Fig. 4. Analysis of different polynucleotides with the same length in M⁺Cl^– (M⁺ = Li⁺ or K⁺). (a) Raw current traces of dA₂₀, dT₂₀ and dC₂₀. (b) The event frequencies and durations of dA₂₀, dT₂₀ and dC₂₀. Event frequencies reveal obvious enhancements for these ssDNA in LiCl. The values of event frequencies and durations were extracted from transformed single-exponential functions (Fig. S7†). Data were obtained at +160 mV in 1 M M⁺Cl^– (M⁺ = Li⁺ or K⁺), 1 mM EDTA, 10 mM Tris buffer, and pH 8.0 with the presence of 2.0 μM ssDNA at the cis side of the AeL nanopore.