In areas ranging from biochemistry and biotechnology to medicine and nanotoxicology, biomolecular interactions are explored both to gain increased knowledge and understanding of biological systems and functions, and to design products such as pharmaceuticals, sensors and materials. Here we present how biomolecular interactions can be analyzed using QSense® QCM-D technology and what information QCM-D measurements offer.
Via time-resolved information on mass, thickness and viscoelastic properties of surface adhering layers, QSense QCM-D can detect and monitor molecular interactions in real-time. QCM-D measures the so called “hydrated mass”, which makes it an excellent complement to the optical time-resolved technologies, which are often used to study biomolecular interactions, and which senses “non-hydrated mass”.
Whereas the non-hydrated mass refers to the mass of the biomolecules, the hydrated mass includes both the molecules and the surrounding solvent. Monitoring the hydrated mass enables not only detection of surface interactions such as adsorption, desorption and binding, but it also enables the detection of molecular arrangement at the surface and changes thereof. Fig 1, illustrates what typical data could look like in the cases of A) adsorption, B) binding and C) enzymatic action.
Figure 1. Schematic illustration (top panel) of (A) molecular adsorption, (B) binding and (C) enzymatic action, characterized by QSense QCM-D (middle panel). The Δf and ΔD data reflect time-resolved mass uptake and layer softness respectively. As indicated by the grey arrows in the schematic graphs, the time-resolved data makes it possible to follow the adsorption, binding and enzymatic action and analyze how fast they are, and how much material that is added to or lost from the surface in the respective process. The absolute amount adsorbed, bound and enzymatically removed can be also analyzed via quantification of the time-resolved layer thickness or mass (not shown).
Running QCM-D analysis at relevant conditions and varying, for example, the surface material, the temperature, the pH, or the salt concentration, the behavior of the biomolecular system can be both characterized for deeper understanding and optimized for a target application.
Interfacial processes and layer properties that can be analyzed are for example:
Download the overview to read more about how biomolecular-based systems can be characterized using QSense QCM-D technology.
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