MF研究者総覧

研究者データベース

詳細
高野　勇太(タカノ　ユウタ)
電子科学研究所　物質科学研究部門
准教授
researchmap個人ページ
Last Updated :2023/12/05

基本情報

所属

  • 電子科学研究所　物質科学研究部門

職名

  • 准教授

学位

  • 博士（理学）（筑波大学）

J-Global ID

研究キーワード

  • 光誘起電子移動   ペロブスカイト型ナノ結晶   カーボンナノホーン   半導体量子ドット   フラーレン (特に内包系)   カーボンナノチューブ   光治療   光物理化学   光機能性分子   

研究分野

  • ライフサイエンス / 生物有機化学
  • ナノテク・材料 / 構造有機化学、物理有機化学
  • ナノテク・材料 / 機能物性化学
  • ナノテク・材料 / ナノ材料科学
  • ナノテク・材料 / 生体化学

担当教育組織

職歴

  • 2017年04月 - 現在 北海道大学 電子科学研究所 准教授
  • 2011年10月 - 2017年03月 京都大学 物質―細胞統合システム拠点 特定拠点助教
  • 2010年04月 - 2011年09月 筑波大学 生命領域学際研究センター 博士研究員

学歴

  • 2005年04月 - 2010年03月   筑波大学大学院   数理物質科学研究科
  • 2007年09月 - 2008年08月   (留学) マドリッド-コンプルテンセ大学   化学部

所属学協会

  • フラーレン・ナノチューブ・グラフェン学会   日本ケミカルバイオロジー学会   アメリカ化学会   日本化学会   

研究活動情報

論文

  • Eri Hirata, Yuta Takano, Daisuke Konishi, Yukari Maeda, Natsumi Ushijima, Masako Yudasaka, Atsuro Yokoyama
    CHEMICAL COMMUNICATIONS 2023年08月 [査読有り]
     
    This study developed a novel antibacterial conjugate based on carbon nanohorns for peri-implantisis, an inflammatory disease around dental implants, which may result in failing implants by bone loss around them. The conjugate demonstrates much better photodurability than commonly used indocyanine green and a significant antibacterial effect under NIR illumination.
  • Jeladhara Sobhanan, Jose V Rival, Abdulaziz Anas, Edakkattuparambil Sidharth Shibu, Yuta Takano, Vasudevanpillai Biju
    Advanced drug delivery reviews 197 114830 - 114830 2023年04月20日 [査読有り]
     
    Luminescent nanomaterials such as semiconductor nanocrystals (NCs) and quantum dots (QDs) attract much attention to optical detectors, LEDs, photovoltaics, displays, biosensing, and bioimaging. These materials include metal chalcogenide QDs and metal halide perovskite NCs. Since the introduction of cadmium chalcogenide QDs to biolabeling and bioimaging, various metal nanoparticles (NPs), atomically precise metal nanoclusters, carbon QDs, graphene QDs, silicon QDs, and other chalcogenide QDs have been infiltrating the nano-bio interface as imaging and therapeutic agents. Nanobioconjugates prepared from luminescent QDs form a new class of imaging probes for cellular and in vivo imaging with single-molecule, super-resolution, and 3D resolutions. Surface modified and bioconjugated core-only and core-shell QDs of metal chalcogenides (MX; M = Cd/Pb/Hg/Ag, and X = S/Se/Te,), binary metal chalcogenides (MInX2; M = Cu/Ag, and X = S/Se/Te), indium compounds (InAs and InP), metal NPs (Ag, Au, and Pt), pure or mixed precision nanoclusters (Ag, Au, Pt), carbon nanomaterials (graphene QDs, graphene nanosheets, carbon NPs, and nanodiamond), silica NPs, silicon QDs, etc. have become prevalent in biosensing, bioimaging, and phototherapy. While heavy metal-based QDs are limited to in vitro bioanalysis or clinical testing due to their potential metal ion-induced toxicity, carbon (nanodiamond and graphene) and silicon QDs, gold and silica nanoparticles, and metal nanoclusters continue their in vivo voyage towards clinical imaging and therapeutic applications. This review summarizes the synthesis, chemical modifications, optical properties, and bioimaging applications of semiconductor QDs with particular references to metal chalcogenide QDs and bimetallic chalcogenide QDs. Also, this review highlights the toxicity and pharmacokinetics of QD bioconjugates.
  • Hanjun Zhao, Yuta Takano, Devika Sasikumar, Yukiko Miyatake, Vasudevanpillai Biju
    Chemistry – A European Journal 2022年10月12日 [査読有り][通常論文]
  • Fumika Kubota, Satrialdi, Yuta Takano, Masatoshi Maeki, Manabu Tokeshi, Hideyoshi Harashima, Yuma Yamada
    Journal of biophotonics 16 3 e202200119  2022年09月01日 [査読有り]
     
    Photodynamic therapy (PDT) is a cancer therapy that uses a photosensitizer (PS) in the presence of oxygen molecules. Since singlet oxygen is highly reactive, it is important to deliver it to the target site. Thus, an efficient drug delivery system (DDS) is essential for enhancing the efficacy of such a treatment and protecting against the side effects of PDT. Here, we report on attempts to increase the therapeutic effect of PDT by using a DDS, a lipid nanoparticle (LNP). We prepared a porphyrin analog, rTPA (PS) that was encapsulated in LNPs using a microfluidic device. The findings indicated that the internal structure of the prepared particles changed depending on the amount of rTPA in LNPs. The photoactivity and cell-killing effect of PS in LNPs also changed when the amount of the cargo increased. These results suggest that the internal structure of LNPs is important factors that affect drug efficacy. This article is protected by copyright. All rights reserved.
  • Devika Sasikumar, Yuta Takano, Hanjun Zhao, Reiko Kohara, Morihiko Hamada, Yasuhiro Kobori, Vasudevanpillai Biju
    Scientific Reports 12 1 2022年07月 [査読有り]
     
    Abstract Singlet oxygen (1O2), one of the most sought-after species in oxidative chemical reactions and photodynamic cancer therapy, is activated and neutralized in the atmosphere and living cells. It is essential to see "when" and "where" 1O2 is produced and delivered to understand and utilize it. There is an increasing demand for molecular sensor tools to capture, store, and supply 1O2, controlled by light and engineered singlet and triplet states, indicating the 1O2-capturing-releasing state. Here, we demonstrate the outstanding potential of an aminocoumarin-methylanthracene-based electron donor–acceptor molecule (1). Spectroscopic measurements confirm the formation of an endoperoxide (1-O2) which is not strongly fluorescent and remarkably different from previously reported 1O2 sensor molecules. Moreover, the photoexcitation on the dye in 1-O2 triggers fluorescence enhancement by the oxidative rearrangement and a competing 1O2 release. The unique ability of 1 will pave the way for the spatially and temporally controlled utilization of 1O2 in various areas such as chemical reactions and phototherapies.
  • Jeladhara Sobhanan, Yuta Takano, Sakiko Sugino, Eri Hirata, Shohei Yamamura, Vasudevanpillai Biju
    NPG ASIA MATERIALS 14 1 2022年01月 [査読有り]
     
    Amid the COVID-19 pandemic, cancer continues to be the most devastating disease worldwide. Liquid biopsy of circulating tumor cells (CTCs) has recently become a painless and noninvasive tool for obtaining carcinoma cell samples for molecular profiling. Here, we report efficient detection and collection of cancer cells in blood samples by combining stem cell antigen (CD44)-specific immunosilica particles and immunofluorescent quantum dots with spectrally and temporally resolved single-photon counting. We accurately detect 1-10 cells among 100 cancer cells of the breast, lungs, or cervix in 1 mL blood samples. In addition, the bright and narrowband emission of CdSe/ZnS quantum dots enables temporally and spectrally resolved photon counting for multiplexed cancer cell detection. The cancer cell-specific and large immunosilica particles helped us collect the specific cells. We validate the detection efficiency and multimodality of this strategy by time-stamped and energy-dispersed single-photon counting of orange- and red-emitting quantum dots and green-fluorescing nuclei stained with Syto-13/25 dye. Thus, the present work highlights the prospects of multimodal CTC detection for noninvasive cancer screening and postsurgical or therapeutic follow-up.
  • Mathias Wolf, Shuichi Toyouchi, Peter Walke, Kazuki Umemoto, Akito Masuhara, Hiroshi Fukumura, Yuta Takano, Michio Yamada, Kenji Hirai, Eduard Fron, Hiroshi Uji-i
    RSC ADVANCES 12 1 389 - 394 2021年12月 [査読有り]
     
    Organic materials have attracted considerable attention in nonlinear optical (NLO) applications as they have several advantages over inorganic materials, including high NLO response, and fast response time as well as low-cost and easy fabrication. Lithium-containing C-60 (Li@C-60) is promising for NLO over other organic materials because of its strong NLO response proven by theoretical and experimental studies. However, the low purity of Li@C-60 has been a bottleneck for applications in the fields of solar cells, electronics and optics. In 2010, highly purified Li@C-60 was finally obtained, encouraging further studies. In this study, we demonstrate a facile method to fabricate thin films of Li@C-60 and their strong NLO potential for high harmonic generation by showing its comparatively strong emission of degenerate-six-wave mixing, a fifth-order NLO effect.
  • Bhagyashree Mahesha Sachith, Takuya Okamoto, Sushant Ghimire, Tomokazu Umeyama, Yuta Takano, Hiroshi Imahori, Vasudevanpillai Biju
    The Journal of Physical Chemistry Letters 12 35 8644 - 8651 2021年09月09日 [査読有り]
     
    Interfacial electron transfer across perovskite-electron acceptor heterojunctions plays a significant role in the power-conversion efficiency of perovskite solar cells. Thus, electron donor-acceptor thin films of halide perovskite nanocrystals receive considerable attention. Nevertheless, understanding and optimizing distance- and thickness-dependent electron transfer in perovskite-electron acceptor heterojunctions are important. We reveal the distance-dependent and diffusion-controlled interfacial electron transfer across donor-acceptor heterojunction films formed by formamidinium or cesium lead bromide (FAPbBr(3)/CsPbBr3) perovskite nanocrystals with TiO2/C-60. Self-assembled nanocrystal films prepared from FAPbBr(3) show a longer photoluminescence lifetime than a solution, showing a long-range carrier migration. The acceptors quench the photoluminescence intensity but not the lifetime in a solution, revealing a static electron transfer. Conversely, the electron transfer in the films changes from dynamic to static by moving toward the donor-acceptor interface. While radiative recombination dominates the electron transfer at 800 mu m or farther, the acceptors scavenge the photogenerated carriers within 100 mu m. This research highlights the significance of interfacial electron transfer in perovskite films.
  • Lata Chouhan, Syoji Ito, Elizabeth Mariam Thomas, Yuta Takano, Sushant Ghimire, Hiroshi Miyasaka, Vasudevanpillai Biju
    ACS Nano 15 2 2831 - 2838 2021年02月23日 [査読有り]
     
    Despite the excellent optoelectronic properties of halide perovskites, the ionic and electronic defects adversely affect the stability and durability of perovskites and their devices. These defects, intrinsic or produced by environmental factors such as oxygen, moisture, or light, not only cause chemical reactions that disintegrate the structure and properties of perovskites but also induce undesired photoluminescence blinking to perovskite quantum dots and nanocrystals. Blinking is also caused by the nonradiative Auger processes in the photocharged quantum dots or nanocrystals. Herein, we find real-time suppression of halide vacancy-assisted nonradiative exciton recombination and photoluminescence blinking in MAPbBr3 and MAPbI3 perovskite quantum dots by filling the vacancies using halide precursors (MABr and MAI). Also, halide vacancy filling increases the photoluminescence quantum efficiencies and lifetimes of the quantum dots. We estimate the rates of halide vacancy-assisted nonradiative recombination at 1 × 108 s-1 for MAPbBr3 and 1.9 × 109 s-1 for MAPbI3 quantum dots. The real-time blinking suppression using the halide precursors and statistical analysis of the ON/OFF blinking time reveal that the halide vacancies contribute to the type-A blinking through charging and discharging. Conversely, the blinking of the quantum dots after halide vacancy filling is dominated by the type-B mechanism.
  • Prem Kumar, Jeladhara Sobhanan, Yuta Takano, Vasudevanpillai Biju
    NPG Asia Materials 13 1 2021年02月 [査読有り]
     
    A coronavirus (CoV) commonly known as SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) and causing COVID-19 (coronavirus disease of 2019) has become a pandemic following an outbreak in Wuhan. Although mutations in the SARS-CoV-2 spike glycoprotein (SGP) are obvious from comparative genome studies, the novel infectious nature of the virus, its new varients detected in the UK, and outside and recovery-death ratios of COVID-19 inspired us to review the mechanisms of the infection, replication, release, and transmission of progeny virions and the immune response in the host cell. In addition to the specificity of SARS-CoV-2 binding to angiotensin-converting enzyme 2 receptor and transmembrane protease serine 2, the varied symptoms and severity of the infection by the original and mutated forms of the virus suggest the significance of correlating the host innate and adaptive immunity with the binding of the virus to the mannose receptor via lipopolysaccharides (LPSs), toll-like receptors via LPS/proteins/RNA, and sialic acid (Sia) via hemagglutinin, or sugar-acid segments of glycans. HA-to-Sia binding is considered based on the innate Sia N-acetylneuraminic acid and the acquired Sia N-glycolylneuraminic acid in the epithelial cells and the sialidase/neuraminidase- or esterase-hydrolyzed release and transmission of CoVs. Furthermore, the cytokine storms common to aged humans infected with SARS-CoV-2 and aged macaques infected with SARS-CoV encourage us to articulate the mechanism by which the nuclear capsid protein and RNAs bypass the pattern recognition-induced secretion of interferons (IFNs), which stimulate IFN genes through the Janus-activated kinase-signal transducer and activator of a transcription pathway, leading to the secretion of antiviral proteins such as myxovirus resistance protein A/B. By considering the complexities of the structure, and the infectious nature of the virus and the structures and functions of the molecules involved in CoV infection, replication, and immune response, a new interface among virology, immunology, chemistry, imaging technology, drug delivery, and nanoscience is proposed and will be developed. This interface can be an essential platform for researchers, technologists, and physicians to collaborate and develop vaccines and medicines against COVID-19 and other pandemics in the future. Coronavirus: Nanomaterials help the fight against Covid-19Scientists in Japan have reviewed how nanoscience is helping us understand infection with SARS-CoV-2, the virus responsible for Covid-19, and the immune response it produces. The coronavirus pandemic has driven international scientific collaboration to identify treatments and develop a vaccine, not only between virologists and immunologists but also with researchers from a broad range of other disciplines including chemists, physicists and materials scientists. Vasudevanpillai Biju from Hokkaido University, Sapporo, and colleagues have reviewed the ongoing research at the interface of infectious diseases, biological chemistry and nanoscience aimed at answering key questions on how the virus functions. The authors summarize the use of nanomaterials in imaging techniques, vaccine development and drug delivery, while investigating problems associated with the toxicity of nanomaterials. Understanding these molecular interactions will help to fight this and future pandemics.Despite the hopeful signs of progress of COVID-19 vaccine development and vaccination, the highly infectious nature and mutations of SARS-CoV-2 are warnings of an infighting annual revival of the virus. This article clarifies the complexities of COVID-19 by referring to the molecular-level mechanisms of the infection, immune response, replication, and transmission of SARS-CoV-2, which are essential during the development of an effective vaccine or a drug to fight the pandemic. Furthermore, this article underscores the significance of an interface among chemistry, nanoscience, cell biology, immunology, and virology to resolve the challenges of COVID-19.
  • Satrialdi, Yuta Takano, Eri Hirata, Natsumi Ushijima, Hideyoshi Harashima, Yuma Yamada
    Nanoscale Advances 3 20 5919 - 5927 2021年 [査読有り]
     
    A photochemical reaction mediated by light-activated molecules (photosensitizers) in photodynamic therapy (PDT) causes molecular oxygen to be converted into highly reactive oxygen species (ROS) that are beneficial for cancer therapy. As the active oxygen consumer and the primary regulator of apoptosis, mitochondria are known as an important target for optimizing PDT outcomes. However, most of the clinically used photosensitizers exhibited a poor tumor accumulation profile as well as lack of mitochondria targeting ability. Therefore, by applying a nanocarrier platform, mitochondria-specific delivery of photosensitizers can be materialized. The present research develops an effective mitochondria-targeting liposome-based nanocarrier system (MITO-Porter) encapsulating a pi-extended porphyrin-type photosensitizer (rTPA), which results in a significant in vivo antitumor activity. A single PDT treatment of the rTPA-MITO-Porter resulted in a dramatic tumor inhibition against both human and murine tumors that had been xenografted in a mouse model. Furthermore, depolarization of the mitochondrial membrane was observed, implying the damage of the mitochondrial membrane due to the photochemical reaction that occurred specifically in the mitochondria of tumor cells. The findings presented herein serve to verify the significance of the mitochondria-targeted nanocarrier system for advancing the in vivo PDT effectivity in cancer therapy regardless of tumor type.
  • Sari Takada, Eri Hirata, Masatoshi Sakairi, Eijiro Miyako, Yuta Takano, Natsumi Ushijima, Masako Yudasaka, Sumio Iijima, Atsuro Yokoyama
    Artificial Cells, Nanomedicine, and Biotechnology 49 1 20 - 29 2021年01月01日 [査読有り]
     
    Direct contact between bone and implant materials is required for dental implants. Titanium is used for the implant material owing to its mechanical and biological properties. The anodisation as the surface treatment was employed to enhance osteogenesis around titanium. Moreover, carbon nanohorn (CNH), a type of nanometer-sized carbon material, was reported to promote the bone formation. Thus, it is expected that if the surface of anodised Ti (AnTi) is modified with CNHs, Ti-bone contact would be enhanced. In this study, the Ti surface was modified with CNHs by electrophoresis and obtained anodised titanium coated with CNHs (CNH/AnTi). In vitro, CNH/AnTi attracted osteoblastic cells more than AnTi, thereby the proliferation of osteoblastic cell was enhanced by CNH/AnTi more than by AnTi. In vivo, at 7 and 28 days after implantation of CNH/AnTi or AnTi into the rat femur, more aggressive bone formation was observed on the surface of CNH/AnTi than on AnTi. More importantly, the area where newly formed bone tissue directly attached to CNH/AnTi was significantly larger than that for AnTi, suggesting that "contact osteogenesis" was accelerated on CNH/AnTi during the early post-implantation period. CNH/AnTi would be advantageous especially for the early stages of bone regeneration after surgery.
  • Yuta Takano, Kazuaki Miyake, Jeladhara Sobhanan, Vasudevanpillai Biju, Nikolai V. Tkachenko, Hiroshi Imahori
    Chemical Communications 56 83 12562 - 12565 2020年09月 [査読有り][通常論文]
     

    (π-Extended porphyrin)–fullerene linked molecules are synthesized to utilize the molecular excited states induced by near-infrared light. One of the molecules successfully alters the membrane potential.

  • Yukari Maeda, Eri Hirata, Yuta Takano, Norihito Sakaguchi, Natsumi Ushijima, Ayumi Saeki, Sadahito Kimura, Ken-ichiro Shibata, Masako Yudasaka, Atsuro Yokoyama
    CARBON 166 36 - 45 2020年09月 [査読有り][通常論文]
  • Devika Sasikumar, Yuta Takano, Vasudevanpillai Biju
    Chemistry – A European Journal 2020年02月11日 [査読有り][通常論文]
  • Sankaramangalam Balachandran Bhagyalakshmi, Sushant Ghimire, Kiyonari Takahashi, Ken-ichi Yuyama, Yuta Takano, Takayoshi Nakamura, Vasudevanpillai Biju
    CHEMISTRY-A EUROPEAN JOURNAL 26 10 2133 - 2137 2020年02月 [査読有り][通常論文]
     
    Repeated absorption of emitted photons, also called photon recycling, in large crystals and thick films of perovskites leads to delayed photoluminescence (PL) and decrease of PL intensity. The role of distinct band gaps, which act as donors and acceptors of energy, and nonradiative energy transfer on such delayed, low intensity emission is yet to be rationalized. Here we report delayed emission by nonradiative energy transfer across a distribution of energy states in close-packed crystallites of cesium lead bromide CsPbBr3, formamidinium lead bromide FAPbBr(3), or the mixed halide FAPb(BrI)(3) perovskite synthesized in the form of thick pellets by the piezochemical method. The PL lifetime of the bromide-rich domain in the mixed halide pellet is considerably decreased when compared with a pure FAPbBr(3) pellet. Here the domains with higher bromide composition act as the energy donor, whereas the iodide-rich domains are the acceptors. Time-resolved PL measurements of CsPbBr3, FAPbBr(3), and the mixed halide FAPb(BrI)(3) perovskite pellets help us to clarify the role of nonradiative energy transfer on photon recycling.
  • Jeladhara Sobhanan, Philip Jones, Reiko Kohara, Sakiko Sugino, Martin Vacha, Challapally Subrahmanyam, Yuta Takano, Fred Lacy, Vasudevanpillai Biju
    Nanoscale 12 2020 22049 - 22058 2020年 [査読有り][通常論文]
     

    The cytotoxicity and genotoxicity of PbS quantum dots by photochemical etching and the release of lead ions.

  • Yuma Yamada, Yuta Takano, Satrialdi, Jiro Abe, Mitsue Hibino, Hideyoshi Harashima
    BIOMOLECULES 10 1 2020年01月 [査読有り][通常論文]
     
    There have been many reports on the relationship between mitochondrial oxidative stress and various types of diseases. This review covers mitochondrial targeting photodynamic therapy and photothermal therapy as a therapeutic strategy for inducing mitochondrial oxidative stress. We also discuss other mitochondrial targeting phototherapeutic methods. In addition, we discuss anti-oxidant therapy by a mitochondrial drug delivery system (DDS) as a therapeutic strategy for suppressing oxidative stress. We also describe cell therapy for reducing oxidative stress in mitochondria. Finally, we discuss the possibilities and problems associated with clinical applications of mitochondrial DDS to regulate mitochondrial oxidative stress.
  • Satrialdi, Reina Munechika, Vasudevanpillai Biju, Yuta Takano, Hideyoshi Harashima, Yuma Yamada
    Chemical Communications 56 7 1145 - 1148 2020年 [査読有り][通常論文]
     
    The uncontrolled production of reactive oxygen species during photodynamic therapy (PDT) induces oxidative stress. The full potential of PDT is accomplished by delivery of a pi-extended porphyrin-type photosensitizer into mitochondria of tumor cells using a MITO-Porter, a mitochondrial targeting nanodevice. This strategy can be implemented for innovative cancer therapy.
  • Tomokazu Umeyama, Takuma Hanaoka, Hiroki Yamada, Yuki Namura, Satoshi Mizuno, Tomoya Ohara, Jinseok Baek, JaeHong Park, Yuta Takano, Kati Stranius, Nikolai V. Tkachenko, Hiroshi Imahori
    Chemical Science 10 27 6642 - 6650 Royal Society of Chemistry ({RSC}) 2019年06月 [査読有り][通常論文]
     
    As structure defined cutouts of the graphene lattice, nanographene molecules have gained plenty of attention because of their high potential for versatile applications in organic electronics and energy conversion devices and as ideal model systems for the better understanding of intrinsic structure-property correlations of graphenes. In this study, well-defined nanographenes with sp2 carbon networks of different sizes, hexa-peri-hexabenzocoronene (HBC) and its rectangularly π-extended version, a short graphene nanoribbon (GNR), have been covalently functionalized with photoactive porphyrin molecules. On the basis of their spectroscopic studies, the photodynamics of the porphyrin-linked nanographenes was found to be influenced substantially by the size of the nanographenes. Photoexcitation of the porphyrin-HBC linked system led to exclusive energy transfer (EnT) from the first singlet excited state (S1) of the nanographene to the porphyrin, whereas opposite selective EnT occurred from the first and second singlet excited states (S1 and S2) of the porphyrin to the nanographene in the porphyrin-GNR linked system. In particular, ultrafast efficient EnTs from both the S2 and S1 states of the porphyrin to GNR mimic the corresponding ultrafast EnTs from the S2 and S1 states of carotenoids to chlorophylls in light-harvesting systems of natural photosynthesis. Such unique photophysical properties will be useful for the rational design of carbon-based photofunctional nanomaterials for optoelectronics and solar energy conversion devices.
  • Sushant Ghimire, Kiyonori Takahashi, Yuta Takano, Takayoshi Nakamura, Vasudevanpillai Biju
    Journal of Physical Chemistry C 123 45 27752 - 27758 2019年 [査読有り][通常論文]
     
    Photon recycling by multiple reabsorption-emission is responsible for the long-range energy transport in large crystals and thick films of lead halide perovskites, resulting in red-shifted and delayed emission. Apart from such a radiative process, nonradiative energy transfer influences photon recycling in perovskites with close-packed donor-acceptor-type states. In this study, we report the role of nonradiative energy transfer on photon recycling in piezochemically synthesized and close-packed pure and mixed halide methylammonium lead perovskites. Here, the pressure applied to precursors of perovskites helps us to synthesize and close-pack perovskite crystallites into pellets. Nonetheless, interestingly, we find that the applied pressure redistributes the emission maxima or band- gap of these perovskites. The temporally and spectrally resolved photoluminescence from the mixed halide sample unveils nonradiative energy transfer from a higher (bromide) to a lower (iodide) band-gap domain, where the rate of relaxation of the bromide domain is higher than that of the pure bromide perovskite. These results help us to confirm the role of nonradiative energy transfer on photon recycling in perovskites.
  • Sushant Ghimire, Lata Chouhan, Yuta Takano, Kiyonori Takahashi, Takayoshi Nakamura, Ken-ichi Yuyama, Vasudevanpillai Biju
    ACS Energy Letters 4 1 133 - 141 American Chemical Society ({ACS}) 2019年01月 [査読有り][通常論文]
     
    Lead halide perovskites are promising for energy harvesting and lighting applications. We show amplified emission from films of organic-inorganic or all-inorganic lead halide perovskite nanocrystals. Also, multicolor emission is detected from interfacial layers of chloride and bromide perovskites. While amplified emission originates from spatial confinement of manifold charge carriers in films, multicolor emission emanates from interfacial halogen-exchanged layers. In a film, the amplified emission is averaged over a large number of nanocrystals, which prevents us from detecting any spectral narrowing. Conversely, amplified spontaneous emission (ASE) and spectral narrowing are detected from an isolated perovskite microcrystal. Interestingly, under low-intensity excitation, a perovskite nanocrystal film shows unusually delayed emission, which becomes extremely fast and spatially confined at higher intensities of excitation light. By precisely detecting photoluminescence from an irradiated area and outside, we reveal the migration as well as confinement of photogenerated charge carriers in the film. The migration of charge carriers is more efficient in a film of organic-inorganic perovskites than that in all-inorganic perovskites.
  • Devika Sasikumar, Reiko Kohara, Yuta Takano, Ken-ichi Yuyama, Vasudevanpillai Biju
    Journal of Chemical Science 131 5 2019年01月 [査読有り][通常論文]
  • Elizabeth Mariam Thomas, Sushant Ghimire, Reiko Kohara, Ajith Nair Anil, Ken-ichi Yuyama, Yuta Takano, K George Thomas, Vasudevan Pillai Biju
    ACS Nano 12 9 9060 - 9069 American Chemical Society ({ACS}) 2018年08月 [査読有り][通常論文]
  • Anisotropic magnetic properties of an endohedral metallofullerene for molecular location sensing
    Yuta Takano, Ryo Tashita, Mitsuaki Suzuki, Hiroshi Imahori, Takeshi Akasaka
    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY 256 535 - ORGN AMER CHEMICAL SOC 2018年08月 [査読有り][通常論文]
  • Sushant Ghimire, Anjaly Sivadas, Ken-ichi Yuyama, Yuta Takano, Raju Francis, Vasudevanpillai Biju
    Nanoscale 10 28 13368 - 13374 Royal Society of Chemistry ({RSC}) 2018年04月 [査読有り][通常論文]
     

    The broad absorption of light in the UV-Vis-NIR region and the size-based tunable photoluminescence color of semiconductor quantum dots make these tiny crystals one of the most attractive antennae in solar cells and phosphors in electrooptical devices.

  • Yuta Takano, Erina Hanai, Hiroshi Imahori
    NANOSCALE 9 45 17909 - 17913 2017年12月 [査読有り][通常論文]
     
    Donor-acceptor-linked molecules have been synthesized and utilized to induce the rapid and site-selective lipid-oxidation in mitochondria by utilizing a photoinduced intermolecular electron transfer reaction. Two water-soluble donor-acceptor molecules (1 and 2) were designed and synthesized for this purpose. 2 was prepared to modulate its affinity to cell membrane in mitochondria. Confocal laser microscopy experiments revealed that 1 and 2 possess high localization abilities in mitochondria. By the photoinduced electron transfer, 2 exhibited the remarkable oxidation ability of lipids, mainly cardiolipin. In HeLa cells, 2 triggered mitochondrial lipid oxidation, which was followed by apoptotic cell death, under illumination within a few seconds. These results show that the present molecular system is highly promising to utilize the photoinduced intermolecular electron transfer reaction in a precise spatiotemporal manner in a cell by using light.
  • Yuta Takano, Reina Munechika, Vasudevanpillai Biju, Hideyoshi Harashima, Hiroshi Imahori, Yuma Yamada
    Nanoscale 9 47 18690 - 18698 Royal Society of Chemistry ({RSC}) 2017年12月 [査読有り][通常論文]
     
    It has been known for decades that intracellular redox reactions control various vital functions in living systems, which include the synthesis of biomolecules, the modulation of protein functions, and cell signaling. Although there have been several reports on the control of such functions using DNA and RNA, the non-invasive optical control of biological functions is an important ongoing challenge. In this study, a hybrid of an electron donor-acceptor linked molecule based on a ferrocene(Fc)-porphyrin(ZnP)-fullerene-(C-60) analogue and an elaborately designed nano-carrier, referred to herein as a MITO-Porter, resulted in a successful photoinduced intermolecular electron transfer reaction via the long-lived intramolecular charge separation, leading to site-specific reductive reactions in the mitochondria of living HeLa cells. A Fc-ZnP-C-60 linked molecule, 1-Oct, was designed and prepared for taking advantage of the unique photophysical properties with excellent efficiency (i.e. a long lifetime and a high quantum yield) for photoinduced charge separation. The targeted delivery of 1-Oct to mitochondria was accomplished by using a combination of the Fc-ZnP-C-60 molecule and a drug delivery nano-carrier, MITO-Porter, that was recently established by our group for intracellular cargo delivery. The successful delivery of 1-Oct by the MITO-Porter permitted the optically-controlled generation of O-2(-) in the mitochondria of HeLa cells and the following induction of apoptosis as a cell signalling response was observed in confocal laser microscopy experiments. The obtained results indicate the use of an electron donor-acceptor system such as this can be a promising tool for the non-invasive triggering of redox-coupled cellular activities in living systems.
  • Ning Cai, Yuta Takano, Tomohiro Numata, Ryuji Inoue, Yasuo Mori, Tatsuya Murakami, Hiroshi Imahori
    JOURNAL OF PHYSICAL CHEMISTRY C 121 32 17457 - 17465 2017年08月 [査読有り][通常論文]
     
    A series of ferrocene-porphyrin-fullerene linked triads (TC1, TC2, and TC4) possessing different numbers of cationic moieties were designed and prepared to achieve a high photoinduced charge-separation (CS) yield in a biological environment. In a solution, TC1, TC2, and TC4 demonstrated the formation of their nanoaggregates. Among the new triads, TC4 possessing the four cationic moieties exhibited the formation of a long-lived charge-separated state with the highest CS yield (86%) ever reported in cell membrane-like lipid bilayers, which is consistent with the largest change in the cell membrane potential of PC12 cells via the photoinduced CS under green light illumination. The highest CS yield in the biological environment can be rationalized by the well-tailored balance in hydrophobicity and hydrophilicity of TC4. This finding provides a strategy to improve greatly the photoinduced charge-separation yield of donor-acceptor linked molecules in the biological environment and also will be informative for extracting the full potential of the photoinduced charge-separated state toward biological applications.
  • Mitsuaki Suzuki, Michio Yamada, Yutaka Maeda, Satoru Sato, Yuta Takano, Filip Uhlik, Zdenek Slanina, Yongfu Lian, Xing Lu, Shigeru Nagase, Marilyn M. Olmstead, Alan L. Balch, Takeshi Akasaka
    CHEMISTRY-A EUROPEAN JOURNAL 22 50 18115 - 18122 2016年12月 [査読有り][通常論文]
     
    We report that Ce@C-2v(9)-C-82 forms a centrosymmetric dimer when co-crystallized with Ni(OEP) (OEP = octaethylporphyrin dianion). The crystal structure of {Ce@C-2v(9)-C-82}(2)center dot 2[Ni(OEP)]center dot 4C(6)H(6) shows that a new C-C bond with a bond length of 1.605(5) angstrom connects the two cages. The high spin density of the singly occupied molecular orbital (SOMO) on the cage and the pyramidalization of the cage are factors that favor dimerization. In contrast, the treatment of Ni(OEP) with M@C-2v(9)-C-82 (M = La, Sc, and Y) results in crystallization of monomeric endohedral fullerenes. A systematic comparison of the X-ray structures of M@C-2v(9)-C-82 (M = Sc, Y, La, Ce, Gd, Yb, and Sm) reveals that the major metal site in each case is located at an off-center position adjacent to a hexagonal ring along the C-2 axis of the C-2v(9)-C-82 cage. DFT calculations at the M06-2X level revealed that the positions of the metal centers in these metallofullerenes M@C-2v(9)-C-82 (M = Sc, Y, and Ce), as determined by single-crystal X-ray structure studies, correspond to an energy minimum for each compound.
  • Yuta Takano, Ryo Tashita, Mitsuaki Suzuki, Shigeru Nagase, Hiroshi Imahori, Takeshi Akasaka
    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 138 25 8000 - 8006 2016年06月 [査読有り][通常論文]
     
    Location recognition at the molecular scale provides valuable information about the nature of functional molecular materials. This study presents a novel location sensing approach based on an endohedral metallofullerene, Ce@C-82, using its anisotropic magnetic properties, which lead to temperature-dependent paramagnetic shifts in H-1 NMR spectra. Five site-isomers of Ce@C82CH2-3,5-C6H3Me2 were synthesized to demonstrate the spatial sensing ability of Ce@C-82. Single-crystal structures, absorption spectra, and density functional theory calculations were used to select the plausible addition positions in the radical coupling reaction, which preferentially happens on the carbon atoms with high electron density of the singly occupied molecular orbital (SOMO) and positive charge. Temperature dependent NMR measurements demonstrated unique paramagnetic shifts of the H-1 peaks, which were derived from the anisotropic magnetism of the f-electron in the Ce atom of the isomers. It was found that the magnetic anisotropy axes can be easily predicted by theoretical calculations using the Gaussian 09 package. Further analysis revealed that the temperature-dependent trend in the shifts is clearly predictable from the distance and relative position of the proton from the Ce atom. Hence, the Ce-encapsulated metallofullerene Ce@C-82 can provide spatial location information about nearby atoms through the temperature-dependent paramagnetic shifts of its NMR signals. It can act as a molecular probe for location sensing by utilizing the anisotropic magnetism of the encapsulated Ce atom. The potentially low toxicity and stability of the endohedral fullerene would make Ce@C-82 suitable for applications in biology and material science.
  • Yuta Takano, Tomohiro Numata, Kazuto Fujishima, Kazuaki Miyake, Kazuya Nakao, Wesley David Grove, Ryuji Inoue, Mineko Kengaku, Shigeyoshi Sakaki, Yasuo Mori, Tatsuya Murakami, Hiroshi Imahori
    CHEMICAL SCIENCE 7 5 3331 - 3337 2016年 [査読有り][通常論文]
     
    A series of porphyrin-fullerene linked molecules has been synthesized to evaluate the effects of substituents and molecular structures on their charge-separation yield and the lifetime of a final charge-separated state in various hydrophilic environments. The selected high-performance molecule effectively achieved depolarization in a plasma cell membrane by visible light as well as two-photon excitation using a near-infrared light laser. Moreover, it was revealed that the depolarization can trigger neuronal firing in rat hippocampal neurons, demonstrating the potential and versatility for controlling cell functions using light.
  • Michio Yamada, Satoru Sato, Yuta Takano, Lai Feng, Shigeru Nagase, Takeshi Akasaka
    Chemical Science of Electron Systems 133 - 153 2015年01月01日 [査読有り][通常論文]
     
    Endohedral metallofullerenes (EMFs) are hybrids of fullerenes and metal atoms or metal-containing clusters. The curved π-electron systems of the fullerene cages in EMFs are influenced strongly by the encaged metal species. The π-electron systems of EMFs, which stem from the electron transfer from the encaged metallic species, differ entirely from those of empty fullerenes. Accordingly, EMFs exhibit unique chemical reactivities and electronic properties that empty fullerenes never have. This chapter exclusively addresses the most recent achievements of our EMF research, ranging from basic chemical reactivity to material performance. This chapter includes four major parts. The first deals with the fascinating chemical reactivity of EMFs encountered very recently in our lab. The second part is devoted to EMF-based donor–acceptor conjugates, in which EMFs can display electron acceptor characters as well as electron donor characters, corresponding to the counterparts. In the third part, carrier transport properties of EMFs are summarized. The fourth part briefly describes the preparation and property of surface-grafted EMFs. Throughout, we hope that this chapter will stimulate readers to familiarize themselves with these fascinating molecules.
  • Yuta Takano, Zdenek Slanina, Jaime Mateos, Takayoshi Tsuchiya, Hirold Kurihara, Filip Uhlik, Maria Angeles Herranz, Nazario Martin, Shigeru Nagase, Takeshi Akasaka
    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 136 50 17537 - 17546 2014年12月 [査読有り][通常論文]
     
    Synthesizing unprecedented diamagnetic adducts of an endohedral metallofullerene was achieved by using 1,3-dipolar cycloaddition reaction of paramagnetic La@C-5-C-82 with a simultaneous hydrogen addition. The selective formation of two main products, La@C-5-C82HCMe2NMeCHPh (2a and 2b), was first detected by HPLC analysis and MALDI-TOF mass spectrometry. 2a and 2b-O, which was readily formed by the oxidation of 2b, were isolated by multistep HPLC separation and were fully characterized by spectroscopic methods, including 1D and 2D-NMR, UVvis-NIR measurements and electrochemistry. The hydrogen atom was found to be connected to the fullerene cage directly in the case of 2a, and the redox behavior indicated that the CH bond can still be readily oxidized. The reaction mechanism and the molecular structures of 2a and 2b were reasonably proposed by the interplay between experimental observations and DFT calculations. The feasible order of the reaction process would involve a 1,3-dipolar cycloaddition followed by the hydrogen addition through a radical pathway. It is concluded that the characteristic electronic properties and molecular structure of La@C-5-C-82 resulted in a site-selective reaction, which afforded a unique chemical derivative of an endohedral metallofullerene in high yields. Derivative 2a constitutes the first endohedral metallofullerene where the direct linking of a hydrogen atom has been structurally proven.
  • Yuta Takano, Yuki Nagashima, M. Angeles Herranz, Nazario Martin, Takeshi Akasaka
    BEILSTEIN JOURNAL OF ORGANIC CHEMISTRY 10 714 - 721 2014年03月 [査読有り][通常論文]
     
    The [4 + 2] cycloaddition of o-quinodimethanes, generated in situ from the sultine 4,5-benzo-3,6-dihydro-1,2-oxathiin 2-oxide and its derivative, to La metal-encapsulated fullerenes, La-2@C-80 or La@C-82, afforded the novel derivatives of endohedral metallofullerenes (3a,b, 4a,b and 5b). Molecular structures of the resulting compounds were elucidated using spectroscopic methods such as MALDI-TOF mass, optical absorption, and NMR spectroscopy. The [4 + 2] adducts of La-2@C-80 (3a,b, and 4a,b) and La@C-82 (5b), respectively, retain diamagnetic and paramagnetic properties, as confirmed by EPR spectroscopy. Dynamic NMR measurements of 4a at various temperatures demonstrated the boat-to-boat inversions of the addend. In addition, 5b revealed remarkable thermal stability in comparison with the reported [4 + 2] cycloadduct of pentamethylcyclopentadiene and La@C-82 (6). These findings demonstrate the utility of sultines to afford thermodynamically stable endohedral metallofullerene derivatives for the use in material science.
  • Yuta Takano
    FULLERENES NANOTUBES AND CARBON NANOSTRUCTURES 22 1-3 243 - 249 2014年01月 [査読有り][通常論文]
     
    Chemical syntheses and intramolecular electron transferring behaviors in the electron donor/acceptor conjugates based on endohedral metallofullerenes, La-2@C-80 and La@C-82, are overviewed. A study on the photo-induced excited states of a La-2@C-80 derivative connected with an electron donor revealed the formation of a distinct radical ion pair state. A La@C-82 derivative linked with an electron donor demonstrated an unprecedented ion/anion pair state, and La-2@C-80 tethered with an acceptor showed a fullerene donor system, in which the fullerene acts as an electron donor. Using endohedral lanthanide metallofullerenes for intramolecular electron transferring systems opens a new door for developing novel molecular materials.
  • Masanori Yamamoto, Yuta Takano, Yoshihiro Matano, Kati Stranius, Nikolai V. Tkachenko, Helge Lemmetyinen, Hiroshi Imahori
    JOURNAL OF PHYSICAL CHEMISTRY C 118 4 1808 - 1820 2014年01月 [査読有り][通常論文]
     
    Diazaporphyrin-C-60 linked dyad has been prepared to assess intrinsic electron transfer properties of diazaporphyrins for the first time. The dyad exhibited the efficient formation of a charge-separated state which has a lifetime 4x longer than that of the corresponding porphyrin-C-60 linked dyad with the same spacer. In accordance with this elongation, a SnO2 nanostructured electrode modified with the diazaporphyrin-C-60 dyad also revealed enhanced photocurrent generation in the visible region in comparison with that with the porphyrin-C-60 dyad. These results show that diazaporphyrins are highly promising building blocks for the construction of artificial photosynthesis and solar energy conversion.
  • Christina Schubert, Marc Rudolf, Dirk M. Guldi, Yuta Takano, Naomi Mizorogi, M. Ángeles Herranz, Nazario Martín, Shigeru Nagase, Takeshi Akasaka
    Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 371 1998 2013年09月13日 [査読有り][通常論文]
     
    In this paper, we report on the design, redox potentials, excited state energies and radical ion pair state energies in electron donor-acceptor conjugates comprising the electron-donating π-extended tetrathiafulvalene and several electron-accepting fullerenes. To this end, we contrast an empty fullerene, that is, C60, with two endohedral metallofullerenes, that is, open-shell La@C82 and closed-shell La2@C80, in terms of charge separation and charge recombination dynamics. © 2013 The Author(s) Published by the Royal Society. All rights reserved.
  • Takeshi Akasaka, Takahiro Tsuchiya, Lai Feng, Yuta Takano, Shigeru Nagase
    PHOSPHORUS SULFUR AND SILICON AND THE RELATED ELEMENTS 188 4 317 - 321 2013年04月 [査読有り][通常論文]
     
    Introducing organosulfur moieties into EMFs is a successful approach for the elucidation of electron transfer behavior of EMFs because the introduced sulfur atoms promote active redox properties in the fullerene molecules. Complexation of La@C-82 and unsaturated thiacrown ether, for instance, shows remarkable host-guest interaction and electron transfer to the fullerene. In contrast to these intermolecular electron-accepting properties of EMFs, intramolecular properties were revealed through studies of covalently bonded La-2@C-80 or La@C-82 and -extended tetrathiafulvalene (exTTF) dyads. These first milestones on the electron transfer behavior have inspired us to ascertain and then expand our knowledge of the unique characteristics of EMFs. These findings suggest potential applications of EMFs based on their unique molecular structure and electronic and magnetic properties as novel carbon nanomaterials.
  • Nuria Crivillers, Yuta Takano, Yuya Matsumoto, Javier Casado-Montenegro, Marta Mas-Torrent, Concepcio Rovira, Takeshi Akasaka, Jaume Veciana
    CHEMICAL COMMUNICATIONS 49 74 8145 - 8147 2013年 [査読有り][通常論文]
     
    A novel endohedral metallofullerene (EMF) has been designed and synthesised for its grafting on gold. The functionalization of the substrate resulted in a multifunctional surface displaying the properties of the EMF in solution.
  • Yuta Takano, Christina Schubert, Naomi Mizorogi, Lai Feng, Azusa Iwano, Mikimasa Katayama, M. Angeles Herranz, Dirk M. Guldi, Nazario Martin, Shigeru Nagase, Takeshi Akasaka
    CHEMICAL SCIENCE 4 8 3166 - 3171 2013年 [査読有り][通常論文]
     
    Intramolecular and intermolecular electronic interactions are important concepts for fabricating fullerene-based nanostructures such as bulk heterojunction (BHJ) solar cells and supramolecular assemblies. To ascertain differences of the molecular interactions depending on the electronic characteristics of the fullerene adducts, we have synthesized and investigated the [5,6]-open and [6,6]-closed adducts of C-60, which are covalently linked to pi-extended tetrathiafulvalene (exTTF) by a flexible sigma-bond chain. The two adducts were synthesized by means of cycloaddition reactions and were characterized using spectroscopic methods such as MALDI-TOF mass spectrometry and NMR spectroscopy. Electronic properties of the [5,6]-open and [6,6]-closed adducts were investigated in the ground and excited states using steady-state absorption spectroscopy, cyclic and differential pulse voltammetry (CV and DPV), fluorescence spectroscopy, and femtosecond time-resolved absorption spectroscopy. DFT calculations of the two adducts predict that the flexible bridge between C-60 and exTTF enables a closer proximity than the interlayer distance of graphite (3.35 angstrom), which dictates considerable pi-pi interactions. In comparing the [5,6]- and [6,6]-adducts, it is noteworthy to mention that the [6,6]-adduct revealed longer lifetimes of the photochemically formed radical ion pair states than that of the [5,6]-adduct, which is in contrast to results of recent investigations related to the photodynamics of [5,6]- and [6,6]-adducts of C-60. Titration experiments using references, namely [5,6]- and [6,6]-PC61BM, inferred that the [6,6]-adduct gives rise to stronger electronic interactions with exTTF than the [5,6]-adduct. Comprehensive understanding of the different molecular properties, which the [5,6]- and [6,6]-adducts exhibit, provides valuable information regarding the morphology and/or the electronic properties of C-60-based nanocomposites, such as C-60-based BHJ solar cells or supramolecular assemblies.
  • Yuta Takano, Shota Obuchi, Naomi Mizorogi, Raul Garcia, M. Angeles Herranz, Marc Rudolf, Dirk M. Guldi, Nazario Martin, Shigeru Nagase, Takeshi Akasaka
    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 134 47 19401 - 19408 2012年11月 [査読有り][通常論文]
     
    An endohedral metallofullerene, La-2@C-80, is covalently linked to the strong electron acceptor 11,11,12,12-tetracyano-9,10-antha-p- quinodimethane (TCAQ) by means of the Prato reaction, affording two different [5,6]-metallofulleropyrrolidines namely 1a and 2a, 1a and 2a were isolated and fully characterized by means of MALDI-TOF mass, UV-Vis-NIR absorption and NMR spectroscopies. In addition, cyclic voltammetry (CV) and differential pulse voltammetry (DPV) corroborated the unique redox character of 2a, that is the presence of the electron donating La-2@C-80 and the electron accepting TCAQ, Although a weak electronic coupling 'dictates the interactions between La-2@C-80 and TCAQ in the ground state, time resolved transient absorption experiments reveal that in the excited (i.e., pi-pi* centered at La-2@C-80) the unprecedented formation of the (La-2@C-80)(center dot+)-(TCAQ)(center dot-) radical ion pair state eevolves in nonpolar and polar media with a quantum efficiency of 33%.
  • Y. Takano, S. Obuchi, N. Mizorogi, R. García, M.A. Herranz, M. Rudolf, S. Wolfrum, D.M. Guldi, N. Martín, S. Nagase, T. Akasaka
    Journal of the American Chemical Society 134 39 16103 - 16106 2012年10月 [査読有り][通常論文]
     
    Electron donor-acceptor conjugates of paramagnetic endohedral metallofullerenes and pi-extended tetrathiafulvalene (exTTF) were synthesized, characterized, and probed with respect to intramolecular electron transfer involving paramagnetic fullerenes. UV-vis-NIR absorption spectroscopy complemented by electrochemical measurements attested to weak electronic interactions between the electron donor, exTTF, and the electron acceptor, La@C-82, in the ground state. In the excited state, photoexcitation powers a fast intramolecular electron transfer to yield an ion and radical ion pair state consisting of one-electron-reduced La@C82 and of one-electron-oxidized exTTF.
  • Tomohiro Numata, Tatsuya Murakami, Fumiaki Kawashima, Nobuhiro Morone, John E. Heuser, Yuta Takano, Kei Ohkubo, Shunichi Fukuzumi, Yasuo Mori, Hiroshi Imahori
    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 134 14 6092 - 6095 2012年04月 [査読有り][通常論文]
     
    The control of ion transport across cell membranes by light is an attractive strategy that allows targeted, fast control of precisely defined events in the biological membrane, Here we report a novel general strategy for the control of membrane potential and ion transport by using charge-separation molecules and light. Delivery of charge-separation molecules to the plasma membrane of PC12 cells by a membranous nanocarrier and subsequent light irradiation led to depolarization of the membrane potential as well as inhibition of the potassium ion flow across the membrane. Photoregulation of the cell membrane potential and ion transport by using charge-separation molecules is highly promising for control of cell functions.
  • Shinji Kitaura, Kei Kurotobi, Maki Sato, Yuta Takano, Tomokazu Umeyama, Hiroshi Imahori
    CHEMICAL COMMUNICATIONS 48 68 8550 - 8552 2012年 [査読有り][通常論文]
     
    The effects of fullerene bisadduct regioisomers on solar cell performance have been examined for the first time and the two substituent positions on C-60 have been found to have a large impact on the solar cell performance.
  • Hiroshi Imahori, Tomokazu Umeyama, Kei Kurotobi, Yuta Takano
    CHEMICAL COMMUNICATIONS 48 34 4032 - 4045 2012年 [査読有り][通常論文]
     
    Large pi-conjugated compounds are promising building blocks for organic thin-film electronics such as organic light-emitting diodes, organic field-effect transistors, and organic photovoltaics. Utilization of porphyrins and phthalocyanines for this purpose is highly fascinating because of their excellent electric, photophysical, and electrochemical properties as well as intense self-assembling abilities arising from pi-pi stacking interactions. This paper focuses on fundamental aspects of self-assembled structures that have been obtained from porphyrin and phthalocyanine building blocks and more complex composites for photoinduced charge separation and charge transport toward the potential applications to organic thin-film electronics.
  • Koji Sawai, Yuta Takano, Marta Izquierdo, Salvatore Filippone, Nazario Martin, Zdenek Slanina, Naomi Mizorogi, Markus Waelchli, Takahiro Tsuchiya, Takeshi Akasaka, Shigeru Nagase
    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 133 44 17746 - 17752 2011年11月 [査読有り][通常論文]
     
    Endohedral metallofullerenes are promising materials in biomedical and material sciences. In particular, they are of interest as agents for magnetic resonance imaging (MRI), photovoltaic devices, and semimetallic components. The synthesis of chiral endofullerenes represents one step further in the potential use of these carbon allotropes; however, this step has not been addressed so far. In this regard, enantiopure endofullerenes are expected to open new, avenues in fields in which chirality is a key issue Here, the synthesis and characterization of the first chiral endohedral metallofullerenes, namely, chiral bis-adducts of La@C(72), are reported: Eight optically active isomers were obtained by enantioselective 1,3-dipolar cycloaddition of a N-metalated azomethine ylide onto a non-isolated-pentagon rule metallofullerene derivative, La@C(72)(C(6)H(3)Cl(2)), catalyzed by a copper chiral complex. The chiral bis-adducts of La@C(72), isolated by nonchiral HPLC, showed optical purities as high as 98% as revealed by the remarkable positive or negative Cotton effects observed in the circular dichroic spectra.
  • Yutaka Maeda, Takahiro Tsuchiya, Xing Lu, Yuta Takano, Takeshi Akasaka, Shigeru Nagase
    NANOSCALE 3 6 2421 - 2429 2011年 [査読有り][通常論文]
     
    Since the first discovery of fullerenes in 1985, the insertion of one or more atoms into a hollow fullerene cage has been attempted. Furthermore, synthesis and extraction of metallofullerene, La@C-n, were reported in 1991. Recent successful isolation and purification of metallofullerenes have facilitated the investigation of their chemical properties. This mini-review presents a summary of the recent progress of chemical functionalization and supramolecular chemistry of M@C-82. Selective functionalization and successful structural analysis of derivatives have revealed their chemical features arising from endohedral metal doping.
  • Tsukasa Nakahodo, Midori O. Ishitsuka, Yuta Takano, Takahiro Tsuchiya, Takeshi Akasaka, M. Angeles Herranz, Nazario Martin, Dirk M. Guldi, Shigeru Nagase
    PHOSPHORUS SULFUR AND SILICON AND THE RELATED ELEMENTS 186 5 1308 - 1311 2011年 [査読有り][通常論文]
     
    Chemical functionalizations of an endohedral metallofullerene, La(2)@I(h)-C(80), and an empty fullerene, C(60), are demonstrated using organosulfur compounds. A novel donor-acceptor system of La(2)@I(h)-C(80)-exTTF (3) synthesized using the Prato reaction shows photo-induced intramolecular charge separation. On the other hand, the photoreaction of C(60) with N-p-toluenesulfonyl sulfilimine affords N-tosyl-1,2-aziridinofullerene (5). The first reversible interconversion of 1,2-aziridinofullerene and 1,6-azafulleroid was found for mono-substituted fullerenes by thermal rearrangement of 5 to 6. S,S-Diphenylsulfilimines (7) with an electron-donating group on the N atom reacts with C(60) to afford corresponding aziridinofullerenes (8-10) regioselectively. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.
  • Nobuaki Ueda, Hidefumi Nikawa, Yuta Takano, Midori O. Ishitsuka, Takahiro Tsuchiya, Takeshi Akasaka
    HETEROATOM CHEMISTRY 22 3-4 426 - 431 2011年 [査読有り][通常論文]
     
    The azacyclobutane structure is introduced into C-60 fullerene using a photochemical reaction with formamidines. Three azetidinofullerenes (2c-2e) were synthesized,. their molecular structures were characterized using H-1, C-13, and 2D NMR, matrix-assisted laser desorption ionization (MALDI) mass spectrometry, visible spectroscopy, and electro-chemistry. Single crystal X-ray crystallographic analysis of 2e reveals a unique strained four-membered ring including nitrogen atom attached on the fullerene cage. (C) 2011 Wiley Periodicals, Inc. Heteroatom Chem 22:426-431, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20703
  • Y. Takano, M.A. Herranz, N. Martín, S.G. Radhakrishnan, D.M. Guldi, T. Tsuchiya, S. Nagase, T. Akasaka
    Journal of the American Chemical Society 132 23 8048 - 8055 2010年06月 [査読有り][通常論文]
     
    Stable donor acceptor conjugates (2, 3) involving an endohedral metallofullerene, La(2) @ l(h)-C(80), and pi-extended tetrathiafulvalene (exTTF) have been synthesized by highly regioselective 1,3-dipolar cycloadditions of exTTF-containing azomethine ylides to the endofullerene, yielding exclusively [5,6] metallofulleropyrrolidines with C(1) symmetry in high yields (68-77%). The cyclic voltammograms (CVs) of the conjugates reveal the redox active character of the system due to the presence of both donor and acceptor groups, that is, exTTF and La(2) @ l(h)-C(80), respectively. Furthermore, the electrochemically reversible character of the endofullerene confirms the presence of the [5,6] adduct. Despite the relatively close proximity between the exTTF and the endohedral metallofullerene (EMF), only a weak electronic interaction was observed in the ground state, as evidenced by absorption spectroscopy and CV measurements of 2 and 3. On the other hand, in the excited state the fast formation of a radical ion-pair state (i.e., 6.0 x 10(10) s(-1)), that is, the reduction of the electron accepting La(2)@C(80) and the oxidation of exTTF, evolves with lifetimes as long as several ns (3.0 x 10(8) s(-1)) in toluene. Transient absorption spectroscopy experiments confirmed these observations.
  • Yuta Takano, Midori O. Ishitsuka, Takahiro Tsuchiya, Takeshi Akasaka, Tatsuhisa Kato, Shigeru Nagase
    CHEMICAL COMMUNICATIONS 46 42 8035 - 8036 2010年 [査読有り][通常論文]
     
    Retro-reaction of radical monoadducts of a paramagnetic endohedral metallofullerene, La@C-2v-C-82, is shown using thermal reaction in the presence of a radical trapping reagent, affording pristine La@C-2v-C-82 in high yield (96%).
  • Yuta Takano, M. Angeles Herranz, Nazario Martin, Gustavo de Miguel Rojas, Dirk M. Guldi, Ivan E. Kareev, Steven H. Strauss, Olga V. Boltalina, Takahiro Tsuchiya, Takeshi Akasaka
    CHEMISTRY-A EUROPEAN JOURNAL 16 18 5343 - 5353 2010年 [査読有り][通常論文]
     
    The decakis(trifluoromethyl)fullerene C-1-C-70(CF3)(10), in which the CF3 groups are arranged on a para(7)-meta-para ribbon of C-6(CF3)(2) edge-sharing hexagons, and which has now been prepared in quantities of hundreds of milligrams, was reacted under standard Bingel-Hirsch conditions with a bis-pi-extended tetrathiafulvalene (exTTF) malonate derivative to afford a single exTTF(2)-C-70(CF3)(10) regioisomer in 80% yield based on consumed starting material. The highly soluble hybrid was thoroughly characterized by using 1D H-1, C-13, and F-19 NMR, 2D NMR, and UV/Vis spectroscopy; matrix-assisted laser desorpdon ionization (MALDI) mass spectrometry; and electrochemistry. The cyclic voltammogram of the exTTF(2)- C-70(CF3)(10) dyad revealed an irreversible second reduction process, which is indicative of a typical retro-Bingel reaction; whereas the usual phenomenon of exTTF inverted potentials (E-ox(1)>E-ox(2)). resulting in a single, two-electron oxidation process, was also observed. Steady-state and time-resolved photolytic techniques demonstrated that the C-1-C-70(CF3)(10) singlet excited state is subject to a rapid electron-transfer quenching. The resulting charge-separated states were identified by transient absorption spectroscopy, and radical pair lifetimes of the order of 300 ps in toluene were determined. The exTTF(2)- C-70(CF3)(10) dyad represents the first example of exploitation of the highly soluble trifluoromethylated fullerenes for the construction of systems able to mimic the photosynthetic process, and is therefore of interest in the search for new materials for photovoltaic applications.
  • Yuta Takano, M. Angeles Herranz, Ivan E. Kareev, Steven H. Strauss, Olga V. Boltalina, Takeshi Akasaka, Nazario Martin
    JOURNAL OF ORGANIC CHEMISTRY 74 17 6902 - 6905 2009年09月 [査読有り][通常論文]
     
    The Diels-Alder reaction of C-1-C-70(CF3)(10) and 3,6-dimethoxy-1,2-quinodimethane leads regioselectively to the fort-nation of a new cycloadduct that has been fully characterized by spectroscopic and electrochemical methods as well its by X-ray diffraction.
  • Yuta Takano, Motoki Aoyagi, Michio Yamada, Hidefumi Nikawa, Zdenek Slanina, Naomi Mizorogi, Midori O. Ishitsuka, Takahiro Tsuchiya, Yutaka Maeda, Takeshi Akasaka, Tatsuhisa Kato, Shigeru Nagase
    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 131 26 9340 - 9346 2009年07月 [査読有り][通常論文]
     
    Derivatives of Ce@C-82(C-2v) have been synthesized and fully characterized, and their anisotropic magnetism has been observed as paramagnetic shifts in NMR measurements. Carbene addition by photochemical reaction afforded two isomers of Ce@C-82(C-2v)Ad (Ad = adamantylidene), 2a and 2b, demonstrating high regioselectivity. The two isomers were characterized using MALDI-TOF mass spectrometry, vis-NIR absorption spectroscopy, H-1 and C-13 NMR spectroscopy, and electrochemistry. The structure of the minor isomer (2b) was elucidated by single-crystal X-ray structural analysis. C-13 and H-1 NMR measurements revealed the characteristic anisotropic interaction between the f electron on the Ce atom and nuclear spins of the carbon atoms of the cage and the protons of the Ad group, respectively.
  • Yuta Takano, Akinori Yomogida, Hidefumi Nikawa, Michio Yamada, Takatsugu Wakahara, Takahiro Tsuchiya, Midori O. Ishitsuka, Yutaka Maeda, Takeshi Akasaka, Tatsuhisa Kato, Zdenek Slanina, Naomi Mizorogi, Shigeru Nagase
    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 130 48 16224 - 16230 2008年12月 [査読有り][通常論文]
     
    The thermal reaction of La@C-82(C-82) with 3-triphenylmethyl-5-oxazolidinone (1) in toluene affords benzyl monoadducts La@C-82(C-2v)(CH2C6H5) (2a-2d). The same monoadducts are also obtained by the photoirradiation of La@C-82(C-2v) in toluene without the existence of 1. These reactions are applicable to paramagnetic metallofullerenes, such as La@C-82(C-s) and Ce@C-82(C-2v). The photoirradiation of La@C-82(C-2v) in 1,2-dichlorobenzene in the presence of alpha,alpha,2,4-tetrachlorotoluene also affords the monoadducts La@C-82(C-2v)(CHClC6H3Cl2) (3a-3d). The monoadducts are fully characterized by spectroscopic analyses. Single-crystal X-ray structure analysis for 3d reveals the unique structure. Theoretical calculations show that the cage carbons having high,spin densities are selectively attacked by radical species to form the monoadducts linked by a carbon-carbon single bond. The thermal reaction of La@C-82(C-2v) with 1 in benzene affords metallofulleropyrrolidine La@C-82(C-2v)(C2H4NCPh3) (5), unlike the reaction in toluene.
  • Yutaka Maeda, Yuta Takano, Akiko Sagara, Masahiro Hashimoto, Makoto Kanda, Shin-ichi Kimura, Yongfu Lian, Tsukasa Nakahodo, Takahiro Tsuchiya, Takatsugu Wakahara, Takeshi Akasaka, Tadashi Hasegawa, Said Kazaoui, Nobutsugu Minami, Jing Lu, Shigeru Nagase
    CARBON 46 12 1563 - 1569 2008年10月 [査読有り][通常論文]
     
    Purified single-walled carbon nanotubes (SWCNTs) were produced using the arc-discharge method with a combination of air oxidation and dispersion-centrifugation processes in a tetrahydrofuran solution containing an amine as a dispersant. Subsequently, SWCNT samples were analyzed using thermo gravimetric analysis, vis-near infrared absorption spectroscopy, scanning electron microscopy, and Raman spectroscopy. Results revealed that metallic SWCNTs were enriched in a supernatant through the dispersion-centrifugation process. (C) 2008 Elsevier Ltd. All rights reserved.
  • Takahiro Tsuchiya, Ryotaro Kumashiro, Katsumi Tanigaki, Yoichiro Matsunaga, Midori O. Ishitsuka, Takatsugu Wakahara, Yutaka Maeda, Yuta Takano, Motoki Aoyagi, Takeshi Akasaka, Michael T. H. Liu, Tatsuhisa Kato, Kazutomo Suenaga, Jong S. Jeong, Sumio Iijima, Fumiko Kimura, Tsunehisa Kimura, Shigeru Nagase
    JOURNAL OF THE AMERICAN CHEMICAL SOCIETY 130 2 450 - + 2008年01月 [査読有り][通常論文]
     
    Nanorods of La@C-82(Ad) (Ad = adamantylidene) were prepared via the liquid-liquid interfacial precipitation method. From the SEM, HRTEM, EELS, and SADEP analyses, it was revealed that the nanorods consist of a single crystal of La@C-82(Ad). The field-effect transistor (FET) measurement of the La@C-82(Ad) nanorods shows a p-type action. The magnetic orientation of the nanorods was observed; that is, the nanorods of La@C-82(Ad) oriented with the nanorod axis perpendicular to the magnetic field.

書籍

  • Wang, Dan Ohtan, Packwood, Daniel 
    Springer 2021年 (ISBN: 9783030559236) viii, 257 p.
  • Chemical Science of pi-Electron Systems Part II. Curved pi-Electron Systems
    M. Yamada, S. Sato, Y. Takano, L. Feng, S. Nagase, T. Akasaka (担当:分担執筆範囲:Endohedral Metallofullerenes: From Chemical Reactivity to Material Performance)
    Springer, Berlin, Germany 2015年
  • Organic Nanomaterials -Synthesis, Characterization, and Device Applications-
    M. Yamada, X. Lu, L. Feng, S. Sato, Y. Takano, S. Nagase, T. Akasaka (担当:分担執筆範囲:Fundamental and Applied Aspects of Endohedral Metallofullerenes as Promising Carbon Nanomaterials)
    Wiley, London, U.K. 2013年

講演・口頭発表等

  • 革新的３次元細胞培養デバイスを利用した 高性能ミトコンドリア標的型光がん治療薬の開発  [招待講演]
    高野 勇太, 山田 勇磨, 宮武 由甲子, 繁富 香織
    第６回北海道大学部局横断シンポジウム 2020年10月
  • High efficiency photothermal convirsion of 9-substituted acridinium using photo-induced metastable betaine  [通常講演]
    高野 勇太, Devika Sasikumar, V. P. Biju
    2020年web光化学討論会 2020年09月
  • 光増感分子rTPAを搭載したミトコンドリア標的型ナノカプセルの構築および担癌モデルマウスを用いた癌光治療戦略の検証  [通常講演]
    山田 勇磨, サトリアルディ, 高野 勇太, Vasudevan, Pillai Biju, 原島 秀吉
    日本薬学会 第140年会 2020年03月 口頭発表（一般）
  • 9-置換アクリジニウムの光誘起準安定ベタインを利用した光熱変換の高効率化  [通常講演]
    高野 勇太, Sasikumar Devika, Vasudevan, Pillai Biju
    日本化学会第100春季年会 2020年03月 口頭発表（一般）
  • Delayed Red-Shifted Emission by Energy Transfer-Induced Photon Recycling in Pressed Lead Halide Perovskites  [通常講演]
    S. Bhagya Lakshmi, S. Ghimire, Y. Takano, K. Yuyama, V. P. Biju
    2019年光化学討論会 2019年09月 口頭発表（一般）
  • The Activated Reaction of Singlet Oxygen Trapped in an Electron Donor-Acceptor Molecular Sensor  [通常講演]
    D. Sasikumar, Y. Takano, M. Hamada, K. Yuyama, Y. Kobori, V. P. Biju
    2019年光化学討論会 2019年09月 ポスター発表
  • Mitochondrial targeting phototherapy by near-infrared light and pi-extended porphyrin/drug delivery carrier conjugate  [招待講演]
    髙野 勇太
    7th International conference for young chemists 2019年08月 口頭発表（招待・特別）
  • 有機分子の特異な光励起状態を利用したミトコンドリア内酸化・還元反応の誘起  [招待講演]
    髙野 勇太
    第72回日本酸化ストレス学会 2019年06月 口頭発表（招待・特別）
  • Steady-state Spectroscopic Studies of the Kinetics of Singlet Oxygen Sensing by 9-Substituted Anthracene Derivatives  [通常講演]
    D. Sasikumar, Y. Takano, K. Yuyama, V. P. Biju
    日本化学会第99春季年会 2019年03月 口頭発表（一般）
  • Conjugate of pi-extended porphyrin/drug delivery carrier for near-infrared cancer phototherapy  [通常講演]
    髙野 勇太, Satrialdi, 宗近 玲那, 原島 秀吉, 山田 勇磨, Vasudevan, Pillai Biju
    日本化学会第99春季年会 2019年03月 口頭発表（一般）
  • Anisotropic magnetic properties of an endohedral metallofullerene for molecular location sensing  [通常講演]
    Y. Takano, R. Tashita, M. Suzuki, H. Imahori, T. Akasaka
    56th The American Chemical Society meeting 2018年08月 口頭発表（一般）
  • Extended Diffusion of Charge Carriers in Perovskite Nanocrystal Assembly  [通常講演]
    S. Ghimire, L. Chouhan, K. Yuyama, Y. Takano, V. P. Biju
    日本化学会第98春季年会 2018年03月 口頭発表（一般）
  • Photoinduced reductive reaction in mitochondria by electron donor/acceptor linked molecules  [通常講演]
    Y. Takano, R. Munechika, V. P. Biju, H. Harashima, H. Imahori, Y. Yamada
    日本化学会第98春季年会 2018年03月 口頭発表（一般）
  • Development of Electron Donor-Acceptor Conjugates for Utilizing Photoinduced Charge Separated State in Cell Environment  [通常講演]
    Y. Takano, T. Numata, K. Fujishima, T. Murakami, M. Kengaku, S. Sakaki, Y. Mori, H. Imahori
    iCeMS International Symposium Hierarchical Dynamics in Soft Materials and Biological Matter 2015年09月 ポスター発表
  • Unprecedented Chemical Reactivities and Potential Utilities of Paramagnetic Endohedral Metallofullerenes  [招待講演]
    Y. Takano, T. Akasaka
    The 227th the Electrochemical Society (ECS) meeting, Chicago, U.S.A. 2015年05月 口頭発表（基調）
  • Development of Porphyrin-Fullerene Based Donor-Acceptor Conjugates for Utilizing Photoinduced Charge Separated State in Cell Environment  [通常講演]
    Y. Takano, H. Imahori
    第二回 ナノカーボンバイオシンポジウム, Tokyo, Japan 2015年02月 口頭発表（一般）
  • Development of Porphyrin-Fullerene Based Donor-Acceptor Conjugates for Utilizing Photoinduced Charge Separated State in Cell Environment  [招待講演]
    髙野 勇太
    International SPIRITS Symposium “Creation of Bio-Inspired, Non-Biological Mesoscale Hybrid Materials”, Kyoto, Japan 2014年11月 口頭発表（招待・特別）
  • Regulation of cell membrane potential and ion transport by utilizing photo-induced charge separation in organic molecules  [招待講演]
    髙野 勇太
    iCeMS International Symposium “Light Control in Cell Biology”, Kyoto, Japan 2014年06月 口頭発表（招待・特別）
  • Synthesis and Photophysical and Photoelectrochemical Properties of Diazaporphyrin-Fullerene Linked Dyad  [通常講演]
    M. Yamamoto, Y. Takano, Y. Matano, K. Stranius, N. V. Tkachenko, H. Lemmetyinen, H. Imahori
    225th the Electrochemical Society (ECS) meeting 2014年05月 口頭発表（一般）
  • Unique Molecular Properties of a Paramagnetic Endohedral Metallofullerene La@C82: Its Chemical Reactivities, and Electronic and Magnetic Properties  [招待講演]
    Y. Takano, J. Veciana, D. M. Guldi, N. Martin, T. Akasaka
    The 225th the Electrochemical Society (ECS) meeting, Orlando, U.S.A. 2014年05月 口頭発表（招待・特別）
  • Photoinduced depolarization in membrane of PC12 by fullerene-porphyrin linked molecules  [通常講演]
    Y. Takano, T. Numata, K. Miyake, T. Murakami, Y. Mori, H. Imahori
    The 36th annual meeting of the Molecular Biology Society of Japan, Kobe, Japan 2013年12月 ポスター発表
  • Unprecedented Chemical, Electronic and Magnetic Properties of a Paramagnetic Endohedral Metallofullerene La@C82  [招待講演]
    Y. Takano, J. Veciana, D. S. Guldi, N. Martin, T. Akasaka
    3th Symposium on Carbon Nanoforms, Madrid, Spain 2013年09月 口頭発表（招待・特別）
  • Intra-molecular electron accepting and donating systems based on endohedral metallofullerenes  [通常講演]
    Y. Takano, M. A. Herranz, N. Martin, D. M. Guldi, S. Nagas, T. Akasaka
    The 15th International Symposium on Novel Aromatic Compounds (ISNA) 2013年07月 ポスター発表
  • Photoregulation of Mammalian Cell Membrane Potential by Porphyrin/Fullerene based Donor/Acceptor Linked Molecules  [通常講演]
    Y. Takano, T. Numata, T. Murakami, F. Kawashima, N. Morone, J. E. Heuser, Y. Mori, H. Imahori
    The 15th International Symposium on Novel Aromatic Compounds (ISNA) 2013年07月 ポスター発表
  • Inhibition of potassium channels and control of cell membrane potentials by photo-induced charge separated molecules  [通常講演]
    Y. Takano, T. Numata, T. Murakami, F, Kawashima, N. Morone, J. E. Heuser, Y. Mori, H. Imahori
    第93回日本化学会春季年会 2013年03月 口頭発表（一般）
  • Establishment of intra-molecular electron accepting and donating systems based on endohedral metallofullerenes  [通常講演]
    Y. Takano, N. Mizorogi, M. A. Herranz, N. Martin, D. M. Guldi, S. Nagase, T. Akasaka
    第43回フラーレン•ナノチューブ・グラフェン総合シンポジウム, Miyagi, Japan 2012年09月 口頭発表（一般）
  • Establishment of intra-molecular electron accepting and donating systems based on endohedral metallofullerenes  [通常講演]
    Y. Takano, S. Obuchi, N. Mizorogi, M. A. Herranz, N. Martin, S. Wolfrum, D. M. Guldi, S. Nagase, T. Akasaka
    10th International Conference on Heteroatom Chemistry (ICHAC), Kyoto, Japan 2012年05月 口頭発表（一般）
  • Donor-Acceptor Conjugates of Lanthanum Endohedral Metallofullerene, La2@C80, and π-Extended Tetrathiafulvalene  [招待講演]
    Y. Takano, M. A. Herranz, N, Martin, S. G. Radhakrishnan, D. M. Guldi, T. Tsuchiya, T. Akasaka
    PACIFICHEM 2010, Honolulu, U.S.A. 2010年12月 口頭発表（招待・特別）
  • Development of Porphyrin-Fullerene Based Amphiphilic Donor-Acceptor Conjugates for Photocontrol on Cell Membrane Potential  [通常講演]
    Y. Takano, T. Numata, M. Kengaku, T. Murakami, Y. Mori, H. Imahori
    第95回日本化学会春季年会, Chiba, Japan 口頭発表（一般）
  • Porphyrin-Fullerene Based Donor-Acceptor Conjugates for Photocontrol of Cell Membrane Potentials  [通常講演]
    Y. Takano, T. Numata, K. Fujishima, T. Murakami, M. Kengaku, Y. Mori, H. Imahori
    The 227th the Electrochemical Society (ECS) meeting, Chicago, U.S.A. 口頭発表（一般）

その他活動・業績

  • 金属有機構造体（MOF）の光エネルギーのリレーを利用したイメージング
    髙野 勇太 日本薬学会誌 ファルマシア 55 (3) 253 -253 2019年03月 [査読無し][招待有り]
  • 光機能性フラーレンを用いた細胞機能の光制御アプローチ
    髙野 勇太 生物工学会誌 95 (12) 705 -707 2017年12月 [査読無し][招待有り]

受賞

  • 2022年03月 日本化学会北海道支部 日本化学会北海道支部奨励賞
  • 2016年10月 フラーレン・ナノチューブ・グラフェン学会 第13回大澤賞
     
    受賞者: 髙野 勇太
  • 2011年08月 日本化学会第4回関東支部大会 優秀講演賞
     
    受賞者: 髙野 勇太

共同研究・競争的資金等の研究課題

  • 高輝度安定型量子ドットと革新的マイクロ細胞組織による光治療薬開発と１分子動態解明
    日本学術振興会：科学研究費助成事業 基盤研究(B)
    研究期間 : 2021年04月 -2025年03月 
    代表者 : 高野 勇太
  • インプラント周囲炎治療を可能とする光応答性ナノカーボンインプラントの開発
    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 : 2020年04月 -2023年03月 
    代表者 : 平田 恵理, 横山 敦郎, 高野 勇太
  • 革新的口腔領域用生体材料を目的としたインテリジェントカーボンナノマテリアルの創製
    日本学術振興会：科学研究費助成事業 基盤研究(B)
    研究期間 : 2019年04月 -2022年03月 
    代表者 : 横山 敦郎, 赤坂 司, 山本 悟, 平田 恵理, 高野 勇太, 湯田坂 雅子, 岡崎 俊也
     
    本研究の目的は、カーボンナノ物質(CNMs)に薬剤や成長因子を担持させ徐放を制御する方法を確立し、CNMsのインテリジェント化を図ることによりインテリジェントカーボンナノマテリアルを創製し（i-CNMs)、i-CNMsとデンタルインプラントやGBR膜からなる革新的口腔領域用生体材料を開発することである。 本年度は、2種類のカーボンナノホーン（未酸化型：as-CNH、酸化型：CNHox550）を、ミノサイクリン（MC）を分散媒として水溶液中に分散させることに成功した。吸収スペクトル、熱重量分析および理論計算により、これらの分散液中ではMCがCNHに付着していることが示された。これらのMC/as-CNH複合体の抗菌活性をStreptcoccus mutans及びAggregatibacter actinomycetemcomitansを用いて調べたところ、MC/as-CNH複合体はMCと同等の細菌増殖抑制活性を維持していることが明らかとなった。透過型電子顕微鏡観察により、MC/as-CNH複合体は細菌と直接接触していることが示された。以上の結果から、MC/as-CNH複合体はインテリジェントカーボンナノマテリアル(i-CNMs)への応用の可能性が示唆された。さらに、ミノサイクリンのように医薬品の中には、内在性の薬効を発揮するとともに、カーボンナノ材料の分散を促進する機能を持つものがあることを明らかにした。 CNH、単層カーボンナノチューブ(SCNT)等のCNMsに関する生体反応の相違についても現在検索を進めている。
  • カーボンナノ物質の生物学的特性を用いた革新的組織修復・骨再生のストラテジーの構築
    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 -2021年03月 
    代表者 : 横山 敦郎, 山本 悟, 平田 恵理, 高野 勇太
     
    本研究の目的は、カーボンナノ物質(CNMs)の生体内分解性（吸収性）と生体に対する反応（刺激）の関係を明らかにするともに、我々が考案したCNMsの軽微な刺激により産生されるサイトカインがマクロファージを誘導、分化し、組織の間葉系細胞などを介して組織修復・骨再生を促進するという仮説を実証することにより、CNMsの生物学的特性を用いた新たな組織修復・骨再生のストラテジーを構築することである。本年度は、チタン(Ti)表面にカーボンナノホーン (CNHs) を修飾したCNH/Ti上でマクロファージを培養し、遺伝子発現を解析するとともに炎症性サイトカインの産生について検索した。 培養1日後のマイクロアレイによるGene Ontology解析において、Tiと比較してCNH/Tiは、マクロファージのDNAの転写、修復ならびに複製に関する遺伝子がdown regulateされていた。培養3日後のサイトカイン発現量については、CNH/TiのTNFαとIL-6はTiと比較して有意に低く、IL-10は、両者の間に有意差を認めなかった。TNFαとIL-6は、M1型マクロファージが分泌する炎症性サイトカインであり、骨形成の阻害因子であることが報告されている。一方、IL-10はM2マクロファージによる抗炎症性サイトカインとして知られている。以上のことから、Ti表面のCNHsは、DNAの転写、修復ならびに複製を制御し、炎症反応に影響を与えることが示唆された。
  • 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 : 2015年04月 -2018年03月 
    代表者 : 高野 勇太, 今堀 博, 村上 達也, 山田 勇磨
     
    本研究では、光による新たな細胞機能制御法および光治療法開発に向けた基盤技術として、分子の光誘起による電荷分離状態を利用した機能性分子開発を行った。主に両親媒性フェロセン-ポルフィリン-フラーレン連結型分子やメシチル-アクリジニウム骨格を有する分子について、細胞内光機能性を検討した。 成果として、細胞膜流動性を高めた分子の開発により高い電荷分離効率によって細胞膜の光誘起脱分極を起こすことに成功した。また、薬物輸送キャリアの利用または分子構造の最適化により生細胞のミトコンドリア選択的な分子輸送に成功し、その上での光照射により細胞内で光酸化・還元反応を引き起こす手法の開発に成功した。
  • 日本学術振興会：科学研究費助成事業 基盤研究(S)
    研究期間 : 2013年05月 -2018年03月 
    代表者 : 今堀 博, 梅山 有和, 高野 勇太, 村上 達也
     
    本研究では、光電荷分離状態を高効率で利用できる学理を確立し、有機太陽電池などの太陽エネルギー変換系の高効率化、および細胞機能制御へと展開していくことを狙った。すなわち、電子ドナー・電子アクセプター界面において、相互作用の指標である電子カップリングを強い状態から弱い状態へと連続的に変化させることで、励起錯体形成と電荷分離状態生成および電荷分離寿命とその生成収率の関係を系統的に明らかにできた。それによって、今まで系ごとに違った“光電荷分離状態”に関する統一した学理を構築する端緒が得られた。
  • 自己組織化による光機能発現
    日本学術振興会：科学研究費助成事業 基盤研究(A)
    研究期間 : 2013年04月 -2017年03月 
    代表者 : 今堀 博, 梅山 有和, 高野 勇太, 村上 達也
     
    本研究では自己組織化と光機能性分子/ナノ材料を組み合わせ、高効率エネルギー変換や新規生体機能を発現する次世代人工光合成を創成していくことを目指した。すなわち、ナノ領域での光機能性分子/ナノ材料、メゾ-マイクロ領域の自己組織化の鍵となる相互作用を理解し、制御することを目的とした。特に次のような学際的な手法により、特異な巨視的特性-機能を発現させることを行った。(1) 種々の分子/ナノ材料を階層的に自己組織化するための構造ー機能相関の学理を解明することを目指した。特にフラーレン・カーボンナノチューブ・グラフェンを半導体電極上に同時に自己組織化し、光電変換特性を発現することに成功した。 (2) ポルフィリン、共役ポリマー、フラーレン誘導体などの光機能性分子/ナノ材料を合理的に電極上に自己組織化させることで高効率太陽光エネルギー変換を実現することを目指した。特に 浸漬溶媒を変化することで酸化チタン上の色素分子の吸着状態を変化させ、結果として色素増感太陽電池性能を制御できることを見いだした。一方、有機薄膜太陽電池では共役ポリマーの主鎖構造にハロゲン原子を導入することでフラーレン誘導体との混合膜状態を変化させ、太陽電池特性を制御することに成功した。(3) 光電荷分離分子と生きた細胞を自己組織化を通じて融合することで細胞機能を光で制御することを行った。具体的には光電荷分離分子を生きた細胞膜に導入し光照射を行うと、細胞膜電位の脱分極が起こること、また光電荷分離寿命と脱分極の大きさに相関があることを見いだした。
  • 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 : 2013年04月 -2015年03月 
    代表者 : 今堀 博, 高野 勇太
     
    人工光合成を用いたエネルギー技術を確立するため、１）世界最高レベルの触媒回転数と触媒回転頻度を有する光増感型水分解触媒の開発、２）上記光増感型触媒を基にした人工光合成水分解デバイスの構築と高効率な物質変換系の実現、を目指した。高い酸化能力を有する一連のポルフィリン誘導体を合成し、光励起により電子移動が可能であること、生成した酸化状態が高い酸化力を有することを証明した。一方、Licheng Sunらが開発した世界最高レベルの水分解触媒活性を有するルテニウム錯体を合成し、両者を半導体電極に共吸着させた光電気化学セルを構築した。その結果、光駆動による水分解触媒反応が起こっていることを確認できた。
  • 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 : 2013年04月 -2015年03月 
    代表者 : 高野 勇太
     
    細胞膜電位は神経細胞等において各種細胞活動を制御する重要な要素である。そのため、膜電位の人為制御は医療分野への利用も期待できる細胞工学的アプローチである。本研究では、光により細胞膜電位を制御する新規手法の開発を行った。この目的のために、細胞環境において光誘起により高効率で電荷分離する分子の構造を模索し、凝集体構造をとりながらも４１%の量子収率を示す分子開発に成功した。この分子と、各種比較対象分子をPC12細胞やラット由来ニューロンの細胞膜に導入し、光照射することにより有意に細胞膜の脱分極を引き起こせることと、その脱分極の度合いが電荷分離状態への量子収率に相関を有していることを見出した。

教育活動情報

主要な担当授業

  • 大学院共通授業科目（一般科目）：自然科学・応用科学
    開講年度 : 2021年
    課程区分 : 修士課程
    開講学部 : 大学院共通科目
    キーワード : Science education, materials science, chemistry, physics, molecular science, nanoscience, nanotechnology, energy harvesting

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