Nanodimensionally driven analyte response reversal in gold nanocluster chemiresistor sensing
The modulation of electron transport through an ensemble of ligand-stabilized gold nanoclusters by the sorption of vapors is made exceptionally sensitive and selective by terminal carboxylic acid functionalization of the alkanethiol ligand. Of further importance, the directionality of the response (...
| Veröffentlicht in: | Langmuir : the ACS journal of surfaces and colloids. - 1999. - 28(2012), 44 vom: 06. Nov., Seite 15438-43 |
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| Weitere Verfasser: | , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2012
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| Zugriff auf das übergeordnete Werk: | Langmuir : the ACS journal of surfaces and colloids |
| Schlagworte: | Journal Article Research Support, U.S. Gov't, Non-P.H.S. Carboxylic Acids Ligands Sulfhydryl Compounds Gold 7440-57-5 |
| Zusammenfassung: | The modulation of electron transport through an ensemble of ligand-stabilized gold nanoclusters by the sorption of vapors is made exceptionally sensitive and selective by terminal carboxylic acid functionalization of the alkanethiol ligand. Of further importance, the directionality of the response (conductance increase or decrease) is strongly dependent on the nanoscale dimensions of the gold core and ligand shell thickness. Films of gold nanoclusters composed of a 2 nm metal core with a 0.5 nm -S(CH(2))(5)COOH shell are compared to those based on an 8 nm core and a 1.5 nm -S(CH(2))(15)COOH shell with the finding of very strong and selective responses to amine vapors but with a reversal of response in the direction of the conductance transduction. This unexpected result cannot be accommodated by known vapor response transduction mechanisms based on a swelling expansion and a dielectric alteration of the ligand shell to modulate conductance in the ensemble. A speculative new mechanism is proposed on the basis of intercluster nanodomains of low and high dielectric character whose domain dimensions are determined by the ligand molecular structure and dielectric character that can range up to that associated with an ionic capacitance if generated by a vapor interaction |
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| Beschreibung: | Date Completed 19.04.2013 Date Revised 06.11.2012 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1520-5827 |
| DOI: | 10.1021/la303319j |