Figure 2.

(a) Distribution of net charge density ρ_e in the nanopore axial-radial plane z-r. Here C_t = 2 M, C_c = 0.1 M, D = 3.5 nm, L = 25 nm, and U_z = 300 mV, just as in the experiments of Wanunu et al. (14). (b) Distribution of salt concentration C (black line) and z-component electric field E_z (blue line) along nanopore axial direction z. (Red symbols) The profile of E_z(z) E_z(z) demands positive net charges near the pore entrance. (Dark-yellow line) E_z(z) under homogeneous salt concentration (C_t = C_c = 1 M).