Object-adapted optical trapping and shape-tracking of energy-switching helical bacteria
Object-adapted optical trapping and shape-tracking of energy-switching helical bacteria
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DOI：
10.1038/nphoton.2012.232
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发表时间：
2012-10-01
期刊：
影响因子：
35
通讯作者：
Rohrbach, Alexander
中科院分区：
文献类型：
--
作者：
Koch, Matthias;Rohrbach, Alexander
光镊是一种灵活的操纵工具，用于在特定点抓取微型物体，但对形状更复杂或不断变化的物体进行受控操纵几乎是不可能的。在这里，我们证明，通过分时光学力，它是可能的，以适应形状的捕获潜力的形状的一个细长的螺旋细菌。与大多数其他被捕获的物体相比，这种结构可以不断改变其螺旋形状（从而改变其机械能），这使得捕获它比捕获微小的非生命物体要困难得多。只有200 nm薄的细菌（螺原体）的形状变形测量空间分辨在800 Hz，利用相干散射捕获光的局部相位差。通过定位细菌的每个斜坡，我们生成了高对比度，超分辨率的三维电影，没有任何物体染色。这种方法将有助于研究单一无壁细菌的纳米力学，同时在宽的时间带宽上对外部刺激做出反应。
Optical tweezers are a flexible manipulation tool used to grab micro-objects at a specific point, but a controlled manipulation of objects with more complex or changing shapes is hardly possible. Here, we demonstrate, by time-sharing optical forces, that it is possible to adapt the shape of the trapping potential to the shape of an elongated helical bacterium. In contrast to most other trapped objects, this structure can continuously change its helical shape (and therefore its mechanical energy), making trapping it much more difficult than trapping tiny non-living objects. The shape deformations of the only 200-nm-thin bacterium (Spiroplasma) are measured space-resolved at 800 Hz by exploiting local phase differences in coherently scattered trapping light. By localizing each slope of the bacterium we generate high-contrast, super-resolution movies in three dimensions, without any object staining. This approach will help in investigating the nanomechanics of single wall-less bacteria while reacting to external stimuli on a broad temporal bandwidth.