Micromechanical observation of the kinetics of biomolecular interactions

Resonant microcantilevers have recently enabled the label-free detection of biomolecules. Here, we observed the kinetics of biomolecular interactions such as antigen-antibody interactions and/or DNA hybridization based on a resonant frequency shift, obeying Langmuir kinetics, measured in a buffer solution. It is shown that the kinetics of DNA adsorptions on the surface is governed by intermolecular interactions between adsorbed DNA molecules. It is also shown that the kinetics of DNA hybridization is determined by the intermolecular interaction. It is implied that resonant microcantilever in buffer solution may allow for gaining insights into the kinetics of various molecular interactions.