Figure 2

(a) Example of recorded current trace for NP₅ as a function of applied voltage for a NaCl concentration of 2.5 mol l⁻¹. Example of current-voltage (3 experiments) curve for (b) NP₂ at NaCl concentration 10⁻³ mol l⁻¹ and NP₅ at NaCl concentration of (c) 10⁻⁴ mol l⁻¹ and (d) 10⁻² mol l⁻¹.