Figure 2.

AFM topographical images in air of eTBA molecules, immobilized onto HOPG by spontaneous adsorption during 3 minutes, from solutions of 1 μg mL⁻¹ eTBA in pH 7.0 0.1 M phosphate buffer: (a, b) in the absence and (c–f) in the presence of (c, d) 100 mM and (e, f) 200 mM K⁺, after (c, e) 1 hour and (d, f) 24 hours of incubation.