Model pores for biological membranes: the properties of track-etched membranes

Abstract Particle track membranes composed of polyethyleneterphthalate (PETP) that have been etched to produce narrow pores show many of the properties of biological ion channels: rapid switching (quantal current flow), selectivity between cations and anions, and modulation by H + and divalent cations such as Zn 2+ and Ca 2+ . PETP membranes modified to alter their surface charge show altered properties. These results have implications for our understanding of ion channels, as well as opening up the possibility for designing new classes of ionic sensors.