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Spectroscopic and Electrochemical Characterization of Interfacial Biomimetic Assemblies for Biosensors
|Paweł G. Krysiński 2, Gary J. Blanchard 1|
1. Michigan State University (MSU), East Lansing, MI 48824-1322, United States
We have synthesized several novel biomimetic interfacial structures through the covalent growth of individual layers on oxide-based, electrochemically active substrates (e.g. gold oxide, ITO, boron-doped diamond). Our goal is to deposit selected biomolecules on conductive substrates in such a manner as to retain their biological activity. We have constructed model hybrid bilayer membrane structures, approximating a lipid bilayer structure. The covalently bound self assembled monolayers (SAMs) we report here are characterized by a hydrophilic region adjacent to the electrode surface, with hydrophobic structure beyond the hydrophilic region. Next there is a second hydrophilic region comprised of amide bonds, that are terminated with aliphatic chains. The route we describe is general; the adlayer moieties can be controlled synthetically and the properties of the substrate can be controlled by choice of material. Our aim is to control the adlayer structure, thickness and spacing of hydrophilic and hydrophobic regions to produce interfacial films that can function as hybrid bilayer matrices (HBMs). We characterize these systems using picosecond time-resolved and steady-state fluorescence and infrared spectroscopies in conjunction with electrochemical measurements. We have studied the role and importance of molecular motion within the layers and evaluated the dipolar coupling between imbedded chromophores and the substrate. While the dominant interactions in SAMs are thought to be the bond between the adlayer molecule head group and the substrate, and between the layer constituent molecules, longer range dipolar interactions between the substrate and any distant adlayer functionalities are often neglected. Such interactions are likely to be important in the formation of hybrid bilayer lipid membrane structures that represent a biomimetic interface capable of hosting and maintaining activity of biomolecules in a non-biological, electronically addressable environment.
Presentation: Tutorial lecture at SMCBS 2003 Workshop, by Paweł G. Krysiński
See On-line Journal of SMCBS 2003 Workshop
Submitted: 2003-09-17 10:03 Revised: 2009-06-08 12:55