THIN-LAYER CHANNEL MEMBRANES FOR SENSOR APPLICATIONS

THIS STUDY WILL DEMONSTRATE THAT AN ION-SELECTIVE CHANNEL MEMBRANE WITH NO COUNTERPART IN NATURE CAN BE USED AS A BIOSENSOR BY BRINGING TOGETHER THE NOVEL COMBINATION OF HIGHLY ORIENTED MONOLAYER FILMS AND GRAMICIDIN-A. THIS PROJECT WILL ELUCIDATE THE MOLECULAR ORIENTATION MECHANISM OF THE MONOLAYERS AND THE HELIX CONFORMATION OF GRAMICIDIN WITHIN THE MONOLAYER TO THE TRANSPORT OF MONOVALENT CATIONS THROUGH THE CHANNEL. ONE PARTICULARLY SUCCESSFUL METHOD TO OBTAIN LARGE-AREA, ULTRATHIN MONOLAYER MEMBRANES IS THROUGH POLYMERIZING LIPID MOLECULES AT THE GAS/WATER INTERFACE USING LANGMUIR-BLODGETTTECHNIQUES. MONOLAYER MEMBRANES WILL BE PREPARED CONSISTINGOF VARIOUS ALIPHATIC DIACETYLENES AND PHOSPHOLIPIDS CONTAINING DIACETYLENES ON AN AQUEOUS SUBPHASE WITH AND WITHOUT GRAMICIDIN-A. VARIABLES WILL BE INTRODUCED TO THE MONOLAYER AND SUBPHASE TO OPTIMIZE MOLECULAR ORIENTATION ANDFILM DENSITY. THE LIPID MONOLAYERS, WITH AND WITHOUT GRAMICIDIN-A, WILL BEPOLYMERIZED WITH ULTRAVIOLET IRRADIATION, TRANSFERRED TO SUITABLE PLANAR SUBSTRATES, AND TESTED FOR SELECTIVE ION TRANSFER. THE TRANSFER OF CATIONS AND PROTONS WILL BE MEASURED ACROSS TWO AQUEOUS PHASES THAT ARE SEPARATED BY A PARTITION CONTAINING THE SUPPORTED MONOLAYER MEMBRANE.