Profile

SHINOHARA, Ken-ichiAssociate Professor

Materials Science, Materials Chemistry Frontiers

Lab

MS Building Ⅲ 3F Tel:0761-51-1601
Access 1-1 Asahidai, Nomi, Ishikawa 923-1292 Japan

To Lab's Site To Area's Site JAIST Repository

Degrees

Ph.D. from Niigata University (1997) 新潟大学

Professional Experience

Specialties

Nanostructure chemistry, Polymer chemistry, Nanobioscience, Nanomaterials

Research Keywords

Artificial life-function, Molecular Motor, Polymer Molecular Motor, Astrobiology, １分子計測, Polyolefine, Rubber, Helical Polymer, Bias Brownian Motion, Molecular Machine, 近接場光学顕微鏡, 走査トンネル顕微鏡, 原子間力顕微鏡, 超分子ポリマー, Chirality, Polymer Synthesis, 1分子イメージング

Research Interests

Single-Molecule Imaging of Synthetic Polymer

π-Conjugated polymers have been developed as advanced materials for photonic or electronic applications. If the π-conjugated polymer chain can be controlled in the higher order structure, novel functions at the molecular level will become available due to the unique π-electron system. Many studies confirming the fact that a π-conjugated polymer has a helical structure have already been completed. Most of these studies have provided us with data on molecular aggregates or data on the average of many molecules. Although we now understand that the main chain of the polymer takes the form of a helix, does one chain have both right- and left-handed helices? What is the ratio of the right-handed helices to the left-handed ones? What about the regions where the helix is reversed and how does it dynamically change? The answers already provided to all these fundamental questions have been based only on conjecture. Therefore, it is necessary to establish a technique that can determine the structure at the single-molecule level in order to achieve the above-mentioned objective. Here we show that a scanning tunneling microscope (STM) allows us to see the π-electron orbital of a chiral quaternary structure, where it was directly observed and its size was even measured with high resolution.

Spectral Fluctuation of Single-Molecules of a Conjugated Polymer in a Solution

Polymer considered in this study is an extremely complicated example due to its generally varied and dynamic structure, so we have had difficulty in clearly defining the correlation between structure and function at the molecular level. In other words, questions such as "What kind of polymer structures indicate the molecular functions?" have been very difficult to clearly answer at the molecular level. This introduces uncertainty as to whether a proposed molecular design is beneficial or not when we are trying to synthesize novel conjugated polymers with improved functions at the molecular level. Therefore, we thought that if we could directly observe an individual molecular structure and its functionality for a single conjugated polymer, it might then become possible to keep this speculation to a minimum, thus enabling a very clear discussion of the relationship between the molecular structure and function at the molecular level. Their observation of a single molecular spectrum for a conjugated substituted poly(phenylenevinylene) in a polystyrene matrix have been reported, but this was not a in solvo system. If the direct measurement of single molecules of a conjugated polymer in solution can be achieved, the observation of unique phenomena can be expected, e.g., the host-guest interaction of single molecules, leading towards the development of novel systems consisting of molecular devices in solution. We have already reported the results of fluorescence imaging experiments conducted on single molecules of the conjugated poly(9,10-anthracenediyl-ethynylene-1,4-phenylene-ethynylene) [poly(AEPE)], which has a rigid-rod main chain, in a tetrahydrofuran (THF) solution at room temperature using a total internal reflection microscope (TIRFM). In the present study, we conducted single molecule fluorescence imaging and single molecule spectroscopy for conjugated poly(AEPE) having a rigid-rod main chain in methanol at room temperature, and we could successfully detect a unique light-emitting phenomenon which fluctuated dynamically with in the time-scale of several seconds.

The creation of the flexible molecular machine

What function does a synthetic polymer have in the single-molecular-level? Does it have such a dynamic multi-functions as protein which a kind of biopolymer? Mankind does not understand the fundamental properties of synthetic polymers yet and still cannot bring the maximum of capabilities out of them. Polymer is highly capable, useful and indispensable material. Especially, conjugated polymers investigated as advanced materials for photonic and electronic applications have made progress, and has caused an ever-increasing interest from both academic research and industrial development. The conjugated polymers are used as laser dyes, organic light-emitting diodes, and so on. In addition recently, there are some applications as an optical resolution membrane materials. Although conjugated polymers are very interesting and important materials, the mechanism in single-molecular-level of these photonic and electronic function are still not clear owing to the various and complicated structure of the conjugated system in the polymer molecules. Thus, the polymers are the complex system of molecules. Therefore, we thought that if direct observation of single molecule of conjugated polymer were achieved, the polymer function would be clear in molecular level toward the polymer functioning at single molecule unit, that is the single-molecule device. In the other, recently, imaging of single protein molecules using fluorescence microscopy has made remarkable progress after development of single fluorophore imaging methods which were used for specimen on an air-dried surface. Single fluorophores in aqueous solution have been imaged using a total internal reflection fluorescence microscope (TIRFM), in which the background fluorescence is greatly reduced, when a laser beam is totally reflected in the interface between the glass surface and solution, illumination is limited to only the vicinity near the glass surface. In our previous study, this single molecules imaging method was expanded to the organic polymer solution system for the direct observation of single molecules of photofunctional rigid-rod conjugated polymer that is a poly(aryleneethynylene) having anthracene units in the main chain. In this study, we report that single molecule imaging of a stereo-regular π-conjugated polymer and detection of single molecule slow-twinkling of the photoluminescence in tetrahydrofuran solution at room temperature for the first time.

Publications

Published Papers

1. Synthesis of two-dimensional multi-functional macromonomer and oxygen permselectivity of its supramolecular and covalent polymer membranes
   Kehan Cheng, Ken-ichi Shinohara, Koichi Higashimine, Masahiro Teraguchi, Takashi Kaneko, Toshiki Aoki Chemistry Letters, -, 2023
2. Synthesis and Permselectivity of a Soluble Two-Dimensional Macromolecular Sheet by Solid–Solid Interfacial Polycondensation Followed by Chemical Exfoliation
   Yanqing Qu, Xiaoyu Du, Kehan Cheng, Yu Zang, Liang Xu, Ken-ichi Shinohara, Masahiro Teraguchi, Takashi Kaneko, Toshiki Aoki
   ACS Materials Letters, 2, 1121-1128, 2020
3. Direct Observation of Long-Chain Branches in a Low-Density Polyethylene
   Ken-ichi Shinohara, Masahiro Yanagisawa, Yuu Makida
   Scientific Reports, 9, 1, 9791-, 2019
4. Antiparallel Arrangement of 2,7-Substituted 9,10-Bis(phenylethynyl)anthracene Assisted by Hydrogen Bonding of Terminal Units
   Takashi Kaneko, Yosuke Araki, Ken-ichi Shinohara, Masahiro Teraguchi, Toshiki Aoki
   Bull. Chem. Soc. Jpn., 92, 10, 1672-1678, 2019
5. One-Step Synthesis of One-Dimensional Supramolecular Assemblies Composed of Helical Macromolecular Building Blocks.
   Yuya Wada, Ken-Ichi Shinohara, Hitoshi Asakawa, Sayaka Matsui, Tetsuya Taima, Tomoyuki Ikai
   Journal of the American Chemical Society, 141, 35, 13995-14002, 2019

Misc

1. ポリマー分子モーター 熱ゆらぎを利用する賢いナノマシン
   篠原 健一
   マテリアルステージ, 18, 62-64, 2018
2. ここまでできるポリマー1分子のイメージング！
   篠原 健一
   高分子, 62, 673-674, 2013
3. ポリマー1分子の直視 キラルらせんπ共役高分子鎖一本の電場応答性の動態イメージング
   篠原健一, 古寺哲幸, 巻田優
   高分子学会予稿集(CD-ROM), 59, 1 Disk1, ROMBUNNO.3PD106-, 2010
4. Hot Topics: Single-Molecules Imaging of the Unidirectional Molecular Motion Surfing the Longitudinal Wave in the Helical Polymer Chain as a Linear Motor
   篠原 健一
   高分子, 59, 133-, 2010
5. ポリマー1分子の直視 らせんπ共役高分子鎖1本に沿って一方向に滑走するリニアモーター分子の動態イメージング
   篠原健一, 古寺哲幸, 安藤敏夫
   高分子学会予稿集(CD-ROM), 58, 2 Disk1, ROMBUNNO.2L5-05-, 2009

Books

1. Ken-ichi Shinohara, Applied Scanning Probe Methods X -Biomimetics and Industrial Applications, Chapter 31: Scanning Probe Microscope Application for Single Molecules in a π-Conjugated Polymer toward the Molecular Devices based on Polymer Chemistry, pp ・・・
   Springer, Berlin, 2008
2. 篠原 健一、高分子の表面改質・解析の新展開、"第2章第2節 走査プローブ顕微鏡法による高分子鎖の構造解析", pp 115-124
   シーエムシー出版, 東京, 2007
3. 篠原 健一、高分子鎖1本のサイエンス［みる・はかる］、高分子学会編、担当 "第1章 ポリマー1分子の直視：π共役高分子鎖1本の構造と機能のイメージング", pp 1-32
   エヌ・ティー・エス, 東京, 2005

Conference Activities & Talks

1. 蛍光・発光タンパク質に基づくマイクロディスプレイ
   日本生物物理学会 第56回年会, 3Pos416, 岡山大学, 岡山市, 2018
2. ポリマー１分子の直視：キラルらせん高分子鎖に沿って一方向性プロセッシブ運動する分子モーターと全原子MDシミュレーション
   高分子学会 第67回高分子討論会, 2L11, 北海道大学、札幌市, 2018
3. グルコースユニット含有光学活性ポリマーの合成とその円偏光発光特性
   高分子学会 第67回高分子討論会, 北海道大学, 札幌市, 2018
4. ポリマー１分子の直視：高分子鎖一本の構造とダイナミクスのイメージング 【招待講演】
   高分子学会・第117回プラスチックフィルム研究会, 主題=高分子フィルムの可能性を究める, 東京工業大学, 東京都目黒区, 2018
5. ポリマー１分子の直視：らせん高分子鎖に沿って分子が歩行する現象の全原子MDシミュレーション
   第67回高分子学会年次大会, 3Pd058, 【プレスリリース選定・パブリシティ賞 受賞】, 名古屋国際会議場, 愛知県名古屋市, 2018

Teaching Experience

1. Evaluation of Properties of Materials, Material Analysis with Training Course, Molecular and Functionality Design of Polymers (E), Instrumental Analytical Chemistry, 物性評価特論, ナノ材料分析論（実習付）, 分子設計特論(E), 機器分析化学特論

Contributions to Society

Academic Society Affiliations

1. 応用物理学会, 日本生物物理学会, 日本化学会, 高分子学会, American Chemical Society

Academic Contribution

1. XXVI International Conference on Organometallic Chemistry (ICOMC 2014) , Chairperson: Hokkaido University, Prof. Tamotsu Takahashi.An Organization Committee: JAIST, Prof. Ken-ichi Shinohara. , 2014 - 2014 , Sapporo, Japan
2. 4th ISAMAP (The International Symposium on Advanced Materials in Asia-Pacific Rim / 第4回先端材料に関するアジア環太平洋国際学会) , Prof. Toshiki Aoki (Chairman), Prof. Ken-ichi Shinohara (Organizing Committee) , 2007 - 2007 , Hotel Nikko Niigata and Niigata Convention Center, Niigata, Japan

Committee Memberships

1. , 平成19年 国際会議主催、4th ISAMAP (The International Symposium on Advanced Materials in Asia-Pacific Rim / 第4回 , 2007-
2. , 平成20年6月1日から平成21年3月31日まで 新潟大学大学院自然科学研究科 非常勤講師
3. , 平成19年度 高分子学会 高分子研究奨励賞選考委員

Academic Awards

1. Nominated as a candidate for the Nobel Prize.
2. 広報委員会パブリシティ賞 , 篠原 健一 , 高分子学会 , 2018
3. 高分子学会および高分子学会関西支部 ヤングサイエンティスト講演賞 , 2005
4. 日本金属学会 奨励賞 , 1999