A self-contained microelectrochemical cavity system comprised of a polymer and phospholipid membrane suspended over a picoliter volume

A 2-dimensional framework of UV-polymerized 10,12-pentacosadiynoic acid integrated with dipalmitoylphophatidyl choline phospholipids was suspended over a ca. 10 mum-diameter and 8-mum-deep microcavity that contained electrodes. The membrane was assembled at the air-water interface of a Langmuir-Blodgett trough and deposited onto a mercaptoundecanoic-acid-modified gold surface that surrounds the microcavity opening during an upward stroke from a subphase of 10 mM potassium ferrocyanide in 0.1 M KCl and 1 mM CaCl2, and covered with a drop of pure electrolyte to minimize evaporation. Cyclic voltammetry confirmed that the redox solution was trapped beneath the membrane and was calculated to be only ca. 0.6 pL volume, consistent with the geometry of the microcavity. Such interfaces to microstructures hold promise for novel biosensor materials and biomimetic phospholipid membranes.