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Au disk nanoelectrode by electrochemical deposition in a nanopore
- Source :
- Analytical chemistry. 82(15)
- Publication Year :
- 2010
-
Abstract
- In this technical note, we report a process in scaling down the fabrication of Au disk nanoelectrodes as small as approximately 4 nm in radii. We have developed a bottom-up approach toward the fabrication of individual disk-shape Au nanoelectrodes. This new approach is based upon electrochemical deposition of Au in a silica nanopore electrode and involves the following four steps. First, a laser-assisted pulling process is employed to fabricate a disk-shape Pt nanoelectrode. Second, a Pt nanopore electrode is obtained by electrochemically etching the Pt from the disk nanoelectrode. Third, a Au metal nanowire is electrochemically deposited using the Pt nanopore electrode as a template. In the last step, the Au electrode is slightly polished to expose a disk-shape Au nanoelectrode, whose size is determined by the size of the initial Pt nanoelectrode. Steady-state voltammetry in the presence of ferrocene has been used to characterize these Au nanoelectrodes. The Au nanoelectrodes are also characterized using cyclic voltammetry in a H2SO4 solution. The results show characteristic peaks corresponding to the formation of Au surface oxides and their subsequent reduction. The Au nanoelectrodes are modified with 6-(ferrocenyl)hexanethiol molecules, and cyclic voltammetry is used to characterize the ferrocene molecules attached at the Au. As an application, we have constructed Au single-nanoparticle electrodes (SNPEs) using the Au disk nanoelectrodes fabricated by electrochemical deposition. Our initial results of such SNPEs show excellent electrochemical response from single Au nanoparticles.
Details
- ISSN :
- 15206882
- Volume :
- 82
- Issue :
- 15
- Database :
- OpenAIRE
- Journal :
- Analytical chemistry
- Accession number :
- edsair.doi.dedup.....0022bffbb2d2de1992f85e065c80ff7a