Department of Physics and Atmospheric Science, Dalhousie University Halifax, Nova Scotia, B3H 3J5, Canada.
Biointerphases. 2006 Mar;1(1):11. doi: 10.1116/1.2188519.
A theoretical framework is developed to analyze molecular bond breaking in dynamic force spectroscopy using atomic force microscopy (AFM). An analytic expression of the observed bond breaking probability as a function of force is obtained in terms of the relevant physical parameters. Three different experimental realizations are discussed, in which (i) the force is increased linearly in time, and (ii) the AFM cantilever is moved at constant speed, and (iii) the force is held constant. We find that unique fitting of the bond parameters such as the potential depth and its width is possible only when data from rather different force-loading rates is used. The complications in the analysis of using the constant velocity mode arising from the intermediate polymer spacer are discussed at length.
本文构建了一个理论框架，用于分析原子力显微镜（AFM）动态力谱中分子键的断裂。根据相关物理参数，得到了观察到的键断裂概率随力的解析表达式。讨论了三种不同的实验实现方式，其中（i）力随时间线性增加，（ii）AFM 悬臂以恒定速度移动，以及（iii）力保持恒定。我们发现，只有当使用相当不同的力加载速率的数据时，才能对键参数（如势深及其宽度）进行独特的拟合。详细讨论了使用恒速模式时由于中间聚合物间隔物而产生的分析复杂性。
