases were observed by I-V measurement of a nanodisk at a temperature of 25 K. These results indicate that the nanodisk fabricated in this research had a precise quantum effect structure and attained the single electron property. This process has great potential in the development of future quantum effect devices. (c) 2006 American Institute of Physics.
  • Thalacker, C., Miura, A., De Feyter, S., De Schryver, F. C., Wurthner, F.
    Organic & Biomolecular Chemistry 3 3 414 - 422 2005年 [査読有り][通常論文]
     
    A series of red and blue highly fluorescent core-substituted naphthalene bisimide dyes has been synthesized and they have been investigated as supramolecular building blocks. NMR and UV-Vis titration experiments of these dyes with complementary melamines revealed the formation of triple hydrogen bonds (DAD-ADA arrays) in solution. At stoichiometric ratios, ditopic melamine receptors could dissolve otherwise insoluble bisimides by means of hydrogen bonding, even in aliphatic solvents. At the solution/graphite interface, one-dimensional chains of hydrogen bonded naphthalene bisimides and two-dimensional adlayers of ditopic melamines are formed for the pure compounds but little evidence for heterocomplexes between the two complementary building blocks could be obtained.
  • De Feyter, S., Miura, A., Yao, S., Chen, Z., Wurthner, F., Jonkheijm, P., Schenning, Aphj, Meijer, E. W., De Schryver, F. C.
    Nano Letters 5 1 77 - 81 2005年 [査読有り][通常論文]
     
    By means of scanning tunneling microscopy, we have explored the two-dimensional self-assembly of functional bicomponent hydrogen-bonding dye systems, leading to well-defined patterns, different from those of the individual components, and providing design rules to immobilize multicomponent systems at the liquid-solid interface.
  • Uji-i, H., Miura, A., Schenning, A., Meijer, E. W., Chen, Z. J., Wurthner, F., De Schryver, F. C., Van der Auweraer, M., De Feyter, S.
    Chemphyschem 6 11 2389 - 2395 2005年 [査読有り][通常論文]
     
    By means of scanning tunneling microscopy (STM), the self-assembly of two organic donor-acceptor-donor triads (donor=oligo(p-phenylene vinylene) (OPV); acceptor=perylene diimide (PDI)) and their mixtures has been investigated at the liquid/solid interface, Both triads differ in the nature of the substituents and, therefore, in the redox properties of the central perylene diimide unit (H or Cl). Thanks to the submolecular resolution, the distinct electronic properties of the units, within a triad and between the two triads, are reflected by the relative STM contrast in the bias-dependent imaging experiments. Moreover, scanning tunneling spectroscopy reveals an inverse rectifying behavior of the OPV and H-substituted PDI units, which is discussed in the framework of quasi-resonant tunneling. A striking difference is observed for the Cl-substituted triad.
  • Koeckelberghs, G., Samyn, C., Miura, A., De Feyter, S., De Schryver, F. C., Sioncke, S., Verbiest, T., de Schaetzen, G., Persoons, A.
    Advanced Materials 17 6 708 - + 2005年 [査読有り][通常論文]
     
    Films of regioregular chiral poly[(S)-3-(3,7-dimethyloctyl)thiophene] (see Figure) prepared via spin-coating and characterized by polarized UV-vis spectroscopy show that order along the film normal is present (which is proportional to the spinning rate). Phase-sensitive second-harmonic generation experiments demonstrate this order to be polar.
  • Miura, A., Jonkheijm, P., De Feyter, S., Schenning, Aphj, Meijer, E. W., De Schryver, F. C.
    Small 1 1 131 - 137 2005年 [査読有り][通常論文]
     
    Enantiomerically pure oligo(p-phenylene vinylene) diaminotriazine derivatives and a short structurally related achiral diaminotriazine derivative, all having a rigid backbone in common, are studied to self-assemble at the solution-graphite interface by scanning tunneling microscopy. As a function of the length of the backbone, different two-dimensional motifs are formed (dimers and rosettes) that are rationalized in terms of the balance between different intermolecular interactions, in this case, intermolecular hydrogen bonding and the packing requirements of the alkyl chains on a graphite surface. In addition, the effect of molecular chirality on monolayer chirality is investigated, revealing molecular size-dependent expressions of the monolayer chirality.
  • Schenning, Aphj, Jonkheijm, P., Hoeben, F. J. M., van Herrikhuyzen, J., Meskers, S. C. J., Meijer, E. W., Herz, L. M., Daniel, C., Silva, C., Phillips, R. T., Friend, R. H., Beljonne, D., Miura, A., De Feyter, S., Zdanowska, M., Uji-i, H., De Schryver, F. C., Chen, Z., Wurthner, F., Mas-Torrent, M., den Boer, D., Durkut, M., Hadley, P.
    Synthetic Metals 147 1-3 43 - 48 2004年 [査読有り][通常論文]
     
    We have demonstrated that it is possible to program pi-conjugated molecules to self-assemble into cylindrical aggregates in solution. By incorporating energy or electron traps in our stacks, energy and electron transfer processes in these one-dimensional assemblies have been studied in solution. The transfer of the single OPV cylinders from solution to a solid support as isolated objects was only possible when specific concentrations and specific solid supports were used. So far, however, we have not been able to measure any current through our fibers. (C) 2004 Elsevier B.V All rights reserved.
  • Jonkheijm, P., Miura, A., Zdanowska, M., Hoeben, F. J. M., De Feyter, S., Schenning, Aphj, De Schryver, F. C., Meijer, E. W.
    Angewandte Chemie-International Edition 43 1 74 - 78 2004年 [査読有り][通常論文]
  • Miura, A., Chen, Z. J., Uji-i, H., De Feyter, S., Zdanowska, M., Jonkheijm, P., Schenning, Aphj, Meijer, E. W., Wurthner, F., De Schryver, F. C.
    Journal of the American Chemical Society 125 49 14968 - 14969 2003年 [査読有り][通常論文]
  • De Feyter S, Abdel-Mottaleb M. M, Miura A
    AIP Conference Proceedings 2003年 [査読有り][通常論文]
  • Miura, A., De Feyter, S., Abdel-Mottaleb, M. M. S., Gesquiere, A., Grim, P. C. M., Moessner, G., Sieffert, M., Klapper, M., Mullen, K., De Schryver, F. C.
    Langmuir 19 16 6474 - 6482 2003年 [査読有り][通常論文]
     
    The light-induced and tip-induced polymerization of two diacetylene derivatives has been investigated at the air/solid interface by scanning tunneling microscopy (STM). One molecule is an isophthalic acid derivative with one diacetylene group, while the other one, a terephthalic acid derivative, contains two diacetylene functions. The design of the molecules (symmetry, presence of alkyl chains and hydrogen bonding moieties) leads to the formation of highly ordered two-dimensional patterns where the diacetylene groups stack in an optimal fashion. Both diacetylene derivatives can be polymerized by UV light irradiation, and locally the polymerization can be initiated and controlled by the STM tip. In addition to the formation of one-dimensional organic structures, it was possible to create two-dimensional organic nanostructures.
  • Y Nabetani, M Yamasaki, A Miura, N Tamai
    THIN SOLID FILMS 393 1-2 329 - 333 2001年08月 [査読有り][通常論文]
     
    The thin film of poly[2-methoxy, 5-(2 ' -ethyl-hexyloxy-p-phenylene vinylene)] (MEH-PPV) was prepared on a glass plate by the spin coating of a chloroform solution. The mesoscopic structures and fluorescence dynamics of the MEH-PPV thin film in small domains were analyzed by AFM and picosecond time-resolved fluorescence SNOM. A wheel structure of MEH-PPV with a sub-mum to a few mum in diameter was found, the size of which was dependent on the position of the film. The formation mechanism of the MEH-PPV wheel and the position dependence of the wheel size were interpreted in terms of the two-dimensional (2D) gas bubble model. A good correlation between the shear-force topography and the fluorescence SNOM image was obtained. The fluorescence decay of the single-chain exciton was found to be much faster in the circumference of the wheel than in the surroundings or the inside of the wheel, which was probably due to the exciton migration among the polymers and trapping by the aggregate of MEH-PPV. (C) 2001 Elsevier Science B.V. All rights reserved.
  • A Miura, Y Yanagawa, N Tamai
    JOURNAL OF MICROSCOPY-OXFORD 202 2 425 - 432 2001年05月 [査読有り][通常論文]
     
    Time-reserved fluorescence SNOM is used to probe the mesoscopic structure and dynamics of long-chain merocyanine (C18MC) J-aggregates on glass plates prepared by spin coating, casting, and casting of water-soluble polymer films. A globular structure with an average diameter of similar to1 mum and a height of similar to 50 nm was attributed to the J-aggregate of C18MC in the spin-coating film. in polymer films, the bandwidth of the absorption of J-aggregate is much narrower in polyvinyl alcohol (PVA, similar to 20 nm) than that in polyvinyl sulphate (PVS, similar to 60 nm). We have demonstrated that the large bandwidth of the spectrum is due to the inhomogeneous distribution of the T-aggregate. The fluorescence image of the T-aggregate in PVA film was rather uniform, whereas non-uniform distribution of the fluorescence was observed in PVS film. The fluorescence of C18MC J-aggregate in a small domain of PVA film was a single exponential decay with a lifetime as short as 19 ps, which was shorter than that in PVS film with a two-exponential decay (average lifetime of similar to 25ps). The fluorescence lifetime of the J-aggregate and its single exponential behaviour are considered to be indicators of the uniform distribution of the J-aggregate. The nonuniform distribution of the J-aggregate in PVS film was interpreted in terms of electrostatic interaction between PVS and merocyanine.
  • A Miura, Y Yanagawa, N Tamai
    JOURNAL OF MICROSCOPY-OXFORD 202 2 401 - 407 2001年05月 [査読有り][通常論文]
     
    Thin films of water-soluble free-base porphyrin, 5,10,15,20-tetraphenyl-21H, 23H-porphinetetrasulphonic acid (TPPS) mixed with poly(diallyldimethyl ammonium chloride) (PDDA) have been prepared by a spin-coating method, in which the monomeric species were observed in the spin-coat film, whereas dimer was formed in the cast film prepared from TPPS/PDDA solution. Mesoscopic structures and dynamics of excitation energy migration and trapping of TPPS/PDDA spin-coat film have been analysed by time-resolved scanning near-field optical microspectroscopy (SNOM) and atomic force microscope. The observed film structure can be classified roughly into two parts: one is a large, flocculated polymer part, and the other is a smooth part widely spread around the flocculated polymers. En the smooth part, the observed spindle-like structure and circular hills and dips are essentially due to PDDA. The ellipsoidal small structures with similar to2 mum length and <1 <mu>m width in the flocculated polymer part show non-exponential fluorescence decays. The non-exponential dynamics originates from the excitation energy migration among TPPS monomers and energy trapping to dimers. From the analysis of fluorescence decay curves based on the equation developed by Klafter and Blumen, the spectral dimension has been estimated to be similar to1.46 for ellipsoidal structures. These results indicate that the distribution of the chromophore is inhomogeneous and a fractal-like structure exists even in the small domains determined by the resolution of the SNOM tip.
  • T Ito, M Naka, A Miura, T Ujiie, H Nakamura, T Matsuo
    BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 74 4 657 - 665 2001年04月 [査読有り][通常論文]
     
    The effects of magnetic fields on the lifetimes of chain-linked triplet biradicals ((3)BRs), generated by photoinduced electron transfer from zinc(II) tetraphenylporphyrin (ZnP) to appended viologen (V2+), were investigated in homogeneous solutions of acetonitrile-water and reversed micellar solutions of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) by means of laser flash photolysis. It was found that the decay rate constants (k(obs)) of the (3)BRs increased significantly in the absence of magnetic fields as the number of carbon atoms (n) in the spacer chain between the ZnP and V2+ moieties increased, and then reached a constant value above n = 8. When the magnetic field was increased, the k(obs) values de creased. A sharp decrease in a low magnetic field was observed, followed by a gradual decrease as the magnetic field was increased, eventually reaching an asymptotic value under the high magnetic field (B > 100 mT) for the compounds with the longer spacer chains. In AOT/2,2.4-trimethylpentane/water reversed micellar solutions, the kobs values were smaller than those in MeCN-H2O homogeneous solutions; this trend became increasingly prominent the longer the spae er chain length. Therefore, the kobs values showed the opposite spacer chain length dependence in comparison with those in homogeneous solutions at B = 470 mT. These results were interpreted in terms of the variation of tripler-singlet energy separation with the interradical distance, Zeeman splitting of the triplet sublevels, electron-nuclear hyperfine coupling, and spin relaxation mechanisms.
  • XJ Yang, ZF Dai, A Miura, N Tamai
    CHEMICAL PHYSICS LETTERS 334 4-6 257 - 264 2001年02月 [査読有り][通常論文]
     
    The synthesized titanium dioxide (TiO2) nanoparticle was found to enhance the formation of J-aggregate of water-soluble porphyrin, tetra (4-sulfonatophenyl) porphyrin dye, 5,10,15,20-tetraphenyl-21H, 23 H-porphine tetrasulfonic acid (TPPS). The forward and back electron transfers (ETs) between adsorbed TPPS and TiO2 nanoparticles were examined by picosecond single-photon timing and femtosecond transient absorption spectroscopy. The ultrafast back ET of similar to0.8 ps was observed both for the protonated monomer and the J-aggregate. The back ET almost completes within a few tens of picoseconds for the. protonated monomer, while >1 ns is required for the J-aggregate. The difference has been interpreted in terms the hole delocalization and electronic coupling of the protonated monomer and J-aggregate adsorbed on TiO2 nanoparticles. (C) 2001 Elsevier Science B.V. All rights reserved.
  • A Miura, N Tamai
    CHEMICAL PHYSICS LETTERS 328 1-2 23 - 31 2000年09月 [査読有り][通常論文]
     
    Fluorescence decay dynamics and fluorescence anisotropy of N,N'-dioctadecylrhodamine B (DORB) at the air/water interface with surface molecular areas of similar to 10(5) Angstrom(2)/molecule were examined by picosecond single photon timing spectroscopy. The interfacial dielectric constant around DORB was estimated to be similar to 21 by the dependence of nonradiative rate constant on polarity parameter E-T(30). The rotational relaxation of DORB at the air/water interface showed two-exponential behavior with lifetimes of 3.15 +/- 0.14 ns and 420 +/- 30 ps. The longer component was interpreted in terms of the formation of a DORB cluster, and the average number of molecules in clusters was estimated to be 7 similar to 8. (C) 2000 Published by Elsevier Science B.V.
  • A Miura, K Matsumura, Su, X, N Tamai
    ACTA PHYSICA POLONICA A 94 5-6 835 - 846 1998年11月 [査読有り][通常論文]
     
    Water-soluble porphyrin, 5,10,15,20-tetraphenyl-21H,23H-porphine-tetrasulfonic acid (TPPS), forms J-aggregate in aqueous solution depending on experimental conditions such as pH, dye concentration, and/or ionic strength. The steady-state fluorescence and picosecond single-photon timing spectroscopy were applied for protonated monomer and J-aggregate in aqueous solution and in thin films to reveal the dynamics in the S-2 and S-1 states. The S-2 fluorescence spectra from the protonated monomer and J-aggregate mere observed in addition to the normal S-1 fluorescence. The lifetime of the S-2 State was estimated to be approximate to 5 ps for J-aggregate, whereas the lifetime is shorter than 1 ps for protonated TPPS monomer. The mesoscopic structures of J-aggregate in thin film with and without polymer on the glass surface were examined by scanning near-field optical microscopy. With the surface topography and scanning near-field optical microscopy transmission images, TPPS J-aggregate was found to form a long and narrow tube-like structure which has a few mu m length, 0.2-0.5 mu m width, and 5-30 nm height. An unidirectional orientation of the structure was also found, which may be originated from the spin-coating process.
  • HB Kim, S Yoshida, A Miura, N Kitamura
    ANALYTICAL CHEMISTRY 70 1 111 - 116 1998年01月 [査読有り][通常論文]
     
    The distribution characteristics of a dye in single melamine resin wall microcapsules containing a dye/toluene solution are studied by a laser trapping-absorption microspectroscopy technique, In the case of Disperse Orange 13 as a dye, the molar absorptivity determined from the slope of a dye absorbance-capsule diameter (d) plot agrees well with that observed in a homogeneous toluene solution, indicating that the dye is solubilized homogeneously in the inner toluene solution of the capsule. For tetraphenylporphyrins (MTPP: (ZnTPP)-T-II, (CoTPP)-T-II, or H2TPP), however, the d dependence of absorbance shows a sigmoidal curve, Since absorbance of a ZnTPP/toluene droplet before polymerization of the melamine resin increases linearly with an increase in the droplet diameter, the sigmoidal d dependence of the absorbance is concluded to originate from distribution of the dye into the resin wall. Detailed analyses of the data indicate that the partitioning ratio of the dye between the toluene and resin phases is dependent on the capsule diameter. Size-dependent distribution of MTPP in single microcapsules is discussed on the basis of a proposed model and the d dependence of the dye absorbance, and it is concluded that the distribution of MTPP to the melamine resin wall is facilitated for larger microcapsules.
  • HB Kim, S Yoshida, A Miura, N Kitamura
    CHEMISTRY LETTERS 1996 11 923 - 924 1996年 [査読有り][通常論文]
     
    Absorption microspectroscopy has been conducted to study chemical properties of single melamine-resin microcapsules containing a zinc tetraphenylporphine (ZnTPP)/toluene solution. Although absorbance of ZnTPP in the capsule increased with increasing the capsule diameter, its tendency was much smaller than that expected from a homogeneous distribution of ZnTPP in the inner toluene solution. The results were discussed in terms of a distribution of ZnTPP in both the melamine-resin and toluene phases.

その他活動・業績

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共同研究・競争的資金等の研究課題

  • 日本学術振興会：科学研究費助成事業 基盤研究(C)
    研究期間 : 2022年04月 -2025年03月 
    代表者 : 三浦 篤志
  • 日本学術振興会：科学研究費助成事業 基盤研究(C)
    研究期間 : 2019年04月 -2022年03月 
    代表者 : 喜多村 昇, 三浦 篤志
     
    これまで水、ジメチルスルホキシド（DMSO）、エタノール（EtOH）、およびホルムアミド（FA）の空気中におけるエアロゾル化とともに、これらの単一微小エアロゾル液滴のレーザー捕捉に成功している。また、レーザー捕捉した単一エアロゾル液滴を対象として顕微時間分解蛍光分光や顕微非偏光・偏光ラマン分光による液体物性研究を試み、下記のような研究成果をあげた。 空気中に浮遊させたDMSO液滴はマイナス60度近辺まで凍結せずに過冷却液体として存在する事を明らかにした。バルク系におけるDMSOは＋18度近辺で凍結するが、空気中に浮遊して空気以外と物理的接触が無いエアロゾルDMSO液滴は氷晶核を生成しづらいために過冷却状態となる。同様な過冷却状態はエアロゾル水滴においても確認されている。また、エアロゾルDMSO液滴の粘度の温度依存性を測定したところ、バルクDMSO液体の粘度の温度依存性に比べ、より大きな温度依存性を示すことを明らかにした。特に、DMSO液体の粘度は室温下においてエアロゾル化させることによりバルク系に比べて上昇することを液滴のレーザー捕捉・顕微偏光ラマン分光から明らかにした。エアロゾル化による液体粘度の上昇は、平坦なバルク液体に比べて球形界面を有する液滴では表面張力が大きくなることに起因するラプラス圧効果によるものと考えられる。これまでのところエアロゾルDMSO液滴について詳細な結果が得られていないが、エアロゾル水滴やEtOH液滴の粘度は液滴サイズの減少とともに表面張力が上昇することを実験的に示すことができ、粘度上昇はラプラス圧効果であることを実験的に明らかにする事ができた。
  • 日本学術振興会：科学研究費助成事業 挑戦的研究(萌芽)
    研究期間 : 2018年06月 -2020年03月 
    代表者 : 三浦 篤志, 藤井 翔
     
    界面レーザー捕捉結晶化法では，光圧と微小物体の相互作用により集光点での局所的濃度上昇・高濃度液滴形成を誘起し，不飽和溶液からもたった一つの結晶を集光点からリアルタイムかつ短時間にその場で形成可能であり，結晶化の学理を研究可能な手法としても，実践的結晶化法としても高いポテンシャルを秘めている。しかし，動的な界面である開放系の気液界面に高強度レーザー光を照射して分子クラスターを捕捉する必要があり技術的に難しい。本研究は，これらの問題を解決する方策としてマイクロ流路中での固体基板へのレーザー照射による光熱変換で安定なマイクロバブルを形成し，このバブル界面でのレーザー捕捉により高濃度領域を形成し，ここへ外部摂動レーザー光を照射して分子配向を制御する事で，in-situかつリアルタイムなレーザー捕捉タンパク質結晶化を実現することを目指している。本年度はタンパク質分子配向のレーザー制御によるその場結晶化に必要不可欠な，外部摂動レーザー光の条件検討を中心に研究を展開した。フェムト秒パルスレーザー，ナノ秒パルスレーザー，CWレーザーなど様々な外部摂動レーザー光を界面レーザー捕捉により生成した高濃度領域へ導入し，外部摂動光の導入により高効率でのタンパク質分子微小固体の形成が可能であることを見いだした。パルスレーザーエネルギーやパルス幅，照射回数，照射レーザー光の偏光といったレーザー条件の詳細な検討より，気液界面におけるレーザー捕捉結晶化によるタンパク質分子のリアルタイム結晶化が可能であることを示す結果を得た。また，酸化物半導体への捕捉レーザー照射によるバブル形成条件の検討も進め，最適条件を見いだすとともに，マイクロ流路デバイスの作製法も確立しつつある。
  • キャビティ増幅顕微鏡による抗がん剤分子取込挙動の定量計測
    物質・デバイス領域共同研究拠点：
    研究期間 : 2019年04月 -2020年03月 
    代表者 : 三浦篤志
  • 光分子配向制御によるタンパク質のレーザー誘起時空間制御結晶化
    光科学技術研究振興財団：
    研究期間 : 2018年 -2020年 
    代表者 : 三浦篤志
  • 増幅吸収/散乱顕微鏡による抗がん剤分子取込量の単一細胞・単一分子レベル定量測定
    物質・デバイス領域共同研究拠点：
    研究期間 : 2018年04月 -2019年03月 
    代表者 : 三浦篤志
  • 吸収顕微鏡を用いた抗がん剤分子投与量の単一分子レベル定量測定
    物質・デバイス領域共同研究拠点：
    研究期間 : 2017年04月 -2018年03月 
    代表者 : 三浦篤志
  • 日本学術振興会：科学研究費助成事業 挑戦的萌芽研究
    研究期間 : 2015年04月 -2017年03月 
    代表者 : 三浦 篤志
     
    タンパク質溶液の気液界面へ捕捉レーザー光を照射すると、集光点の近傍に局所的な高濃度ドメインを形成できる。この時空間的に制御された高濃度ドメインを利用し、効率的かつ短時間での新規結晶化法を着想し、界面レーザー捕捉による結晶化を試みた。捕捉レーザー照射下で誘起される現象（集合体形成過程、液滴形成・消失、結晶形成）の詳細な分光学的検討から、レーザー捕捉下におけるタンパク濃度変化と分子配向変化を明らかにした。リゾチームや対称性の高い球殻状タンパク質フェリチンのレーザー誘起結晶化より、界面レーザー捕捉により結晶形成時間の大幅な短縮と、結晶成長速度の大幅な向上が可能であることを明らかにした。
  • 吸収顕微鏡を用いた細胞内ナノ結晶観測法の開発
    物質・デバイス領域共同研究拠点：
    研究期間 : 2016年04月 -2017年03月 
    代表者 : 三浦篤志
  • National Science Council, Taiwan：
    研究期間 : 2012年08月 -2014年07月 
    代表者 : 三浦篤志
  • 日本学術振興会：科学研究費助成事業 若手研究(B)
    研究期間 : 2007年 -2008年 
    代表者 : 三浦 篤志
     
    発光材料応用に向け,球殻状超分子タンパク質,リステリアフェリチンを利用したCdSナノ粒子の形成条件の最適化を行い,合成された半導体ナノ粒子の分光特性解析よりフェリチン半導体ナノ粒子の発光効率向上,発光メカニズム・ダイナミクスに関して検討した.また,電荷注入型発光デバイスへの応用検討として,リステリア-CdSナノ粒子を発光層とする積層デバイスを作製・動作確認を行うと共に,金属酸化物フェリチンナノ粒子での電荷注入メカニズムに関する検討も併せて行った.

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  • 一般教育演習(ﾌﾚｯｼｭﾏﾝｾﾐﾅｰ)
    開講年度 : 2021年
    課程区分 : 学士課程
    開講学部 : 全学教育
    キーワード : 化学　機能性物質　環境　健康　ものづくり　化学産業　高分子科学　生物物理学　科学倫理　
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    開講年度 : 2021年
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    開講年度 : 2021年
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    キーワード : See the English version
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    開講年度 : 2021年
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    開講学部 : 理学部
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