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タイトル: 紫外励起熱レンズ顕微鏡/液体クロマトグラフィーを用いるペプチドの無標識高感度検出著者: 比企, 伸一郎; 渡慶次, 学; 角田, 正也; 馬渡, 和真; 菊谷, 善国; 佐藤, 記一; 火原, 彰秀; 志村, 清仁; 内田, 直行; 北森, 武彦抄録: A UV excitation thermal-lens microscope (UV-TLM) with an excitation beam wavelength of 266 nm and liquid chromatograph (LC) were connected to build a new system (LC/UV-TLM) for the separation and highly sensitive label-free determination of biomolecules, such as peptides. A variation in the composition of the mobile phase with time, as in gradient elution, is very commonly utilized in LC for improved separations. Thermal-lens signals are generally highly dependent on the properties of the media surrounding the photo-absorber. This effect must be carefully considered in such situations where the composition of a solution drastically changes in time. Therefore, we tested the developed ...

タイトル: デスクトップ熱レンズ顕微鏡の開発著者: 比企, 伸一郎; 渡慶次, 学; 火原, 彰秀; 北森, 武彦抄録: A desktop-sized thermal lens microscope (DT-TLM) having high sensitivity and wide applicability was developed. The operationality of the DT-TLM compared with that of a big-sized TLM has been remarkably improved by simplifying the optics and optimizing the optical configuration. In order to evaluate the performance, the DT-TLM was applied to the ultrasensitive detection of a non-fluorescent molecule (dye: Sunset Yellow) in water. The concentration dependence of the thermal lens signal (calibration curve) showed good linearity in the range of 1×10－8～1×10－7 M. From the value of twice the standard deviation （2σ）of this calibration curve, the lower limit of the quantitative determination was estimated to be 1.10×10－8 M. The lower limit of detection was estimated as 8.27×10－9 M from the conditions of the signal-to-noise ration S/N=2 ...

タイトル: チップ内マルチイオンセンシングを目指したセグメントフロー : 多相流形成の基礎検討著者: 久本, 秀明; 堀内, 隆之; 火原, 彰秀; 渡慶次, 学; 北森, 武彦抄録: A new fluid flow inside the microchannel was successfully developed. The flow created here involves segmented flow injection of plural organic phases into a microchannel followed by contact with a single aqueous phase to form stable organic-aqueous two-layer flow inside the microchannel. Fundamental study on the developed flow inside the microchannel was performed by monitoring the dye-doped segmented organic phases by thermal lens microscopy (TLM). Excellent repeatability and very small injection volume in developing segmented flow were realized. The new fluid flow created here is expected to allow us multi-ion sensing, which is not easily demonstrated by conventional ion sensor technology using a solvent polymeric membrane, by combining with neutral ionophore-bas ...

タイトル: Sub-Zeptomole Detection in a Microfabricated Glass Channel by Thermal-Lens Microscopy.著者: SATO, Kiyoshi; KAWANISHI, Hiroaki; TOKESHI, Manabu; KITAMORI, Takehiko; SAWADA, Tsuguo抄録: A thermal-lens microscope which we developed was applied to an ultramicro quantity determination of a dye in an aque-ous solution filling a microchannel (150 µm wide and 100 µm deep) fabricated in a quartz glass substrate. The detection volume, which corresponded to the confocal volume, was estimated to be 1.3 fl. The detection limit of the dye molecules was 160 ymol, and the calibration line showed good linearity in the sub-zmol-to-zmol region. This detection sensitivity is equivalent to that of laser-induced fluorometry. The thermal-lens signal measured in the microchannel was more stable than that measured in a liquid micro space between a slide glass and a cover glass, which was much wider than the microchannel. This may have been due to a suppression of convection in the microchan ...

タイトル: DD Newsletter No.13

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