研究者業績

Tadao Takada

  (高田 忠雄)

Profile Information

Affiliation
准教授, 大学院 工学研究科 応用化学専攻, 兵庫県立大学
Degree
博士(工学)(大阪大学)

Researcher number
60511699
J-GLOBAL ID
202001013389685624
researchmap Member ID
R000010387

Papers

 58
  • Shuya Fan, Tadao Takada, Atsushi Maruyama, Mamoru Fujitsuka, Kiyohiko Kawai
    Chemistry – A European Journal, 29(19), Feb 27, 2023  
    Abstract Fluorescence imaging uses changes in the fluorescence intensity and emission wavelength to analyze multiple targets simultaneously. To increase the number of targets that can be identified simultaneously, fluorescence blinking can be used as an additional parameter. To understand and eventually control blinking, we used DNA as a platform to elucidate the processes of electron transfer (ET) leading to blinking, down to the rate constants. With a fixed ET distance, various blinking patterns were observed depending on the DNA sequence between the donor and acceptor units of the DNA platform. The blinking pattern was successfully described with a combination of ET rate constants. Therefore, molecules with various blinking patterns can be developed by tuning ET. It is expected that the number of targets that can be analyzed simultaneously will increase by the power of the number of blinking patterns.
  • Shuya Fan, Tadao Takada, Atsushi Maruyama, Mamoru Fujitsuka, Kiyohiko Kawai
    Bulletin of the Chemical Society of Japan, 95(12) 1697-1702, Dec, 2022  
    Current understanding of electron transfer (ET) kinetics is largely based on ensemble measurements that obscure the underlying single-molecule behavior. We previously reported systematic distance-dependent single molecule ET measurements that show a large heterogeneity. Here we study and discuss this heterogeneity in more detail and suggest that it is a rather fundamental phenomenon that is difficult to explain solely by the distribution of DNA conformations. This heterogeneity may arise from the uniqueness of each molecule, or it may reflect the uncertainty of ET kinetics.
  • Mitsunobu Nakamura, Hibiki Yoshioka, Tadao Takada
    ChemistrySelect, 7(29), Aug 5, 2022  
  • Tadao Takada, Nao Shimogaki, Moe Naruo, Mitsunobu Nakamura, Kazushige Yamana
    ChemPhotoChem, 6(8), Aug, 2022  
    The molecular arrangement of functional chromophores is essential to construct functional nanomaterials. Synthetic DNA has been used as a structural scaffold to control and construct molecular assembly. We now describe the formation of artificial DNA/porphyrin complexes where porphyrins working as photoactive molecules were placed at specific locations on the DNA through a non-covalent interaction. Spectroscopic analysis by UV/vis, circular dichroism (CD), and melting temperature measurements showed that the binding of water-soluble porphyrin derivatives with methylpyridinium groups (TMPyP and DMPyP) to DNA can be directed by hydrophobic cavities composed of a pair of abasic site analogs (dS). CD measurements showed that the two porphyrins can be accommodated at two specific sites when the DNA molecule had two cavities, as evidenced by the exciton-coupled CD spectra of the porphyrins. Photoelectrochemical experiments showed that the DNA complexes accommodating DMPyP at specific locations can respond to light excitation to generate a photocurrent when immobilized on the electrode surface. Our results demonstrated that the control of the porphyrin binding using the dS/dS pair is a useful approach to construct artificial DNA with porphyrin molecules, leading to the design of photoresponsive materials and photoelectrochemical sensors.
  • Tadao Takada, Koma Nishida, Yurika Honda, Aoi Nakano, Mitsunobu Nakamura, Shuya Fan, Kiyohiko Kawai, Mamoru Fujitsuka, Kazushige Yamana
    ChemBioChem, 22(17) 2729-2735, Sep 2, 2021  

Misc.

 14
  • Tadao Takada, Mamoru Fujitsuka, Tetsuro Majima
    PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 104(27) 11179-11183, Jul, 2007  
    DNA charge transfer highly depends on the electronic interaction between base pairs and reflects the difference in the base position and sequence. For the purpose of investigating the transfer process of individual DNA molecules and the optical readout of DNA information at the single-molecule level, performed single-molecule observation of the DNA charge process by using single-molecule fluorescence spectroscopy. DNA charge transfer process, leading to the oxidation of fluorescent dye, was explored by monitoring the on-off signal the dye after the charge injection by the excitation of a sitizer. The photobleaching efficiency of the dyes by the charge transfer specifically depended on the base sequence and mismatch base pair, demonstrating the discrimination of the individual DNA information. Based on this approach, the optical readout of a single-base mismatch contained in a target DNA was performed at the single-molecule level.
  • Tadao Takada, Chunyan Lin, Tetsuro Majima
    Angewandte Chemie - International Edition, 46(35) 6681-6683, 2007  
    (Figure Presented) Got a light? The importance of the relationship between the charge recombination and charge transfer during photocurrent generation through DNA films is described. The photocurrent efficiency for DNA films, in which the charge-transfer and recombination rates were modulated by changing the sequence, was investigated by using the photoelectrochemical measurements on an Au electrode. © 2007 Wiley-VCH Verlag GmbH &amp Co. KGaA.
  • T Takada, K Kawai, M Fujitsuka, T Majima
    ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 45(1) 120-122, 2006  
  • K Kawai, Y Osakada, T Takada, M Fujitsuka, T Majima
    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 126(40) 12843-12846, Oct, 2004  
    A series of naphthalimicle (Nl)- and 5-bromocytosine (C-br)-modified oligodeoxynucleotides (ODNs) were prepared, and their lifetimes of the charge-separated states during the photosensitized one-electron oxidation of DNA were measured. Various lifetimes of the charge-separated states were observed depending on the sequence and the incorporation sites of C-br, and the oxidation potential of G in the C-br:G base-pair relative to that of G in the C:G base-pair and in the GGG sequence was determined by comparing the lifetimes of the charge-separated states. The change in the cytosine C5 hydrogen to bromine resulted in a 24 mV increase in the oxidation potential of G in the C-br:G base-pair as compared to that of G in the C:G base-pair, the value of which is comparable to a 58 mV decrease in the oxidation potential of G in the GGG sequence. These results clearly demonstrate that hole transfer in DNA can be controlled through hydrogen bonding by introducing a substituent on the cytosine.
  • K Kawai, H Yoshida, T Takada, S Tojo, T Majima
    JOURNAL OF PHYSICAL CHEMISTRY B, 108(35) 13547-13550, Sep, 2004  
    Doubly internally pyrene (Py) modified oligodeoxynucieotides (ODNs) were synthesized, and the formation rates of the Py dimer radical cation (PY2.+) were measured upon one-electron oxidation during pulse radiolysis. The formation Of Py-2(.+) with an optical absorption at 1550 nm (charge resonance band) was observed in the time range of 1 mus to 1 ms after an electron pulse during the pulse radiolysis of a D2O solution of the doubly internally Py modified ODN in the presence of K2S2O8. The formation rate Of Py-2(.+) in DNA reflected the dynamics of the DNA, which allows the interaction between Py.+ and Py, and was affected by the distance between the two Py's and the local environment of each Py. The trapping of the transiently formed DNA conformation by the attractive charge resonance interaction was demonstrated to be useful to obtain structural and dynamic information of the fluctuating DNA in the time range of 1 mus to 1 ms.

Research Projects

 11