ARTIFICIAL ION-CHANNEL PROVIDING ION FLUX ACROSS LIPID BILAYER-MEMBRANE

Basic principles for the design of artificial ion channels which produce large ionic flux across lipid bilayer membranes were described. Several supramolecular approaches were successful to observe single ion channel currents across planar lipid bilayers with characteristics in a close analogy to those of natural ion channels. Stable and constant conductance levels were observed with transitions between open and closed states at a ms to s range. The channels were cation selective over anion. A unimolecular channel Was also designed by,using macrocyclic resorcinol tetramer, which gave a single conductance and a sharp ion selectivity. Ionic currents across the membrane through ion channel mechanism were also modulated by the application of membrane potential or photochemical isomerization.