arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0909.5131physics.opticsphysics.ins-det
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total internal reflection显微镜应用的新前景

Novel perspectives for the application of total internal reflection microscopy

Giovanni Volpe, Thomas Brettschneider, Laurent Helden, Clemens Bechinger

摘要:

全内反射显微镜(TIRM)是一种灵敏的非侵入性技术,用于测量胶体颗粒与壁之间的相互作用势,分辨率为飞秒牛顿。对颗粒-壁分离距离z的平衡分布进行采样,监测在渐逝照明下由布朗颗粒散射的强度I。数据分析的核心是I和相应z之间关系的知识,其通常必须是先验已知的。这对TIRM可以应用的实验条件(倏逝波的短穿透深度,透明表面)造成了相当大的限制。在这里,我们介绍了一种方法来实验确定I(z),仅依赖于距离依赖的颗粒壁流体动力学相互作用。我们证明,这种方法在很大程度上扩展了TIRM可访问的条件范围,甚至允许在高度反射的金表面上进行测量,其中多次反射导致复杂的I(z)。

英文摘要:

Total Internal Reflection Microscopy (TIRM) is a sensitive non-invasive technique to measure the interaction potentials between a colloidal particle and a wall with femtonewton resolution. The equilibrium distribution of the particle-wall separation distance z is sampled monitoring the intensity I scattered by the Brownian particle under evanescent illumination. Central to the data analysis is the knowledge of the relation between I and the corresponding z, which typically must be known a priori. This poses considerable constraints to the experimental conditions where TIRM can be applied (short penetration depth of the evanescent wave, transparent surfaces). Here, we introduce a method to experimentally determine I(z) by relying only on the distance-dependent particle-wall hydrodynamic interactions. We demonstrate that this method largely extends the range of conditions accessible with TIRM, and even allows measurements on highly reflecting gold surfaces where multiple reflections lead to a complex I(z).

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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