High-speed atomic force microscopy is a powerful tool for the imaging of protein in solution and alive cells in spatial-resolution of nanometer and in time-resolution of several tens milliseconds, which so far made it possible to visualize the variety of biomolecules in process. In this symposium, we will make a presentation regarding our recent topics on the actual images of CRISPR-Cas9 that is the genome editing tool and membrane proteins.

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We describe the membrane surface-enhanced Raman spectroscopy (MSERS) using phospholipidmodified Au nanoparticles (Au@PL), and report the properties of the self-assembled PL membranes on the Au nanoparticle. The Raman intensity per PL concentration increased by 50-170 times with Au@PL, depending on the aggregation degree of Au@PLs. The enhancement at 714 cm-1 (EF(714)) varied with the hydrocarbon chain length of the PLs and the assembleddegree of Au@PLs. In calculation, the EF(714),assembled was estimated to be 111-142 when the distance between AuNPs was 7.0-7.5 nm, which was correlated to the speculative enhancement factor, suggesting that the assembly of the Au@PLs contributed to the MSERS. We prepared the DC-cholesterol modified Au nanoparticles (Au@PL), and applied them to induce the complex formation with small nucleic acid such as tRNA, amyloid beta peptide.

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By using cryo-TEM, we have determined the conformation of receptors and ion channels in thin ice under vacuum. For the observation in water, SEM system was improved to develop the atomospheric SEM (ASEM). ASEM allows us to observe samples within 2-3 μm in depth. The resolution near SiN film was 8 nm. We have directly observed fixed cells and tissues in aqueous liquid by using ASEM. We are aiming further understandings of targets using both techniques.

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Understanding the dynamics of lubricants on friction surfaces under lubricating condition is important for improving their tribological properties. Nonlinear optical techniques, such as sum-frequency generation (SFG), are particularly attractive tools for studying buried interfaces nondestructively at submonolayer sensitivity. Therefore, we developed a prism-on-disk tribometer equipped with infrared-visible SFG spectroscopy to analyze the buried friction interface. Using this equipment, we analyze the molecular orientation of oiliness additive of stearic acid with respect to the friction direction.

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Ionic liquid expected to be new candidate for lubricant oil. It was well known that the adsorption structures of ionic liquid play a very important role in lubrication mechanism. However, the presence of water impairs the tribological performance of ionic liquid. The understanding of effect of water on adsorption structures of ionic liquids is very important issue. In this study, the adsorption structures of ionic liquids and the effect of water on these structures were investigated using frequency modulation atomic force microscopy.

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[in Japanese]

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[in Japanese]

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Muon spin relaxation method can probe distribution of local magnetic field and dynamics, and it is a sensitive method for dynamics in the MHz to GHz band. Thus, it is a complementary method to nuclear magnetic resonance and electron spin resonance. In the presentation, we report the result of molecular dynamics probed by muon spin relaxation. We also discuss the application to the interface measurement by muon spin relaxation.

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Sum frequency generation (SFG) spectroscopy is a surface-sensitive technique that can be applied to liquid and solid surfaces and interfaces. We upgraded SFG to heterodyne-detected (HD-) SFG and applied it to water and ice surfaces. In the oral presentation, I will show the principle of HD-SFG, the present status of SFG studies all over the world, and our latest results.

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Liquid interface is a special region in which the solvent structure, the electrostatic potential, and the intermolecular interaction exhibit sudden changes in a very thin region. Because the reaction intermediates and molecular aggregates that can not form in the bulk phase are easily generated, liquid interface provides a specific reaction field. In the present study, we investigated the initial dissolution of molecules into the interfacial surface of ionic liquid (IL) [C₄min] [NTf2] by using the King and Wells (KW) method.

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SIMS with swift heavy ions provides us new opportunities to enhance secondary ion yields of organic molecules but also to measure in the “Ambient” using their high transmission properties. SIMS measurement of volatile organic molecules and moisturized materials is possible under ambient pressure. We will discuss surface prosperities of liquid surfaces and solid-liquid interfaces.

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We present simulation studies of solid-liquid interface in molecular level. At the interface, solid materials, solvent and solute exists. We introduce an analysis of the surface of the binder of the negative electrode of secondary battery and show the electrical dynamics at the surface. As an example of non-polar system, we show an example of the analysis of the formation process of boundary lubrication oil film, and discuss the coloid science of non-polar solution.

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[in Japanese]

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Ion transfer at interface between electrode/electrolye plays an important role for energy conversion devices such as lithium-ion batteries. In this conference, I will talk about the lithium-ion transfer at interfaces between electrode/electorlyte and electrolyte/electrolyte together with activation energies. Further, anion transfer at interface between electrode/electrolyte for hybrid capacitor will be described.

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Oxide semiconductors have various useful material properties such as a wide bandgap and capability of low temperature film formation and therefore can be formed on a glass or plastic substrate by a sputtering or other methods. A thin film transistor is becoming its major application as a pixel driver for LCD or OLEDs. We focused on zinc oxide among oxide semiconductors and evaluated the electron transport properties using a single crystal heterostructure formed by MBE in order to evaluate the potential performance of ZnO based electronic devices. In addition to material physical properties, we also report application to sensors.

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[in Japanese]

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[in Japanese]

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[in Japanese]

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We have prepared 20-nm-thick nitrogen-doped LaB₆ film on SiO₂ substrate, and performed ex-situ measurements on the work function and the local density of states using STM.
Our results demonstrates that, even after air exposure, the work function of 2.35 eV was revived by annealing at 500 ℃ under UHV conditions. Furthermore, the characteristic features in the obtained dI/dV spectrum have good agreements with the previous photoemission data and the theoretical calculation on the pristine clean LaB₆.
We anticipate that the N-doped LaB₆ is a low work-function film material exhibiting high chemical stability.

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Exotic functions of thin films are quite often connected to the unique atomic and molecular features of buried layers and interfaces. In reality, the structures are far from uniform, but seeing such inhomogeneity is extremely difficult. The present research concerns how to solve the difficulty. The novel technique developed is the X-ray reflectivity imaging. While ordinary X-ray reflectivity gives very precise information on the electron density profile along the depth in thin films, the method can have some imaging capability, by combining with the image reconstruction scheme. Some practical applications will be reported.

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[in Japanese]

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Tin monoxide (SnO) is one of the p-type semiconductors, which can be applied to many electronic and photonic devices. We demonstrated rf-sputtering using various oxygen partial pressures to prepare oxide thin films, and then their crystal structure and optical property were investigated. As a result, although the SnO₂ phase is stable, the p-type of the SnO films were successfully obtained. Further, Sn₃O₄ or Sn₅O₆ were observed in films formed by oxygen partial pressure below 0.03Pa.

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[in Japanese]

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Spin transport and spin conversion in solids using spin current has been attracting tremendous attention in solid state physics. In this talk, spin current propagation in two-dimensional electron gases formed in oxide hetero-interface at room temperature and spin relaxation physics will be introduced and discussed.

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[in Japanese]

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We studied the growth of graphene on the Ni(110) surface covered with sulfur atoms by using Auger electron microscopy and scanning tunneling microscopy with the aid of density functional theory calculations. We found that the existence of sulfur atoms greatly suppresses the growth speed and the size of graphene.

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[in Japanese]

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During the chemical vapor deposition growth of graphene, the sample temperature reaches 1000℃. The thermal radiation intensities from the graphene and substrate are proportional to their emissivity. The emissivity of graphene is expected to be high, since graphene shows the high absorptance up to 2.3% for monolayer. Here we report the in-situ microscopic observation of the graphene growth on Cu and Au substrates with low emissivity using thermal radiation contrast. We revealed the kinetics of the graphene growth by chemical vapor deposition on such the substrates.

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Reservoir computing is a bio-inspired, machine-learning system. Dynamics within the reservoir is harnessed for further computation and problem-solving. Phosphomolybdic acid (PMo₁₂) molecules functionalised on carbon nanotube (CNT) could provide dynamics for the implementation of reservoir computing system. CNTs were aligned in parallel to each other between two electrodes, and soaked in PMo₁₂ solution for functionalisation. Insertion of PMo₁₂ molecule between the CNT and the electrode has caused conductance switching phenomenon in the output current. Output signals with rich dynamics have been obtained, indicating the feasibility of CNT-PMo₁₂ device as a candidate for reservoir computing implementation in nano-scale system.

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Graphene has high transparency, flexibility and electric conductivity. It can be used for electronic devices. High quality graphene is obtained on metal substrates such as Au, Cu, and Ni. The surface of such a graphene can be modified by electrochemical grafting to control its electronic properties. However, effects of underlying metal substrates on the electrochemical reactivity of graphene are unclear. In this study, we performed electrochemical grafting of aryl molecules onto graphene supported on Au, Cu, and Ni. Graphene before and after molecular grafting was characterized by spectroscopic techniques including Raman spectroscopy.

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Thermoelectric generation is a potential key technology for recovering energy from waste heat. Enhancement of thermoelectric (TE) performance is an important issue, but it is not easy to develop the high-performance TE materials due to the trade-off relation between conductivity and Seebeck coefficient. In this study, we focused on the bilayer graphene, whose band-edge structure can be modulated by the vertical electric field. To validate TE performance of the bilayer graphene, we have investigated TE response using thermal Green’s function methods and Kubo formula. Furthermore, we present thermoelectric properties of bilayer graphene on ferroelectrics substrate.

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Monolayer graphene exhibits excellent mechanical strength, and thus has been attracted attention as novel energy storage material. In this study, storage of hydrogen molecule at the graphene-Au(111) interface was evaluated by electrochemical method. Hydrogen molecules were intercalated at the graphene/Au(111) interface by electrochemical hydrogen evaluation reaction process. STM analysis showed that after the reaction, several nanometer-size bubble structures could be produced at the interface, suggesting high possibility of usage of novel hydrogen storage.

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[in Japanese]

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[in Japanese]

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Revolutional development on the apratus for the high-resolution electron energy loss spectrpscopy has enabled us to probe the surface phonon dispersion in a drastically shortened time than the conventional one. In the presentation, the investigation on the change in the phonon dispersion of the acoustic modes of the graphene/graphite caused by the inter-layer interaction, and the electron-phonon coupling.

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In this research, we have developed spectro-electric technique for the recognition of the adsorption site in the single molecular junction. We measured current-voltage (I-V) response and surface enhanced Raman scattering of the BDT molecular junction at ambient condition. As a result, we detected the SERS signal of the BDT molecular junction and we detected the three distinct conductance states of the BDT molecular junction. By analyzing the I-V response, we successfully assigned these three conductance states to each adsorption site in the single molecular junction.

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[in Japanese]

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In order to express for the information processing function with molecular element, it has been proposed Au nanoparticles-molecular network system, which is composed of Au nanoparticles with high conductive molecules. Such network is induced by energy barrier at multiple interfaces. In this study, we measured the conductivity of 2-dimentional network structure formed between multiple electrodes of self-doped polyaniline and Au nanoparticles. This network system composed of 2-dimensional array at nanoparticles spacing. In addition, relationship between structure and electrical characteristic of interface in Au-polyaniline network system was investigated by use of laser Raman spectroscopy.

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Understanding and utilization of the nonlinear electrical properties via molecules are important for the realization of information processable molecular devices.
To date, we reported the nonlinear electrical conduction with the clear threshold voltage of Ru complex (N719) using the device structure in which gold nanoparticles are bridged on a nanogap electrodes modified with N719 and a self-assembled monolayer.
In this publication, we report the condition of decoupling of the electronic state between N719 and electrode. Moreover, we present that electrical conduction of N719 was realized by the resonant tunneling conduction model.

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We previously reported stochastic resonance (SR) in DNA/Cytochrome C molecular network with an external noise generator. For the realization of SR with molecular device, molecular noise generator is required. In this work, we report the line patterned conductive polymer / gold nanoparticles network in which the electrical noise was generated with the light irradiation (λ=532nm). The network was fabricated between the gold electrodes by nanopipette. The noise amplitude was approximately 10^-3 times the current level and stable during the optical stimulation. We will also discuss the mechanism of noise generation at the presentation.

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Polyoxometalate (POM) shows multivalent oxidation-reduction characteristics, and interesting electrical properties such as negative differential resistance and pulse generation have been reported and attracted attention as a neuro-mimetic substance. In this research, electrical characteristics when POM is networked with gold fine particles were investigated. In the electrical characteristics up to the applied voltage of 80 V, two kinds of results were obtained, the current value being approximately 10^-4 A and roughly classified into 10^-9 A . Negative differential resistance was observed in the former case, and hysteresis characteristics were observed in the latter case.

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Design and control of gold nanoparticles(AuNP)/ semiconductor interface is necessary for charge separation because electrons generated by AuNP plasmon absorption have quit short life time. We reveal charge separation is achieved by inserting organic molecule layer between TiO₂ and AuNP so far. We mainly report the effect of HF treatment of TiO₂ on the alignment of electronic state and the charge separation by means of Kelvin probe force microscopy.

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In this study, we focus on ruthenium dinuclear complexes (Ru-comp) as the molecular elements with switching characteristics, and the electrical properties of Ru-comp monolayer on ITO substrate were investigated using atomic force microscopy. Different nonlinear I-V characteristics were observed depending on slight difference in the chemical structure of the bridging ligands of Ru-comp. We also found the Ru-comp which showed current hysteresis characteristics and investigated its voltage dependence and relaxation time. In this presentation, the correlation between mixed valence states and switching characteristics will be also discussed.

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[in Japanese]

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In the current-voltage measurement of DNA-protein complex, the characteristics show threshold properties depending on temperature, and these properties can be explained by Coulomb blockade model.
In our research, we reported electric characteristics of the ultrathin film of cytochrome c and compared this results with previous reports. As a result, it is confirmed that the charge energy determines threshold voltage comes from single protein molecules, and as the structural factor, DNA determines the dimension of the Coulomb blockade array.

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[in Japanese]

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To simulate solid-liquid interfaces, LAUE-RISM simulation has attracted much attention. This method is a hybrid of density functional theory for electronic structure and RISM for liquid distribution specialized on electrochemical interfaces. By using the LAUE-RISM method, we can simulate interface properties such as electric-double layer structure and ionic adsorption with low computational cost. Here, we would like to present our simulation results on the mica-KCl aqueous solution interfaces.

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Steric effect in O2 sticking on Pt(553) and (533) surfaces has been investigated by using a state-selected O2 beam to understand the reactivity of steps on Pt surface. The results indicate the followings. (1) O2 molecules parallel to the step are more reactive than those perpendicular to it. This tendency is larger on (533) surface. (2) O2 molecules perpendicular to the step surface are less reactive than those parallel to it. (3) No steric effect is included in O2 trapping process.

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