Abstract
We report about two new types of nanostructured gold electrodes that can be heated electrically. At the directly heated gold micro-wire electrode, the microelectrode behavior is diminished upon galvanic deposition of gold nanostructures. The voltammetric waves observed with ferrocyanide turned into peaks. This suggests that it is the active electrode area rather than the mere geometric dimensions, what determines microelectrode behavior. Direct heating of this nanostructured gold wire electrode brought back the wave-like voltammogramms typical for microelectrodes. We also demonstrate with a second type of heated gold electrode, an indirectly heated sensor based on low temperature co-fired ceramics (LTCC), that DNA hybridization response of covalently attached enzyme labels is greatly improved by nanostructures. The voltammetric signal increase for the nanostructured electrode was 22-fold at 5°C and 6-fold at 70°C electrode temperature. We think that a trapping effect in the gold pores greatly increases sensitivity, in particular at lower electrode temperature.
| Original language | English |
|---|---|
| Pages (from-to) | 502-509 |
| Number of pages | 8 |
| Journal | Sensors and Actuators, B: Chemical |
| Volume | 233 |
| Early online date | 19 Apr 2016 |
| DOIs | |
| Publication status | Published - 5 Oct 2016 |
Funding
The authors thank the Deutsche Forschungsgemeinschaft ( DFG FL 384/4-1 , FL 384/4-2 and FL 384/7-2 Heisenberg Fellowship), the State University of New York, as well as the Interdisciplinary Faculty of the University of Rostock for financial support. Appendix A The following are Supplementary data to this article: Anne Walter received her diploma in chemistry in 2008 from the University of Rostock. She is currently working on her Ph.D. thesis in analytical chemistry in the group of Gerd-Uwe Flechsig at the University of Rostock, Germany. In 2009, she received a 5-months DAAD scholarship to conduct research on DNA sensor arrays in the group of Joseph Wang (UC San Diego, USA). Her research work is focused on electrochemical detection of enzyme-labeled DNA at electrically heatable electrodes. Fanny Langschwager received her B.Sc. degree in 2012 at the University of Rostock. After completing her M.Sc. degree, she is currently working on her Ph.D. thesis about lipase catalyzed synthesis of esters in the group of Udo Kragl. Frank Marken has in 2004 been appointed to a Lecturer position and in 2011 promoted to a personal chair at the Department of Chemistry, University of Bath. He obtained a Dr. rer. nat. degree at RWTH Aachen (1992) and was postdoctoral researcher at La Trobe University (Australia) and at Oxford University (UK), as well as Lecturer at Loughborough University (UK). Research interests are predominantly in fundamental and applied aspects of electrochemistry. Gerd-Uwe Flechsig graduated in 1997 as a Diplom-Chemiker (M.Sc. in chemistry) at Rostock University. He was awarded Dr. rer. nat. (Ph.D.) in 2001 and Dr. rer. nat. habil. (Habilitation) in 2006, both in the field of analytical chemistry with theses regarding heated electrodes. His adviser for many years has been Prof. Peter Gründler. Gerd-Uwe Flechsig’s research focuses mainly on heated electrochemical detectors and biosensors for DNA and proteins. He received the Metrohm-Award in 2003 and a Heisenberg Fellowship of the German Research Foundation (DFG) in 2008. From 2013 to 2014, he worked at Manchester Metropolitan University (UK) as a Lecturer in Nano- and Inorganic Chemistry. Currently, he serves as an Asst. Professor in the Department of Chemistry at the University at Albany, SUNY, USA.
Keywords
- Alkaline phosphatase
- DNA hybridization
- Gold nanostructures
- Heated electrode
- Single base mismatch
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Instrumentation
- Condensed Matter Physics
- Surfaces, Coatings and Films
- Metals and Alloys
- Electrical and Electronic Engineering
- Materials Chemistry