Rapid Molecular Mechanotyping with Microfluidic Force Spectroscopy

Abstract

Molecular mechanotyping, the quantification of changes in the stability of supramolecular interactions and chemical bonds under the action of mechanical forces, is an essential tool in the field of mechanochemistry. This is conventionally done in single-molecule force-spectroscopy (smFS) assays, for example with optical tweezers or Atomic Force Microscopy. While these techniques provide detailed mechanochemical insights, they are time-consuming, technically demanding and expensive; as a result, high-throughput screening of the mechanochemical properties of molecules of interest is challenging. To resolve this, we present a rapid, simple and low-cost mechanotyping assay: microfluidic force spectroscopy ({micro}FFS), which probes force-dependent bond stability by measuring the detachment of microparticles, bound to microfluidic channels by the interaction of interest, under hydrodynamic forcing. As this allows the simultaneous observation of hundreds of microparticles, we obtain a quantitative mechanotype in a single measurement, using readily available equipment. We validate our method by studying the stability of DNA duplexes, previously characterized through smFS. We further show that we can quantitatively describe the experimental data with simulations, which allows us to link the {micro}FFS data to single-bond mechanochemical properties. This opens the way to use ({micro}FFS) as a rapid molecular mechanotyping tool.