Book/Dissertation / PhD Thesis

FZJ-2018-02973

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Ultrathin gold nanowires - Chemistry, electrical characterization and application to sense cellular biology

Kisner, A. (Corresponding author)FZJ*

2012
Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag Jülich
ISBN: 978-3-89336-824-2

Please use a persistent id in citations: http://hdl.handle.net/2128/18548

Abstract: The recent advances in the field of nanoscience and nanotechnology have motivated andchallenged the fabrication of nanomaterials that can be assembled into functional networks.Based on this, ultrathin metal nanowires are considered essential building blocks that can be usedto construct nanoelectronic devices for applications in sensors, photonics, and waveguides. Inthis thesis, we have endeavored to produce and understand the synthesis of ultrathin gold (Au)nanowires with diameter of ≈ 2 nm and lengths of up to 8 μm (aspect ratio of about 4,000). Thenanowires could be synthesized employing a simple wet chemical approach using the organicmolecule cis-oleylamine and AuCl as a metal precursor. Cis-oleylamine acted simultaneously asa surfactant, stabilizing and reducing agent of Au(I) ions, avoiding in this case the addition offurther chemicals into the reaction. The influence of relativistic effects in the liquid phasesolution of Au ions in an oxidation state +1 was investigated and demonstrated that these Au(I)species can form complexes with oleylamine. These complexes, which are believed to be formedthrough aurophilic interactions can induce as demonstrated from a series of spectroscopictechniques, the formation of such ultrathin nanowires.Electrical resistors based on Au nanowire devices were produced through the assembly ofthese nanowires over silicon/silicon dioxide surfaces having lithographically produced metalelectrodes to electrically contact the nanowires. Electrical characterization showed that theultrathin Au nanowires present an increase in electrical resistance that was predicted by sizeeffects. Additionally, correlating with observations from analysis of high-resolution transmissionelectron microscopy, which showed that the surface of the nanowires after the synthesis wascovered with oleylamines molecules, the influence of contact resistance in the junctionnanowires-metal electrodes was investigated. Measurements of resistance dependent ontemperature demonstrated that the junction resistances were dominant and the linear electricalconduction presented an activation energy only near room temperature. Surface modification ofnanowires with alkanethiols presenting functional groups with different charges when ionizedshowed that the electrical resistance of nanowires can readily be affected by minute amounts ofthese molecules on their surface. Besides, I–V curves of these devices in solution demonstratedthat the ionic charges of functional groups of alkanethiols can promote re-arrangements inelectrical double layer, and this can directly influence the electrical transport on the nanowires.Finally, it was shown that these devices were biocompatible and neuronal cells werenicely grown on their top. Attempts to electrically stimulate and record ionic currents from thesecells were performed and demonstrated promising results to application of such nanowires inelectrophysiological experiments with high spatial resolution.

Keyword(s): Nanodraht ; Gold ; Siliciumdioxid ; Metalloberfläche ; Widerstand ; Elektrophysiologie

Note: RWTH Aachen, Diss., 2012

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Contributing Institute(s):

1. Bioelektronik (ICS-8)
2. PGI-8-PT (PGI-8-PT)

Research Program(s):

1. 899 - ohne Topic (POF3-899) (POF3-899)

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Database coverage:

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