Restructuring and cleaavage of ferrocene-alkanethiol ester SAMs in lipase-based activity assays.

Anders B. Olesen ,  Majken Hansen ,  Stepan Shipovskov ,  Duncan Sutherland ,  Kurt Gothelf ,  Elena E. Ferapontova 

University of Aarhus, Chemistry Department, Center for DNA Nanotechnology (CDNA), Langelandsgade 140, Aarhus 8000, Denmark

Abstract

Electrochemical activity of ferrocene (Fc)-terminated SAM of alkane ester immobilised on gold electrode is shown to depend on the buffer conditions used. It is demonstrated that upon electrochemical activation in phosphate buffer solutions and further in sulphuric acid solutions the SAMs undergo restructuring, which stabilises the signal from the Fc groups and exposes the internal ester groups to the SAM/solution interface. The restructuring of the SAM enables efficient hydrolysis of the ester bond by lipase enzyme accompanied by the release of the part of the Fc redox active groups from the electrode surface, thus decreasing the electrochemical signal from the surface-confined Fc groups. This reaction was used in electrochemical sandwich DNA hybridisation assay with lipase as a label.

 

Legal notice
  • 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: http://science24.com/paper/21845 must be provided.

 

Related papers
  1. Electrochemistry of redox-labelled DNAs immobilized onto electrodes through the de-novo designed triazene linkerĀ 
  2. Application of DNA and RNA Beacons in Electroanalysis: What Are Limits for Sensitivity and Selectivity?
  3. Electrochemical DNA biosensors for label-free detection of nucleic acids exploiting DNA conformational transitions upon hybridization event
  4. Electron Transfer Reactions of Heme-containing Enzymes at the Electrodes: Bioelectrocatalysis and its Optimisation
  5. Electron Transfer in Complex Two-cofactor-containing Enzymes at Alkanethiol-modified Gold Electrodes

Presentation: Poster at SMCBS'2009 International Workshop, by Anders B. Olesen
See On-line Journal of SMCBS'2009 International Workshop

Submitted: 2009-08-30 17:01
Revised:   2009-08-30 17:11