FIG. 13.

Basic concept of sensing molecules with nanopores. (a) Application of a voltage across the membrane induces a steady electric current carried by small ions passing through the pore. (b) When charged molecules, such as DNA, are added to the chamber, the transmembrane voltage electrophoretically attracts the molecules into the pore. The molecules stochastically enter the pore, producing a measurable “electric current blockade.” First-order parameters that can help in characterizing the sample are the dwell time (t_d), the average current blockade amplitude (δI), and the time between successive blockade events (δt). Reproduced with permission from M. Wanunu, Phys. Life Rev. 9, 125 (2012). Copyright 2012 Elsevier.¹⁶⁴