title: Steady-state electrochemical determination of lipidic nanotube diameter utilizing an artificial cell model.
abstract: By exploiting the capabilities of steady-state electrochemical measurements, we have measured the inner diameter of a lipid nanotube using Fick's first law of diffusion in conjunction with an imposed linear concentration gradient of electroactive molecules over the length of the nanotube. Fick's law has been used in this way to provide a direct relationship between the nanotube diameter and the measurable experimental parameters Deltai (change in current) and nanotube length. Catechol was used to determine the Deltai attributed to its flux out of the nanotube. Comparing the nanotube diameter as a function of nanotube length revealed that membrane elastic energy was playing an important role in determining the size of the nanotube and was different when the tube was connected to either end of two vesicles or to a vesicle on one end and a pipet tip on the other. We assume that repulsive interaction between neck regions can be used to explain the trends observed. This theoretical approach based on elastic energy considerations provides a qualitative description consistent with experimental data.
authors.affiliation: Department of Chemistry, 104 Chemistry Research Building, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
authors.forename: Kelly L
authors.initials: KL
authors.lastname: Adams
authors.forename: Johan
authors.initials: J
authors.lastname: Engelbrektsson
authors.forename: Marina
authors.initials: M
authors.lastname: Voinova
authors.forename: Bo
authors.initials: B
authors.lastname: Zhang
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Eves
authors.forename: Roger
authors.initials: R
authors.lastname: Karlsson
authors.forename: Michael L
authors.initials: ML
authors.lastname: Heien
authors.forename: Ann-Sofie
authors.initials: AS
authors.lastname: Cans
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Ewing
mesh_terms: D002396:Catechols / Q000032:analysis*; D004058:Diffusion; D055664:Electrochemical Techniques / Q000379:methods*; D008081:Liposomes / Q000737:chemistry; D008958:Models, Molecular; D043942:Nanotubes / Q000737:chemistry*
chemical_list: D002396:Catechols; D008081:Liposomes; C034221:catechol