title: Ion channel mimetic micropore and nanotube membrane sensors.
abstract: This paper describes synthetic micropore and nanotube membranes that mimic the function of a ligand-gated ion channel; that is, these membranes can be switched from an "off" state (no or low ion current through the membrane) to an "on" state (higher ion current) in response to the presence of a chemical stimulus. Ion channel mimics based on both microporous alumina and Au nanotube membranes were investigated. The off state was obtained by making the membranes hydrophobic by chemisorbing either a C18 silane (alumina membrane) or a C18 thiol (Au nanotube membrane). Water and electrolyte are forbidden from entering these very hydrophobic pores/nanotubes. The transition to the on state was induced by the partitioning of a hydrophobic ionic species (e.g., a drug or a surfactant) into the membrane. The membrane switches to the on state because at a sufficiently high concentration of this ionic analyte species, the pores/nanotubes flood with water and electrolyte. A pH-responsive membrane was also prepared by attaching a hydrophobic alkyl carboxylic acid silane to the alumina membrane.
authors.affiliation: Department of Chemistry, University of Florida, Gainesville 32611-7200, USA.
authors.forename: Erich D
authors.initials: ED
authors.lastname: Steinle
authors.forename: David T
authors.initials: DT
authors.lastname: Mitchell
authors.forename: Marc
authors.initials: M
authors.lastname: Wirtz
authors.forename: Sang Bok
authors.initials: SB
authors.lastname: Lee
authors.forename: Vaneica Y
authors.initials: VY
authors.lastname: Young
authors.forename: Charles R
authors.initials: CR
authors.lastname: Martin
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D057927:Hydrophobic and Hydrophilic Interactions; D007473:Ion Channels; D008567:Membranes, Artificial; D018716:Molecular Mimicry; D036103:Nanotechnology; D016062:Porosity
chemical_list: D007473:Ion Channels; D008567:Membranes, Artificial