Quartz Crystal Microbalance as a Sensor to Characterize Macromolecular Assembly Dynamics
Figure 15
Surface specific vesicle adsorption kinetics on solid substrates. Illustration of (a) supported lipid bilayer on SiO2 and (b) intact vesicles on gold. (c) The typical two-step kinetics of vesicle fusion from small unilamellar vesicles to form a bilayer on SiO2. Note that the critical coverage occurred at 7.5 minutes. Three different overtones (3rd, 5th, and 7th) are also presented here for viscoelastic modeling. (d) The typical vesicle adsorption kinetics on a gold substrate are also presented. The huge mass uptake is caused by vesicle adorption. Due to the viscoelastic nature of vesicles, the overtones do not merge. (e) Comparison of two different thickness calculation-based Sauberbery and Voigt-based models to characterize the vesicle fusion process. Note the deviation at the critical coverage at 7.5 minutes due to the highly viscoelastic character of intact vesicles. (f) Comparison of two different thickness models by Sauerbrey and Voigt-based models for an adsorbed intact vesicle monolayer. Due to the viscoelastic nature of intact vesicles, the overtones do not merger. Since the adlayer’s viscoelasticity causes high energy dissipation, the Sauerbrey model significantly underestimates the adlayer thickness compared with the Voigt-based model.
