Supplementary Fig. 15: Analysis of individual resistive pulses from low-noise ionic current measurements and the effect of solvent.
From: Electrical recognition of the twenty proteinogenic amino acids using an aerolysin nanopore
(a) Typical resistive pulse measured using a low-noise setup and an equimolar mixture of LR7 and IR7 peptides at –40 mV in 4 M KCl. This resistive pulse consists of the following five levels: two visits to the long-lasting level and three short visits to a deeper blocked level. The dashed red line corresponds to the current level at the midpoint between the two maxima for LR7 and IR7: the red continuous lines show the extremes of the range of mean current levels that are included in determining the resistive pulse mean 〈Ib/I0〉 value. Blue markers show start and end of resistive pulse (vertical arm) and mean current value (horizontal arm). Green and red vertical lines show onset and end of transitions as detected by the DetectiVent algorithm. Vertical (b) and horizontal (c) expansions of (a) to show details. (d) Power spectral density of three blocked (red) and unblocked (black) current levels in the presence of 2 M KCl/2 M KNO3. (e) Comparison of the difference of averages in 4 M KCl (blue, same as in Supplementary Fig. 14f) and 2 M KCl/2 M KNO3 (black).
