With QCM-D, two parameters - frequency and dissipation - are monitored simul-taneosuly, in real-time, as molecular layers form on the sensor surface. This is what a raw data plot could look like:
Binding of a small globular molecule Moderate frequency response, Δf (mass change), but low dissipation, ΔD(structural change).
Binding of a large elongated molecule Forms a softer and thicker layer which can be seen by higher Δf and much higher ΔD levels.
Rinsing with buffer The elongated molecule is removed, frequency and dissipation reduce again.
For all applications, Q-Sense systems enable:
Mass measurements. Nanogram sensitivity, less than 1% of a protein monolayer is detectable.
Structural properties. Simultaneously determine the orientation of molecules at the surface.
Real time, in situ and label free. Study kinetics, pH dependence etc. using the native molecule.
Flexible choice of substrate. Metals, polymers; any material that can be applied as a thin film can be used.