Browsing by Author "Maruyama, Mihoko"

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Laser ablation for protein crystal nucleation and seeding
(2014)
Yoshikawa, Hiroshi Y.
;
Murai, Ryota
;
Adachi, Hiroaki
;
Sugiyama, Shigeru
;
Maruyama, Mihoko
With the recent development in pulsed lasers with ultrashort pulse widths or wavelengths, spatially precise, low- damage processing by femtosecond or deep- UV laser ablation has shown promise for the production of protein single crystals suitable for X- ray crystallography. Femtosecond laser processing of supersaturated solutions can shorten the protein nucleation period or can induce nucleation at low supersaturation, which improves the crystal quality of various proteins including membrane proteins and supra- complexes. In addition to nucleation, processing of protein crystals by femtosecond or deep- UV laser ablation can produce single crystalline micro- or macro- seeds without deterioration of crystal quality. This tutorial review gives an overview of the successful application of laser ablation techniques to nucleation and seeding for the production of protein single crystals, and also describes the advantages from a physico-chemical perspective.
Plasmonic Heating-Assisted Laser-Induced Crystallization from a NaCIO3 Unsaturated Mother Solution
(2017-02)
Niinomi, Hiromasa
;
Sugiyama, Teruki
;
Tagawa, Miho
;
Maruyama, Mihoko
;
Ujihara, Toni
We provide a novel laser-induced crystallization mechanism which explains crystallization induced by visible laser trapping of silver nanoparticles (AgNPs) at the air/unsaturated mother solution interface from the focal spot [Niinomi et al.CrystEngComm 2016, 18, 7441-7448]. Simultaneous in situ microscopic observation of Raman scattering and polarized-light image revealed that the optical trapping of nanoparticles that exhibit surface-enhanced Raman scattering (SERS) triggers the crystallization, showing the excitation of localized surface plasmon resonance (LSPR) significantly promotes the crystallization. Numerical analysis of temperature distribution based on the combination of finite-difference time-domain electromagnetic and finite-difference heat transfer calculations shows that temperature reaches 390 degrees C at the focal spot because of plasmonic heating, the energy dissipation of the plasmon-enhanced electromagnetic field as heat. A conceivable mechanism of the crystallization is local increment of supersaturation caused by local solvent evaporation via the Plasmonic heating. This plasmonic heating assisted laser-induced nucleation process has the possibility to provide not only a novel approach for spatiotemporal control of crystallization but also a novel nucleation field based on nonlinear light matter interaction originating from the plasmon-enhanced electromagnetic near field through heterogeneous nucleation on the surface of plasmonic particles.