4Dスキャニングトランスミッション超高速電子顕微鏡:単粒子のイメージングとスペクトロスコピー
Volkan Ortalan1, Ahmed H Zewail
1Physical Biology Center for Ultrafast Science and Technology, Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125, USA.
Journal of the American Chemical Society
|May 28, 2011
まとめ
ダイナミックなナノ構造物の画像を撮るための4Dスキャニングトランスミッション超高速電子顕微鏡 (ST-UEM) を開発しました. この高度な技術は,単一の粒子からの詳細な運動およびスペクトルデータを捕捉し,材料科学と生物学に関する新しい洞察を可能にします.
科学分野:
- マテリアルサイエンス 材料科学
- ナノテクノロジー ナノテクノロジー
- 顕微鏡による顕微鏡検査
背景:
- 従来の顕微鏡の方法は,多くの場合,複数の粒子のダイナミクスを平均し,個々の行動を遮断します.
- ナノ構造物のダイナミックなプロセスを理解するには,高い空間と時間の解像度が必要です.
研究 の 目的:
- 4Dスキャニングトランスミッション超高速電子顕微鏡 (ST-UEM) の開発と実証.
- 単一のナノ構造物の同時イメージングとスペクトロスコピーを可能にします.
- 高精度で,孤立したおよび埋め込まれたナノ構造のダイナミックなプロセスを探査する.
主な方法:
- 4Dスキャニングトランスミッション超高速電子顕微鏡 (ST-UEM) を利用しました.
- この技術を銀ナノワイヤと金ナノ粒子の画像に適用した.
- 同時にダークフィールド画像と電子エネルギー損失スペクトルを取得しました.
主要な成果:
- 銀ナノワイヤの機械的運動と形状のダイナミクスを画像化しました.
- ナノワイヤの動きの定まった共振周波数と相変化時間.
- 単一の金ナノ粒子で同時にダークフィールド画像と電子エネルギー損失スペクトロスコピーを達成しました.
結論:
- ST-UEMは,ダイナミックなプロセスのための前例のないローカルプローブ機能を提供します.
- この方法は,アンサンブル平均測定の限界を克服します.
- 材料科学と単粒子生物画像の新たな道を開く.
関連する概念動画
Electron Microscope Tomography and Single-particle Reconstruction
Transmission electron microscopy (TEM) can be used to determine the 3D structure of biological samples with the help of techniques such as electron microscope tomography and single-particle reconstruction. While single-particle reconstruction can examine macromolecules and macromolecular complexes in vitro conditions only, tomography permits the study of cell components or small cells in vivo.
Electron Tomography
Electron tomography can be performed either in TEM or STEM (scanning transmission...
Electron Tomography
Electron tomography can be performed either in TEM or STEM (scanning transmission...
Transmission Electron Microscopy
In 1931, physicist Ernst Ruska—building on the idea that magnetic fields can direct an electron beam just as lenses can direct a beam of light in an optical microscope—developed the first prototype of the electron microscope. This development led to the development of the field of electron microscopy. In the transmission electron microscope (TEM), electrons are produced by a hot tungsten element and accelerated by a potential difference in an electron gun, which gives them up to 400 keV in...
Overview of Electron Microscopy
The wavelengths of visible light ultimately limit the maximum theoretical resolution of images created by light microscopes. Most light microscopes can only magnify 1000X, and a few can magnify up to 1500X. Electrons, like electromagnetic radiation, can behave like waves, but with wavelengths of 0.005 nm, they produce significantly greater resolution up to 0.05 nm as compared to 500 nm for visible light. An electron microscope (EM) can create a sharp image that is magnified up to 2,000,000X.
Scanning Electron Microscopy
A scanning electron microscope (SEM) is used to study the surface features of a sample by using an electron beam that scans the sample surface in a two-dimensional manner. Typically, areas between ~1 centimeter to 5 micrometers in width can be imaged. SEM can be used to image bacteria, viruses, tissues as well as larger samples like insects. Conventional SEM gives a magnification ranging from 20X to 30,000X and spatial resolution of 50 to 100 nanometers.
Fundamental Principles
Accelerated...
Fundamental Principles
Accelerated...
Overview of Microscopy Techniques
The early pioneers of microscopy opened a window into the invisible world of microorganisms. In 1830, Joseph Jackson Lister created an essentially modern light microscope. The 20th century saw the development of microscopes that leveraged nonvisible light, such as fluorescence microscopy that uses an ultraviolet light source and electron microscopy that uses short-wavelength electron beams. These advances significantly improved magnification, image resolution, and contrast. By comparison, the...
Super-resolution Fluorescence Microscopy
Super-resolution fluorescence microscopy (SRFM) provides a better resolution than conventional fluorescence microscopy by reducing the point spread function (PSF). PSF is the light intensity distribution from a point that causes it to appear blurred. Due to PSF, each fluorescing point appears bigger than its actual size, and it is the PSF interference of nearby fluorophores that causes the blurred image. Various approaches to achieving higher resolution through SRFM have recently been developed.

