Measuring nanoparticle diffusion in an ABELtrap
Measuring nanoparticle diffusion in an ABELtrap
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DOI：
10.1088/2040-8986/aaa6fc
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发表时间：
2018-03-01
影响因子：
2.1
通讯作者：
Boersch, M.
中科院分区：
文献类型：
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作者：
Dienerowitz, M.;Dienerowitz, F.;Boersch, M.
监测单个纳米物体的布朗运动是研究其输运性质及其与封闭环境相互作用的关键。大多数技术依赖于通过检测体积或固定的瞬时扩散，这限制了观察时间或运动性。我们测量了单个纳米粒子和DNA分子在反布朗电动势阱（ABELtrap）中的扩散系数和表面电荷。该仪器是一种主动反馈陷阱，通过基于粒子的当前位置施加电场，将纳米粒子的布朗运动限制在检测位点。我们模拟布朗运动的纳米球在我们的样品几何形状，包括壁效应，由于部分限制在第三维。理论预测值与我们在ABEL阱中的扩散测量非常一致。我们还证明了ABELtrap在变性过程中测量不同大小的DNA折纸结构的能力。
Monitoring the Brownian motion of individual nanoscopic objects is key to investigate their transport properties and interactions with their close environment. Most techniques rely on transient diffusion through a detection volume or immobilisation, which restrict observation times or motility. We measure the diffusion coefficient and surface charge of individual nanoparticles and DNA molecules in an anti-Brownian electrokinetic trap (ABELtrap). This instrument is an active feedback trap confining the Brownian motion of a nanoparticle to the detection site by applying an electric field based on the particle's current position. We simulate the Brownian motion of nanospheres in our sample geometry, including wall effects, due to partial confinement in the third dimension. The theoretically predicted values are in excellent agreement with our diffusion measurements in the ABELtrap. We also demonstrate the ABELtrap's ability to measure varying sizes of DNA origami structures during denaturation.