Scanning electrochemical microscope (SECM) can be used to extract first-order rate constants from approach curves in the feedback mode. For the analysis of more complex reaction mechanisms, this first-order rate constants can be related to different rate laws. In this example the conductivity of TiN thin film of different thickness was analysed. The experiment consisted in vertical approach of an amperometric ultramicroelectrode (UME) of controlled size and overall geometry to the sample surface (TiN film) while a reversible redox couple (ferrocene methanol / ferrocenium methanol) undergoes a diffusion-controlled electron transfer (et) reaction at the UME. The sample was biased at a potential so that it re-reduces the species being produced at the UME closing the reaction cycle. The UME current depends on the kinetics at the sample. At large tip-substrate distance the feedback is controlled by diffusion and as it approaches the surface is controlled by the kinetics of reactions at the substrate interface. The normalised current-distance curves were fit to the theoretical model in order to find the standard rate constant (k⁰) and then conductivity.

• Legal notice:
  

  Copyright (c) Pielaszek Research, all rights reserved.
  The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
  In every case, proper references including Author(s) name(s) and URL of this webpage: https://science24.com/paper/4821 must be provided.

1. Local Control of Cell Adhesion by Electrochemically Patterned Oligoethyleneglycol-Terminated Self-Assembled Monolayers
2. Moving Scanning Electrochemical Microscopy to Real World Problems
3. Bilirubin oxidase modified carbon ceramic electrode for bioelectrocatalytic reduction of dioxygen supplied from gas phase
4. Application of gold, silica and titania surfaces for the PM IRRAS: structural studies of biologically relevant films
5. Scanning electrochemical microscopy study of laccase embedded in sol-gel processed silicate film
6. Extraction of local kinetic information from SECM approach curves to enzymatically active materials
7. Patterned Organic Thin Films: Reactivity Imaging from Micrometer towards Nanometer Size Regimes with Scanning Electrochemical Microscopy