Active control of surfaces with electrochemically generated composition gradients

COLL 511

Paul Bohn, Susan Plummer, Qian Wang, Brian Coleman, Amy Swint, and Patrick Castle. Dept. of Chemistry, Univ. of Illinois, 600 S. Mathews, Urbana, IL 61801
Gradients in alkanethiol surface composition on thin Au electrodes are fabricated by taking advantage of their electrosorption properties. Injecting milliamp currents yields significant in-plane voltage gradients so that, rather than assuming a single value of potential, an in-plane potential distribution, V(x), is imposed on the electrode surface. The in-plane electric potential gradient means that, relative to a solution reference couple, electrochemical reactions occur at defined spatial positions corresponding to the standard potential, V(x) ~ E0. By arranging the electrochemical potential drop to span the region of E0des for the alkanethiol of interest a gradient in alkanethiol surface coverage can be created. Of particular interest are schemes in which the thiols are terminated with ligands which can direct cellular adhesion or the assembly of multilayer architectures.
 

Adamson Award Symposium Honoring Dave Allara and Ralph Nuzzo

Division of Colloid and Surface Chemistry
The 225th ACS National Meeting, New Orleans, LA, March 23-27, 2003