PHYS 618 |
| Methods for the construction of fluid state lipid bilayer networks of high geometrical and topological complexity are presented. Nanocircuits consisting of surface-immobilized unilamellar vesicles (~5-25 um in diameter) conjugated with nanotubes 50-150 nm in radius including fully connected recurrent networks with genus=3 topology, and higher, were produced by novel micromanipulation techniques. Within networks, self-organizing branching nanotube architectures were produced where intersections spontaneously arrange themselves into three-way junctions with an angle of 120º between each nanotube. Formation of branching nanotube networks appears to follow a minimum-bending energy algorithm that solves for pathway-minimization. In the strong adhesion regime, nanotube networks can have arbitrary geometries because the contact potentials are so high that it restricts nanotube self organization. The membrane composition (e.g. lipids, transporters, receptors, and catalytic sites) and container contents (e.g. catalytic particles, organelles, and reactants) can be controlled on the single-container level allowing complex chemical programming of networks. Fluid movement in nanotubes and materials exchange between conjugated containers can be obtained by using a moving boundary or by transport of vesicles integrated with the nanotube wall. In both instances, transport is modulated by changes in membrane tension. Furthermore, materials contained in the networks can be routed using electrophoresis and electroosmosis. Thus, networks of nanotubes and vesicles serve as a platform to build nanofluidic devices operating with single molecules and particles and offers new opportunities to study chemistry in confined biomimetic compartments. The networks can also be used to build nanoscale chemical laboratories for applications in analytical devices as well as to construct computational and complex sensor systems that also can be integrated to living cells. |
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Frontiers in Single-Molecule Biophysical Chemistry and Imaging
8:20 AM-12:00 PM, Thursday, 14 September 2006 Grand Hyatt San Francisco -- Plaza Ballroom East, Oral
Division of Physical Chemistry |