Theoretical description of the ion transport across nanopores with titratable fixed charges: analogies between ion channels and synthetic pores.
Recently developed nanometer-sized synthetic pores display several properties so far believed to be distinctive features of a large variety of biological wide ion channels. Thus conductance in the pS-nS range, pH-dependent ion selectivity, fluctuations of current between open and closed states, flux inhibition caused by protons or divalent cations, current rectification, and the ability to perform selective macromolecule sizing and counting are found in synthetic and biological channels alike. Despite other differences such as pore size and geometry, the similarities open a new field for exploring specific technological applications via the chemical modification of synthetic pores with biological molecules. This article reviews some of the basic concepts and theories relevant to ion transport in nanopores with titratable charges stressing the analogies between synthetic pores and biological ion channels. The ultimate goal is to show that continuum theories may account for the essential features of these systems. A simple electrodiffusion model and its comparison with experimental results are chosen as a case study.
Ramírez
P
P
Departamento de Física Aplicada, Universidad Politécnica de Valencia, Camino de Vera s/n, E-46022 Valencia, Spain.
Aguilella-Arzo
M
M
Alcaraz
A
A
Cervera
J
J
Aguilella
V M
VM
D007473:Ion Channels / Q000737:chemistry / Q000378:metabolism; D017136:Ion Transport; D008567:Membranes, Artificial; D008954:Models, Biological; D049329:Nanostructures; D018272:Porins / Q000737:chemistry / Q000378:metabolism
D007473:Ion Channels; D008567:Membranes, Artificial; D018272:Porins