The design of a reliable, highly sensitive and fast method to detect dangerous explosives, hazardous chemicals, and life threatening biological molecules has become an extremely important issue. Peptide ion channels are being studied as microanalytical systems that can act as biosensors. Gramicidin A is one of nature's examples of peptide forming nanopore ion channels. For improved performance the nanopore-forming peptides should have well-defined conformations, form appropriately sized pores, and should be able to form channels through lipid membranes. Here we have designed functional ion channels from beta-helical synthetic peptides. These have a defined conformation and can be easily varied in length, pore size and chemistry to increase analyte-pore interactions.