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51 Synthesis of gold nanoshells and their use in sensing applications
Author(s): Yugang Sun, Younan Xia (Affiliation: Dept. of Chem., Washington Univ., Seattle, WA, USA)
Editor(s): O.D.Velev, T.J.Bunning, Y.Xia, P.Yang
Conference: Unconventional Approaches to Nanostructures with Applications in Electronics, Photonics, Information Storage and Sensing Symposium, San Francisco, CA, USA
Conference Date: 21-25 April 2003
Publication: Unconventional Approaches to Nanostructures with Applications in Electronics, Photonics, Information Storage and Sensing Symposium (Mater. Res. Soc. Symposium Proceedings Vol.776)
Publisher: Mater. Res. Soc, USA, 2003
Language: English
ISBN: 1 55899 713 X Page: 31-6
Document type: Conference paper
Abstract: A general approach involved template-engaged, galvanic replacement reactions has been developed to prepare metallic nanostructures with hollow interiors by reacting solutions of appropriate salts with metallic solid nanoparticles. The reaction between aqueous chloroauric acid and silver nanoparticles was used as a typical example to demonstrate the synthesis of gold nanoshells. The morphology, void space, and wall thickness of these hollow structures were all determined by the silver templates, which were completely converted into soluble species during the replacement reaction. The extinction peaks of these gold nanoshells were considerably redshifted as compared to solid gold colloids having approximately the same dimensions. In addition, the surface plasmon resonance of gold nanoshells exhibited a much more sensitive response toward environmental changes even when compared with solid colloids with a mean size much smaller than that of gold nanoshells (9 refs.)
Inspec No.: 8253424
52 Self-assembling around templates - creating nano dots and pits for chemical sensing
Author(s): F.L. Dickert, P.A. Lieberzeit, O. Hayden, R. Bindeus, K.-J. Mann, C. Haderspock (Affiliation: Inst. of Anal. Chem., Vienna Univ., Austria)
Editor(s): O.D.Velev, T.J.Bunning, Y.Xia, P.Yang
Conference: Unconventional Approaches to Nanostructures with Applications in Electronics, Photonics, Information Storage and Sensing Symposium, San Francisco, CA, USA
Conference Date: 21-25 April 2003
Publication: Unconventional Approaches to Nanostructures with Applications in Electronics, Photonics, Information Storage and Sensing Symposium (Mater. Res. Soc. Symposium Proceedings Vol.776)
Publisher: Mater. Res. Soc, USA, 2003
Language: English
ISBN: 1 55899 713 X Page: 37-42
Document type: Conference paper
Abstract: Nano- and micro-structured materials are a powerful tool in the development of chemical sensors. Surface imprinting of different biogenous species into pre-polymerized, highly crosslinked reaction mixtures (polyurethanes, polystyrenes, sol-gel materials etc.) yields self-assembled structures that are optimized to re-incorporate the template particle. Surface properties are tuned both on the micrometer as well as the molecular scale, as selectivity studies suggest the formation of strongly adapted interaction networks between the polymer and the species used for imprinting (10 refs.)
Inspec No.: 8253425
53 Chalcogen nanowires: synthesis and properties
Author(s): B.T. Mayers, Younan Xia (Affiliation: Dept. of Chem., Washington Univ., Seattle, WA, USA)
Editor(s): O.D.Velev, T.J.Bunning, Y.Xia, P.Yang
Conference: Unconventional Approaches to Nanostructures with Applications in Electronics, Photonics, Information Storage and Sensing Symposium, San Francisco, CA, USA
Conference Date: 21-25 April 2003
Publication: Unconventional Approaches to Nanostructures with Applications in Electronics, Photonics, Information Storage and Sensing Symposium (Mater. Res. Soc. Symposium Proceedings Vol.776)
Publisher: Mater. Res. Soc, USA, 2003
Language: English
ISBN: 1 55899 713 X Page: 75-80
Document type: Conference paper
Abstract: We have demonstrated a variety of solution-phase approaches for the synthesis of 1-dimensional nanostructures from chalcogens such as Se and Te. These nanostructures include uniform, single crystalline nanowires and nanorods (lateral dimensions from 10 to 1000 nm, and lengths ranging from 2 to > 100 ìm). These nanostructures grew via a solidsolution-solid transformation mechanism, in which Se and Te atoms were transported from the less stable source (amorphous colloids) into the more stable product (trigonal phase nanocrystallites). The nanocrystallites (or seeds) were formed either through temperature driven homogeneous nucleation or by sonochemical cavitation. As directed by the highly anisotropic crystal structure, the growth could be confined to one particular direction. These nanowires could be prepared both as dispersions in various solvents or as networked arrays on solid supports (14 refs.)
Inspec No.: 8253431
54 Synthesis of CdO nanoneedles for photonic and sensing applications
Author(s): Xiaolei Liu, Chao Li, Song Han, Chongwu Zhou (Affiliation: Dept. of E.E.-Electrophys., Southern California Univ., Los Angeles, CA, USA)
Editor(s): O.D.Velev, T.J.Bunning, Y.Xia, P.Yang
Conference: Unconventional Approaches to Nanostructures with Applications in Electronics, Photonics, Information Storage and Sensing Symposium, San Francisco, CA, USA
Conference Date: 21-25 April 2003
Publication: Unconventional Approaches to Nanostructures with Applications in Electronics, Photonics, Information Storage and Sensing Symposium (Mater. Res. Soc. Symposium Proceedings Vol.776)
Publisher: Mater. Res. Soc, USA, 2003
Language: English
ISBN: 1 55899 713 X Page: 89-94
Document type: Conference paper
Abstract: Single-crystalline needle-shaped CdO nanostructures were synthesized using a chemical vapor deposition method and characterized using a variety of techniques. Devices consisting of individual CdO nanoneedles were fabricated and high conductance as well as high carrier concentrations was observed. The temperature dependence of the conductance revealed thermal excitation as the dominating transport mechanism. Our devices exhibited good sensitivity to both infrared light and diluted NO2 gas, indicating potential applications as infrared photo-detectors and toxic gas sensors (18 refs.)
Inspec No.: 8253433
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