Name: atomic force microscopy for surface mapping
Uploaded: 2023-04-30T12:00:37.000Z
Duration: 1 min 8 s
Channel: JoVE

Атомно-силовая микроскопия (АСМ) генерирует изображение с помощью нанозонда для получения топографической информации об образце с нанометровым разрешением.
В то время как оптический микроскоп может увеличивать до 1000 раз, потенциал увеличения АСМ составляет до 1 000 000 раз.
АСМ может создавать изображения как фиксированных, так и живых образцов, что позволяет ему захватывать динамические клеточные процессы, такие как динамика актина.
Нанозонд АСМ прикреплен к концу гибкой консоли, и вместе они сканируют образец. Зонд повторяет контуры поверхности образца, перемещаясь вверх и вниз, что смещает консоль.
В одном типе АСМ лазерный луч направлен на консоль, и при его движении происходит и отражение лазера.
Позиционно-чувствительный фотоприемник фиксирует отклонение лазерного луча.
Данные отправляются на компьютер, где программное обеспечение может обработать их для создания трехмерного изображения поверхности образца.

<ol>
	<li>Казузо, Игнасио, Феликс Рико и Саймон Шойринг. "Биологическая АСМ: откуда мы пришли – где мы находимся – куда мы можем пойти." Журнал молекулярного распознавания 24.3 (2011): 406-413.</li>
	<li>Гарсия, Рикардо и Рубен Перес. "Методы динамической атомно-силовой микроскопии." Отчеты по науке о поверхности 47.6-8 (2002): 197-301.</li>
</ol>

Атомно-силовая микроскопия

Atomic Force Microscopy

Атомно-силовая микроскопия (АСМ) — это тип сканирующей зондовой микроскопии, с помощью которой можно анализировать топографические детали различных образцов, таких как керамика, стекло, полимеры и биологические образцы. АСМ предлагает более чем в 1000 раз большее разрешение, чем система оптической визуализации. Изображения, полученные с помощью АСМ, представляют собой трехмерные профили поверхности, что дает преимущество перед плоскими двумерными изображениями, полученными при использовании других методов визуализации. АСМ-зонд Зонд считается важнейшей частью любой установки АСМ и состоит из кантилевера и узла наконечника. Зонды — это наиболее часто заменяемая деталь в микроскопах этого типа, поскольку постоянное взаимодействие с образцами изнашивает наконечник. Поэтому выбор материала зонда зависит от свойств образца. Кремниевые зонды, используемые для анализа твердых образцов, более жесткие и острые, чем зонды из нитрида кремния, которые лучше подходят для сканирования более мягких образцов. Эти острые наконечники изготавливаются с использованием электрохимического травления или углеродных нанотрубок для более точного анализа. Режимы визуализации АСМ В АСМ топография поверхности изучается с использованием взаимодействия кончика зонда и поверхности образца. Существует два основных режима визуализации — статический режим, также называемый контактным режимом, и динамический режим. В статическом или контактном режиме кончик зонда находится в постоянном контакте с поверхностью образца. Когда игла скользит по поверхности, силы отталкивания между образцом и иглой приводят к изгибу кантилевера, который и регистрируется. Вся поверхность образца сканируется вперед и назад по осям X и Y, что называется растровым сканированием, в то время как вертикальное движение кантилевера фиксирует ось Z, создавая таким образом трехмерное изображение. В динамическом режиме зонд колеблется непосредственно над поверхностью образца, приближаясь к ней, но не касаясь ее. Силы притяжения и отталкивания определяют изменение расстояния между зондом и образцом, влияя на амплитуду колебаний кантилевера. Эта обратная связь записывается для построения топографии поверхности образца.

Атомно-силовая микроскопия (АСМ) - это тип сканирующей зондовой микроскопии, который позволяет анализировать топографические детали различных образцов, таких как керамика, стекло, ...

Education

JoVE Core

Cell Biology

Клеточная биология

Unit 1

Раздел 1

Visualizing Cells, Tissues, and Molecules

Визуализация клеток, тканей и молекул

KEY TERMS AND CONCEPTS

ОСНОВНЫЕ ТЕРМИНЫ И ПОНЯТИЯ

atomic force microscopy for surface mapping

Atomic force microscopy is used to map the surface details of materials. It can examine ceramics, glass, polymers, and biological samples. The method gives far more resolution than an optical imaging system and produces three-dimensional surface profiles instead of flat 2D images.

The probe is the key part of an AFM setup. It includes the cantilever and tip assembly, and it is also the part that is replaced most often. Constant contact with samples wears down the tip, so probe choice depends on the sample being scanned. Silicon probes are stiffer and sharper, which makes them useful for hard samples. Silicon nitride probes are better for softer samples.

AFM tips can be made with electrochemical etching or with carbon nanotubes to improve accuracy. The microscope reads surface topography by tracking how the probe tip interacts with the sample surface. This interaction is recorded as the probe scans across the surface.

AFM uses two main imaging modes. In static mode, also called contact mode, the tip stays in continuous contact with the surface. As it drags across the sample, repulsive forces bend the cantilever, and that bending is recorded. The sample is scanned back and forth in the x- and y-axes, which is called raster scanning, while the vertical motion of the cantilever records the z-axis and builds a 3D image.

In dynamic mode, the probe oscillates just above the sample surface. It comes close to the surface without touching it. Attractive and repulsive forces change the distance between the tip and the sample and affect the oscillation amplitude. That feedback is then used to construct the surface topography.

Atomic Force Microscopy for Surface Mapping

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imaging biological samples with optical microscopy

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How Light Microscopes Bring Samples Into View

Optical microscopy uses light and lenses to make tiny biological samples visible. Antonie van Leeuwenhoek built the first compound optical microscope in the 17th century to view blood cells, bacteria, and yeast cells. In 1830, Joseph Jackson Lister developed an essentially modern light microscope. During the 20th century, microscopes gained better magnification and resolution. A sample is placed on a glass slide and clipped onto the stage, which is the flat platform of the microscope. The...

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Surface-Only Imaging with TIRF Microscopy

Total internal reflection fluorescence microscopy, or TIRF, is a microscope method used to view fluorophores near a solid surface with a higher refractive index, such as a glass coverslip. It is useful when scientists want to study signals close to the cell surface. TIRF works when light from a medium with a lower refractive index, such as air, hits the glass coverslip at a critical angle. Instead of entering the glass, the light undergoes total internal reflection. This reflection creates an...

atomic force microscopy

Atomic force microscopy is used to map the surface details of materials. It can examine ceramics, glass, polymers, and biological samples. The method gives far more resolution than an optical imaging system and produces three-dimensional surface profiles instead of flat 2D images. The probe is the key part of an AFM setup. It includes the cantilever and tip assembly, and it is also the part that is replaced most often. Constant contact with samples wears down the tip, so probe choice depends...

super-resolution fluorescence microscopy

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How SEM Reveals Surface Details

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3D Imaging with Electron Microscopy

Transmission electron microscopy (TEM) can build 3D images of biological samples. It does this with electron microscope tomography and single-particle reconstruction. Tomography can show cell parts or small cells in vivo, while single-particle reconstruction is used for macromolecules and macromolecular complexes in vitro only. Electron tomography can be done in TEM or in STEM, which stands for scanning transmission electron microscopy. STEM is mainly used for thick biological specimens. It...

key terms and concepts

Learn how atomic force microscopy maps surfaces, why probe choice matters, and how contact and dynamic modes build detailed 3D images of samples.

Atomic Force Microscopy for Surface Mapping | JoVE K12

cell biology

JoVE Core Cell Biology illustrates complex cellular processes in easy-to-understand yet comprehensive animated video lessons. This collection focuses on the essential components and functions of cells, including organelles and membranes, cellular transport, and cell energetics. It is complemented by scientist-in-action videos that demonstrate the application of cell biology in real-world research experiments.

Atomic Force Microscopy for Surface Mapping

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