Summer 2011 Intern Project- Sam Ivry

ELECTRON TRANSFER ACROSS LIPOSOMES USING OLIGOELECTROLYTES


Sam Ivry

Chemical Engineering
UC Santa Barbara

Mentor: Alex Thomas
Faculty Advisor: Gui Bazan
Department: Chemistry and Biochemistry

Specially designed conjugated oligoelectrolytes (COEs) have been shown to orient themselves within lipid bilayers and facilitate electron transfer from an electrode to aqueous, redox-active compounds.  Here, we use liposomes in a proof of concept experiment to determine COEs’ ability to mediate electron transfer between two solubilized species. Specifically, we probe whether oligoelectrolytes can facilitate electron transfer from an external reductant to a liposome-entrapped oxidant. Specific redox-active compounds are chosen so that UV/Vis spectrometry could be used to monitor reduction and/or oxidation. A 16-carbon tail lipid doped with up to 25% cholesterol or stearic acid is found to form the best liposomes in terms of stability and leakiness. Several COEs are tested with various oxidants of differing redox potentials.  Additionally, the incorporation and ordered orientation of the oligoelectrolytes within the lipid bilayer are confirmed using confocal microscopy.

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