武田 佳宏 TAKEDA Yoshihiro

コンポン研究所/主幹研究員
研究領域:微粒子クラスター

Recent progress

1, Degradation of Protein in Nanoplasma Generated around Gold Nanoparticles in Solution by Laser Irradiation
We developed a method of protein degradation in an aqueous solution containing gold nanoparticles by irradiation of a pulse laser. In the present study, lysozyme was used as an example. Lysozyme degradation proceeded most efficiently when a pH of the solution was so adjusted that it is at the isoelectric point. The scheme of the lysozyme degradation is as follows: (1) Lysozyme molecules in the solution are neutralized and adsorbed on the gold nanoparticles with its pH value adjusted at the isoelectric point, (2) nanoplasma is generated in the close vicinity of a gold nanoparticle which is excited by an intense 532-nm laser, (3) lysozyme molecules in the nanoplasma are degraded into small fragments. Lysozyme degradation does not proceed efficiently at a pH value deviated from the isoelectric point because the lysozyme molecules are dissolved uniformly so that only a small portion of the lysozyme molecules are located in the vicinity of gold nanoparticles which create the nanoplasma.

2, Formation of Au(III)-DNA Coordinate Complex by Laser Ablation of Au Nanoparticles in Solution
We discovered that an Au(III)-DNA coordinate complex, Au(III)(DNA-base)2(amine)L, are formed by laser ablation of Au nanoparticles in an aqueous solution containing DNA molecules in the presence of amines and multi-valent cations, where L represents an unknown ligand (either amine or water). Optical absorption spectrum of the solution after laser ablation exhibited a 360 nm absorption peak assigned to ligand -->Au(III) charge transfer (LMCT) band of the coordinate complex. The complex is considered to be formed as follows: (1) the DNA molecules are neutralized by binding the multi-valent cations to their negatively charged phosphate groups, and adsorbed on the surface of the Au nanoparticles by a hydrophobic interaction, (2) Au(III) ions are liberated from the Au nanoparticles by laser ablation, and (3) an Au(III) ion reacts with amine and two DNA bases of a DNA molecule into an Au(III)(DNA-base)2(amine)L.


List of Publication (under construction)

  1. “Self-assembly of gold nanoparticles in protein crystal”
    Y. Takeda, T. Kondow, F. Mafuné
    Chem. Phys. Lett. 504, 175 (2011)
  2. “Selective decomposition of nucleic acids by laser irradiation on probe-tethered gold nanoparticles in solution”
    Y. Takeda, T. Kondow, and F. Mafuné
    Phys. Chem. Chem. Phys, 13, 586 (2011)
  3. “Selective Degradation of Proteins by Laser Irradiation onto Gold Nanoparticles in Solution”
    Y. Takeda, F. Mafuné, and T. Kondow
    J. Phys. Chem. C, 113, 5027 (2009).
  4. “Hybridization of ssDNA with Complementary DNA Probe Tethered to Au Nanoparticle - Effect of Steric Hindrance Caused by Conformation”
    Y. Takeda, T. Kondow, and F. Mafuné
    J. Phys. Chem. C, 112, 89 (2008).
  5. "Degradation of Protein in Nanoplasma Generated around Gold Nanoparticles in Solution by Laser Irradiation"
    Y. Takeda, T. Kondow, and F. Mafuné
    J. Phys. Chem. B, 110, 2393 (2006).
  6. "Formation of Au(III)-DNA coordinate complex by laser ablation of Au nanoparticles in solution"
    Y. Takeda, F. Mafuné, and T. Kondow
    J. Photochem. Photobiol. A, 171, 215, (2005).
  7. "Aggregation and fast diffusion of dye molecules on air-glycerol interface observed by confocal fluorescence microscopy"
    Y. Takeda, F. Mafuné, and T. Kondow
    Nucleoside, Nucleotides Nucleic Acids, 24, 1215 (2005).
  8. "Self-organization of histone-jointed three-dimensional DNA network"
    Y. Takeda, F. Mafuné, and T. Kondow
    Materials Science & Engineering, C, C24, 769, (2004).
  9. "Entropy production mapping on stretched DNA interacted with proteins"
    Y. Takeda, F. Mafuné, and T. Kondow
    J. Biotechnology, 114, 47, (2004).
  10. "Surface Properties of Surfactant-Free Oil Droplets Dispersed in Water Studied by Confocal Fluorescence Microscopy"
    T. Sakai, Y. Takeda, F. Mafuné, and T. Kondow
    J. Phys. Chem. B, 108, 6359 (2004).
  11. "Formation of Gold Nanonetworks and Small Gold Nanoparticles by Irradiation of Intense Pulsed Laser onto Gold Nanoparticles"
    F. Mafuné, J. Kohno, Y. Takeda, and T. Kondow
    J. Phys. Chem. B, 107, 12589 (2003).
  12. "Formation of Stable Platinum Nanoparticles by Laser Ablation in Water"
    F. Mafuné, J. Kohno, Y. Takeda, and T. Kondow
    J. Phys. Chem. B, 107, 4218 (2003).
  13. "Monitoring Growth of Surfactant-Free Nanodroplets Dispersed in Water by Single-Droplet Detection"
    T. Sakai, Y. Takeda, F. Mafuné, Abe, M. and T. Kondow
    J. Phys. Chem. B, 107, 2921, (2003).
  14. "Nanoscale soldering of metal nanoparticles for construction of higher-order structures"
    F. Mafune, J. Kohno, Y. Takeda, and T. Kondow
    J. Am. Chem. Soc., 125, 1686, (2003).
  15. "Growth of Gold Clusters into Nanoparticles in a Solution Following Laser-Induced Fragmentation"
    F. Mafune, J. Kohno, Y. Takeda, and T. Kondow
    J. Phys. Chem. B, 106, 8555, (2002).
  16. "Full Physical Preparation of Size-Selected Gold Nanoparticles in Solution: Laser Ablation and Laser-Induced Size Control"
    F. Mafuné, J. Kohno, Y. Takeda, and T. Kondow
    J. Phys. Chem. B, 106, 7575, (2002).
  17. "Dye Transfer between Surfactant-Free Nanodroplets Dispersed in Water" T. Sakai, Y. Takeda, F. Mafuné, M. Abe, and T. Kondow
    J. Phys. Chem. B, 106, 5017, (2002).
  18. "Dissociation and aggregation of gold nanoparticles under laser irradiation"
    F. Mafuné, J. Kohno, Y. Takeda, and T. Kondow
    J. Phys. Chem. B, 105, 9050 (2001).
  19. "Formation of gold nanoparticles by laser ablation in aqueous solution of surfactant"
    F. Mafuné, J. Kohno, Y. Takeda, T. Kondow, and H. Sawabe
    J. Phys. Chem. B, 105, 5114 (2001).
  20. "Formation and Size Control of Silver Nanoparticles by Laser Ablation in Aqueous Solution"
    F. Mafuné, J. Kohno, Y. Takeda, T. Kondow, and H. Sawabe
    J. Phys. Chem. B, 104, 9111 (2000).
  21. "Structure and stability of silver nanoparticles in aqueous solution produced by laser ablation"
    F. Mafuné, J. Kohno, Y. Takeda, T. Kondow, and H. Sawabe
    J. Phys. Chem. B, 104, 8333 (2000).
  22. "Inhomogeneous solvation in an aniline-ethanol solution studied by laser photoionization of a liquid beam"
    F. Mafuné, Y. Takeda, T. Nagata, and T. Kondow
    Chem. Phys. Lett., 218, 234 (1994).
  23. "Formation and ejection of cluster ions from a liquid beam of aniline-ethanol solution by laser photoionization"
    F. Mafuné, Y. Takeda, T. Nagata, and T. Kondow
    Chem. Phys. Lett., 199, 615 (1992).

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研究領域

E-mail Address

  • takeda at clusterlab.jp
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