nn6b03262_si_001.pdf (799.5 kB)

# Fundamental High-Speed Limits in Single-Molecule, Single-Cell, and Nanoscale Force Spectroscopies

journal contribution

posted on 2016-06-30, 00:00 authored by Carlos
A. Amo, Ricardo GarciaForce 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.