Quartz Crystal Microbalance-Dissipation Technique for Tracking Dynamic Biomacromolecular Interactions

The quartz crystal microbalance-dissipation (QCM-D) technique is a highly surface-sensitive technique for measuring biomacromolecular interactions that occur at solid–liquid interfaces. Key advantages of the acoustic-based QCM-D technique include its label-free format, fast measurement response, compatibility with various material interfaces, and high sensitivity to detect not only the amount and configuration of biomacromolecular adsorbates but also hydrodynamically coupled solvent near the sensor surface. This sensitivity is particularly important for detecting structural changes associated with dynamic biomacromolecular interactions relevant to biological systems. In this chapter, the main objective is to introduce how the QCM-D technique is useful for medical and biotechnology applications related to tracking dynamic biomacromolecular interactions. The basic measurement principles of the QCM-D technique and popular modeling approaches are introduced before reviewing a selection of classical and recent application examples that involve lipid membranes, proteins, peptides, biosurfactants, and detergents. Two main classes of dynamic biomacromolecular interactions are covered as representative cases of different measurement scenarios, i.e., the structural transformation of (1) soft adsorbates into rigid adsorbates and (2) rigid adsorbates into soft adsorbates. Particular focus is placed on biomimetic lipid membrane platforms and on critically discussing the suitability of applying physics-based models to interpret QCM-D measurement data in specific biomacromolecular interaction cases. Alternative interpretation strategies based on empirical testing are also described in order to support biologically directed analyses. As presented in this chapter, ongoing progress in the field supports that the QCM-D technique has a bright future for studying complex biological phenomena at solid–liquid interfaces across a wide range of topics spanning fundamental and translational viewpoints.