Browsing by Author "Yuyama, Ken-ichi"

Now showing 1 - 20 of 31

A Single Spherical Assembly of Protein Amyloid Fibrils Formed by Laser Trapping
(2017-06-06)
Yuyama, Ken-ichi
;
Ueda, Mariko
;
Nagao, Satoshi
;
Hirota, Shun
;
Sugiyama, Teruki
Protein amyloids have received much attention owing to their correlation with serious diseases and to their promising mechanical and optical properties as future materials. Amyloid formation has been conducted by tuning temperature and chemical conditions, so that its nucleation and the following growth are analyzed as ensemble dynamics. A single spherical assembly of amyloid fibrils of cytochrome c domain-swapped dimer was successfully generated upon laser trapping. The amyloid fibrillar structure was confirmed by fluorescence characterization and electron microscopy. The prepared spheres were further manipulated individually in solution to fabricate a three-dimensional microstructure and a line pattern. Amyloid formation dynamics and amyloid-based microstructure fabrication are demonstrated based on direct observation of a single spherical assembly, which foresees a new approach in amyloid studies.
Assembling and crystallization of amino acids and proteins by intense laser irradiation in solution
(2011-08-28)
Masuhara, Hiroshi
;
Sugiyama, Teruki
;
Yuyama, Ken-ichi
;
Uwada, Takayuki
;
Miura, Atsushi
Bubble generation and molecular crystallization at solution surface by intense continuous-wave laser irradiation
(2018-08-01)
Chen, Jim Jui-Kai
;
Yuyama, Ken-ichi
;
Sugiyama, Teruki
;
Masuhara, Hiroshi
;
應用化學系
We demonstrate bubble generation outside the focus induced by irradiating a focused 1064 nm continuous-wave laser beam into the surface of water and L-phenylalanine H2O solutions. In the former case of water, bubbles stay at positions distant from the focus during the irradiation, and their size and location are controllable by the laser power. In the latter solution, bubbles move outward toward the surrounding area, and subsequently crystallization takes place at the focus. We discuss these behaviors from the viewpoints of the temperature elevation accompanying the decrease in air solubility as well as the optical trapping of L-phenylalanine clusters giving a single crystal. (C) 2018 The Japan Society of Applied Physics
Control of Crystal Polymorph of Glycine by Photon Pressure of a Focused Continuous Wave Near-Infrared Laser Beam
(2010-02-04)
Rungsimanon, Thitiporn
;
Yuyama, Ken-ichi
;
Sugiyama, Teruki
;
Masuhara, Hiroshi
;
Tohnai, Norimitsu
Crystal polymorph of glycine is controlled by tuning the power of a linearly polarized continuous wave 1064-nm laser beam. Upon focusing the beam to the air/solution interface of a supersaturated glycine/D(2)O solution, it single crystal is spatiotemporally formed at a focal spot within a few seconds to a few ten of seconds. Fourier transform infrared measurement and single-crystal X-ray crystallographic analysis of the fabricated single crystal reveal that two polymorphs of alpha- and gamma-forms are prepared depending on the laser power. The probability of gamma-form are prepared depending on the laser power. The probability of gamma-form preparation, which is not available under ambient conditions arises upto 50% at 1.3 W laser power after an objective lens. The mechanism of the polymorph control is discussed in view of both photon pressure and local temperature elevation due to laser irradiation at the focal spot.
Crystal Growth and Dissolution Dynamics of L-Phenylalanine Controlled by Solution Surface Laser Trapping
(2018-11-01)
Yuyama, Ken-ichi
;
Chiu, Ding-Shiang
;
Liu, Yen-En
;
Sugiyama, Teruki
;
Masuhara, Hiroshi
We present sequential behavior of nucleation, growth, and dissolution of an L-phenylalanine plate-like crystal which is induced by a focused continuous-wave near-infrared laser beam in unsaturated solution. Upon the laser irradiation into the air/solution interface, the single crystal is generated from the focus and continuously grows two-dimensionally while being trapped by the laser. The crystal growth is stopped when the laser power is decreased. The crystal size is kept constant for a certain time period, and then the crystal starts dissolution. The dissolution is also induced by moving the crystal from the focus at the air/solution interface. When the crystal is shifted far from the original position where the crystallization is induced, the crystal starts dissolution at a certain distant position. Based on the demonstrations of the crystal size change during the laser manipulation, we conclude that the L-phenylalanine crystal is surrounded by a highly concentrated domain of a few hundreds of micrometers consisting of L-phenylalanine liquid-like clusters.
Crystal Growth of Lysozyme Controlled by Laser Trapping
(2014-01-01)
Tu, Jing-Ru
;
Miura, Atsushi
;
Yuyama, Ken-ichi
;
Masuhara, Hiroshi
;
Sugiyama, Teruki
We demonstrate the growth of a tetragonal crystal of hen egg-white lysozyme (HEWL) in D2O buffer solution controlled by laser trapping with a focused continuous-wave (CW) near-infrared (NIR) laser beam. The focal spot was located at 10 mu m away from the edge of the target crystal that was generated spontaneously, and the crystal growth was observed although the focal spot size was much smaller than the distance. The growth rate of (101) and {110} faces of the tetragonal crystal was examined with various laser powers and polarizations. The rate observed under the irradiation was much different from those in spontaneous growth, namely, the growth rate of the {1 10} face showed a large decrease or increase depending on the irradiation time. The dynamics and mechanism of this unusual crystal growth behavior is discussed from the viewpoint of a large stable domain formation of the HEWL liquidlike clusters through liquid nucleation and growth and by considering the anisotropy of the cluster domain.
Crystallization in Unsaturated Glycine/D(2)O Solution Achieved by Irradiating a Focused Continuous Wave Near Infrared Laser
(2010-11-01)
Rungsimanon, Thitiporn
;
Yuyama, Ken-ichi
;
Sugiyama, Teruki
;
Masuhara, Hiroshi
;
應用化學系
The crystallization of glycine in unsaturated solution is made possible by laser trapping of its molecular clusters due to photon pressure of a focused continuous wave near-infrared laser beam. Always one single crystal is spatiotemporally formed at a focal spot, and then it undergoes dissolution, eventually leading to repetitive crystallization and dissolution. The polymorph characterization of the crystal formed in unsaturated solution confirmed the gamma-form, which is not obtainable by conventional crystallization methods. The preparation probability of the gamma-form compared to the alpha-form is much higher than that in the supersaturated solution.
Crystallization in Unsaturated Glycine/D2O Solution Achieved by Irradiating a Focused Continuous Wave Near Infrared Laser
(2010-11-01)
Rungsimanon, Thitiporn
;
Yuyama, Ken-ichi
;
Sugiyama, Teruki
;
Masuhara, Hiroshi
;
應用化學系
The crystallization of glycine in unsaturated solution is made possible by laser trapping of its molecular clusters due to photon pressure of a focused continuous wave near-infrared laser beam. Always one single crystal is spatiotemporally formed at a focal spot, and then it undergoes dissolution, eventually leading to repetitive crystallization and dissolution. The polymorph characterization of the crystal formed in unsaturated solution confirmed the gamma-form, which is not obtainable by conventional crystallization methods. The preparation probability of the gamma-form compared to the alpha-form is much higher than that in the supersaturated solution.
Dynamics and Mechanism of Laser Trapping-Induced Crystal Growth of Hen Egg White Lysozyme
(2015-10-01)
Tu, Jing-Ru
;
Yuyama, Ken-ichi
;
Masuhara, Hiroshi
;
Sugiyama, Teruki
;
應用化學系
We propose the dynamics and mechanism of laser trapping-induced crystal growth of hen egg-white lysozyme (HEWL). A continuous-wave near-infrared laser beam is used as a trapping light source and focused at a point 10 mu m away from a target tetragonal HEWL crystal that is spontaneously generated in solution. Laser trapping of HEWL liquid-like clusters in solution increases local concentration in the focus, where the free motion and orientation of the clusters are strongly restricted, and the clusters show high rigidity and ordering. The cluster association and reorientation at the micrometer-sized focus is evolved to a large highly concentrated domain of the clusters, where the specific target crystal is grown. Initially, the high rigidity and ordering of the clusters strongly suppress the crystal grow rate compared to spontaneous crystal growth. Continuous laser trapping at the of the initially formed domain, however, leads to the transition to another domain with different concentration, rigidity, and ordering of the clusters, which surprisingly enhances the crystal growth rate. More interestingly, the clusters in both domains have anisotropic features reflecting the laser polarization direction, which also contributes to the crystal growth.
Femtosecond-Laser-Enhanced Amyloid Fibril Formation of Insulin
(2017-08-22)
Liu, Tsung-Han
;
Yuyama, Ken-ichi
;
Hiramatsu, Takato
;
Yamamoto, Naoki
;
Chatani, Eri
Femtosecond (fs)-laser-induced crystallization as a novel crystallization technique was proposed for the first time by our group, where the crystallization time can be significantly shortened under fs laser irradiation. Similarly, we have further extended our investigation to amyloid fibril formation, also known as a nucleation-dependence process. Here we demonstrate that the necessary time for amyloid fibril formation can be signifiCantly shortened by fs laser irradiation, leading to favorable enhancement. The enhancement was confirmed by both spectral measurements and direct observations of amyloid fibrils. The thioflavin T fluorescence intensity of laser-irradiated solution increased earlier than that of the control solution, and such a difference was simultaneously revealed by ellipticity changes. At the same time before intensity Saturation in fluorescence, the number of amykid fibrils obtained under laser irradiation was generally mote than that in the control. Solution. Besides, such an enhancement is correlated to the laser power threshold of cavitation bubbling. Possible mechanisms are proposed by referring to fs-laser-induced crystallization and ultrasonication-induced amyloid fibril formation.
Formation, Dissolution, and Transfer Dynamics of a Millimeter-Scale Thin Liquid Droplet in Glycine Solution by Laser Trapping
(2012-03-29)
Yuyama, Ken-ichi
;
Rungsimanon, Thitiporn
;
Sugiyama, Teruki
;
Masuhara, Hiroshi
;
應用化學系
The formation, dissolution, and transfer of a millimeter-scale dense liquid droplet are demonstrated by focusing a CW near-infrared laser beam into a thin film of glycine solution in heavy water. The entire process is investigated by directly monitoring the temporal change in the two-dimensional surface profile using a laser displacement meter. Upon laser irradiation, the surface depression is initially induced by laser heating, followed by the formation of the shallow convex-shaped droplet around the focal spot, in which the droplet is always in contact with the surrounding solution through the ultrathin solution layer. After the laser is switched off, the dissolution occurs through the recovery from the ultrathin layer toward the original solution film. When the laser is set to the outside of the droplet, the solution depression is similarly induced, and subsequently the droplet starts moving toward the focal spot. These processes are summarized and discussed in view of laser-induced effects of concentration increase and temperature elevation.
Highly-integrated, laser manipulable aqueous metal carbonyl vesicles (MCsomes) with aggregation-induced emission (AIE) and aggregation-enhanced IR absorption (AEIRA)
(2016)
Murshid, Nimer
;
Yuyama, Ken-ichi
;
Wu, San-Lien
;
Wu, Kuan-Yi
;
Masuhara, Hiroshi
A highly-integrated, laser manipulable multi-functional metal carbonyl nanovesicle (MCsome) with aggregation-induced emission (AIE) and aggregation-enhanced IR absorption (AEIRA) is created via the self-assembly of a bithiophene tethered-Fp acyl derivative (Fp: CpFe(CO)(2)) (1). Although 1 is hydrophobic and non-surface-active, the molecule can self-assemble in water into vesicles without detectable critical aggregation concentration (CAC). The water-carbonyl interaction (WCI) is responsible for the colloidal stability. The bilayer membrane structure with the bithiophene moieties associated within the inner wall and the iron-carbonyl units exposed to water is confirmed by transmission electron microscopy (TEM), atomic force microscopy (AFM), and cyclic voltammetry (CV) experiments. The synchrotron small-angle X-ray scattering (SAXS) experiment suggests that the bithiophene groups are interdigitated within the membrane. The spatial segregation of the AIE-active bithiophene domain from the iron-carbonyl units by the butanoyl spacers prevents the quenching effect of the iron and renders the MCsome photoluminescent. The polarizable iron-carbonyl groups on the surface of the MCsome create an enhanced optical field upon infrared (IR) irradiation, resulting in an enhancement (ca. 100-fold) in IR absorption for the carbonyl groups as compared to the same concentration of molecule 1 in THF. When the MCsome interacts with a focused continuous-wave near-IR (NIR) laser beam, a strong gradient (trapping) force is generated allowing the laser trapping of the MCsome without using additives. A sharp contrast in the refractive index (RI) of 1 (RI = 1.71) with water (RI = 1.33) accounts for this laser manipulability that is difficult to be achieved for nanosized liposomes (RI = 1.46). As illustrated, the MCsome of 1 represents a novel group of vesicular colloids, which is amenable to functional materials complementary to extensively studied liposomes and polymersomes.
In situ reflection imaging and microspectroscopic study on three-dimensional crystal growth of L-phenylalanine under laser trapping
(2019-11-01)
Chen, Jim Jui-Kai
;
Yuyama, Ken-ichi
;
Sugiyama, Teruki
;
Masuhara, Hiroshi
;
交大名義發表
We investigate growth behavior of an L-phenylalanine crystal formed by laser trapping with the use of reflection imaging and microspectroscopy. Optical reflection micrographs show colored images of the crystal due to constructive interference of incident white light. The color distribution on the crystal is dynamically changed under laser trapping, which is in addition to enlargement of the crystal plane area. The temporal change in the crystal thickness is examined by measuring reflection spectra of the crystal. We discuss the three-dimensional crystal growth under laser trapping by comprehensively considering the changes in crystal thickness and crystal plane area. (C) 2019 The Japan Society of Applied Physics
Laser Trapping and Assembling of Nanoparticles at Solution Surface Studied by Reflection Micro-spectroscopy
(2015-01-01)
Wang, Shun-Fa
;
Yuyama, Ken-ichi
;
Suigiyama, Teruki
;
Masuhara, Hiroshi
;
應用化學系
We present the laser power dependent behavior of optical trapping assembling of 208-nm polystyrene (PS) nanoparticles at the solution surface layer. The assembling dynamics is examined by reflection microspectroscopy as well as transmission and backscattering imaging. The transmission imaging shows that the laser irradiation at the solution surface layer forms a nanoparticle assembly, whose diameter becomes large with the increase in the laser power. The backscattering image of the assembly gives structural color, meaning that nanoparticles are periodically arranged over the whole assembly region. In reflection microspectroscopy, one band appears at long wavelength and is gradually shifted to the short wavelength with the irradiation. After the blue shift, the reflection band is located at the shorter wavelength under the laser irradiation at the higher power. We discuss these spectral changes from the viewpoint of the inter-particle distance determined by the dynamic balance between attractive optical force and repulsive electrostatic force among nanoparticles.
Laser Trapping and Crystallization Dynamics of L-Phenylalanine at Solution Surface
(2013-08-01)
Yuyama, Ken-ichi
;
Sugiyama, Teruki
;
Masuhara, Hiroshi
;
應用化學系
;
應用化學系分子科學碩博班
We present laser trapping behavior of L-phenylalanine (L-Phe) at a surface of its unsaturated aqueous solution by a focused continuous-wave (CW) near-infrared (NIR) laser beam. Upon the irradiation into the solution surface, laser trapping of the liquid-like clusters is induced concurrently with local laser heating, forming an anhydrous plate-like crystal at the focal spot. The following laser irradiation into a central part of the plate-like crystal leads to laser trapping at the crystal surface not only for L-Phe molecules/clusters but also for polystyrene (PS) particles. The particles are closely packed at crystal edges despite that the crystal surface is not illuminated by the laser directly. The molecules/clusters are also gathered and adsorbed to the crystal surface, leading to crystal growth. The trapping dynamics and mechanism are discussed in view of optical potential formed at the crystal surface by light propagation inside the crystal.
Laser trapping assembling and crystallization of nanoparticles at solution surface
(2016-03-13)
Masuhara, Hiroshi
;
Yuyama, Ken-ichi
;
Muramatsu, Masayasu
;
Sugiyama, Teruki
;
應用化學系
Laser Trapping Chemistry: From Polymer Assembly to Amino Acid Crystallization
(2012-12-01)
Sugiyama, Teruki
;
Yuyama, Ken-ichi
;
Masuhara, Hiroshi
;
應用化學系
;
應用化學系分子科學碩博班
Laser trapping has served as a useful tool in physics and biology, but, before our work, chemists had not paid much attention to this technique because molecules are too small to be trapped in solution at room temperature. In late 1980s, we demonstrated laser trapping of micrometer-sized particles, developed various methodologies for their manipulation, ablation, and patterning in solution, and elucidated their dynamics and mechanism. In the 1990s, we started laser trapping studies on polymers, micelles, dendrimers, and gold, as well as polymer nanoparticles. Many groups also reported laser trapping studies of nanoclusters, DNA, colloidal suspensions, etc. Following these research streams, we have explored new molecular phenomena induced by laser trapping. Gradient force leading to trapping, mass transfer by local heating, and molecular reorientation following laser polarization are intimately coupled with molecular cluster and aggregate formation due to their intermolecular interactions, which depend on whether the trapping position is at the interface/surface or in solution. In this Account, we summarize our systematic studies on laser trapping chemistry and present some new advances and our future perspectives. We describe the laser trapping of nanoparticles, polymers, and amino acid clusters in solution by focusing a continuous wave 1064 nm laser beam on the molecules of interest and consider their dynamics and mechanism. In dilute solution, nanoparticles with weak mutual interactions are individually trapped at the focal point, while laser trapping of nanoparticles in concentrated solution assembles and confines numerous particles at the focal spot. The assembly of polymers during their laser trapping extends out from the focal point because of the interpolymer interactions, heat transfer, and solvent flow. When the trapping laser is focused at an interface between a thin heavy water solution film of glycine and a glass substrate, the assembled molecules nucleate and evolve to a liquid liquid phase separation, or they will crystallize if the trapping laser is focused on the solution surface. Laser trapping can induce spatiotemporally the liquid and solid nucleation of glycine, and the dense liquid droplet or crystal formed can grow to a bulk scale. We can control the polymorph of the formed glycine crystal selectively by tuning trapping laser polarization and power. These results provide a new approach to elucidate dynamics and mechanism of crystallization and are the fundamental basis for studying not only enantioselective crystallization but also confined polymerization, trapping dynamics by ultrashort laser pulses, and resonance effect in laser trapping.
Laser trapping dynamics of 200 nm-polystyrene particles at a solution surface
(2013)
Yuyama, Ken-ichi
;
Sugiyama, Teruki
;
Masuhara, Hiroshi
;
應用化學系
;
Department of Applied Chemistry
We present laser trapping behaviors of 200 nm-polystyrene particles in D2O solution and at its surface using a focused continuous-wave laser beam of 1064 nm. Upon focusing the laser beam into the solution surface, the particles are gathered at the focal spot, and their assembly is expanded to the outside and becomes much larger than the focal volume. The resultant assembly is observed colored under halogen lamp illumination, which is due to a periodic structure like a colloidal crystal. This trapping behavior is much different compared to the laser irradiation into the inside of the solution where a particle-like assembly with a size similar to that of the focal volume is prepared. These findings provide us new insights to consider how radiation pressure of a focused laser beam acts on nanoparticles at a solution surface.
Laser trapping dynamics of L-alanine depending on the laser polarization
(2012)
Yuyama, Ken-ichi
;
Ishiguro, Kei
;
Sugiyama, Teruki
;
Masuhara, Hiroshi
;
應用化學系
We successfully demonstrate crystallization and crystal rotation of L-alanine in D2O solution using a focused laser beam of 1064 nm with right- or left-handed circularly polarization. Upon focusing each laser beam into a solution/air interface of the solution thin film, one single crystal is generally formed from the focal spot. The necessary time for the crystallization is systematically examined against polarization and power of the trapping laser. The significant difference in the average time is observed between two polarization directions at a relatively high laser power, where the left-handed circularly polarized laser takes 3 times longer than the right-handed one. On the other hand, the prepared crystal is stably trapped and rotated at the focal point by circularly polarized lasers after the crystallization, and the rotation direction is completely controlled by the polarization of the trapping laser. The mechanisms for the crystallization and the crystal rotation are discussed in terms of trapping force and rotation torque of circularly polarized lasers acting on the liquid-like clusters and its bulk crystal, respectively.
Laser trapping-induced crystallization of L-phenylalanine through its high-concentration domain formation
(2014)
Yuyama, Ken-ichi
;
Wu, Chi-Shiun
;
Sugiyama, Teruki
;
Masuhara, Hiroshi
;
應用化學系
We present the laser trapping-induced crystallization of L-phenylalanine through high-concentration domain formation in H2O and D2O solutions which is achieved by focusing a continuous-wave (CW) near-infrared laser beam at the solution surface. Upon laser irradiation into the H2O solution, laser trapping of the liquid-like clusters increases the local concentration, accompanying laser heating, and a single plate-like crystal is eventually prepared at the focal spot. On the other hand, in the D2O solution, a lot of the monohydrate needle-like crystals are observed, not at the focal spot where the concentration is high enough to trigger crystal nucleation, but in the 0.5-1.5 mm range from the focal spot. The dynamics and mechanism of the amazing crystallization behaviour induced by laser trapping are discussed from the viewpoints of the concentration increase due to laser heating depending on solvent, the large high-concentration domain formation by laser trapping of liquid-like clusters, and the orientational disorder of molecules/clusters at the domain edge.