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Description
Title: | Sensing Molecular Adsorption Through Interfacial Electron Scattering in Atom -Scale Junctions |
Author(s): | Castle, Patrick James |
Doctoral Committee Chair(s): | Bohn, Paul W. |
Department / Program: | Chemistry |
Discipline: | Chemistry |
Degree Granting Institution: | University of Illinois at Urbana-Champaign |
Degree: | Ph.D. |
Genre: | Dissertation |
Subject(s): | Chemistry, Analytical |
Abstract: | The goal of this work was to fabricate Au atom-scale junctions as the basis for robust, regenerable, nanostructured sensors to use with mass-limited samples for improved protection of health and safety. Atom-scale junctions were formed between two Au thin film electrodes. The inter-electrode gap was lithographically defined, and a microfluidic channel was aligned over the inter-electrode gap. The inter-electrode gap was reduced with electrodeposition, which was terminated at an atom-scale junction by setting a comparator to trigger a relay at a current corresponding to a junction conductance comparable to the conductance quantum. Based on conductance measurements and estimates from SEM images, atom-scale junctions were successfully formed. Lewis bases were introduced to atom-scale junctions, and the resulting alternating current impedance change was measured. For example, the interfacial scattering from chemisorption of 10 mM hexadecanethiol (HDT) on a 2.6 G0 atom-scale junction caused a normalized impedance change of 71% +/- 1%, with a noise level consistent with a population fluctuation of only 1 HDT molecule. To regenerate the device in situ, the junction was broken with a potential sweep and reformed with comparator-terminated electrodeposition. The atom-scale junction capability to measure small numbers of adsorption/desorption events makes a powerful case for pushing the limits of sensitivity for electrical measurements of single molecule events. |
Issue Date: | 2005 |
Type: | Text |
Language: | English |
Description: | 142 p. Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2005. |
URI: | http://hdl.handle.net/2142/84182 |
Other Identifier(s): | (MiAaPQ)AAI3198938 |
Date Available in IDEALS: | 2015-09-25 |
Date Deposited: | 2005 |
This item appears in the following Collection(s)
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Dissertations and Theses - Chemistry
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Graduate Dissertations and Theses at Illinois
Graduate Theses and Dissertations at Illinois