Instituto de Ciencia de Materiales de Madrid, CSIC , c/Sor Juana Ines de la Cruz 3, 28049 Madrid, Spain.
ACS Nano. 2016 Jul 26;10(7):7117-24. doi: 10.1021/acsnano.6b03262. Epub 2016 Jul 6.
Force spectroscopy is enhancing our understanding of single-biomolecule, single-cell, and nanoscale mechanics. Force spectroscopy postulates the proportionality between the interaction force and the instantaneous probe deflection. By studying the probe dynamics, we demonstrate that the total force acting on the probe has three different components: the interaction, the hydrodynamic, and the inertial. The amplitudes of those components depend on the ratio between the resonant frequency and the frequency at which the data are measured. A force-distance curve provides a faithful measurement of the interaction force between two molecules when the inertial and hydrodynamic components are negligible. Otherwise, force spectroscopy measurements will underestimate the value of unbinding forces. Neglecting the above force components requires the use of frequency ratios in the 50-500 range. These ratios will limit the use of high-speed methods in force spectroscopy. The theory is supported by numerical simulations.
力谱学增强了我们对单生物分子、单细胞和纳米力学的理解。力谱学假设相互作用力与瞬时探针挠度之间存在比例关系。通过研究探针的动力学，我们证明作用在探针上的总力有三个不同的分量：相互作用力、流体动力和惯性力。这些分量的幅度取决于共振频率与数据测量频率之比。当惯性和流体动力分量可以忽略不计时，力-距离曲线可以提供两个分子之间相互作用力的真实测量值。否则，力谱学测量值将低估解键力的值。忽略上述力分量需要使用 50-500 范围内的频率比。这些比率将限制力谱学中高速方法的使用。该理论得到了数值模拟的支持。
