Fig. 6: Model of polyzwitterion translocation.
a Three stages of translocation. b Sketch of free energy (F) landscape corresponding to the three stages. M and N are the pore length and chain length in units of monomer length ℓ. c Model of the conformation of a segment of a polyzwitterion chain inside the nanopore with its central axis along the x-coordinate in units of ℓ. Blue curve denotes the profile of the electric potential ψ due to the applied voltage. q1 and q2 denote the charges of the ionic groups closer and distant to the chain backbone, respectively. d is the dipole length in units of ℓ, and θ is the angle subtended by the zwitterionic group with respect to the chain backbone taken along the central axis of the nanopore. xi is the x-coordinate of the center of the i-th zwitterionic group.
