Analytical Sciences

Abstract − Analytical Sciences, 18(11), 1199 (2002).

Characterization and Manipulation of Microscopic Biochemically Active Regions by Scanning Electrochemical Microscopy (SECM)
Gunther WITTSTOCK*  and Thomas WILHELM**
*Carl von Ossietzky University Oldenburg, Department of Chemistry and Institute of Chemistry and Biology of the Marine Environment (ICBM), D- 26111 Oldenburg, Germany
**University of Leipzig, Wilhelm-Ostwald-Institute, Linnéstrasse 2, D-04103 Leipzig, Germany
Preparation and characterization of microscopic biochemically active regions are important for the development of miniaturized bioanalytical systems with proteins, such as miniaturized enzyme electrode arrays. Scanning electrochemical microscopy (SECM) has emerged as an ideal tool for prototyping such systems. The technique is based on electrochemical conversions of dissolved species at a micrometer-sized probe electrode. It offers several mechanisms for local surface modifications under conditions compatible with conservation of protein functionality of enzymes and antibodies. The subsequent imaging of the immobilized activity provieds direct information about local immobilized enzyme activities. The working modes of the techniques are illustrated by recent studies from this laboratory for the design and characterization of patterned enzyme layers covalently linked to gold surfaces via thiol self-assembly chemistry.