Figure 3.

Detection of the change of proton lateral conduction along the BSA film with the monolayer compression. (A) In the fluorescence approach, the dissipation of the pH jump is described by the two parameters T_H⁺ (delay between the acid injection and the decrease in fluorescence) and ΔF (the relative amplitude in fluorescence decrease) (see text). In this experiment, the film packing density was 350 nm²/mol. (B) Dependence of the proton lateral conduction on the molecular area. Conduction was observed by the fluorescence approach. T_H⁺ in the bulk phase without spreading film was larger than 2000 s. (C) In the conductance method, the change is recorded with a background signal associated with the free air/water interface equivalent to 1.7 ± 0.1 μS. (When not shown, error bars are in the symbols.)