Extraction of local kinetic information from SECM approach curves to enzymatically active materials

Gunther Wittstock 

Carl von Ossietzky University Oldenburg, School of Mathematics and Natural Sciences, n/a, Oldenburg D-26111, Germany

Abstract

Scanning electrochemical microscopy (SECM) has become an indispensable tool for the characterization of reactivities at interfaces such as reactions of immobilized enzymes and other biomolecules. The analysis is based on the detection of redox active species generated by an immobilized enzyme though conversion at the scanning ultramicroelectrode (UME).

When imaging surfaces of sensors some special attention has to be made for correctly designing the experiments to avoid artefacts from other side reactions. This will be illustrated by several examples.

Recently, very much effort has to be devoted to extracting rate constants fro various reactions from approach curves to different materials. This can be done either in the feedback mode or in the generation collection mode. The talk will discuss, when the modes are appropriate and give a special instruction how carry out the analysis in feedback mode. Attention must be paid to three stages of the analysis: precise measurement of the curves and the control experiments, data treatment to extract the pseudo-first order rate constant and kinetic analysis of more complex reaction mechanisms to relate the pseudo-first order constant to more complex reaction mechanisms.

 

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Presentation: Tutorial lecture at SMCBS'2005 Workshop, by Gunther Wittstock
See On-line Journal of SMCBS'2005 Workshop

Submitted: 2005-08-29 15:19
Revised:   2009-06-07 00:44