Fig. 3

Demonstration of individual detection of P. aeruginosa (P.a.) and E. coli (E.c.) with the α-HL. Original current recordings showing reversible current blockage events induced by the association of P.a. (a) and E.c. (b), respectively, with the α-HL. The amplitude histograms showed on the right side indicate the nearly complete ionic flow obstruction through the nanopore by either bacterium. Selected time intervals characterizing the frequency (τ _on) and duration (τ _off) of bacteria-α-HL interactions are shown in the inset of a. c, d Scatter plots of current blockade versus dwell time of blockade events reflecting the P. aeruginosa (P.a.) and E. coli (E.c.) interaction with the α-HL. The distinct states of the nanopore, i.e., free and temporarily blocked by a bacterium, are denoted in c. The applied transmembrane potential was ΔV = −80 mV