Studies On Supramolecular Assembly Of Supported Bilayer Lipid Membranes And Ion Channels

The post doctoral research thesis, composed of 3 chapters, deal with the supramolecular assembly of supported bilayer lipid membranes and ion channels. The contents are as follows:1. The review was presented on the applications of bilayer lipid membranes (BLMs) biosensor in food hygiene, toxin detection and environmental science. Recent construction of gene biosensors based on BLMs was also described. The methods of immobilization and incorporation of various nucleic acid probe, the mechanism of response and the application were summarized.2. The electrochemical devices for phosphate based on metal supported bilayer lipid membrane (s-BLM) was developed. It can be used as phosphate biosensor with the incorporation of phosphate ionophore into the lipid bilayer. The sensor showed excellent sensitivity and large linear scope for dibasic phosphate activity. The high degree of selectivity for this ion over other phosphate species and commonly occurring ions was also obtained.3. A novel kind of supported BLM—patch pipette-BLM was constructed with the tip of patch pipette. The excellent stability, permeability and biological compatibility of this kind of BLM provided more opportunity to investigate the ion channel in mimetic biomembrane system. The property of phosphate ionophore channel formed in patch pipette-BLM and underlying principles was approached.4. The electrochemical investigation of ion transport through patch pipette-BLM and a technology suitable for development of an ammonium ion minisensor are represented. Gramicidin D was used as a channel-forming ionophore for selective conduction of ammonium ion through lipid molecular bilayer. The ammonium ion sensor exhibits good mechanical stability, longevity (routinely over 48h) and reverse response to a given concentration of ammonium ion in solution.5. The response of s-BLM, sb-BLM and patch pipette-BLM to pH of aqueous solution was studied. The parameters of the three kinds of supported BLM pH sensor are characterized, which is the foundation for the further study on the property of hydrogen ion channel incorporated into the supported BLMs.