Figure 6
From: Imaging in Biologically-Relevant Environments with AFM Using Stiff qPlus Sensors
FM-AFM images of a lipid bilayer adsorbed on mica and measured in buffer solution. (a) Topography overview scan of the lipid bilayer with a large artificially created defect and an additional line profile along the cyan colored line is included. The imaging parameters were A = 200 pm and Δf = +25 Hz. (b) High resolution image of the lipid heads in Δf feedback taken in quasi-constant height mode with A = 100 pm and Δf = +20 Hz. The sensor’s resonance frequency f0 was 15.57 kHz. The rectangular lattice (α = 90°) is indicated by the headgroup positions marked by blue dots with lattice vectors \({\overrightarrow{a}}_{1}\) and \({\overrightarrow{a}}_{2}\). (c) Image of the lipid heads in Δf feedback taken in quasi-constant height mode with A = 106 pm and Δf = +76 Hz. The sensor’s resonance frequency f0 was 15.72 kHz. The headgroup positions marked by blue dots indicate an oblique lattice. The angle β between the lattice vectors \({\overrightarrow{b}}_{1}\) and \({\overrightarrow{b}}_{2}\) was 64°.
